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    1. t is well known that the war economy provided unprecedented levels of research funding for American physics, particularly for the development of weapons systems,

      This reminds me more broadly of the "benefits" that can result from war. I wonder how we can achieve them in other, less harmful ways.

    1. n healthpromotion and on quality-of-lifeeducation.

      I am enjoying the way the author is approaching this discussion. Although we want students to be fit, that is really not the end goal. It is something that people become fixated on though. It reminds me of how many adults want to be fit, so they set lofty goals (e.g. work out four times a week) that they cannot realistically meet. When it doesn't work, they quit until they have inspiration again. Another issue is that once people consider themselves "out of shape," there can be significant mental barriers to change. Many people do not know how to progress themselves toward a goal, as they were never taught how to. In my opinion, many people want to be fit. It is a common goal. The issue I see is that many people have no idea how to actually reach their goal or what exactly they are wanting from their goal (e.g. mobility, strength, confidence). If we as educators would be able to help students think about how fitness fits into their lives, I think those students will grow up with a better idea of how to continue with fitness.

    1. 1)TOPIC: In the poem Bury Me in a Free Land, Frances Ellen Watkins Harper talks about slavery and the contradiction of Americans valuing freedom while keeping people enslaved.

      OPINION: Harper makes readers face the hypocrisy of Americans and realize how wrong it is to allow slavery.

      SO WHAT? This matters because it makes us question our morals and reminds us that injustice must end.

    1. data scientists all too often lose sight of the folkson the receiving end of the transaction

      Reminds me of the biases people hold - they're so focused on debating to prove they are right that they forget they are fighting with and against PEOPLE

    1. I decided to pick up thebook myself and struggle my way through.

      This reminds me of the first book series I read. Cirque Du Freak by Darren Shane (The Vampire Assistant books). There were 13 books in the series, and I just couldn't put them down. Then twilight like everyone else and the harry potter books, The wheel of time series was amazing as well. I get so lost in them. Some I can't read at night because I won't sleep.

    1. Social workers should consider ethical theory and principles generally, social work theory and research, laws, regulations, agency policies, and other relevant codes of ethics, recognizing that among codes of ethics social workers should consider the NASW Code of Ethics as their primary source.

      I highlighted this section to relate it to some of the times at work I have seen social workers fail their clients and not live up to the ethical standards placed by the NASW. While the NASW Code of Ethics is an important guide, putting it into practice isn’t as straightforward as it sometimes sounds. Our decisions are shaped not only by ethical theory and agency policies, but also by the real-life systems our clients are navigating every day. Many of the communities social workers work with, immigrants, people of color, those living in poverty and dealing with homelessness, are dealing with systems that were never designed with them in mind or rather it was staged as it was . Laws, policies, and even helping institutions can unintentionally reinforce the same inequalities they claim to address. As a Latina woman, I can’t ignore how racism, classism, and gender inequality show up in these systems, because I see how they directly impact the people sitting across from me. The code of ethics reminds social workers constantly to keep questioning the role social workers play within these power structures. Are we truly advocating for our clients, or are we sometimes acting as gatekeepers for systems that continue to marginalize them? Regardless there is much that needs to change.

    1. The political climate of a country is another critical factor for managers to consider in day-to-day business operations. The amount of government activity, the types of laws it passes, and the general political stability of a government are three components of political climate.

      This reminds me how sometimes the opposite can occur where a large business can actually influence politics with enough wealth an power.

    1. we were experiencing a fading of thereal, a pervasive derealization he saw asintimately linked to technology and in particularto technologies of image reproduction likecinema and television, which offer powerful-yet-bogus impressions of reality in the absence ofreality itself.

      This reminds me of the documentary covering a homicide that AI-generated a family photo of the victim smiling

    1. It takes will and effort, and ifyou are like me, some days you won't be able to do it, or you just flat outwon't want to

      This idea reminds me of the quote (from somewhere) "do not attribute to malice what you can attribute to ignorance," giving people the benefit of the doubt when they fall short of what you expect them to do

    1. ‘repulsive creatures’’ who men-aced the very foundations of American civilization

      It's interesting how this fear has not subsided as we get to modern times, just been redirected. Even though the overwhelming majority of Americans trace their roots to immigration, there is constantly a sense of "us versus them", born from the fear of the unknown. This also reminds me of a book set around this time that I'm sure a lot of us have read in our English classes --- The Jungle by Upton Sinclair.

    1. Use generative AI wisely or not at all.

      This stands out because AI tools are so normal now for studying and drafting ideas, so being told to limit or avoid them feels different from most classes. It reminds me that the goal of this course is probably about practicing my own voice and critical thinking rather than just producing polished work. I see it as pushing us to struggle through the process ourselves, which might actually lead to deeper learning.

    1. Itis often also a term of blame or limitation, in these senses: (a) that what isdescribed or represented is seen only superficially, in terms of its outwardappearance rather than its inner reality;

      This is also really interesting because it reminds me of the rule "show, not tell." Even though you can describe something literally (It exploded), you can leave out details that are just as important in describing reality (It burst into flames).

    1. If you are surrounded by people that quit early, before achieving their goals, you may find it acceptable to give up early as well. On the other hand, if your peers are all achievers with grit, you will tend to exhibit grit yourself.

      This reminds me of what my mother used to tell me, be careful of the company you keep. And the famous saying "Birds of the same feather stick together."

    2. In other words, your first attempt was not a complete failure, but it did not achieve the end goal, so you try again with a different method.

      This is the complete opposite of insanity, which states doing the same thing expecting different results. Its always best to re-try a failure in a different way, sometimes, many different ways. That reminds me of the Disney cartoon movie Meet The Robinsons. The young boy tried his experiment over and over in many different ways until he finally figured it out.

  2. drive.google.com drive.google.com
    1. U.S. management of natural systems was based on a utilitarian and exploitative worldview that assumed limitless resources and human dominion over nature

      Reflection: This historical point of view emphasizes the danger of disregard of ecological boundaries. In my career concern on sustainable development, it reminds me that policies or projects should not only look at short-term benefits of extracting resources or generating financial benefits without looking at the environmental effects on the long-term. It supports the role of considering ecological and social aspects when planning.

    1. My father loved books, and since I loved my father with an aching devotion, I decided to love books as well.

      This sentence connects to me because it shows that loving something his father loved helped him feel closer to both the books and his father. It reminds me of my own relationship with my father, and how sharing an interest with him can create a deeper connection between us.

    1. The choice of research design is determined by the research question and the logistics involved.

      This stands out because it frames research as a set of tradeoffs, not "one best method". It reminds me that the "best" design isn't always the most controlled one, it's the one that answers the question while staying feasible and ethical.

    1. This means that we need to study the problems of today, not those of yesterday.

      I like this point because it reminds me that work today looks very different than it used to. Studying old workplace problems might not fully explain things like remote jobs or work–life balance issues people face now.

    1. plays or even tragedies follow this structure exactly

      Reminds me of the Heroes Journey and how lots of stories follow the basic plan of that.

    1. witter, Youtube, and streaming television services, literature might seem like a relic of the past. Indeed, fewer people are reading literature than ever

      this reminds me of our discussion in class on how it is slowly becoming less popular today and there is a cultural shift away from the books, but not that literature is not important today or has no value.

    2. those who question the purpose of poetry have "earth-creeping" minds and are "momes" (AKA fools, blockheads).

      This reminds me of the book Fahrenheit 451 because they shamed books and therefore they became mindless.

    1. Misogyny dictated these bounds, but one beneficial side effect was that common plants were preserved by women even as they were dismissed by male scientists.

      Everything is worth archiving! I'm glad these women were able to conserve "common' plants disregarded by their male counterparts. We never know how impermanent seemingly permanent things are. It reminds me of chestnut trees! Once everywhere in Appalachia, they nearly all died due to chestnut blight.

    1. (17.18) At first glance, this chunk of text reads somewhat like a boomer ranting about the integration of technology into everyday life (for a lack of a better comparison). The disdain for purple seems to stem from the idea of ritual propriety that Confucius heavily pushes for in the analects —he is against the replacement of more traditional practices that are grounded in some type of moral history for something that is shallow or convenient (this reminds me somewhat of modern-day fast fashion, in a way). Despite my initial take, I would not compare Confucius to a boomer because his concern is not unfounded or superficial. He seems to be concerned that people will lead themselves astray by draining their symbols and virtues of meaning (rituals, behavior, etc.).

  3. Jan 2026
    1. Cortisol reacts with numerous intracellular GRs (Table 11.2) to exert diverse biologic actions (see Chapter 21). Cortisol regulates many functions, including arousal, cognition, mood, sleep, metabolism, maintenance of cardiovascular tone, the immune and antiinflammatory responses, and growth and reproduction.

      This reminds me of the commercials that discuss lowering cortisol levels for weight loss. I have recently been reading about how lymphatic drainage, red light therapy and apple cider vinegar can potentially help to lower cortisol levels.

      Stress plays a large role in cortisol levels. As mentioned by the author, cortisol regulates mood and sleep. Whenever I am stressed, I have difficulty falling asleep and I tend to be moody.

    2. A clear example of the effects of chronic psychosocial stress in adults is burnout, a syndrome associated with a number of negative consequences to workers’ well-being and health. Uncontrolled work stress is a significant predictor of adverse physical consequences, including hypercholesterolemia, type 2 diabetes, coronary heart disease, and hospitalization caused by a cardiovascular disorder, musculoskeletal pain, changes in pain experiences, prolonged fatigue, headaches, gastrointestinal issues, respiratory problems, severe injuries, and early mortality at age younger than 45 years. Potential mechanisms contributing to burnout include dysregulation of the HPA axis and ANS, which are accompanied by impaired immune function and inflammation.47 These interrelated stress systems increase the risk of adopting poor health choices (e.g., smoking, lack of physical activity and sleep, bad eating habits) that make the individual vulnerable to infectious disease, such as flu-like illnesses, the common cold, and gastroenteritis.

      This reminds me of burnt out nurses. I am sure that everyone has encountered at least one. They cope with stress through poor health choices: smoking, junk food, lack of exercise, etc. This eventually leads to increased call ins partially due to a weakened immune system.

    3. Stress is broadly defined as a perceived or anticipated threat that disrupts a person's well-being, or homeostasis, and exceeds the individual's capacity to meet the demands. The demands can be physical in nature (e.g., exposure cold temperatures, moving heavy equipment) or psychological (e.g., rush to meet exam deadlines, attempting to complete multiple job assignments)

      This is a great definition and reminds me of a patient I had just the other day in the emergency department. He came in for cold exposure and had pulseless BLE. Unfortunately, given his homelessness he had frostbite and ended up losing both of his legs. Obviously the temperature outside put stress on his body and he was no longer able to regulate or maintain homeostasis.

    4. Insomnia is the inability to fall or stay asleep; it is accompanied by fatigue, malaise, and difficulty with performance during wakefulness and may be mild, moderate, or severe. It may be transient, lasting a few days or months (primary insomnia), and related to travel across time zones or caused by acute stress, or very commonly inadequate “sleep hygiene.” Sleep hygiene simply refers to behavioral and environmental practices that are intended to promote better-quality sleep (e.g., avoiding all-nighters and caffeine late in the evening). Chronic insomnia lasts at least 3 months and can be idiopathic, start at an early age, and be associated with drug or alcohol abuse, chronic pain disorders, chronic depression, the use of certain drugs, obesity, aging, genetics, and environmental factors that result in hyperarousal.69

      Several years ago, I directly experienced chronic insomnia due to stress and NOC shift work. I struggled to fall asleep and stay asleep over several weeks which left me fatigued, irritable, and unable to focus during the day. This scenario reminds me of how acute stress combined with sleep disorders disrupt normal physiologic function, as discussed on page 490 of the textbook. I will always remember that even mild or transient insomnia can impact cognitive performance and mood, which is clinically relevant for my future psych NP practice when assessing patients with sleep complaints or insomnia.

    1. The storyteller looks into the eyes of the audience and together they co-create the experience of the tale. The storyteller begins to see and recreate, through voice and gesture, a series of mental images

      I like how this explains that storytelling is active and when someone tells a story out loud it feels more engaging than just reading silently. This reminds me of activities like class presentations, where speaking helps students understand content better and retain information for longer in my opinion.

    1. And in the same place, in the words ’that whichmay be known of God is manifest in them’, we seem to betold that everything that can be known of God can be shownby reasons that have no other source but our own mind

      Our own mind. Reminds me of the philosophical concept where I know I am a concise being but I can't know another person is because I don't know their mind and state of consciousness personally.

    1. “Is there a single word that could guide a person throughout life?” Confucius replied, “How about ‘reciprocity’! Never impose on others what you would not choose for yourself.” (Analects XV.24) The Chinese, who valued silver higher than gold, called this the silver rule.

      When I see the silver rule, it reminds me of the golden rule I grew up hearing, "Treat people how you want to be treated". I wonder if this rule was adapted by Confucius and his students' conversation about reciprocity.

    1. What can you do to set yourself up for success in this and the following chapters if the goals are to labor, to learn, and to expand through both strength and struggle?

      This reading reminds me of a statement I heard during a diversity training from Baylor's Dean of Intercultural Engagement: "Diversity is a fact, unity is a choice, inclusion is an action, belonging is the outcome, and justice is the reason."

      During that training one of the main emphasis was on the power of reconciliation through willingness to encounter difference. We wrote down our own identities (i.e. eldest daughter, musician, college student, etc.) and considered the impact those have had on our opportunities, treatment, and experiences. From that lecture and today's reading alike, I am encouraged to lean into difference and encounter discomfort in order to learn what shapes struggle around me that I may never see otherwise.

    1. Births, deaths, marriages, and other population data were carefully recorded on quipus, the knotted cords that served as an accounting device.

      I think customs like this that include physical media are so cool. This particular example reminds me of the custom of the Na’vi, from the movie ‘Avatar’, in which they create ‘song cords’ with twine and beads representing major life experiences. Of course there are many other examples of art customs, like the Shabti Figures in Ancient Egypt or cylinder seals from Ancient Mesopotamia.

    1. On the other hand, some bots are made with the intention of harming, countering, or deceiving others.

      This reminds me that bots are not inherently beneficial. They are just automated programs that can be good or bad.

    1. One of the early ways of social communication across the internet was with Email [e5], which originated in the 1960s and 1970s. These allowed people to send messages to each other, and look up if any new messages had been sent to them.

      The invention of Email can be seen as one of the great step of how people communicate. The time to transport an information was significantly reduced within few minutes. This reminds me a fun fact that Her Majesty Queen Elizabeth II, the queen of Great Britain was one of the earliest adopters of email, probably the first ever email from a head of the state!

    1. hatis,pollutionisbestunderstoodastheviolenceofcolo-

      Reminds me of a class I took in the english department where we looked at American literature through the lens of extraction and prioritizing material wealth rather than experiential wealth.

    1. If you want more intelligent children, read them more fairy tales.

      this adage reminds me of our in class discussion about how fairytales foster creativity and expand curiosity within the youth

    2. to make sense of nonsense.

      "making sense of nonsense" reminds me of how fairy tales gain extended meaning as people get older and brains develop further ex. adults noticing metaphors that they never saw as a child

    1. O my cursed foolishness! I was flattering my self, and pleasing my self with vain dreams ofwhat I would do hereafter, and when I was saying peace and safety, then sudden destruction cameupon me.”

      This reminds me of The Picture of Dorian Gray.

    1. Notice that equality and equity are not synonymous. If everyone who reads this text is gifted a pair of reading glasses because the author indicates a desire to be inclusive and remove any barriers to reading ability, an equality approach might be to send everyone the same pair of glasses with the same prescription as the author. However, this wouldn’t actually level the playing field, would it? In fact, it might actually disadvantage some readers to use a prescription that would cause their eyes further strain, while advantaging people who happen to have the same prescription as the author.

      Equality and equity aren’t the same, and I see that clearly in my job in healthcare. An equality approach would mean treating every patient exactly the same way—giving everyone the same instructions, the same amount of time, and the same type of support. But in reality, patients come in with very different needs. For example, I might have two patients with the same diagnosis, but one understands medical terms easily while the other struggles with health literacy or is overwhelmed by stress. If I give them both the exact same explanation in the same way, only one of them is truly being helped. The other might leave confused, anxious, and less able to follow their care plan.

      For me, equity shows up when I adjust how I support each patient. I might slow down, use simpler language, check for understanding, or connect someone to extra resources. I’ve seen how much more effective this is than a one-size-fits-all approach. Just like giving everyone the same pair of glasses wouldn’t actually help everyone see, treating every patient the same doesn’t help them heal the same. My job constantly reminds me that fairness isn’t about sameness—it’s about meeting people where they are so they can actually move forward.

    1. Graffiti and other notes left on walls were used for sharing updates, spreading rumors, and tracking accounts

      This being an example of pre-internet social media is so interesting. It reminds me of community based social media platforms such as reddit threads where messages are posted on one dedicated page. Would current graffiti tagging still be considered social media?

    1. Friction is anything that gets in the way of a user performing an action.

      This reminds me of how following someone on social media is often quick and effortless, while unfollowing brings up a confirmation pop-up. Reading this made me reflect on how friction is designed into everyday digital interactions, sometimes to guide behavior. It also inspired me to think about how intentional friction could be added to personal devices to help reduce addictive usage.

    1. But it would be Darden herself, as a Black woman with technical expertise.d-undefined, .lh-undefined { background-color: rgba(0, 0, 0, 0.2) !important; }, working at a federal agency in which sexism and racism openly prevailed.d-undefined, .lh-undefined { background-color: rgba(0, 0, 0, 0.2) !important; }2Michela Banks, ethan chang

      Learning about Christine Mann Darden reminds me of "Hidden Figures", which highlighted three African American women: Katherine Johnson, Dorothy Vaughan, and Mary Jackson, essential mathematicians and engineers at NASA during the Space Race in the 1950s and 1960s, also overcoming racial and gender discrimination.

    1. To better understand the persuasive power of Collapsus as a whole,we can direct our attention to what documentary theorist Michael Renovcalls “the four fundamental tendencies or rhetorical/aesthetic functionsattributable to documentary practice,” which are to express, to analyzeor interrogate, to reveal, and to persuade or promote (

      Reminds me of McLuhan's tetrad!

    Annotators

    1. Participation Assignments are your primary weekly work in the class through which you will read texts and do related exercises, discussing them with classmates.

      This reminds me of Lara Boyd's ted talk and how she Acknowledges healthy brain exercises. Activities together as classmates based off of a variety of interesting texts sounds like amazing weekly brain exercising!

    1. A photo that is likely from a click-farm, where a human computer is paid to do actions through multiple accounts, such as like a post or rate an app. For our purposes here, we consider this a type of automation, but we are not

      this reminds me of an article I read for an earlier assignment about how a large portion of social media users are fake. It is bizarre the time that we makes this a profitable industry. It is safe to say we live in an attention based economy.

    1. some of the most advanced facial-recognition software failed to accurately identify dark-skinned women 35% of the time, compared to a 1% error rate for white men

      yuck

      reminds me a little bit about how black people weren't photographed in the early photography era because they didn't feel like figuring out how to more aptly design the process...the only reason it changed was because chocolate companies wanted pictures of their food in advertisements

    1. What about Students with Disabilities? Students with disabilities are sometimes the most informed when it comes to making decisions about their own learning. They should understand that it is in their best interest to take ownership of their own approach to education, especially when it comes to leveraging resources and opportunities. In this section, you will learn about the laws that regulate education for students with disabilities as well as look at some resources that are available to them. Just like anyone else, under the law, qualified students with disabilities are entitled to the same education colleges and universities provide to students without disabilities. Even though a particular disability may make attending college more difficult, awareness on the part of the government, learning institutions, and the students themselves has brought about a great deal of change over the years. Now, students with disabilities find that they have available appropriate student services, campus accessibility, and academic resources that can make school attendance and academic success possible.

      This passage reminds me of a news article I read about universities improving accessibility for students with disabilities, like adding more adaptive technology and inclusive classroom designs. It also makes me think of how the Americans with Disabilities Act has changed opportunities over time. I can relate because I've seen friends benefit from these resources, which help them succeed just like any other student. It shows that support and awareness really makes a difference in education.

    2. Adjustments to College Are Inevitable College not only will expand your mind, but it may also make you a little uncomfortable, challenge your identity, and at times, make you doubt your abilities. It is hard to truly learn anything without getting messy. This is what education does: it transforms us. For that to happen, however, means that we will need to be open to the transformation and allow the changes to occur. Flexibility, transition, and change are all words that describe what you will experience.

      I like how the text says learning can be messy. It reminds me that growth isn't always comfortable, but it's worth it in the long run.

    1. There is no way in which police can maintain dignity in seizing and destroying a donkey on whose flank a political message has been inscribed.

      INFO 103 Winter 2026. I think this is absolutely right. It reminds me of the rapid development of AI in recent years. One point that people are extremely worried about is that if Ai really becomes so powerful that even humans cannot control it, and if it invays media platforms like a hacker and then changes the direction of public opinion, this would be a very terrifying thing. But at this point, how should we convict?

    1. Or a computer program can repeat an action until a condition is met:

      This reminds me of when youtubers post videos of followers doing "day x until y" messages. I never considered the possibility that it was fake until now. If you combine this with the sleep feature and randomize the timeframe of the post, it could look very real. I also wonder if in the near future this could be done with AI to create automated videos.

    1. When Indigenous peoples talk about culture, it is ofsomething foundational to their lives, inseparable from them.

      When I think of this I think of slavery, and Malatesta's anarchic thought experiment of having your leg immobilised and telling you this is needed to walk, much like Arslan Senki's golden cage. Living in an isolated casquet means sensory and life reduction. If you've liven in and about rites, you will partake on those and these may look necessary to you. Most people today would not let go of on-demand shows or music, let alone their phones! These are engraved, inseparable of how they live, from their identities, an extension of their selves, a la McLuhan's cyborgs.

      It also reminds me of absurdist takes like those of Camus whereby one lives to rebel in one way. To maximise your own identity in this already set-in-stone world, we need a maximal diversity of alternatives, else risk suicide out of meaninglessness.

    Annotators

    1. We also see this phrase used to say that things seen on social media are not authentic, but are manipulated, such as people only posting their good news and not bad news, or people using photo manipulation software to change how they look.

      I think this idea shows how social media can distort people's lives. When all we see is mostly good news, filters, and edited photos, it's easy to compare ourselves to something that was never real. Over time, this can affect our self-esteem and our expectations of what is "normal". This reminds me that we often forget that social media is more like a highlight reel than real life.

    1. favorite part of Silicon Valley is the cultivation of community. Tech founders are a close-knit group, always offering help to each other, but they circulate actively amidst the broader community too

      yes, reminds me of the 'getting to an explosive mix' work of the MIT guy I met in AMS. What backgrounds or skills are missing in a specific location, to make something fly.

    Annotators

  4. Dec 2025

    Annotators

    1. Reading back all those old posts and weeknotes I have here is super nice and reminds me:Keeping a record of things is really valuable. Just write and trust that it will come in handy at some point.I used to do so many things in a given week. Compared to what I’m doing now, my life was insanely eventful.I was consistently (too) early on a lot of things. For instance: I read myself complaining about restaurants and food in Amsterdam, something which is mostly solved now.

      Like myself Alper is his own most frequent reader of his blog. Mentions realising how much he did in a week earlier in his life. Same for me, things that now might be a big thing in a week, were Tuesday afternoon 15yrs ago. It's not just age I suspect, but also an overall attenuation that Covid brought?

    1. thered’ b

      Connect: This kind of racially charged behavior and attitude reminds me about something similar from my cultural media studies, specifically on the fixation of "the Other," where certain racial groups were objectified and their cultures were misconstrued. This potentially may have contributed to the influence of implicit biases in the viewers of that specific content.

    1. There is some value to reminding ourselves that we humans are relatively new, and certainly our recorded history only makes up a tiny sliver at the end of a very long past.

      This sentence is reminds me and other people have been around for only a short time compare to how long the earth has existed, and our writing history is just a small part of that long time. This help us stay humble and remember that many thing we think are important may not last forever

    1. One approach that often leads to a difficult writing process and a clunky result is the pursuit of “academese”

      This is really helpful because it shows that professors don’t want complicated words just to sound smart. Using simple, clear language actually makes your ideas stronger. I sometimes overthink words to sound “fancy,” but this reminds me that clarity is more important than sounding scholarly.

    1. This sort of opportunity would not exist if there were an adequate supply of potential entrepreneurs with access to capital.

      This seems like a loaded statement, let's break it down.

      If the laundromats were all independently owned this math would not work. The capacity to leverage oneself to buyout companies is a privilege of a specific caste.

      This reminds me of the story about how Pornhub (Mindgeek), being a tech company not a porn company, was a member of this specific caste. Pornhub, like youtube at the time, allowed anyone to upload whatever copyrighted material they wanted to share for free. This put the porn producing companies all out of business because no one bought their product since it was on Pornhub for free. As these porn producing companies went brankupt, Pornhub, with access to cheap debt was able to buy them all up.

    1. But what if you didn’t need to wait for nature? What if you manufactured the dependency in days and provided the relief in minutes? Create the craving, sell the satisfaction. Scale that across millions of people. The formation time collapses to nothing. The extraction becomes continuous.

      This reminds me of Soma (Brave New World) - Wikipedia

    1. At its core, the book advocates for the critical need for work across academic disciplines. The sciences needhumanistic inquiry, and the humanities need the sciences. The future of the planet depends on it. For biologists, thisbook historicizes the field, making a familiar world unfamiliar. For social scientists and humanists, it introducesbotanical worlds in a new idiom, making unfamiliar worlds more familiar. An interdisciplinary approach is criticalfor the problems we face. The natural world and its myriad environmental crises cannot be adequately understood bythe tools of botany alone. In opening up the worlds of botany and feminism through interdisciplinary approaches, wesee new multispecies possibilities

      REMINDS ME OF POLI SCI

    2. Crip theory eloquently captures ableism with the term . As Eli Clare writes, the supercrip is one of the"dominant images of disabled people. We are taught to celebrate the boy without hands who bats well, or a blind manwho hikes the Appalachian Trail, or an adolescent girl with Down’s syndrome who learns to drive. The nondisabledworld is suffused with such stories where resilience against all odds is celebrated—a visible and repeated lesson thatdisabled people must overcome disability to be celebrated

      ONLY PHYSICAL THOUGH AND REMINDS ME OF MY OWN INVISIBLE ONES

    3. or example, in a naturecultural world, plants are often assigned ethnonationalgroups even as they develop new ecologies in changing networks of botanical and political geographies. In theUnited States, for example, we identify some plants with such names as Japanese knotweed or Chinese privet and yetanoint the Georgia peach as American even though it is of Chinese origin.

      THIS IDEA REMINDS ME OF THE INVISIBLE GIRL READING

    4. For example, how did the tumbleweed, aforeign and indeed invasive plant, become an icon of the American West? Why are some plants reviled and otherscelebrated? Rememorying plant life through naturecultures helps us narrate embrangled lives under and in the wakeof slavery, colonialism, conquest, and servitude, helping us imagine more just futures.

      THIS REMINDS ME OF THE WITCH

    5. The rise of botany transposed colonial views onto nature. No surprise,then, that there is more scientific work on competition than on cooperation, more on conflict than on coexistence,more on battle between the sexes than on joyful cooperative living. Colonial worldviews ground branches ofbiology—both botany and zoology

      Ecofeminism- this also reminds me of western v.s Indigenous Epistimoogy

    Annotators

    1. What it would be like for a human to be in a bat’s situation. Not what it was like to be a bat. The hardware was too different. The approximation broke down. What remained was projection.

      This reminds me of people that speak languages, their narrative self speaks a specific language but they can learn a new one and switch too it. I wonder if we can do that for new sensory systems

    1. There needs to be a balance. Specific praise offered within a system that includes the previous three interventions is a powerful and empowering experience. Students know they have worked well and to the best of their ability. They are also aware that you are aware of their efforts. “Catch them being good” is the old adage. It is not only applicable but also an achievable goal in our music classrooms.

      I’ve learned how much students light up when I point out something they did well, even if it seems small. When I make an effort to notice the good choices such as when a student stays focused, helps a friend, or gives their best effort the entire class environment changes. It reminds me that praise builds trust, confidence, and a stronger classroom environment.

    1. In older films, all the (brief ) production credits generally appear at the beginning, and the namesof the leading actors are sometimes repeated in (andconstitute) the closing credits. Today opening creditsvary widely, but closing credits are lengthy and ofteninclude hundreds of names, accounting for virtuallyeveryone who worked on the film or had something todo with it (e.g., caterers, animal handlers, accountants).

      Movies that are made now have long credits that people do not sit for to read, however in older films, it would generally consist of a small preview of those who worked on the film. This reminds me of how Marvel would include a sneak peak of a film at the end of their movies, showcasing the credits. I think that that is good because it truly honors everyone’s hard work and you can see most names which is good.

    1. Of all the tactics inspired by Nat Eliason, this is my favorite. As you’re writing, put “TK” anywhere you aren’t sure of a detail, or where you need to add more context later. One of the main reasons we stop writing or fall out of flow is getting stuck on some detail giving me trouble, and by dropping in a TK to come back to it later, I can maintain the flow. Why TK? Think of it as “To Come.” It  reminds me to add more context later. That letter combination doesn’t appear in any English word, so when you CMD+F for it after you’re done writing, you’ll only find the instances where you used it as a place marker.

      This entire section is plagiarized from Eliason. Bizarre.

    1. Experts chimed in to declare that everything Summers had said about sex differences was within the scientific mainstream. These rational appeals had no effect on the mob hysteria.

      Reminds me of the theme in Wicked: For Good where "The Wizard" of says if Alphaba tells the people of Oz the truth they will not believe her because they will not want to

    1. For example, howdid the tumbleweed, a foreign and indeed invasive plant, become an icon ofthe American West? Why are some plants reviled and others celebrated?

      This reminds me of the invasive species of the European Pine trees placed in Palestine during the Nakba. The Israeli forces planted pine trees while occupying Palestinian villages to replicate the European infrastructures, this is a biological warfare of colonialism (Josephson 2025). https://origins.osu.edu/read/environmental-nakba-israel-palestine-water

    2. Histories of care work remain deeply feminized and racialized

      This reminds me of a conversation I had in my sociology class about hate crime and racial discrimination in the healthcare systems. How the demographics of nurses are BIPOC and women, and have faced tremendous racism and sexism at workplace during the COVID-19 pandemic.

    3. Linnaeus’s nuptaiae plantarum (or the marriageof plants) opened up a polyandrous and polygynous sexual imagination wheremultiple husbands and wives were housed in flowers.

      I find it quite pathetic how easily people sexualize objects and living things and I cannot understand how that works, but I see the influence of scientists like Linnaeus encouraging this type of objectification in scientific studies. This reminds me of Paasnonen's concept of objectification, where people and things simply exist to be objectified, and that is due to the cultural dynamics and social constructions of a society.

    Annotators

    1. In academic writing, readers expect each paragraph to have a sentence or two that captures its main point. They’re often called “topic sentences,” though many writing instructors prefer to call them “key sentences.” There are at least two downsides of the phrase “topic sentence.” First, it makes it seem like the paramount job of that sentence is simply to announce the topic of the paragraph. Second, it makes it seem like the topic sentence must always be a single grammatical sentence. Calling it a “key sentence” reminds us that it expresses the central idea of the paragraph.

      The examples of Version A vs. Version B help me understand why key sentences matter. They don’t just introduce topics—they connect each paragraph to the argument.

    2. Effective paragraphs are the fundamental units of academic writing; consequently, the thoughtful, multifaceted arguments that your professors expect depend on them. Without good paragraphs, you simply cannot clearly convey sequential points and their relationships to one another

      This section reminds me how important paragraph organization is. I used to think content and style were separate, but the author shows they work together.

    1. Cindy, on the other hand, is challenged to unmaskand unlearn White settler colonial ways of thinking and being in the world,and to listen and learn from Indigenous people.

      I resonate a lot with Cindy. I think trying to unlearn colonial ways can be difficult, but once you're aware of what they look like, it makes it a bit easier. This reminds me of when bell hooks stated, "The enemy within must be transformed before we can confront the enemy out." when referring to internalized sexism (hooks 2014, 12). Broadly speaking, when we talk about internalized sexism, it is all these internalized thoughts that we carry with us about gender norms that may be harmful to us. I think this is quite similar to colonial ways of thinking because, just like internalized sexism, colonial thinking is built into us because it played a role in every step of our lives when growing up in a Western society.

      Often, we have a lot of behaviour that is deeply rooted in colonialism and patriarchy, yet we don't even realize it. So, it's important to understand this can happen, analyze what we need to change, and try to break free from these norms so that we can work towards decolonization.

    1. I want to tell a story about two girls capable of retrieving what remainsdormant—the purchase or claim of their lives on the present—without committing furtherviolence in my own act of narration.

      Hartman's dilemma reminds me of Audre Lorde's famous quote published in This Bridge Called my Back about not using the master's tools to dismantle the master's house (Lorde, 2022). The author wants to help share marginalized stories but is afraid of committing further violence. In my opinion, this "further violence" is likely continuing to keep some voices/perspectives hidden or misinterpreting them to suit their own ideals (which Western epistemologies and archives have done).

    2. One cannot ask, “Who is Venus?” because it would be impossible to answer such a ques-tion. There are hundreds of thousands of other girls who share her circumstances and thesecircumstances have generated few stories. And the stories that exist are not about them, butrather about the violence, excess, mendacity, and reason that seized hold of their lives, trans-formed them into commodities and corpses, and identified them with names tossed-off asinsults and crass jokes. The archive is, in this case, a death sentence, a tomb, a display of theviolated body, an inventory of property, a medical treatise on gonorrhea, a few lines about awhore’s life, an asterisk in the grand narrative of history.

      Here, Hartman reminds me of Sara Ahmed's description of a "feminist killjoy," which is a feminist that is not complicit or silent to injustices even when others may prioritize agreeability (Ahmed, 2017). Like a killjoy, she refuses to allow readers to enjoy a sanitized version of history. By highlighting structural violence, she “kills the joy” of comfortable narratives and exposes what the archive hides.

    3. What are the kinds of stories to be told by those and about those who live in such anintimate relationship with death? Romances? Tragedies? Shrieks that find their way into speechand song? What are the protocols and limits that shape the narratives written as counter-history, an aspiration that isn’t a prophylactic against the risks posed by reiterating violentspeech and depicting again rituals of torture? How does one revisit the scene of subjectionwithout replicating the grammar of violence? Is the “terrible beauty” that resides in such ascene something akin to remedy as Fred Moten would seem to suggest?14 The kind of terriblebeauty and terrible music that he discerns in Aunt Hester’s screams transformed into the songsof the Great House Farm or in the photograph of Emmett Till’s destroyed face, and the “acuityof regard,”15 which arises from a willingness to look into the open casket

      Hartman raises a central ethical problem in feminist and Black studies: how to represent historical violence without reproducing it. This reminds me of discussions that are made in regards to horror movies or other media that depict sensitive subject matter, which is "what draws the line between accurate portrayal and the glamourization/aestheticization of abuse and suffering?" If the victims, like Emmett Till who was mentioned in the passage, cannot decide that how can historians decide what's appropriate?

    1. As scholar-activists, we ask how we might locate our solidaritywithin and across various family and community spaces, rather than onlyin more visible activist sites

      This is an interesting point because it reminds me of the romanticization of social movements. This romanticization often views the process of liberatory struggles through an idealized and oversimplified lens, and overlooks internal conflicts and flaws. This means that progress is only measured through public-facing spectacles/displays of justice, rather than something that happens simultaneously behind closed doors and isn't easily televisual. In regards to this text, a romanticization of these struggles can often dismiss intellectual labour and progress that takes place in unconventional spaces such as within families, homes, and community spaces, or even within ourselves. The authors are trying to make the point that struggling for liberation and decolonialization isn't a one-size-fits-all-approach.

    2. As a verb, queer is a deconstructivepractice focused on challenging normative knowledges, identities, behav-iors, and spaces thereby unsettling power relations and taken-for-grantedassumptions. Queerness is then less about a way of “being,” and more about“doing,” and offers the potential for radical social critique.

      This is a central theme: the reframing of "queer" beyond its initial identity label. Most of my peers think that queer describes a particular sexual orientation or identity. But to be queer is defined through practices and actions that are inherently anti-oppressive.

      This reminds me of a quote from bell hooks, where hook's describe queer as "the self that is at odds with everything around it and has to invent and create and find a place to speak and to thrive and to live." In this way, queerness is not a sexual identity but a method of moving through the world, a method that involves self-creation in opposition to hetero-normativity and patriarchy.

    Annotators

    1. blocking or delaying adversaries’ access to key resources like chips and semiconductor equipment

      Reminds me of how nuclear weapons have been regulated and only certain countries are able to develop/possess them

    2. An aligned AI would not want to do these things

      This reminds me of our discussion about the movie Megan and how we would have to implement safeguards in AI in order to preserve the interests of the human race

    1. I N MY WORK AS A SOCIAL SCIENTIST, I have visited dozens of class-rooms-surely more than a hundred-and observed, both systemati-cally and informally, exceptional teachers working in various environments across the United States-urban, suburban, and rural. Some of these are places that those on the outside might consider inadequate or substandard.

      This sentence shows that the writer has actually been to many classrooms and seen really good teachers in all kinds of schools, even in places that outsiders usually think are “bad” or “not enough.” It kind of breaks the easy idea that good education only happens in rich or famous schools, and that poor schools equal poor teaching. It reminds me of how some people think community college or less “prestige” schools must be low quality, but then you meet one prof who change the whole way you think about a subject. My question is, who really has the right to call a school “substandard” if they never sit inside the classroom and watch what happens there?

    1. encourage you to think about writing with sources is a “They Say/I Say” process.

      This “They Say / I Say” idea makes a lot of sense to me because in many past essays I either depended too much on sources or summarized them without connecting to my own point. Guptill’s explanation shows that good writing balances both: listening to what “they” say, then adding what I think. It reminds me that my voice matters, as long as I connect it directly to the sources.

    1. Thamus replied: […] this discovery of yours will create forgetfulness in the learners’ souls, because they will not use their memories; they will trust to the external written characters and not remember of themselves. The specific which you have discovered is an aid not to memory, but to reminiscence, and you give your disciples not truth, but only the semblance of truth; they will be hearers of many things and will have learned nothing; they will appear to be omniscient and will generally know nothing; they will be tiresome company, having the show of wisdom without the reality.

      This reminds me of how some people thought the invention of calculators would make people dumber and unable to do calculations themselves. However calculators just enabled people to learn harder math. I wonder what other inventions we judge too pessimistically at first.

    1. it also canmask the reality that Cindy’s family benefits materially from owning land andthis ability to buy land is directly related to other forms of prior land theftof her White settler ancestors (and her partner’s

      There is material privilege from genocide. This reminds me of the statement "No one is illegal on stolen Indigenous lands", used to condemn the abuse that ICE is perpetrating in the US right now. Link to an article: https://www.culturalsurvival.org/news/no-one-illegal-stolen-indigenous-lands

    2. As Sarah (forthcoming) has argued elsewhere, “the forced disappearance oflocally defined systems of gender is central to the settler project of nativedisappearance” as gender plays a central role in understanding and definingIndigenous peoples’ identities.

      This showcases gender regulation as a tool of genocide. It reminds me of the unproportioned violence rates against Indigenous queer people and Two-Spirit individuals. Link to the article: https://www.gbvlearningnetwork.ca/our-work/backgrounders/GBV%20Against%20Two%20Spirit%20Indigenous%20Peoples/index.html

    Annotators

    1. Most guys, when they see a girl, instantly conclude thatshe plays badly. Even if she’s actually a good player,it’s not enough for guys. If a guy and a girl of an equalskill make a mistake in-game, it’s okay for the guy, ithappens, but in case with the girl, she would do it “be-cause she’s a girl”, and not because even top tier playerssometimes make mistakes. Youtube has lots of fail montagesfrom female tournaments. Why point it out specifically,if any tournament has tons of mistakes.

      Indeed! Reminds me of cherry picked Islamophobic assault compilations. Ragebait. Polarisation devices. This can also lead perhaps not too trauma, but to imposter syndrome, to loss of confidence, to de-motivation, and burnout. Surely, males experience these too, but less frequently, and notably, on their own. Not sharing and taking a stoic toxic masculinity stance then builds up to projection, hate, impotency, outward attacks not so much as inner pitying (it's others who are wrong, and I must defend myself). There is a certain dread and anguish I feel sorry males have to go through, much unhealthier than fems.

    Annotators

  5. www.literacyworldwide.org www.literacyworldwide.org
    1. Digital literacies are not solely about technical proficiency but about the issues, norms, and habits of mind surrounding technologies used for a particular purpose.

      I like this point—it reminds me that digital literacies go beyond just knowing how to use tools. They include understanding the social, ethical, and practical context of technology use. #LiDA101

  6. keywords.nyupress.org keywords.nyupress.org
    1. Society” is a word too often used in a sloppy or vague way. When teachers share their pet peeves about student writing, they frequently name “society” as the word they would most like to ban. There are typically two reasons given for this antipathy. First, the term falsely implies universality (when you say “society,” do you really mean to refer to every single person in the world?). Second, it attributes agency to an abstraction (how can “society” actually do anything like oppress someone or believe something?). Baked into such usages is often a simplistic if widely recognizable story about how an amorphous “social” pressure is applied to equally amorphous “individuals” who either succumb to that pressure or resist it by “being themselves.” You can find versions of this story in a blog post about how well the free market organizes “society,” a sociology paper about gangs’ “antisocial” activity, or a political speech blaming “society” for certain behavior. But wherever this story is told, if it lacks any specifics about what is meant by “society,” readers are likely to see it as a cliché, an overgeneralizing formula.

      The author points out that “society” is often used without clear meaning, and I notice that I also tend to use the word in a broad and imprecise way. This section reminds me that academic writing requires specificity. When people blame “society,” they usually refer to certain institutions or groups, not every person. The author’s criticism pushes me to be more intentional about who or what I actually mean when I use the term.

    1. 20.3. Colonialism in Programming# Colonialism shows up in programming languages as well. 20.3.1. Programming in English# Most programming languages are based in English, and there are very few non-English programming languages [t26], and those that exist are rarely used. The reason few non-English programming languages exist is due to the network effect, which we mentioned last chapter. Once English became the standard language for programming, people who learn programming learn English (or enough to program with it). Attempts to create a non-English programming language face an uphill battle, since even those that know that language would still have to re-learn all their programming terms in the non-English language. Now, since many people do speak other languages, you can often find comments, variable names, and even sometimes coding libraries which use non-English languages, but the core coding terms (e.g., for, if, etc.), are still almost always in English. See also this academic paper: Non-Native English Speakers Learning Computer Programming: Barriers, Desires, and Design Opportunities [t27] 20.3.2. Programming Adoption Through Silicon Valley# The book Coding Places: Software Practice in a South American City [t28] by Dr. Yuri Takhteyev explores how programming in Brazil differs from programming in Silicon Valley. Dr. Takhteyev points out that since tech companies are centralized in Silicon Valley, this then means Silicon Valley determines which technologies (like programming languages or coding libraries) get adopted. He then compares this to how the art world works: “If you want to show [your art] in Chicago, you must move to New York. He then rewords this for tech: if you want your software to be used widely in Brazil, you should write it in Silicon Valley. We can see this happening in a study by StackOverflow [t29]. They found that some technologies which are gaining in popularity in Silicon Valley (Python and R), are not commonly used in poorer countries, whereas programming tech that is considered outdated in Silicon Valley (android and PHP), is much more popular in poorer countries. In his book, Takhteyev tracks the history of the [Lua programming language](https://en.wikipedia.org/wiki/Lua_(programming_language) [t30]), which was invented in Brazil but became adopted in Silicon Valley. In order to gain popularity in Silicon Valley (and thus the rest of the world), the developers had to make difficult tradeoffs, no longer customizing it for the needs of their Brazilian users.

      Honestly, this chapter made me realize how invisible the role of English is in programming. I always took it for granted that terms like if, while, or return were “universal,” but they’re only universal because English basically colonized the coding world. It makes me think about how much harder programming must be for people who don’t speak English well. We talk a lot in tech about making things “accessible,” but the foundation of programming itself is already biased toward one language.

      The part about Silicon Valley deciding what technologies the rest of the world uses also stood out to me. It feels weird that a whole country’s developers might rely on “outdated” languages just because the global tech trends are controlled by one region. It reminds me of how fashion or music trends spread — people follow whatever the cultural “center” is doing, even if it doesn’t fit their own needs.

      One question I have is: would programming look totally different today if the early pioneers weren’t mostly English-speaking? Like, if the first mainstream languages came from Brazil or Japan, would we all be learning those instead? It makes me wonder how many innovations never spread just because they weren’t born in the “right” place.

    1. Plot

      The chapter emphasizes plot as the most important part of drama, and I like how it connects this to fiction. What stands out is the idea that plot structure isn’t fixed playwrights can shape events however they want as long as it creates an emotional effect. This reminds me that drama depends on intention more than a rigid formula.

    1. what we’retalking about is the fact that in the notion of representations is the idea of givingmeaning.

      this reminds me that we shouldn't just accept things at face value. we have to actually pay attention to how things are being shown and what message that creates. Hall's basically saying that the media doesn't just reflect reality, it shapes it by adding meaning, changing meaning, or even creating it from scratch. so when we see people or events in the media, we're not seeing the real thing, we're seeing someone else's version of it.

  7. Nov 2025
  8. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. xkcd comics. The Pace of Modern Life. June 2013. URL: https://xkcd.com/1227/ (visited on 2023-12-10).

      I particularly like this xkcd comic titled "The Pace of Modern Life". It vividly conveys the feeling that our pace of life is getting faster and faster, as if there is never enough time and information comes too fast. After reading it, I couldn't help laughing and felt somewhat empathetic. I realized that my speed of using social media and handling emails is completely unable to keep up with the pace of the world. This comic reminds me that sometimes slowing down and giving oneself some breathing space is more important than constantly chasing after things.

    1. Just 502.9 metres by 106.7 metres (1650 feet by 350 feet),the island is small, which made it attractive to the slavetraders intending to build a fort there. Local accountsdescribe how Tasso was the first site considered for a slavefort, but proved unsuitable due to the breadth of terraininto which an escaped slave could flee. Bunce was thereforedeemed a better site and had the advantage of lying justbefore the point where the river grows too shallow for deep-water vessels to navigate.

      Chokepoints, vigilancy guard towers, straits. Kinda reminds me of The Witness architectural analysis (https://www.gdcvault.com/play/1020552/The-Art-of-The).

    Annotators

  9. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Steve Jobs. December 2023. Page Version ID: 1189127326. URL: https://en.wikipedia.org/w/index.php?title=Steve_Jobs&oldid=1189127326 (visited on 2023-12-10).

      Whenever I see the page about Steve Jobs, I always think of him not just as a technological innovator, but more like a person who constantly challenges the norm. His story reminds me that success often comes from the courage to pursue what one truly loves, rather than just following the routine. Reading about his experiences makes one feel that entrepreneurship, creation, and even life itself can be full of passion and creativity.

    1. metimes the change is in the

      This reminds me of our own personal moʻolelo. I had a conversation with one of my hoa from Keaukaha about Kamapuaʻa and how she had a different recollection of the moʻolelo from her other friend who was in the next town over, but the ending/moral of the story was still the same. It's interesting to see this play out in different cultures as well.

  10. keywords.nyupress.org keywords.nyupress.org
    1. Outside of the arena of national policy, perhaps the most influential nonmilitary use of “war” in recent decades has been in what came to be called the culture wars. Most prominent in the 1980s and 1990s, the phrase “culture wars

      The section on “culture wars” shows how the word “war” doesn’t just describe conflict — it produces it. Jeffords connects the term to debates over education, art, and politics, which reminds me of how the “celebrity” essay explored power structures and social influence. What inspires me here is the method: Jeffords uses history, politics, and examples from public controversies to show how a keyword reflects deeper tensions in American culture. For my research project, I can follow this model by showing how my own keyword shapes debates, identities, or values today.

    2. The second half of the twentieth century also saw the increasing use of “war” to refer to more than just direct military encounters, thus shifting the emphasis from the first definition of “war” (conflicts among nations) to the second (conditions of antagonism). Dwight D. Eisenhower, who served in World War II as general of the US Army, in his last speech to the nation before stepping down as president, acknowledged that the post–World War II military environment would be different from any in the past because of the emergence of a permanent, economically profitable armaments industry, or “military-industrial complex

      Jeffords shows how the meaning of “war” expands in the 20th century to describe social problems — the “war on poverty,” “war on drugs,” and “war on terror.” This reminds me of the “celebrity” essay because both authors explore how language shapes public attitudes. By calling these issues “wars,” politicians create urgency, fear, and conflict even when the situation is not military at all. This metaphorical framing is something I want to use in my own research: analyzing not just what a word means, but what it does in society.

    3. Tug-of-war, Cold War, war on terror, World War II, “Make love, not war,” WarGames, War on Poverty, prisoner of war, War of the Worlds, Iraq War, war on drugs, antiwar, “All’s fair in love and war”—these are just a few of the myriad ways that the word “war” is used every day in the English language. It is difficult today to turn on a television, check a news feed, or go to a movie theater anywhere in the United States without encountering a verbal or a visual reference to war. Whether through reports of wars around the globe; declarations of “war on” a variety of social issues, from AIDS to poverty to drugs to crime; or descriptions of sporting events (“throwing a bomb,” “blitzing,” “sudden death”)—references to war permeate US culture.

      Jeffords’s opening reminds me of last week’s “celebrity” essay because both authors start by showing how a single word appears constantly in everyday life. Just like “celebrity” was more complicated than it first seemed, “war” also carries multiple meanings beyond literal combat. I like how Jeffords uses examples from sports, politics, and media to show how the term shapes how Americans think about conflict. This approach gives me ideas for my own keyword project — especially the strategy of starting with common uses before digging into deeper cultural meanings.

    1. And now, byMohammed, our great Prophet, I swear that this man lies in saying that I havestolen his money, for that money is truly mine.”

      The mirrored words here make it almost certain this is a fabrication. This reminds me of passages from the bible where phrases are repeatedly identically.

    Annotators

    1. The parent may then comfort the child to let the child know that they are not being rejected as a person, it was just their action that was a problem.

      This sentence reminds me of when I was a child and was scolded by adults. If I only heard, "How could you be so undisciplined!" that kind of hurt would linger in my heart for a long time. But if someone added a sentence after being angry, "I still love you very much, but you can't do this thing," the feeling would be completely different. It makes the child know that mistakes can be corrected, but they are not unlovable just because they made a mistake. Such comfort is actually teaching the child a safe self-perception: I can make mistakes, but I can also become better.

    1. In addition to deterrence, another reason for the adoption of strict discipline policies has been to avoid the racial discrimination that occurs when school officials have discretion in deciding which students should be suspended or expelled

      This loosely related to the topic at hand, but this in the section just above that I made a note on actually reminds me of the TV show. Everyone hates Chris and that we see how segregate schools once combined. They still fundamentally hold racism and their teachings in their educational methods and also punishment wise. I know the show was based around Chris and how everyone is against him but punishment wise we see in several different episodes of Chris is harshly punished compared to that of his white counterparts simply because of his blackness

    1. That gargantuan hunk of meat, dominating the meagrefruit and vegetable matter beneath, leaves us in no doubt as to theprincipal part of this meal.

      The second icon, yes, it reminds me of Minecraft hunger bars, which were not represented by energy, but rather by chicken wings.

    2. play like a loser. At the end of Into the Dead, when you lose, your com-panion is killed, too

      Reminds me of the infatigable environment of Rain World, Death Stranding, and Frostpunk. Death looms.

    Annotators

    Annotators

  11. rws511.pbworks.com rws511.pbworks.com
    1. Sure,Facebook and Twitter sometimes feel like places where masses of people experience thingstogether simultaneously. But in reality, posts are targeted and delivered privately, screen byscreen by screen.

      The idea of things being 'experienced simultaneously but separately' is so interesting. It reminds me of discussions I have heard or seen that debate whether or not social media has made us more connected or more isolated/lonely.

    1. Author Response

      Reviewer #2 (Public Review):

      "The cellular architecture of memory modules in Drosophila supports stochastic input integration" is a classical biophysical compartmental modelling study. It takes advantage of some simple current injection protocols in a massively complex mushroom body neuron called MBON-a3 and compartmental models that simulate the electrophysiological behaviour given a detailed description of the anatomical extent of its neurites.

      This work is interesting in a number of ways:

      • The input structure information comes from EM data (Kenyon cells) although this is not discussed much in the paper - The paper predicts a potentially novel normalization of the throughput of KC inputs at the level of the proximal dendrite and soma - It claims a new computational principle in dendrites, this didn’t become very clear to me Problems I see:

      • The current injections did not last long enough to reach steady state (e.g. Figure 1FG), and the model current injection traces have two time constants but the data only one (Figure 2DF). This does not make me very confident in the results and conclusions.

      These are two important but separate questions that we would like to address in turn.

      As for the first, in our new recordings using cytoplasmic GFP to identify MBON-alpha3, we performed both a 200 ms current injection and performed prolonged recordings of 400 ms to reach steady state (for all 4 new cells 1’-4’). For comparison with the original dataset we mainly present the raw traces for 200 ms recordings in Figure 1 Supplement 2. In addition, we now provide a direct comparison of these recordings (200 ms versus 400 ms) and did not observe significant differences in tau between these data (Figure 1 Supplement 2 K). This comparison illustrates that the 200 ms current injection reaches a maximum voltage deflection that is close to the steady state level of the prolonged protocol. Importantly, the critical parameter (tau) did not change between these datasets.

      Regarding the second question, the two different time constants, we thank the reviewer for pointing this out. Indeed, while the simulated voltage follows an approximately exponential decay which is, by design, essentially identical to the measured value (τ≈ 16ms, from Table 1; ee Figure 1 Supplement 2 for details), the voltage decays and rises much faster immediately following the onset and offset of the current injections. We believe that this is due to the morphology of this neuron. Current injection, and voltage recordings, are at the soma which is connected to the remainder of the neuron by a long and thin neurite. This ’remainder’ is, of course, in linear size, volume and surface (membrane) area much larger than the soma, see Fig 2A. As a result, a current injection will first quickly charge up the membrane of the soma, resulting in the initial fast voltage changes seen in Fig 2D,F, before the membrane in the remainder of the cell is charged, with the cell’s time constant τ.

      We confirmed this intuition by running various simplified simulations in Neuron which indeed show a much more rapid change at step changes in injected current than over the long-term. Indeed, we found that the pattern even appears in the simplest possible two-compartment version of the neuron’s equivalent circuit which we solved in an all-purpose numerical simulator of electrical circuitry (https://www.falstad.com/circuit). The circuit is shown in Figure 1. We chose rather generic values for the circuit components, with the constraints that the cell capacitance, chosen as 15pF, and membrane resistance, chosen as 1GΩ, are in the range of the observed data (as is, consequently, its time constant which is 15ms with these choices); see Table 1 of the manuscript. We chose the capacitance of the soma as 1.5pF, making the time constant of the soma (1.5ms) an order of magnitude shorter than that of the cell.

      Figure 1: Simplified circuit of a small soma (left parallel RC circuit) and the much larger remainder of a cell (right parallel RC circuit) connected by a neurite (right 100MΩ resistor). A current source (far left) injects constant current into the soma through the left 100MΩ resistor.

      Figure 2 shows the somatic voltage in this circuit (i.e., at the upper terminal of the 1.5pF capacitor) while a -10pA current is injected for about 4.5ms, after which the current is set back to zero. The combination of initial rapid change, followed by a gradual change with a time constant of ≈ 15ms is visible at both onset and offset of the current injection. Figure 3 show the voltage traces plotted for a duration of approximately one time constant, and Fig 4 shows the detailed shape right after current onset.

      Figure 2: Somatic voltage in the circuit in Fig. 1 with current injection for about 4.5ms, followed by zero current injection for another ≈ 3.5ms.

      Figure 3: Somatic voltage in the circuit, as in Fig. 2 but with current injected for approx. 15msvvvvv

      While we did not try to quantitatively assess the deviation from a single-exponential shape of the voltage in Fig. 2E, a more rapid increase at the onset and offset of the current injection is clearly visible in this Figure. This deviation from a single exponential is smaller than what we see in the simulation (both in Fig 2D of the manuscript, and in the results of the simplified circuit here in the rebuttal). We believe that the effect is smaller in Fig. E because it shows the average over many traces. It is much more visible in the ’raw’ (not averaged) traces. Two randomly selected traces from the first of the recorded neurons are shown in Figure 2 Supplement 2 C. While the non-averaged traces are plagued by artifacts and noise, the rapid voltage changes are visible essentially at all onsets and offsets of the current injection.

      Figure 4: Somatic voltage in the circuit, as in Fig. 2 but showing only for the time right after current onset, about 2.3ms.

      We have added a short discussion of this at the end of Section 2.3 to briefly point out this observation and its explanation. We there also refer to the simplified circuit simulation and comparison with raw voltage traces which is now shown in the new Figure 2 Supplement 2.

      • The time constant in Table 1 is much shorter than in Figure 1FG?

      No, these values are in agreement. To facilitate the comparison we now include a graphical measurement of tau from our traces in Figure 1 Supplement 2 J.

      • Related to this, the capacitance values are very low maybe this can be explained by the model’s wrong assumption of tau?

      Indeed, the measured time constants are somewhat lower than what might be expected. We believe that this is because after a step change of the injected current, an initial rapid voltage change occurs in the soma, where the recordings are taken. The measured time constant is a combination of the ’actual’ time constant of the cell and the ’somatic’ (very short) time constant of the soma. Please see our explanations above.

      Importantly, the value for tau from Table 1 is not used explicitly in the model as the parameters used in our simulation are determined by optimal fits of the simulated voltage curves to experimentally obtained data.

      • That latter in turn could be because of either space clamp issues in this hugely complex cell or bad model predictions due to incomplete reconstructions, bad match between morphology and electrophysiology (both are from different datasets?), or unknown ion channels that produce non-linear behaviour during the current injections.

      Please see our detailed discussion above. Furthermore, we now provide additional recordings using cytoplasmic GFP as a marker for the identification of MBON-alpha3 and confirm our findings. We agree that space-clamp issues could interfere with our recordings in such a complex cell. However, our approach using electrophysiological data should still be superior to any other approach (picking text book values). As we injected negative currents for our analysis at least voltage-gated ion channels should not influence our recordings.

      • The PRAXIS method in NEURON seems too ad hoc. Passive properties of a neuron should probably rather be explored in parameter scans.

      We are a bit at a loss of what is meant by the PRAXIS method being "too ad hoc." The PRAXIS method is essentially a conjugate gradient optimization algorithm (since no explicit derivatives are available, it makes the assumption that the objective function is quadratic). This seems to us a systematic way of doing a parameter scan, and the procedure has been used in other related models, e.g. the cited Gouwens & Wilson (2009) study.

      Questions I have:

      • Computational aspects were previously addressed by e.g. Larry Abbott and Gilles Laurent (sparse coding), how do the findings here distinguish themselves from this work

      In contrast to the work by Abbott and Laurent that addressed the principal relevance and suitability of sparse and random coding for the encoding of sensory information in decision making, here we address the cellular and computational mechanisms that an individual node (KC>MBON) play within the circuitry. As we use functional and morphological relevant data this study builds upon the prior work but significantly extends the general models to a specific case. We think this is essential for the further exploration of the topic.

      • What is valence information?

      Valence information is the information whether a stimulus is good (positive valence, e.g. sugar in appetitive memory paradigms, or negative valence in aversive olfactory conditioning - the electric shock). Valence information is provided by the dopaminergic system. Dopaminergic neurons are in direct contact with the KC>MBON circuitry and modify its synaptic connectivity when olfactory information is paired with a positive or negative stimulus.

      • It seems that Martin Nawrot’s work would be relevant to this work

      We are aware of the work by the Nawrot group that provided important insights into the processing of information within the olfactory mushroom body circuitry. We now highlight some of his work. His recent work will certainly be relevant for our future studies when we try to extend our work from an individual cell to networks.

      • Compactification and democratization could be related to other work like Otopalik et al 2017 eLife but also passive normalization. The equal efficiency in line 427 reminds me of dendritic/synaptic democracy and dendritic constancy

      Many thanks for pointing this out. This is in line with the comments from reviewer 1 and we now highlight these papers in the relevant paragraph in the discussion (line 442ff).

      • The morphology does not obviously seem compact, how unusual would it be that such a complex dendrite is so compact?

      We should have been more careful in our terminology, making clear that when we write ’compact’ we always mean ’electrotonically compact," in the sense that the physical dimensions of the neuron are small compared to its characteristic electrotonic length (usually called λ). The degree of a dendritic structure being electrotonically compact is determined by the interaction of morphology, size and conductances (across the membrane and along the neurites). We don’t believe that one of these factors alone (e.g. morphology) is sufficient to characterize the electrical properties of a dendritic tree. We have now clarified this in the relevant section.

      • What were the advantages of using the EM circuit?

      The purpose of our study is to provide a "realistic" model of a KC>MBON node within the memory circuitry. We started our simulations with random synaptic locations but wondered whether such a stochastic model is correct, or whether taking into account the detailed locations and numbers of synaptic connections of individual KCs would make a difference to the computation. Therefore we repeated the simulations using the EM data. We now address the point between random vs realistic synaptic connectivity in Figure 4F. We do not observe a significant difference but this may become more relevant in future studies if we compute the interplay between MBONs activated by overlapping sets of KCs. We simply think that utilizing the EM data gets us one step closer to realistic models.

      • Isn’t Fig 4E rather trivial if the cell is compact?

      We believe this figure is a visually striking illustration that shows how electrotonically compact the cell is. Such a finding may be trivial in retrospect, once the data is visualized, but we believe it provides a very intuitive description of the cell behavior.

      Overall, I am worried that the passive modelling study of the MBON-a3 does not provide enough evidence to explain the electrophysiological behaviour of the cell and to make accurate predictions of the cell’s responses to a variety of stochastic KC inputs.

      In our view our model adequately describes the behavior of the MBON with the most minimal (passive) model. Our approach tries to make the least assumptions about the electrophysiological properties of the cell. We think that based on the current knowledge our approach is the best possible approach as thus far no active components within the dendritic or axonal compartments of Drosophila MBONs have been described. As such, our model describes the current status which explains the behavior of the cell very well. We aim to refine this model in the future if experimental evidence requires such adaptations.

      Reviewer #3 (Public Review):

      This manuscript presents an analysis of the cellular integration properties of a specific mushroom body output neuron, MBON-α3, using a combination of patch clamp recordings and data from electron microscopy. The study demonstrates that the neuron is electrotonically compact permitting linear integration of synaptic input from Kenyon cells that represent odor identity.

      Strengths of the manuscript:

      The study integrates morphological data about MBON-α3 along with parameters derived from electrophysiological measurements to build a detailed model. 2) The modeling provides support for existing models of how olfactory memory is related to integration at the MBON.

      Weaknesses of the manuscript:

      The study does not provide experimental validation of the results of the computational model.

      The goal of our study is to use computational approaches to provide insights into the computation of the MBON as part of the olfactory memory circuitry. Our data is in agreement with the current model of the circuitry. Our study therefore forms the basis for future experimental studies; those would however go beyond the scope of the current work.

      The conclusion of the modeling analysis is that the neuron integrates synaptic inputs almost completely linearly. All the subsequent analyses are straightforward consequences of this result.

      We do, indeed, find that synaptic integration in this neuron is almost completely linear. We demonstrate that this result holds in a variety of different ways. All analyses in the study serve this purpose. These results are in line with the findings by Hige and Turner (2013) who demonstrated that also synaptic integration at PN>KC synapses is highly linear. As such our data points to a feature conservation to the next node of this circuit.

      The manuscript does not provide much explanation or intuition as to why this linear conclusion holds.

      We respectfully disagree. We demonstrate that this linear integration is a combination of the size of the cell and the combination of its biophysical parameters, mainly the conductances across and along the neurites. As to why it holds, our main argument is that results based on the linear model agree with all known (to us) empirical results, and this is the simplest model.

      In general, there is a clear takeaway here, which is that the dendritic tree of MBON-α3 in the lobes is highly electrotonically compact. The authors did not provide much explanation as to why this is, and the paper would benefit from a clearer conclusion. Furthermore, I found the results of Figures 4 and 5 rather straightforward given this previous observation. I am sceptical about whether the tiny variations in, e.g. Figs. 3I and 5F-H, are meaningful biologically.

      Please see the comment above as to the ’why’ we believe the neuron is electrotonically compact: a model with this assumption agrees well with empirically found results.

      We agree that the small variations in Fig 5F-H are likely not biologically meaningful. We state this now more clearly in the figure legends and in the text. This result is important to show, however. It is precisely because these variations are small, compared to the differences between voltage differences between different numbers of activated KCs (Fig 5D) or different levels of activated synapses (Fig 5E) that we can conclude that a 25% change in either synaptic strength or number can represent clearly distinguishable internal states, and that both changes have the same effect. It is important to show these data, to allow the reader to compare the differences that DO matter (Fig 5D,E) and those that DON’T (Fig 5F-H).

      The same applies to Fig 3I. The reviewer is entirely correct: the differences in the somatic voltage shown in Figure 3I are minuscule, less than a micro-Volt, and it is very unlikely that these difference have any biological meaning. The point of this figure is exactly to show this!. It is to demonstrate quantitatively the transformation of the large differences between voltages in the dendritic tree and the nearly complete uniform voltage at the soma. We feel that this shows very clearly the extreme "democratization" of the synaptic input!

    1. When tasks are done through large groups of people making relatively small contributions, this is called crowdsourcing. The people making the contributions generally come from a crowd of people that aren’t necessarily tied to the task (e.g., all internet users can edit Wikipedia), but then people from the crowd either get chosen to participate, or volunteer themselves.

      This reminds me of Wikipedia, but it also makes me wonder: if anyone can anonymously edit a page, what happens when someone adds misleading or inappropriate content? And what mechanisms exist to detect and correct these issues?

  12. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Kickstarter. URL: https://www.kickstarter.com/ (visited on 2023-12-08).

      I find the Kickstarter source interesting because it reflects how crowdfunding has changed the way people launch creative projects. Instead of relying on traditional investors, creators can pitch directly to the public, which makes the process feel more democratic. But at the same time, looking at this platform also reminds me that many projects never deliver what they promise, and backers take on risks without real protection. This makes me think about how trust works online and how platforms should balance creativity with accountability.

    1. Multiple measurements from the same set of subjects cannot be treated as separate, unrelated data sets

      This point is well taken, and it is easy to make a mistake. Treating repeated measurements as if they were separate artificially inflates the sample size and may result in misleading p-values. It reminds me of the importance of study design: often, statistical mistakes reflect structural problems in how evidence was collected and analyzed.

    1. text- the words are in a regular text but in all black to get their message across but not in a harsh forcing way, it talks about property and hunger. color- the red and blue kind of remind me of the usa flag, the red reminds me of urgency,and hunger, while the blue reminds me of coldness and isolation. meaning- the target for this poster is for someone who is passionate about their nation

    1. Becoming self-aware can be difficult and uncomfortable

      This self-reflection is always the first step towards any type of change, and it also reminds me of the positionality readings we did earlier on in the term. As teachers (or tutors!), we are bringing our own identities to the classroom, and it would be a shame to not understand our strengths and also our limitations before interacting with others.

    2. students of color make up the majority of students enrolled in U.S. public school

      This reminds me of the statistic Dorinda Carter Andrews shared in her TED Talk, that there is an "inherent cultural mismatch" between students of color and the majority of their teachers being white. So when teachers preach "I don't see color" and try to approach every student in the same way without understanding the inequalities some students are facing, then they're failing as educators.

    1. Whilesome religious traditions may be the root of some cultural disapproval ofhomosexuality, most religious traditions do not require their adherents todemand doctrinal discipline from those outside their faith tradition.

      This sentence reminds me of the meaning of a religion.There are nice religions that give people hope and tide people together for spiritual comfort, but there are some other religions, or maybe cult, tend to control people and force them to do things that hurt themselves. When religions trying to disapprove people from homosexuality, is it because of the religion or is it because of the group of people not want homosexuality to appear and view them as 'heretic'? I think the idea of religion represents the mindset for 'what is good' of a group of people.

    1. My daughter and I are tired of being bent over backward by her ascribed labels. As do others in her position, she wants to be known by her name, not her label,

      This closing statement is emotional and powerful. It captures the author’s plea for humanity, insisting that Lydia’s identity is far richer than her diagnosis. I think this quote reinforces the central message of the article: that true inclusion requires seeing every child as a full person with strengths, dreams, and dignity—rather than as a category to manage. It also reminds me how important it is for educators to acknowledge students as individuals, not labels.

    1. What foolish forgetfulness of mortality to postpone wholesome plans to the fiftieth and sixtieth year, and to intend to begin life at a point to which few have attained!

      This reminds me of the common idea of college students to make a lot of money in the ten years after college and then do what they're passionate about. I agree with this point on a larger scale, that tossing away years as a number is foolish.

  13. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Sarah T. Roberts. Behind the Screen. Yale University Press, September 2021. URL: https://yalebooks.yale.edu/9780300261479/behind-the-screen (visited on 2023-12-08). [o2] Tarleton Gillespie. Custodians of the Internet. Yale University Press, August 2021. URL: https://yalebooks.yale.edu/9780300261431/custodians-of-the-internet (visited on 2023-12-08). [o3] Reddit. URL: https://www.reddit.com/ (visited on 2023-12-08). [o4] ShiningConcepts. r/TheoryOfReddit: reddit is valued at more than ten billion dollars, yet it is extremely dependent on mods who work for absolutely nothing. Should they be paid, and does this lead to power-tripping mods? November 2021. URL: www.reddit.com/r/TheoryOfReddit/comments/qrjwjw/reddit_is_valued_at_more_than_ten_billion_dollars/ (visited on 2023-12-08). [o5] Wikipedia. URL: https://www.wikipedia.org/ (visited on 2023-12-08). [o6] Wikipedia:Administrators. November 2023. Page Version ID: 1187624916. URL: https://en.wikipedia.org/w/index.php?title=Wikipedia:Administrators&oldid=1187624916 (visited on 2023-12-08). [o7] Wikipedia:Paid-contribution disclosure. November 2023. Page Version ID: 1184161032. URL: https://en.wikipedia.org/w/index.php?title=Wikipedia:Paid-contribution_disclosure&oldid=1184161032 (visited on 2023-12-08). [o8] Wikipedia:Wikipedians. November 2023. Page Version ID: 1184672006. URL: https://en.wikipedia.org/w/index.php?title=Wikipedia:Wikipedians&oldid=1184672006 (visited on 2023-12-08). [o9] Brian Resnick. The 2018 Nobel Prize reminds us that women scientists too often go unrecognized. Vox, October 2018. URL: https://www.vox.com/science-and-health/2018/10/2/17929366/nobel-prize-physics-donna-strickland (visited on 2023-12-08). [o10] Maggie Fick and Paresh Dave. Facebook's flood of languages leaves it struggling to monitor content. Reuters, April 2019. URL: https://www.reuters.com/article/idUSKCN1RZ0DL/ (visited on 2023-12-08). [o11] David Gilbert. Facebook Is Ignoring Moderators’ Trauma: ‘They Suggest Karaoke and Painting’. Vice, May 2021. URL: https://www.vice.com/en/article/m7eva4/traumatized-facebook-moderators-told-to-suck-it-up-and-try-karaoke (visited on 2023-12-08). [o12] Billy Perrigo. TikTok's Subcontractor in Colombia Under Investigation. Time, November 2022. URL: https://time.com/6231625/tiktok-teleperformance-colombia-investigation/ (visited on 2023-12-08). [o13] Mike Masnick, Randy Lubin, and Leigh Beadon. Moderator Mayhem: A Content Moderation Game. URL: https://moderatormayhem.engine.is/ (visited on 2023-12-17).

      Sarah T. Roberts’ Behind the Screen really opened my eyes to how hidden and emotionally damaging content moderation work can be. The book reveals how the people who clean up the internet—filtering through disturbing images, videos, and hate speech—are often underpaid, outsourced, and given little emotional support. What struck me the most was how invisible this labor is, even though it’s essential for keeping social media platforms usable. Reading about the trauma moderators face makes me think differently about platforms like Facebook or TikTok, which profit from user-generated content but rely on poorly supported workers to make it “safe.” It makes me question whether platforms should be legally required to provide better pay, mental health care, and transparency about their moderation processes.

    2. ShiningConcepts. r/TheoryOfReddit: reddit is valued at more than ten billion dollars, yet it is extremely dependent on mods who work for absolutely nothing. Should they be paid, and does this lead to power-tripping mods? November 2021. URL: www.reddit.com/r/TheoryOfReddit/comments/qrjwjw/reddit_is_valued_at_more_than_ten_billion_dollars/ (visited on 2023-12-08).

      This Reddit post raises an important ethical question about unpaid labor on large online platforms. It’s surprising that Reddit, a company worth billions, depends so heavily on volunteer moderators who receive no compensation. I think this shows a contradiction between the platform’s profit and the unpaid effort that keeps it running. It reminds me of how Wikipedia also relies on unpaid editors, but in Reddit’s case, the moderators face more pressure and even harassment. Personally, I believe moderators should receive at least some form of payment or recognition for their work. Without them, Reddit would not function — so their contribution deserves more respect and support.

  14. minio.la.utexas.edu minio.la.utexas.edu
    1. n any nonviolent campaign there are four basic steps: collection of the facts to determine whetherinjustices exist; negotiation; self-purification; and direct action

      I like how MLK Jr. breaks this down into steps. It kind of reminds me of how a teacher would explain a process. This quote shows how peaceful protests were actually built on a smart plan, and not just emotion. I wonder if he realized back then actually realized how organized and thoughtful he actually was.

    1. Alternative histories of technology and design help to recuperate and center people, practices, and forms of expertise that have long been erased by mainstream design theory and history, both in scholarly and popular writing.

      I think this is a really important point when it comes to thinking about designing in an inclusive way. This reminds me of some of the stuff I learned about when I took INFO 102: Gender and Technology, when we focused on the many instances of people with marginalized identities creating tech and not being given credit for it. Learning about "alternative histories of technology" can help us understand today how important it is to have different voices involved in a design process (and credited for it).

    1. Author response:

      The following is the authors’ response to the original reviews

      Public Reviews:

      Reviewer #1 (Public Review):

      Wang et al. studied an old, still unresolved problem: Why are reaching movements often biased? Using data from a set of new experiments and from earlier studies, they identified how the bias in reach direction varies with movement direction, and how this depends on factors such as the hand used, the presence of visual feedback, the size and location of the workspace, the visibility of the start position and implicit sensorimotor adaptation. They then examined whether a visual bias, a proprioceptive bias, a bias in the transformation from visual to proprioceptive coordinates and/or biomechanical factors could explain the observed patterns of biases. The authors conclude that biases are best explained by a combination of transformation and visual biases.

      A strength of this study is that it used a wide range of experimental conditions with also a high resolution of movement directions and large numbers of participants, which produced a much more complete picture of the factors determining movement biases than previous studies did. The study used an original, powerful, and elegant method to distinguish between the various possible origins of motor bias, based on the number of peaks in the motor bias plotted as a function of movement direction. The biomechanical explanation of motor biases could not be tested in this way, but this explanation was excluded in a different way using data on implicit sensorimotor adaptation. This was also an elegant method as it allowed the authors to test biomechanical explanations without the need to commit to a certain biomechanical cost function.

      We thank the reviewer for their enthusiastic comments.

      (1) The main weakness of the study is that it rests on the assumption that the number of peaks in the bias function is indicative of the origin of the bias. Specifically, it is assumed that a proprioceptive bias leads to a single peak, a transformation bias to two peaks, and a visual bias to four peaks, but these assumptions are not well substantiated. Especially the assumption that a transformation bias leads to two peaks is questionable. It is motivated by the fact that biases found when participants matched the position of their unseen hand with a visual target are consistent with this pattern. However, it is unclear why that task would measure only the effect of transformation biases, and not also the effects of visual and proprioceptive biases in the sensed target and hand locations. Moreover, it is not explained why a transformation bias would lead to this specific bias pattern in the first place.

      We would like to clarify two things.

      Frist, the measurements of the transformation bias are not entirely independent of proprioceptive and visual biases. Specifically, we define transformation bias as the misalignment between the internal representation of a visual target and the corresponding hand position. By this definition, the transformation error entails both visual and proprioceptive biases (see Author response image 1). Transformation biases have been empirically quantified in numerous studies using matching tasks, where participants either aligned their unseen hand to a visual target (Wang et al., 2021) or aligned a visual target to their unseen hand (Wilson et al., 2010). Indeed, those tasks are always considered as measuring proprioceptive biases assuming visual bias is small given the minimal visual uncertainty.

      Author response image 1.

      Second, the critical difference between models is in how these biases influence motor planning rather than how those biases are measured. In the Proprioceptive bias model, a movement is planned in visual space. The system perceives the starting hand position in proprioceptive space and transforms this into visual space (Vindras & Viviani, 1998; Vindras et al., 2005). As such, bias only affects the perceived starting position; there is no influence on the perceived target location (no visual bias).

      In contrast, the Transformation bias model proposes that while both the starting and target positions are perceived in visual space, movement is planned in proprioceptive space. Consequently, both positions must be transformed from visual space to proprioceptive coordinates before movement planning (i.e., where is my sensed hand and where do I want it to be). Under this framework, biases can emerge from both the start and target positions. This is how the transformation model leads to different predictions compared to the perceptual models, even if the bias is based on the same measurements.

      We now highlight the differences between the Transformation bias model and the Proprioceptive bias model explicitly in the Results section (Lines 192-200):

      “Note that the Proprioceptive Bias model and the Transformation Bias model tap into the same visuo-proprioceptive error map. The key difference between the two models arises in how this error influences motor planning. For the Proprioceptive Bias model, planning is assumed to occur in visual space. As such, the perceived position of the hand (based on proprioception) is transformed into the visual space. This will introduce a bias in the representation of the start position. In contrast, the Transformation Bias model assumes that the visually-based representations of the start and target positions need to be transformed into proprioceptive space for motor planning. As such, both positions are biased in the transformation process. In addition to differing in terms of their representation of the target, the error introduced at the start position is in opposite directions due to the direction of the transformation (see fig 1g-h).”

      In terms of the motor bias function across the workspace, the peaks are quantitatively derived from the model simulations. The number of peaks depends on how we formalize each model. Importantly, this is a stable feature of each model, regardless of how the model is parameterized. Thus, the number of peaks provides a useful criterion to evaluate different models.

      Figure 1 g-h illustrates the intuition of how the models generate distinct peak patterns. We edited the figure caption and reference this figure when we introduce the bias function for each model.

      (2) Also, the assumption that a visual bias leads to four peaks is not well substantiated as one of the papers on which the assumption was based (Yousif et al., 2023) found a similar pattern in a purely proprioceptive task.

      What we referred to in the original submission as “visual bias” is not an eye-centric bias, nor is it restricted to the visual system. Rather, it may reflect a domain-general distortion in the representation of position within polar space. We called it a visual bias as it was associated with the perceived location of the visual target in the current task. To avoid confusion, we have opted to move to a more general term and now refer to this as “target bias.”

      We clarify the nature of this bias when introducing the model in the Results section (Lines 164-169):

      “Since the task permits free viewing without enforced fixation, we assume that participants shift their gaze to the visual target; as such, an eye-centric bias is unlikely. Nonetheless, prior studies have shown a general spatial distortion that biases perceived target locations toward the diagonal axes(Huttenlocher et al., 2004; Kosovicheva & Whitney, 2017). Interestingly, this bias appears to be domain-general, emerging not only for visual targets but also for proprioceptive ones(Yousif et al., 2023). We incorporated this diagonal-axis spatial distortion into a Target Bias model. This model predicts a four-peaked motor bias pattern (Fig 1f).”

      We also added a paragraph in the Discussion to further elaborate on this model (Lines 502-511):

      “What might be the source of the visual bias in the perceived location of the target? In the perception literature, a prominent theory has focused on the role of visual working memory account based on the observation that in delayed response tasks, participants exhibit a bias towards the diagonals when recalling the location of visual stimuli(Huttenlocher et al., 2004; Sheehan & Serences, 2023). Underscoring that the effect is not motoric, this bias is manifest regardless of whether the response is made by an eye movement, pointing movement, or keypress(Kosovicheva & Whitney, 2017). However, this bias is unlikely to be dependent on a visual input as similar diagonal bias is observed when the target is specified proprioceptively via the passive displacement of an unseen hand(Yousif et al., 2023). Moreover, as shown in the present study, a diagonal bias is observed even when the target is continuously visible. Thus, we hypothesize that the bias to perceive the target towards the diagonals reflects a more general distortion in spatial representation rather than being a product of visual working memory.”

      (3) Another weakness is that the study looked at biases in movement direction only, not at biases in movement extent. The models also predict biases in movement extent, so it is a missed opportunity to take these into account to distinguish between the models.

      We thank the reviewer for this suggestion. We have now conducted a new experiment to assess angular and extent biases simultaneously (Figure 4a; Exp. 4; N = 30). Using our KINARM system, participants were instructed to make center-out movements that would terminate (rather than shoot past) at the visual target. No visual feedback was provided throughout the experiment.

      The Transformation Bias model predicts a two-peaked error function in both the angular and extent dimensions (Figure 4c). Strikingly, when we fit the data from the new experiment to both dimensions simultaneously, this model captures the results qualitatively and quantitatively (Figure 4e). In terms of model comparison, it outperformed alternative models (Figure 4g) particularly when augmented with a visual bias component. Together, these results provide strong evidence that a mismatch between visual and proprioceptive space is a key source of motor bias.

      This experiment is now reported within the revised manuscript (Lines 280-301).

      Overall, the authors have done a good job mapping out reaching biases in a wide range of conditions, revealing new patterns in one of the most basic tasks, but unambiguously determining the origin of these biases remains difficult, and the evidence for the proposed origins is incomplete. Nevertheless, the study will likely have a substantial impact on the field, as the approach taken is easily applicable to other experimental conditions. As such, the study can spark future research on the origin of reaching biases.

      We thank the reviewer for these summary comments. We believe that the new experiments and analyses do a better job of identifying the origins of motor biases.

      Reviewer #2 (Public Review):

      Summary:

      This work examines an important question in the planning and control of reaching movements - where do biases in our reaching movements arise and what might this tell us about the planning process? They compare several different computational models to explain the results from a range of experiments including those within the literature. Overall, they highlight that motor biases are primarily caused by errors in the transformation between eye and hand reference frames. One strength of the paper is the large number of participants studied across many experiments. However, one weakness is that most of the experiments follow a very similar planar reaching design - with slicing movements through targets rather than stopping within a target. Moreover, there are concerns with the models and the model fitting. This work provides valuable insight into the biases that govern reaching movements, but the current support is incomplete.

      Strengths:

      The work uses a large number of participants both with studies in the laboratory which can be controlled well and a huge number of participants via online studies. In addition, they use a large number of reaching directions allowing careful comparison across models. Together these allow a clear comparison between models which is much stronger than would usually be performed.

      We thank the reviewer for their encouraging comments.

      Weaknesses:

      Although the topic of the paper is very interesting and potentially important, there are several key issues that currently limit the support for the conclusions. In particular I highlight:

      (1) Almost all studies within the paper use the same basic design: slicing movements through a target with the hand moving on a flat planar surface. First, this means that the authors cannot compare the second component of a bias - the error in the direction of a reach which is often much larger than the error in reaching direction.

      Reviewer 1 made a similar point, noting that we had missed an opportunity to provide a more thorough assessment of reaching biases. As described above, we conducted a new experiment in which participants made pointing movements, instructed to terminate the movements at the target. These data allow us to analyze errors in both angular and extent dimensions. The transformation bias model successfully predicts angular and extent biases, outperformed the other models at both group and individual levels. We have now included this result as Exp 4 in the manuscript. Please see response to Reviewer 1 Comment 3 for details.

      Second, there are several studies that have examined biases in three-dimensional reaching movements showing important differences to two-dimensional reaching movements (e.g. Soechting and Flanders 1989). It is unclear how well the authors' computational models could explain the biases that are present in these much more common-reaching movements.

      This is an interesting issue to consider. We expect the mechanisms identified in our 2D work will generalize to 3D.

      Soechting and Flanders (1989) quantified 3D biases by measuring errors across multiple 2D planes at varying heights (see Author response image 2 for an example from their paper). When projecting their 3-D bias data to a horizontal 2D space, the direction of the bias across the 2D plane looks relatively consistent across different heights even though the absolute value of the bias varies (Author response image 2). For example, the matched hand position is generally to the leftwards and downward of the target. Therefore, the models we have developed and tested in a specific 2D plane are likely to generalize to other 2D plane of different heights.

      Author response image 2.

      However, we think the biases reported by Soechting and Flanders likely reflect transformation biases rather than motor biases. First, the movements in their study were performed very slowly (3–5 seconds), more similar to our proprioceptive matching tasks and much slower than natural reaching movements (<500ms). Given the slow speed, we suspect that motor planning in Soechting and Flanders was likely done in a stepwise, incremental manner (closed loop to some degree). Second, the bias pattern reported in Soechting and Flanders —when projected into 2D space— closely mirrors the leftward transformation errors observed in previous visuo-proprioceptive matching task (e.g., Wang et al., 2021).

      In terms of the current manuscript, we think that our new experiment (Exp 4, where we measure angular and radial error) provides strong evidence that the transformation bias model generalizes to more naturalistic pointing movements. As such, we expect these principles will generalize were we to examine movements in three dimensions, an extension we plan to test in future work.

      (2) The model fitting section is under-explained and under-detailed currently. This makes it difficult to accurately assess the current model fitting and its strength to support the conclusions. If my understanding of the methods is correct, then I have several concerns. For example, the manuscript states that the transformation bias model is based on studies mapping out the errors that might arise across the whole workspace in 2D. In contrast, the visual bias model appears to be based on a study that presented targets within a circle (but not tested across the whole workspace). If the visual bias had been measured across the workspace (similar to the transformation bias model), would the model and therefore the conclusions be different?

      We have substantially expanded the Methods section to clarify the modeling procedures (detailed below in section “Recommendations for the Authors”). We also provide annotated code to enable others to easily simulate the models.

      Here we address three points relevant to the reviewer’s concern about whether the models were tested on equal footing, and in particular, concern that the transformation bias model was more informed by prior literature than the visual bias model.

      First, our center-out reaching task used target locations that have been employed in both visual and proprioceptive bias studies, offering reasonable comprehensive coverage of the workspace. For example, for a target to the left of the body’s midline, visual biases tend to be directed diagonally (Kosovicheva & Whitney, 2017), while transformation biases are typically leftward and downward (Wang et al, 2021). In this sense, the models were similarly constrained by prior findings.

      Second, while the qualitative shape of each model was guided by prior empirical findings, no previous data were directly used to quantitatively constrain the models. As such, we believe the models were evaluated on equal footing. No model had more information or, best we can tell, an inherent advantage over the others.

      Third, reassuringly, the fitted transformation bias closely matches empirically observed bias maps reported in prior studies (Fig 2h). The strong correspondence provides convergent validity and supports the putative causality between transformation biases to motor biases.

      (3) There should be other visual bias models theoretically possible that might fit the experimental data better than this one possible model. Such possibilities also exist for the other models.

      Our initial hypothesis, grounded in prior literature, was that motor biases arise from a combination of proprioceptive and visual biases. This led us to thoroughly explore a range of visual models. We now describe these alternatives below, noting that in the paper, we chose to focus on models that seemed the most viable candidates. (Please also see our response to Reviewer 3, Point 2, on another possible source of visual bias, the oblique effect.)

      Quite a few models have described visual biases in perceiving motion direction or object orientation (e.g., Wei & Stocker, 2015; Patten, Mannion & Clifford, 2017). Orientation perception would be biased towards the Cartesian axis, generating a four-peak function. However, these models failed to account for the motor biases observed in our experiments. This is not surprising given that these models were not designed to capture biases related to a static location.

      We also considered a class of eye-centric models where biases for peripheral locations are measured under fixation. A prominent finding here is that the bias is along the radial axis in which participants overshoot targets when they fixate on the start position during the movement (Beurze et al., 2006; Van Pelt & Medendorp, 2008). Again, this is not consistent with the observed motor biases. For example, participants undershoot rightward targets when we measured the distance bias in Exp 4. Importantly, since most our tasks involved free viewing in natural settings with no fixation requirements, we considered it unlikely that biases arising from peripheral viewing play a major role.

      We note, though, that in our new experiment (Exp 4), participants observed the visual stimuli from a fixed angle in the KinArm setup (see Figure 4a). This setup has been shown to induce depth-related visual biases (Figure 4b, e.g., Volcic et al., 2013; Hibbard & Bradshaw, 2003). For this reason, we implemented a model incorporating this depth bias as part of our analyses of these data. While this model performed significantly worse than the transformation bias model alone, a mixed model that combined the depth bias and transformation bias provided the best overall fit. We now include this result in the main text (Lines 286-294).

      We also note that the “visual bias” we referred to in the original submission is not restricted to the visual system. A similar bias pattern has been observed when the target is presented visually or proprioceptively (Kosovicheva & Whitney, 2017; Yousif, Forrence, & McDougle, 2023). As such, it may reflect a domaingeneral distortion in the representation of position within polar space. Accordingly, in the revision, we now refer to this in a more general way, using the term “target bias.” We justify this nomenclature when introducing the model in the Results section (Lines 164-169). Please also see Reviewer 1 comment 2.

      We recognize that future work may uncover a better visual model or provide a more fine-grained account of visual biases (or biases from other sources). With our open-source simulation code, such biases can be readily incorporated—either to test them against existing models or to combine them with our current framework to assess their contribution to motor biases. Given our explorations, we expect our core finding will hold: Namely, that a combination of transformation and target biases offers the most parsimonious account, with the bias associated with the transformation process explaining the majority of the observed motor bias in visually guided movements.

      Given the comments from the reviewer, we expanded the discussion session to address the issue of alternative models of visual bias (lines 522-529):

      “Other forms of visual bias may influence movement. Depth perception biases could contribute to biases in movement extent(Beurze et al., 2006; Van Pelt & Medendorp, 2008). Visual biases towards the principal axes have been reported when participants are asked to report the direction of moving targets or the orientation of an object(Patten et al., 2017; Wei & Stocker, 2015). However, the predicted patterns of reach biases do not match the observed biases in the current experiments. We also considered a class of eye-centric models in which participants overestimate the radial distance to a target while maintaining central fixation(Beurze et al., 2006; Van Pelt & Medendorp, 2008). At odds with this hypothesis, participants undershot rightward targets when we measured the radial bias in Exp 4. The absence of these other distortions of visual space may be accounted for by the fact that we allowed free viewing during the task.”

      (4) Although the authors do mention that the evidence against biomechanical contributions to the bias is fairly weak in the current manuscript, this needs to be further supported. Importantly both proprioceptive models of the bias are purely kinematic and appear to ignore the dynamics completely. One imagines that there is a perceived vector error in Cartesian space whereas the other imagines an error in joint coordinates. These simply result in identical movements which are offset either with a vector or an angle. However, we know that the motor plan is converted into muscle activation patterns which are sent to the muscles, that is, the motor plan is converted into an approximation of joint torques. Joint torques sent to the muscles from a different starting location would not produce an offset in the trajectory as detailed in Figure S1, instead, the movements would curve in complex patterns away from the original plan due to the non-linearity of the musculoskeletal system. In theory, this could also bias some of the other predictions as well. The authors should consider how the biomechanical plant would influence the measured biases.

      We thank the reviewer for encouraging us on this topic and to formalize a biomechanical model. In response, we have implemented a state-of-the-art biomechanical framework, MotorNet

      (https://elifesciences.org/articles/88591), which simulates a six-muscle, two-skeleton planar arm model using recurrent neural networks (RNNs) to generate control policies (See Figure 6a). This model captures key predictions about movement curvature arising from biomechanical constraints. We view it as a strong candidate for illustrating how motor bias patterns could be shaped by the mechanical properties of the upper limb.

      Interestingly, the biomechanical model did not qualitatively or quantitatively reproduce the pattern of motor biases observed in our data. Specifically, we trained 50 independent agents (RNNs) to perform random point-to-point reaching movements across the workspace used in our task. We used a loss function that minimized the distance between the fingertip and the target over the entire trajectory. When tested on a center-out reaching task, the model produced a four-peaked motor bias pattern (Figure 6b), in contrast to the two-peaked function observed empirically. These results suggest that upper limb biomechanical constraints are unlikely to be a primary driver of motor biases in reaching. This holds true even though the reported bias is read out at 60% of the reaching distance, where biomechanical influences on the curvature of movement are maximal. We have added this analysis to the results (lines 367-373).

      It may seem counterintuitive that biomechanics plays a limited role in motor planning. This could be due to several factors. First, First, task demands (such as the need to grasp objects) may lead the biomechanical system to be inherently organized to minimize endpoint errors (Hu et al., 2012; Trumbower et al., 2009). Second, through development and experience, the nervous system may have adapted to these biomechanical influences—detecting and compensating for them over time (Chiel et al., 2009).

      That said, biomechanical constraints may make a larger contribution in other contexts; for example, when movements involve more extreme angles or span larger distances, or in individuals with certain musculoskeletal impairments (e.g., osteoarthritis) where physical limitations are more likely to come into play. We address this issue in the revised discussion.

      “Nonetheless, the current study does not rule out the possibility that biomechanical factors may influence motor biases in other contexts. Biomechanical constraints may have had limited influence in our experiments due to the relatively modest movement amplitudes used and minimal interaction torques involved. Moreover, while we have focused on biases that manifest at the movement endpoint, biomechanical constraints might introduce biases that are manifest in the movement trajectories.(Alexander, 1997; Nishii & Taniai, 2009) Future studies are needed to examine the influence of context on reaching biases.”

      Reviewer #3 (Public review):

      The authors make use of a large dataset of reaches from several studies run in their lab to try to identify the source of direction-dependent radial reaching errors. While this has been investigated by numerous labs in the past, this is the first study where the sample is large enough to reliably characterize isometries associated with these radial reaches to identify possible sources of errors.

      (1) The sample size is impressive, but the authors should Include confidence intervals and ideally, the distribution of responses across individuals along with average performance across targets. It is unclear whether the observed “averaged function” is consistently found across individuals, or if it is mainly driven by a subset of participants exhibiting large deviations for diagonal movements. Providing individual-level data or response distributions would be valuable for assessing the ubiquity of the observed bias patterns and ruling out the possibility that different subgroups are driving the peaks and troughs. It is possible that the Transformation or some other model (see below) could explain the bias function for a substantial portion of participants, while other participants may have different patterns of biases that can be attributable to alternative sources of error.

      We thank the reviewer for encouraging a closer examination of the individual-level data. We did include standard error when we reported the motor bias function. Given that the error distribution is relatively Gaussian, we opted to not show confidence intervals since they would not provide additional information.

      To examine individual differences, we now report a best-fit model frequency analysis. For Exp 1, we fit each model at the individual level and counted the number of participants that are best predicted by each model. Among the four single source models (Figure 3a), the vast majority of participants are best explained by the transformation bias model (48/56). When incorporating mixture models, the combined transformation + target bias model emerged as the best fit for almost all participants across experiments (50/56). The same pattern holds for Exp 3b, the frequency analysis is more distributed, likely due to the added noise that comes with online studies.

      We report this new analysis in the Results. (see Fig 3. Fig S2). Note that we opted to show some representative individual fits, selecting individuals whose data were best predicted by different models (Fig S2). Given that the number of peaks characterizes each model (independent of the specific parameter values), the two-peaked function exhibited for most participants indicates that the Transformation bias model holds at the individual level and not just at the group level.

      (2) The different datasets across different experimental settings/target sets consistently show that people show fewer deviations when making cardinal-directed movements compared to movements made along the diagonal when the start position is visible. This reminds me of a phenomenon referred to as the oblique effect: people show greater accuracy for vertical and horizontal stimuli compared to diagonal ones. While the oblique effect has been shown in visual and haptic perceptual tasks (both in the horizontal and vertical planes), there is some evidence that it applies to movement direction. These systematic reach deviations in the current study thus may reflect this epiphenomenon that applies across modalities. That is, estimating the direction of a visual target from a visual start position may be less accurate, and may be more biased toward the horizontal axis, than for targets that are strictly above, below, left, or right of the visual start position. Other movement biases may stem from poorer estimation of diagonal directions and thus reflect more of a perceptual error than a motor one. This would explain why the bias function appears in both the in-lab and on-line studies although the visual targets are very different locations (different planes, different distances) since the oblique effects arise independent of plane, distance, or size of the stimuli. When the start position is not visible like in the Vindras study, it is possible that this oblique effect is less pronounced; masked by other sources of error that dominate when looking at 2D reach endpoint made from two separate start positions, rather than only directional errors from a single start position. Or perhaps the participants in the Vindras study are too variable and too few (only 10) to detect this rather small direction-dependent bias.

      The potential link between the oblique effect and the observed motor bias is an intriguing idea, one that we had not considered. However, after giving this some thought, we see several arguments against the idea that the oblique effect accounts for the pattern of motor biases.

      First, by the oblique effect, perceptual variability is greater along the diagonal axes compared to the cardinal axes. These differences in perceptual variability have been used to explain biases in visual perception through a Bayesian model under the assumption that the visual system has an expectation that stimuli are more likely to be oriented along the cardinal axes (Wei & Stocker, 2015). Importantly, the model predicts low biases at targets with peak perceptual variability. As such, even though those studies observed that participants showed large variability for stimuli at diagonal orientations, the bias for these stimuli was close to zero. Given we observed a large bias for targets at locations along the diagonal axes, we do not think this visual effect can explain the motor bias function.

      Second, the reviewer suggested that the observed motor bias might be largely explained by visual biases (or what we now refer to as target biases). If this hypothesis is correct, we would anticipate observing a similar bias pattern in tasks that use a similar layout for visual stimuli but do not involve movement. However, this prediction is not supported. For example, Kosovicheva & Whitney (2017) used a position reproduction/judgment task with keypress responses (no reaching). The stimuli were presented in a similar workspace as in our task. Their results showed four-peaked bias function while our results showed a two-peaked function.

      In summary, we don’t think oblique biases make a significant contribution to our results.

      A bias in estimating visual direction or visual movement vector Is a more realistic and relevant source of error than the proposed visual bias model. The Visual Bias model is based on data from a study by Huttenlocher et al where participants “point” to indicate the remembered location of a small target presented on a large circle. The resulting patterns of errors could therefore be due to localizing a remembered visual target, or due to relative or allocentric cues from the clear contour of the display within which the target was presented, or even movements used to indicate the target. This may explain the observed 4-peak bias function or zig-zag pattern of “averaged” errors, although this pattern may not even exist at the individual level, especially given the small sample size. The visual bias source argument does not seem well-supported, as the data used to derive this pattern likely reflects a combination of other sources of errors or factors that may not be applicable to the current study, where the target is continuously visible and relatively large. Also, any visual bias should be explained by a coordinates centre on the eye and should vary as a function of the location of visual targets relative to the eyes. Where the visual targets are located relative to the eyes (or at least the head) is not reported.

      Thank you for this question. A few key points to note:

      The visual bias model has also been discussed in studies using a similar setup to our study. Kosovicheva & Whitney (2017) observed a four-peaked function in experiments in which participants report a remembered target position on a circle by either making saccades or using key presses to adjust the position of a dot. However, we agree that this bias may be attenuated in our experiment given that the target is continuously visible. Indeed, the model fitting results suggest the peak of this bias is smaller in our task (~3°) compared to previous work (~10°, Kosovicheva & Whitney, 2017; Yousif, Forrence, & McDougle, 2023).

      We also agree with the reviewer that this “visual bias” is not an eye-centric bias, nor is it restricted to the visual system. A similar bias pattern is observed even if the target is presented proprioceptively (Yousif, Forrence, & McDougle, 2023). As such, this bias may reflect a domain-general distortion in the representation of position within polar space. Accordingly, in the revision, we now refer to this in a more general way, using the term “target bias”, rather than visual bias. We justify this nomenclature when introducing the model in the Results section (Lines 164-169). Please also see Reviewer 1 comment 2 for details.

      Motivated by Reviewer 2, we also examined multiple alternative visual bias models (please refer to our response to Reviewer 2, Point 3.

      The Proprioceptive Bias Model is supposed to reflect errors in the perceived start position. However, in the current study, there is only a single, visible start position, which is not the best design for trying to study the contribution. In fact, my paradigms also use a single, visual start position to minimize the contribution of proprioceptive biases, or at least remove one source of systematic biases. The Vindras study aimed to quantify the effect of start position by using two sets of radial targets from two different, unseen start positions on either side of the body midline. When fitting the 2D reach errors at both the group and individual levels (which showed substantial variability across individuals), the start position predicted most of the 2D errors at the individual level – and substantially more than the target direction. While the authors re-plotted the data to only illustrate angular deviations, they only showed averaged data without confidence intervals across participants. Given the huge variability across their 10 individuals and between the two target sets, it would be more appropriate to plot the performance separately for two target sets and show confidential intervals (or individual data). Likewise, even the VT model predictions should differ across the two targets set since the visual-proprioceptive matching errors from the Wang et al study that the model is based on, are larger for targets on the left side of the body.

      To be clear, in the Transformation bias model, the vector bias at the start position is also an important source of error. The critical difference between the proprioceptive and transformation models is how bias influences motor planning. In the Proprioceptive bias model, movement is planned in visual space. The system perceives the starting hand position in proprioceptive space and transforms this into visual space (Vindras & Viviani, 1998; Vindras et al., 2005). As such, the bias is only relevant in terms of the perceived start position; it does not influence the perceived target location. In contrast, the transformation bias model proposes that while both the starting and target positions are perceived in visual space, movements are planned in proprioceptive space. Consequently, when the start and target positions are visible, both positions must be transformed from visual space to proprioceptive coordinates before movement planning. Thus, bias will influence both the start and target positions. We also note that to set the transformation bias for the start/target position, we referred to studies in which bias is usually referred to as proprioception error measurement. As such, changing the start position has a similar impact on the Transformation and the Proprioceptive Bias models in principle, and would not provide a stronger test to separate them.

      We now highlight the differences between the models in the Results section, making clear that the bias at the start position influences both the Proprioceptive bias and Transformation bias models (Lines 192200).

      “Note that the Proprioceptive Bias model and the Transformation Bias model tap into the same visuo-proprioceptive error map. The key difference between the two models arises in how this error influences motor planning. For the Proprioceptive Bias model, planning is assumed to occur in visual space. As such, the perceived position of the hand (based on proprioception) is transformed into visual space. This will introduce a bias in the representation of the start position. In contrast, the Transformation Bias model assumes that the visually-based representations of the start and target positions need to be transformed into proprioceptive space for motor planning. As such, both positions are biased in the transformation process. In addition to differing in terms of their representation of the target, the error introduced at the start position is in opposite directions due to the direction of the transformation (see fig 1g-h).”

      In terms of fitting individual data, we have conducted a new experiment, reported as Exp 4 in the revised manuscript (details in our response to Reviewer 1, comment 3). The experiment has a larger sample size (n=30) and importantly, examined error for both movement angle and movement distance. We chose to examine the individual differences in 2-D biases using this sample rather than Vindras’ data as our experiment has greater spatial resolution and more participants. At both the group and individual level, the Transformation bias model is the best single source model, and the Transformation + Target Bias model is the best combined model. These results strongly support the idea that the transformation bias is the main source of the motor bias.

      As for the different initial positions in Vindras et al (2005), the two target sets have very similar patterns of motor biases. As such, we opted to average them to decrease noise. Notably, the transformation model also predicts that altering the start location should have limited impact on motor bias patterns: What matters for the model is the relative difference between the transformation biases at the start and target positions rather than the absolute bias.

      Author response image 3.

      I am also having trouble fully understanding the V-T model and its associated equations, and whether visual-proprioception matching data is a suitable proxy for estimating the visuomotor transformation. I would be interested to first see the individual distributions of errors and a response to my concerns about the Proprioceptive Bias and Visual Bias models.

      We apologize for the lack of clarity on this model. To generate the T+V (Now Transformation + Target bias, or TR+TG) model, we assume the system misperceives the target position (Target bias, see Fig S5a) and then transforms the start and misperceived target positions into proprioceptive space (Fig S5b). The system then generates a motor plan in proprioceptive space; this plan will result in the observed motor bias (Fig. S5c). We now include this figure as Fig S5 and hope that it makes the model features salient.

      Regarding whether the visuo-proprioceptive matching task is a valid proxy for transformation bias, we refer the reviewer to the comments made by Public Reviewer 1, comment 1. We define the transformation bias as the discrepancy between corresponding positions in visual and proprioceptive space. This can be measured using matching tasks in which participants either aligned their unseen hand to a visual target (Wang et al., 2021) or aligned a visual target to their unseen hand (Wilson et al., 2010).

      Nonetheless, when fitting the model to the motor bias data, we did not directly impose the visual-proprioceptive matching data. Instead, we used the shape of the transformation biases as a constraint, while allowing the exact magnitude and direction to be free parameters (e.g., a leftward and downward bias scaled by distance from the right shoulder). Reassuringly, the fitted transformation biases closely matched the magnitudes reported in prior studies (Fig. 2h, 1e), providing strong quantitative support for the hypothesized causal link between transformation and motor biases.

      Recommendations for the authors:

      Overall, the reviewers agreed this is an interesting study with an original and strong approach. Nonetheless, there were three main weaknesses identified. First, is the focus on bias in reach direction and not reach extent. Second, the models were fit to average data and not individual data. Lastly, and most importantly, the model development and assumptions are not well substantiated. Addressing these points would help improve the eLife assessment.

      Reviewer #1 (Recommendations for the authors):

      It is mentioned that the main difference between Experiments 1 and 3 is that in Experiment 3, the workspace was smaller and closer to the shoulder. Was the location of the laptop relative to the participant in Experiment 3 known by the authors? If so, variations in this location across participants can be used to test whether the Transformation bias was indeed larger for participants who had the laptop further from the shoulder.

      Another difference between Experiments 1 and 3 is that in Experiment 1, the display was oriented horizontally, whereas it was vertical in Experiment 3. To what extent can that have led to the different results in these experiments?

      This is an interesting point that we had not considered. Unfortunately, for the online work we do not record the participants’ posture.

      Regarding the influence of display orientation (horizontal vs. vertical), Author response image 4 presents three relevant data points: (1) Vandevoorde and Orban de Xivry (2019), who measured motor biases in-person across nine target positions using a tablet and vertical screen; (2) Our Experiment 1b, conducted online with a vertical setup; (3) Our in-person Experiment 3b, using a horizontal monitor. For consistency, we focus on the baseline conditions with feedback, the only condition reported in Vandevoorde. Motor biases from the two in-person studies were similar despite differing monitor orientations: Both exhibited two-peaked functions with comparable peak locations. We note that the bias attenuation in Vandevoorde may be due to their inclusion of reward-based error signals in addition to cursor feedback. In contrast, compared to the in-person studies, the online study showed reduced bias magnitude with what appears to be a four peaked function. While more data are needed, these results suggest that the difference in the workspace (more restricted in our online study) may be more relevant than monitor orientation.

      Author response image 4.

      For the joint-based proprioceptive model, the equations used are for an arm moving in a horizontal plane at shoulder height, but the figures suggest the upper arm was more vertical than horizontal. How does that affect the predictions for this model?

      Please also see our response to your public comment 1. When the upper limb (or the lower limb) is not horizontal, it will influence the projection of the upper limb to the 2-D space. Effectively in the joint-based proprioceptive model, this influences the ratio between L1 and L2 (see  Author response image 5b below). However, adding a parameter to vary L1/L2 ratio would not change the set of the motor bias function that can be produced by the model. Importantly, it will still generate a one-peak function. We simulated 50 motor bias function across the possible parameter space. As shown by  Author response image 5c-d, the peak and the magnitude of the motor bias functions are very similar with and without the L1/L2 term. We characterize the bias function with the peak position and the peak-to-valley distance. Based on those two factors, the distribution of the motor bias function is very similar ( Author response image 5e-f). Moreover, the L1/L2 ratio parameter is not recoverable by model fitting ( Author response image 5c), suggesting that it is redundant with other parameters. As such we only include the basic version of the joint-based proprioceptive model in our model comparisons.

      Author response image 5.

      It was unclear how the models were fit and how the BIC was computed. It is mentioned that the models were fit to average data across participants, but the BIC values were based on all trials for all participants, which does not seem consistent. And the models are deterministic, so how can a log-likelihood be determined? Since there were inter-individual differences, fitting to average data is not desirable. Take for instance the hypothetical case that some participants have a single peak at 90 deg, and others have a single peak at 270 deg. Averaging their data will then lead to a pattern with two peaks, which would be consistent with an entirely different model.

      We thank the reviewer for raising these issues.

      Given the reviewers’ comments, we now report fits at both the group and individual level (see response to reviewer 3 public comment 1). The group-level fitting is for illustration purposes. Model comparison is now based on the individual-level analyses which show that the results are best explained by the transformation model when comparing single source models and best explained by the T+V (now TG+TR) model when consider all models. These new results strongly support the transformation model.

      Log-likelihoods were computed assuming normally distributed motor noise around the motor biases predicted by each model.

      We updated the Methods section as follows (lines 841-853):

      “We used the fminsearchbnd function in MATLAB to minimize the sum of loglikelihood (LL) across all trials for each participant. LL were computed assuming normally distributed noise around each participant’s motor biases:

      [11] LL = normpdf(x, b, c)

      where x is the empirical reaching angle, b is the predicted motor bias by the model, c is motor noise, calculated as the standard deviation of (x − b). For model comparison, we calculated the BIC as follow:

      [12] BIC = -2LL+k∗ln(n)

      where k is the number of parameters of the models. Smaller BIC values correspond to better fits. We report the sum of ΔBIC by subtracting the BIC value of the TR+TG model from all other models.

      For illustrative purposes, we fit each model at the group level, pooling data across all participants to predict the group-averaged bias function.”

      What was the delay of the visual feedback in Experiment 1?

      The visual delay in our setup was ~30 ms, with the procedure used to estimate this described in detail in Wang et al (2024, Curr. Bio.). We note that in calculating motor biases, we primarily relied on the data from the no-feedback block.

      Minor corrections

      In several places it is mentioned that movements were performed with proximal and distal effectors, but it's unclear where that refers to because all movements were performed with a hand (distal effector).

      By 'proximal and distal effectors,' we were referring to the fact that in the online setup, “reaching movements” are primarily made by finger and/or wrist movements across a trackpad, whereas in the inperson setup, the participants had to use their whole arm to reach about the workspace. To avoid confusion, we now refer to these simply as 'finger' versus 'hand' movements.

      In many figures, Bias is misspelled as Bais.

      Fixed.

      In Figure 3, what is meant by deltaBIC (*1000) etc? Literally, it would mean that the bars show 1,000 times the deltaBIC value, suggesting tiny deltaBIC values, but that's probably not what's meant.

      ×1000' in the original figure indicates the unit scaling, with ΔBIC values ranging from approximately 1000 to 4000. However, given that we now fit the models at the individual level, we have replaced this figure with a new one (Figure 3e) showing the distribution of individual BIC values.

      Reviewer #2 (Recommendations for the authors):

      I have concerns that the authors only examine slicing movements through the target and not movements that stop in the target. Biases create two major errors - errors in direction and errors in magnitude and here the authors have only looked at one of these. Previous work has shown that both can be used to understand the planning processes underlying movement. I assume that all models should also make predictions about the magnitude biases which would also help support or rule out specific models.

      Please see our response to Reviewer 1 public review 3.

      As discussed above, three-dimensional reaching movements also have biases and are not studied in the current manuscript. In such studies, biomechanical factors may play a much larger role.

      Please see our response to your public review.

      It may be that I am unclear on what exactly is done, as the methods and model fitting barely explain the details, but on my reading on the methods I have several major concerns.

      First, it feels that the visual bias model is not as well mapped across space if it only results from one study which is then extrapolated across the workspace. In contrast, the transformation model is actually measured throughout the space to develop the model. I have some concerns about whether this is a fair comparison. There are potentially many other visual bias models that might fit the current experimental results better than the chosen visual bias model.

      Please refers to our response to your public review.

      It is completely unclear to me why a joint-based proprioceptive model would predict curved planned movements and not straight movements (Figure S1). Changes in the shoulder and elbow joint angles could still be controlled to produce a straight movement. On the other hand, as mentioned above, the actual movement is likely much more complex if the physical starting position is offset from the perceived hand.

      Natural movements are often curved, reflecting a drive to minimize energy expenditure or biomechanical constraints (e.g., joint and muscle configuration). This is especially the case when the task emphasizes endpoint precision (Codol et al., 2024) like ours. Trajectory curvature was also observed in a recent simulation study in which a neural network was trained to control a biomechanical model (2-limb, 6muscles) with the cost function specified to minimize trajectory error (reach to a target with as straight a movement as possible). Even under these constraints, the movements showed some curvature. To examined whether the endpoint reaching bias somehow reflects the curvature (or bias during reaching), we included the prediction of this new biomechanical model in the paper to show it does not explain the motor bias we observed.

      To be clear, while we implemented several models (Joint-based proprioceptive model and the new biomechanical model) to examine whether motor biases can be explained by movement curvature, our goal in this paper was to identify the source of the endpoint bias. Our modeling results reveal a previously underappreciated source of motor bias—a transformation error that arises between visual and proprioceptive space—plays a dominant role in shaping motor bias patterns across a wide range of experiments, including naturalistic reaching contexts where vision and hand are aligned at the start position. While the movement curvature might be influenced by selectively manipulating factors that introduce a mismatch between the visual starting position and the actual hand position (such as Sober and Sabes, 2003), we think it will be an avenue for future work to investigate this question.

      The model fitting section is barely described. It is unclear how the data is fit or almost any other aspects of the process. How do the authors ensure that they have found the minimum? How many times was the process repeated for each model fit? How were starting parameters randomized? The main output of the model fitting is BIC comparisons across all subjects. However, there are many other ways to compare the models which should be considered in parallel. For example, how well do the models fit individual subjects using BIC comparisons? Or how often are specific models chosen for individual participants? While across all subjects one model may fit best, it might be that individual subjects show much more variability in which model fits their data. Many details are missing from the methods section. Further support beyond the mean BIC should be provided.

      We fit each model 150 times and for each iteration, the initial value of each parameter was randomly selected from a uniform distribution. The range for each parameter was hand tuned for each model, with an eye on making sure the values covered a reasonable range. Please see our response to your first minor comment below for the range of all parameters and how we decide the iteration number for each model.

      Given the reviewers’ comments in the individual difference, we now fit the models at individual level and report a frequency analysis, describing the best fitting model for each participant. In brief, the data for a vast majority of the participants was best explained by the transformation model when comparing single source models and by the T+V (TR+TG) model when consider all models. Please see response to reviewer 3 public comment 1 for the updated result.

      We updated the method session, and it reads as follows (lines 841-853):

      _“_We used the fminsearchbnd function in MATLAB to minimize the sum of loglikelihood (LL) across all trials for each participant. LL were computed assuming normally distributed noise around each participant’s motor biases:

      [11]       𝐿𝐿 = 𝑛𝑜𝑟𝑚𝑝𝑑𝑓(𝑥, 𝑏, 𝑐)

      where x is the empirical reaching angle, b is the predicted motor bias by the model, c is motor noise, calculated as the standard deviation of x-b.

      For model comparison, we calculated the BIC as follows:

      [12] BIC = -2LL+k∗ln(n)

      where k is the number of parameters of the models. Smaller BIC values correspond to better fits. We report the sum of ΔBIC by subtracting the BIC value of the TR+TG model from all other models.

      Line 305-307. The authors state that biomechanical issues would not predict qualitative changes in the motor bias function in response to visual manipulation of the start position. However, I question this statement. If the start position is offset visually then any integration of the proprioceptive and visual information to determine the start position would contain a difference from the real hand position. A calculation of the required joint torques from such a position sent through the mechanics of the limb would produce biases. These would occur purely because of the combination of the visual bias and the inherent biomechanical dynamics of the limb.

      We thank the reviewer for this comment. We have removed the statement regarding inferences about the biomechanical model based on visual manipulations of the start position. Additionally, we have incorporated a recently proposed biomechanical model into our model comparisons to expand our exploration of sources of bias. Please refer to our response to your public review for details.

      Measurements are made while the participants hold a stylus in their hand. How can the authors be certain that the biases are due to the movement and not due to small changes in the hand posture holding the stylus during movements in the workspace. It would be better if the stylus was fixed in the hand without being held.

      Below, we have included an image of the device used in Exp 1 for reference. The digital pen was fixed in a vertical orientation. At the start of the experiment, the experimenter ensured that the participant had the proper grip alignment and held the pen at the red-marked region. With these constraints, we see minimal change in posture during the task.

      Author response image 6.

      Minor Comments

      Best fit model parameters are not presented. Estimates of the accuracy of these measures would also be useful.

      In the original submission, we included a Table S1 that presented the best-fit parameters for the TR+TG (Previously T+V) model. Table S1 now shows the parameters for the other models (Exp 1b and 3b, only). We note the parameter values from these non-optimal models are hard to interpret given that core predictions are inconsistent with the data (e.g., number of peaks).

      We assume that by "accuracy of these measures," the reviewers are referring to the reliability of the model fits. To assess this, we conducted a parameter recovery analysis in which we simulated a range of model parameters for each model and then attempted to recover them through fitting. Each model was simulated 50 times, with the parameters randomly sampled from distributions used to define the initial fitting parameters. Here, we only present the results for the combined models (TR+TG, PropV+V, and PropJ+V), as the nested models would be even easier to fit.

      As shown in Fig. S4, all parameters were recovered with high accuracy, indicating strong reliability in parameter estimation. Additionally, we examined the log-likelihood as a function of fitting iterations (Fig. S4d). Based on this curve, we determined that 150 iterations were sufficient given that the log-likelihood values were asymptotic at this point. Moreover, in most cases, the model fitting can recover the simulated model, with minimal confusion across the three models (Fig. S4e).

      What are the (*1000) and (*100) in the Change in BIC y-labels? I assume they indicate that the values should be multiplied by these numbers. If these indicate that the BIC is in the hundreds or thousands it would be better the label the axes clearly, as the interpretation is very different (e.g. a BIC difference of 3 is not significant).

      ×1000' in the original figure indicates the unit scaling, with ΔBIC values ranging from approximately 1000 to 4000. However, given that we now fit the models at the individual level, we have replaced this figure with a new one showing the distribution of individual BIC values.

      Lines 249, 312, and 315, and maybe elsewhere - the degree symbol does not display properly.

      Corrected.

      Line 326. The authors mention that participants are unaware of their change in hand angle in response to clamped feedback. However, there may be a difference between sensing for perception and sensing for action. If the participants are unaware in terms of reporting but aware in terms of acting would this cause problems with the interpretation?

      This is an interesting distinction, one that has been widely discussed in the literature. However, it is not clear how to address this in the present context. We have looked at awareness in different ways in prior work with clamped feedback. In general, even when the hand direction might have deviated by >20d, participants report their perceived hand position after the movement as near the target (Tsay et al, 2020). We also have used post-experiment questionnaires to probe whether they thought their movement direction had changed over the course of the experiment (volitionally or otherwise). Again, participants generally insist they moved straight to the target throughout the experiment. So it seems that they unaware of any change in action or perception.

      Reaction time data provide additional support that participants are unaware of any change in behavior. The RT function remains flat after the introduction of the clamp, unlike the increases typically observed when participants engage in explicit strategy use (Tsay et al, 2024).

      Figure 1h: The caption suggests this is from the Wang 2021 paper. However, in the text 180-182 it suggests this might be the map from the current results. Can the authors clarify?

      Fig 1e is the data from Wang et al, 2021. We formalized an abstract map based on the spatial constrains observed in Fig 1e, and simulated the error at the start and target position based on this abstraction (Fig 1h). We have revised the text to now read (Lines 182-190):

      “Motor biases may thus arise from a transformation error between these coordinate systems. Studies in which participants match a visual stimulus to their unseen hand or vice-versa provide one way to estimate this error(Jones et al., 2009; Rincon-Gonzalez et al., 2011; van Beers et al., 1998; Wang et al., 12/2020). Two key features stand out in these data: First, the direction of the visuo-proprioceptive mismatch is similar across the workspace: For right-handers using their dominant limb, the hand is positioned leftward and downward from each target. Second, the magnitude increases with distance from the body (Fig 1d). Using these two empirical constraints, we simulated a visual-proprioceptive error map (Fig. 1h) by applying a leftward and downward error vector whose magnitude scaled with the distance from each location to a reference point.”

      Reviewer #3 (Recommendations for the authors):

      The central idea behind the research seems quite promising, and I applaud the efforts put forth. However, I'm not fully convinced that the current model formulations are plausible explanations. While the dataset is impressively large, it does not appear to be optimally designed to address the complex questions the authors aim to tackle. Moreover, the datasets used to formulate the 3 different model predictions are SMALL and exhibit substantial variability across individuals, and based on average (and thus "smoothed") data.

      We hope to have addressed these concerns with the two major changes to revised manuscript: 1) The new experiment in which we examine biases in both angle and extent and 2) the inclusion in the analyses of fits based on individual data sets.

    1. 25. Let me point out, Tiny Tim has been fucking me over since 1843. If I'm happy, it's taken for a miracle; if I'm not, I remind them of all they have and all the work they have to do. I could be a big smile, a raised fist, an eye glittered with tears.

      This reminds us of the conversation we'd had about tropes like the "bitter cripple"

    1. While tempting to store meaningful information in formatting like color codes or bolded text, this is a very bad idea. Formatting gets easily broken between software versions and applications.

      This reminds me of Dante manuscripts because from what I have been learning so far, the pages can be really decorative and visually interesting, but that does not automatically make them easy to analyze. Good looking does not always mean simple to understand.

    1. ritten more than twenty years afterthe events it depicts by a writer who had never been to India, Tennyson’s

      Good context. This is reminds me of the poem by Drayton.

    Annotators

  15. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Anya Kamenetz. Facebook's own data is not as conclusive as you think about teens and mental health. NPR, October 2021. URL: https://www.npr.org/2021/10/06/1043138622/facebook-instagram-teens-mental-health (visited on 2023-12-08).

      This article points out that Facebook's research about Instagram and teen mental health wasn't as clear as people thought. I like that it reminds us how complicated this issue really is. It's easy to blame social media for everything, but the truth is more mixed. For some teens it might make things worse, but for others it can be a place to find support. It made me think we should focus more on how people use these apps instead of just saying they're good or bad.

    1. Oral argument was a cornerstone of university curriculathrough the Middle Ages, the Renaissance, and into the 18thcentury. Written forms of argumentation did not take precedencein university settings until the 1800s, and coinciding with increas-ing specialization found both within and outside of the university

      This reminds me of how class debates feel more engaging and thought-provoking than formal research papers.

    1. You know, it forces kids to not just live their experience but be nostalgic for their experience while they’re living it, watch people watch them, watch people watch them watch them.

      This sentence is really interesting because it reminds me of how many people's first instinct when restaurant food comes is to take a picture of it. Even while having fun and being excited for food, the first instinct is to take a picture to remember it/show it to people. It's almost like having an extra observer in your brain judging everything.

    1. The impact of AI should also be considered at the more global level of managing organizations and non-medical staff. Areas affected include patient triage in the emergency room and the management and distribution of human resources across different services. This is where organizational ethics comes in, with human resources management and social dialogue figuring as major concerns. Indeed, in the health sector, the layers of the social fabric are particularly thick, diverse, and interwoven: changes in a healthcare institution affect many, if not all, of its workers, with major repercussions in the lives of users and patients too. The care of individuals who interact with medical assistants or diagnostic applications is also shifting. Thus, such “evolutions, introduced in a too radical and drastic way, damage the social fabric of a society” [120]. Moreover, these transformations also blur the boundary between work and private life and alter the link between the company and its employees, both old and new [140].

      AI affects everyone from patients to healthcare workers to society. When new evolutions are introduced too quickly, they can harm the social fabric. It reminds me of how the internet changed society after COVID hit. It became our main way to work and learn, but it also took away a lot of real human connection. Instead of hanging out or talking face-to-face, we started relying on screens and text messages for almost everything.

    1. When physical mail was dominant in the 1900s, one type of mail that spread around the US was a chain letter [l7]. Chain letters were letters that instructed the recipient to make their own copies of the letter and send them to people they knew. Some letters gave the reason for people to make copies might be as part of a pyramid scheme [l8] where you were supposed to send money to the people you got the letter from, but then the people you send the letter to would give you money. Other letters gave the reason for people to make copies that if they made copies, good things would happen to them, and if not bad things would, like this:

      I think this is interesting because it reminds me of copypastas that can be found on the internet. Sometimes, there will be a TikTok in my feed that is of the same nature, urging people to repost and use the audio for good luck. I did not know chain letters were a thing and it's really interesting to see how they are carried over in the digital age.

    2. Fig. 12.2 An example chain letter from https://cs.uwaterloo.ca/~mli/chain.html [l9].

      This reminds me so much of the chain texts people sent in middle school. I remember receiving these texts and actually being scared that bad things would happen. I think it's interesting that this format has stayed the same and that it exploits people's superstitions through a carrot and stick method.

    3. The book Writing on the Wall: Social Media - The First 2,000 Years [l6] describes how, before the printing press, when someone wanted a book, they had to find someone who had a copy and have a scribe make a copy. So books that were popular spread through people having scribes copy each other’s books. And with all this copying, there might be different versions of the book spreading around, because of scribal copying errors, added notes, or even the original author making an updated copy. So we can look at the evolution of these books: which got copied, and how they changed over time.

      This reminds me that, before the printing press, the version of book might be slightly different due to the error of coping. This might cause the misunderstanding for the past people. Also the way of approaching a book was pretty hard, and this limit the spread of knowledge in ancient time.

    4. 12.2.1. Books# The book Writing on the Wall: Social Media - The First 2,000 Years [l6] describes how, before the printing press, when someone wanted a book, they had to find someone who had a copy and have a scribe make a copy. So books that were popular spread through people having scribes copy each other’s books. And with all this copying, there might be different versions of the book spreading around, because of scribal copying errors, added notes, or even the original author making an updated copy. So we can look at the evolution of these books: which got copied, and how they changed over time. 12.2.2. Chain letters# When physical mail was dominant in the 1900s, one type of mail that spread around the US was a chain letter [l7]. Chain letters were letters that instructed the recipient to make their own copies of the letter and send them to people they knew. Some letters gave the reason for people to make copies might be as part of a pyramid scheme [l8] where you were supposed to send money to the people you got the letter from, but then the people you send the letter to would give you money. Other letters gave the reason for people to make copies that if they made copies, good things would happen to them, and if not bad things would, like this: You will receive good luck within four days of receiving this letter, providing, you in turn send it on. […] An RAF officer received $70,000 […] Gene Walsh lost his wife six days after receiving the letter. He

      Reading this section about pre-internet virality really made me reflect on how deeply rooted our desire to share and connect is. The example of chain letters especially stood out to me — even without social media, people still felt compelled to pass messages along, sometimes out of fear, sometimes out of hope. It’s interesting that what motivated them was often emotional rather than logical. This reminds me of how similar patterns appear today on social media: people still share posts promising “good luck” or “positive energy,” and even I’ve occasionally reshared something because it felt comforting or meaningful at the moment. It makes me realize that virality isn’t just about algorithms or technology; it’s about human emotions — our longing to be part of something bigger, our belief that our small actions can ripple outward.

    1. A meme is a piece of culture that might reproduce in an evolutionary fashion, like a hummable tune that someone hears and starts humming to themselves, perhaps changing it, and then others overhearing next. In this view, any piece of human culture can be considered a meme that is spreading (or failing to spread) according to evolutionary forces. So we can use an evolutionary perspective to consider the spread of:

      This reminds me of something quite silly but I think it's worth mentioning. While this term was later adapted to refer to what we today call a meme, it was still in use a this definition before and did circle through media, which made the media retroactively very comedic through the redefining of the word meme. My favorite example of this is the 2013 game Metal Gear Rising: Revengeance, which has a plot points revolving around how the only thing that truly matters to a persons self and decisions is memes and the ideas that their culture pass on to them. But with our modern definition, all the thoughtful speeches throughout the game become unintentionally very funny.

    2. Biological Evolution

      I find the description of internet memes as "cultural genes" quite interesting. It reminds me that the evolution of online information mirrors biological evolution; the most "adapted" ideas survive because they spread faster or attract more attention. However, unlike biological evolution, internet memes don't require authenticity to survive. Therefore, social media algorithms, like "natural selection," prioritize promoting content with the highest engagement.

  16. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Gina Vaynshteyn. I Made The Viral SpaghettiO And Milk Pie So That You Don’t Have To. February 2021. URL: https://www.scarymommy.com/spotted/spaghettio-pie (visited on 2023-12-08).

      This is content I often see on social media, it could be content related to books, shows or movies ("I read ___ so you don't have to"). However this kind of content related to food reminds me of tiktok trends in 2020 where people were trying weird food or watching people try weird foods out of pure boredom. This could be a kind of trolling, people trying bad or weird food combinations to get views, engagement or create discourses online.

    2. Dennis Lee. I made that viral Spaghettio pie that everyone is crapping themselves over. January 2021. URL: https://foodisstupid.substack.com/p/i-made-that-viral-spaghettio-pie (visited on 2023-12-08).

      This type of content reminds me a lot of what we have learned about trolling. This type of non-sensical reaction-evoking content, often called rage bait, is made to prompt viewers to interact with the content and ultimately make the creator more money by getting them more views. I think it is interesting how emotionally invested people get in non-consequential, silly content that doesn't truly affect them.

    3. Oliver Tearle. Who Said, ‘A Lie Is Halfway Round the World Before the Truth Has Got Its Boots On’? June 2021. URL: https://interestingliterature.com/2021/06/lie-halfway-round-world-before-truth-boots-on-quote-origin-meaning/ (visited on 2023-12-08).

      The article explains how the quote “A lie is halfway around the world before the truth has its boots on” has changed over time, I thought it was interesting how many people wrongly credit it to Mark Twain or Churchill, which shows how we like to attach big names to make a saying sound more powerful. It really reminds me of how fast misinformation spreads on social media today,people share things so quickly that the truth never has time to catch up. Even though the quote is old, it still feels completely true in our world now.

    1. If the first woman God ever made was strong enough to turn the world upside down all alone, these women together ought to be able to turn it back , and get it right side up again! And now they is asking to do it, the men better let them.

      This line really stood out to me because it captures both empowerment and unity. Sojourner Truth reminds her audience that women’s strength has always been transformative, Eve “turned the world upside down,” and now women collectively have the power to restore justice and balance. I find this message timeless because it speaks not only to women’s resilience but also to the importance of solidarity in achieving equality. Truth’s words challenge the idea that women are passive or fragile; instead, she reframes them as powerful agents of change who can reshape society when they work together.

    1. Not much holding themtogether. So far this essay of philosophizing mixed with examplesmight make you think that I let my students write anything they wantand that I’m encouraging you, as well, to write anything you want; inother words, trading rules for freedom. I don’t think writers have tochoose one over the other. I don’t think you can. If I try to convinceyou to write whatever you want, I’m using a traditional strategy forengaging students: your choice, your interests, your whatever. But anywriting choice is a choice. At the end of a semester, Adbe Guerrero,a former student, taught me about the positions that expertise andchoice occupied in relation to his experiences, my teaching, and oneof our later readings

      Charlton argues for experimentation instead of over-focusing on rigid form. I like his honesty that "focus" can limit invention; reminds me to explore ideas before narrowing. In my personal projects, I also "drift" before finding structure, it's the same creative process. He claims too much focus harms learning, which is true but I believe some structure helps.

    1. There’s really nothing that can substitute for the certainty of actually watching someone struggle to use your design, but these analytical approaches are quick ways to get feedback, and suitable fallbacks if working with actual people isn’t feasible.

      I like this sentence because it recognizes both the value and the limits of analytical evaluation. The author acknowledges that while direct user observation provides the most authentic insight, analytical methods still play a vital role when testing with users isn’t possible. This balance between practicality and depth reflects a realistic approach to design research. It reminds me that good designers use every tool available but never lose sight of real human experience.

    1. Observation, of course, requires empirical methods

      I found this sentence powerful because it highlights the importance of grounding design evaluation in real evidence rather than assumption. The author emphasizes that observation allows designers to see how users truly interact with a system, revealing insights that intuition alone might miss. This focus on empirical methods encourages a more objective and reliable approach to improving design. Overall, it reminds me that true understanding in design comes from watching people, not guessing their needs.

    1. AI makes it possible for machines to learn from experience, that means AI is susceptible to the same bias of the humans it's simulating.

      I found it really interesting how AI isn't truly neutral or objective. It learns directly from us, which means that it also absorbs our biases. The data that trains AI often reflects existing social inequalities like racism, sexism, etc. so those same patterns end up built into the technology itself. AI systems are constantly trained from the information we give them, and that training shapes how they make decisions. This reminds me of how social media algorithms or facial recognition systems sometimes produce unfair outcomes. It's not because the technology is evil, but because it's mirroring the biases it's been taught.

    1. Groups develop a shared identity based on their task or purpose, previous accomplishments, future goals, and an identity that sets their members apart from other groups.

      This reminds me of my philosophy class's small group, we mostly discuss the class and each of our respective opinions on the discussions we have in class, and it's so much fun honestly, and also, I love to have each discussion with people

    2. Participating in groups can also increase our exposure to diversity and broaden our perspectives. Although groups vary in the diversity of their members, we can strategically choose groups that expand our diversity, or we can unintentionally end up in a diverse group. When we participate in small groups, we expand our social networks, which increase the possibility to interact with people who have different cultural identities than ourselves.

      This reminds me of how my groups at homeschool co-ops were. My experience was small classes, which increased discussion, and also helped with the intellectual diversity of the class.

  17. Oct 2025
    1. The information you share online can last a long time and may be seen by thousands of people all around the world.

      This part really makes me think about how permanent our online actions are. I like that it reminds readers that small posts can have lasting consequences.

    1. What can video ethnographic studies of family interactions in everyday, outdoor learning contexts (berry picking, fishing, forest walks, etc.) tell us about the multitude of ways that people go about making relations, or teaching and learning, about/with the natural world? What insights can we gain about learning by focusing on the organization of talk, action, and embodied movement in these learning environments?

      This reminds me of my Gramma and my Mamaw, (her mom) who always took me on outings to the mountains, the beach, fishing and more because they both would always have a bag that we kept for trash. This bag was to make sure that we left the places we went to better than how we came across them. If that meant emptying our bag a couple of times then so be it but we never left trash if we came across something while we were out. My husband’s family was horrified that we picked up trash when we went out and just could not understand why we did. I taught this to my children and we all would forget sometimes to bring a bag then we would wash our finds that ended up in our pockets. It has become a bit of a laughing point because of all the little finds that come home with me. My son and I compare fishing hooks and lures that we find while fishing.

    2. The idea of allowing children to participate is one that we have mentioned multiple times and is the one that we would like to emphasize as we end this chapter. In LOPI, children are allowed to participate even if their skill level would not be deemed to be “sufficiently competent” in certain areas. We would note that children become more competent in activity if they are allowed to participate in it; however, age-graded schooling is built on the assumption that there are skills that are only available to children once they have reached the appropriate level of maturity, the right age, or the right level of competence (Rogoff et al., 2005). This is counter to the idea that everyone can contribute, which is often seen in family and community activity where LOPI is common.

      I like that the segment emphasizes the importance of encouraging participation regardless of current ability. This reminds me so much of the work done within the behavior classroom that I work in. We help children complete a task until they can master it themselves. Encouragement, inclusion, and engagement can go a long way.

    3. Studies conducted with families of toddlers showed that three-year-old children were often eager to participate in chores; however, this desire disappeared as children were not allowed to participate or not deemed competent enough to participate. Interviews with European American and Mexican heritage mothers of two- to three-year-old children in California showed that the Mexican heritage mothers incorporated their toddlers in ongoing work, whereas European American mothers tried to avoid having their children involved in ongoing work. In the interviews, over half of the European American mothers said they avoided including their toddler in joint work, often because they wanted to spend the time engaging with their child in a more meaningful or cognitively enriching way. Sometimes, this was also done in the name of efficiency (Coppens & Rogoff, 2017b). Mexican heritage mothers, in contrast, emphasized the joint nature of the activity and the idea that helping developed the desire to help even more within their children.

      This segment truly deepened my understanding of the concept of LOPI and its role in my life and the lives of those around me. My grandmother, a German immigrant, practiced LOPI. My great-grandmother, an African American woman, did the same. This was at sharp contrast to many of my peers at my PWI. This segment also reminds me of some of the work that is done in the enclosed classroom that I work in. When teaching children life. skills, we hand-over-hand the aspects that they are having difficulty with until they themselves develop the ability to complete the action. One program that is very successful in this is washing hands.

    1. Elon Musk’s view expressed in that tweet is different than some of the ideas of the previous owners, who at least tried to figure out how to make Twitter’s algorithm support healthier conversation [k6].

      This reminds me a lot of the original story of Justine Sacco's tweet. And as much as I vehemently disagree with Musk's views and rhetoric, him being open about the way the Twitter/X algorithm works is interesting to me. I previously said that social media doesn't benefit off of positive interactions, but rather being the paper on which arguments are written. And Musk outright states that, interaction, positive or negative, is interaction, and will boost content in that vein whether you like it or not, so as to try and elicit more participation from you.

  18. inst-fs-iad-prod.inscloudgate.net inst-fs-iad-prod.inscloudgate.net
    1. Many of those respondents, however, who were concentrated in theadvanced curriculum tracks in high school—with smaller and more support-ive learning environments that gave them access to key school personnel—drew upon relationships with teachers and counselors to disclose their sta-tus and to seek out help. These respondents told us that they felt comfort-able talking about their problems with school personnel because the trustwas already there.

      This passage shows how important trust and relationships are for undocumented students navigating in school. Those placed in advanced tracks had smaller classes and more access to teachers and counselors, which helped them feel safe enough to share their status and ask for help. It wasn’t just about academics, it was about being seen and supported. When students feel like someone genuinely cares, they’re more likely to open up and get the guidance they need. This reminds me how many school structures can either build or block those connections, and how much that matters for students facing extra challenges.

    2. Seeing friends move forward punctuated our respondents’ own immo-bility. Confusion about the future constrained their decisions regarding the present. Ruben, from Seattle, explained to us that his entire future was turned upside down. You know, you grew up thinking, dreaming of your future. Like, “I’m going to be a fi refi ghter when I grow up”. You know, like that. I thought I could be something more. It’s hard to swallow realizing that you’re just an immigrant. How do you say? Undocumented? It really stopped me in my tracks

      From the perspective of immigrant students, this passage reveals how uncertainty about the future can deeply affect motivation and self-worth. Many undocumented students grow up believing in the same dreams as their peers—going to college, finding a good job, contributing to society—but later realize that their immigration status limits those possibilities. Seeing friends move forward while they remain stuck creates a painful sense of immobility and isolation. The confusion about what’s even possible makes it hard for them to plan or stay engaged in the present. For these students, education becomes a source of both hope and frustration—it represents opportunity but also reminds them of the barriers they face just to belong.

    1. All the life squeezed out of them so that they fit into one headline. Sentences become coffins too small to contain all the multitudes of grief.

      Why this truth is important: This line tells a hard truth: that the news often makes stories of war and pain too small. When we read about people suffering, the headlines don’t show how big and real their pain is. The image of “sentences as coffins” means that sometimes writing can hide people’s emotions instead of showing them. It reminds me that we must use words carefully, because they can give life or take it away.

    1. The third component of the love triangle is commitment/decision (Sternberg, 1986, 1988). This component refers to the decision to love someone and the commitment to maintain that love. Because commitment is based on cognition and decision making, Sternberg referred to it as the “cool” or “cold” component. Of the three components of the love triangle, commitment is most stable over time with commitment typically building gradually and then stabilizing (Acker & Davis, 1992). Commitment is a stronger predictor of relationship satisfaction and longevity than either intimacy or passion (Acker & Davis, 1992; S. S. Hendrick, Hendrick, & Adler, 1988). In a study by Fehr (1988), college-aged students rated how closely various words or phrases, such as affection and missing each other when apart, relate to love. Of the 68 words and phrases Fehr listed, the word trust was rated as most central to love. Commitment ranked 8th overall, suggesting that it is also critical in people’s conceptualizations of love. The other two components of the triangular theory of love were also important, although less central, with intimacy ranking 19th and sexual passion rating 40th. Fehr (1988) also had college-aged students rate words and phrases describing the concept of commitment. Loyalty, responsibility, living up to one’s word, faithfulness, and trust were the top five descriptors of commitment, suggesting that commitment involves being there for someone over the long haul. Yet commitment alone is not enough to keep a relationship happy. Fatuous love is rooted in commitment and passion without intimacy. This type of love is relatively rare in modern times. Relationships that exemplify fatuous love are committed but are based on sex rather than intimacy. Historically these included mistress relationships where there was an arrangement for long-term support for sex without emotional intimacy. Some modern-day friends-with-benefits relationships also fit this description to some extent, especially when two people are long-term hookup buddies but do not have the type of emotional connection that romantic couples have (see Chapters 9 and 10 for more on friends-with-benefits relationships). Most hookup buddies, however, have little commitment. In general, these relationships are less satisfying than those characterized by consummate or romantic love. Fatuous love: A type of love characterized by commitment and passion without intimacy. The least satisfying relationships are characterized by empty love, which means they have commitment but relatively low levels of intimacy and passion. Some long-term relationships fall into this category. For instance, if partners no longer feel attached to each other but stay together for religious reasons or because of the children, their love might be characterized as empty. In other cases, empty love characterizes the beginning of a relationship. For example, spouses in arranged marriages may begin their relationships with empty love. Intimacy and passion may, or may not, emerge later.

      This passage explains how commitment functions as the rational or “cool” part of Sternberg’s triangular theory of love, emphasizing decision making and long term stability. I found it interesting that commitment is described as a stronger predictor of relationship satisfaction than intimacy or passion. It shows that emotional or physical connection alone isn’t enough to sustain love. The mention of trust being rated as most central to love makes sense because trust reinforces reliability and loyalty which are essential for long term relationships. What stands out is that even though commitment is crucial, the passage reminds us that it can’t exist in isolation. Without intimacy, relationships can become mechanical or unfulfilling, like the “fatuous love” described. This makes me think about how modern relationships often emphasize passion early on but may struggle to build the consistent trust and loyalty that real commitment requires.

    1. As you can see, prototyping isn’t strictly about learning to make things, but also learning how to decide what prototype to make and what that prototype would teach you. These are judgements that are highly contextual because they depend on the time and resources you have and the tolerance for risk you have in whatever organization you’re in.

      I really agree with the idea that prototyping isn’t just about making something, it is about figuring out what’s worth making and why. I think that perspective is super useful because it reminds me that not every idea needs a polished version right away and sometimes a quick, rough prototype can teach you more. It also made me realize how much context matters like how your time, resources, or even your team’s comfort with risk can totally change what kind of prototype makes sense.

    2. the purpose of a prototype isn’t the making of it, but the knowledge gained from making and testing it. This means that what you make has to be closely tied to how you test it.

      This part really changed my mind. I agree that prototyping isn’t about making something perfect, but about learning through testing. For example, in a project last quarter, I spent hours creating a polished mockup for a class app prototype without testing it with anyone. When I finally received feedback, I realized some of my design assumptions were completely wrong, and much of my work went to waste. Ko’s point makes me see that starting with quick sketches or paper prototypes can be much more effective, even if they look messy. It also reminds me to focus on what questions I want answered before building anything, so I can learn as much as possible from each test. For current group project in class and my future projects, I believe this approach will absolutely save a lot of time and also improve my design decisions,.

    3. Designers use prototypes to resolve these uncertainties, iterate on their design based on feedback, and converge toward a design that best addresses the problem.

      I agree with this idea because it shows how important it is to view design as a process of learning rather than just building. Prototyping encourages creativity and flexibility, allowing designers to adapt based on real feedback instead of assumptions. I think this approach saves time and resources while leading to stronger, more user-centered outcomes. It reminds me that good design isn’t about getting it perfect the first time, it’s about improving through continuous discovery.

    4. As you can see, prototyping isn’t strictly about learning to make things, but also learning how to decide what prototype to make and what that prototype would teach you. These are judgements that are highly contextual because they depend on the time and resources you have and the tolerance for risk you have in whatever organization you’re in.

      Agreed and again, this just reminds me that design thinking requires extensive research and evaluation. The example of the pizza app just reminds me that you can't simply design a good product by prototype -> test -> improve. Somewhere within that process, you must stop to evaluate whether this is the right problem to solve and if you even have the correct solution, and how you can test these hypothesis.

  19. inst-fs-iad-prod.inscloudgate.net inst-fs-iad-prod.inscloudgate.net
    1. econd year of the study, we asked students, "What do you think are the main obstacles to getting ahead in the United States?" Fifty-six percent spontaneously responded "•IIIIFlfft'l~Mrl~h"-singling out not knowing English as a greater impediment than even discrimination, lack of re-sources, or not being documented. We then listed a number of obstacles that over the years we have learned are concerns for new immigrants. Fully 90 percent of our participants responded that learning English was a chal-lenge they needed to overcome to get ahead. In the last year of the study, we also asked students what they perceived were obstacles to getting to college. Of those who thought they would go to college, 45 percent responded that their English fluency presented a prob-

      This paragraph highlights how language barriers remain one of the biggest challenges for immigrant students in the U.S. It’s striking that many students viewed learning English as an even greater obstacle than discrimination or lack of resources. This shows how deeply language proficiency is tied to access and opportunity—students feel that without English fluency, they cannot fully participate or advance academically and socially. This reminds me of when I first came abroad to study. My school offered specialized English transition classes for international students. While local students were learning a second foreign language, we were studying English. But this approach actually made it difficult for international students to make local friends, and we still couldn't complete a full second foreign language by graduation.

    1. The Google search page actually accepts many other implicit inputs too. There are a variety of personalization settings, such as search history, search preferences, and even sensor input (such as your location) that it also accepts as input. The user interface doesn’t provide explicit controls for providing this input, but it is user input nonetheless. These implicit inputs contain issues of justice. For example, what harms may come by Google tracking your location when you search? For many, no harm, but what about people do not secure their accounts, and might be stalked by a violent ex, or someone in witness protection?

      I agree that these implicit inputs, like location tracking and personalized history, create serious ethical concerns because the consequences aren’t evenly distributed across all users. For someone with stable circumstances and no threats to their safety, personalized search may feel convenient and harmless. But for someone vulnerable, like a stalking victim or a person relying on anonymity for protection, the same data trail becomes a map for harm. I find this perspective really useful because it makes me rethink digital design as not only about convenience but about protecting the worst-case scenario user. Google may not intend to create danger, yet the system can accidentally amplify risk for people who are already at risk. It reminds me that “smart” features aren’t universally smart — sometimes they’re sharp objects that require careful safety guards.

    2. Conventions are design patterns (combinations of design decisions) that people have already learned

      This is highly dependent on what users are used to and reminds me of a story I heard about designing a music streaming app for rural users in the US for a mobile company. The product manager chose an extremely simple layout (e.g. pre-built playlist in the home screen, 2 clicks to play music), showing how important it is to factoring in your users's technical literacy when designing an UI.

    3. clear affordances11 Rex Hartson (2003). Cognitive, physical, sensory, and functional affordances in interaction design. Behaviour & Information Technology. . An affordance is a relationship between a person and a property of what can be done to an interface in order to produce some effect. For example, a physical computer mouse can be clicked, which allows information to be communicated to a computer. However, these are just a property of a mouse; affordances arise when a person recognizes that opportunity and knows how to act upon it. To know that a user interface has an affordance, user interfaces provide signifiers, which are any sensory or cognitive indicator of the presence of an affordance. Consider, for example, how you know that a computer mouse can be clicked.

      I really agree with the idea in this passage about affordances — it makes so much sense when thinking about how we interact with interfaces every day. The point that affordances are not just about what something can do, but whether the user recognizes what can be done, feels super relevant. It’s one thing for a button to be clickable, but it’s another for users to know it’s clickable. I also like how the passage connects affordances to signifiers, like visual or sensory cues that guide users. It reminds me of how modern apps use animations, color changes, or shadows to make buttons feel “touchable.” It’s a small detail, but it really changes how intuitive something feels.

  20. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Many of the disabilities we mentioned above were permanent disabilities, that is, disabilities that won’t go away. But disabilities can also be temporary disabilities, like a broken leg in a cast, which may eventually get better. Disabilities can also vary over time (e.g., “Today is a bad day for my back pain”). Disabilities can even be situational disabilities, like the loss of fine motor skills when wearing thick gloves in the cold, or trying to watch a video on your phone in class with the sound off, or trying to type on a computer while holding a baby.

      I particularly agree with the idea in this passage that "disability is situational". It reminds us that disability is not always a "physical problem" of an individual, but rather depends on the environment, tools and social support. For instance, when we wear thick gloves, hold a baby, or watch a video without sound, we actually temporarily "lose" some abilities. This perspective makes me rethink what "normal" really means - perhaps what is called "normal" is just the kind of ability that society currently chooses to support. If we could provide corresponding conveniences for all kinds of differences as we do for wearing glasses, then the word "disability" might not carry so much stigma.

    2. A disability is an ability that a person doesn’t have, but that their society expects them to have.[1] For example: If a building only has staircases to get up to the second floor (it was built assuming everyone could walk up stairs), then someone who cannot get up stairs has a disability in that situation. If a physical picture book was made with the assumption that people would be able to see the pictures, then someone who cannot see has a disability in that situation. If tall grocery store shelves were made with the assumption that people would be able to reach them, then people who are short, or who can’t lift their arms up, or who can’t stand up, all would have a disability in that situation. If an airplane seat was designed with little leg room, assuming people’s legs wouldn’t be too long, then someone who is very tall, or who has difficulty bending their legs would have a disability in that situation. Which abilities are expected of people, and therefore what things are considered disabilities, are socially defined [j1]. Different societies and groups of people make different assumptions about what people can do, and so what is considered a disability in one group, might just be “normal” in another.

      I really appreciate how this section reframes disability as a social design issue rather than an individual problem. The examples about stairs and color vision made me realize how often our environments are built for a narrow idea of normal. I've never thought about how something as simple as shelf height or screen brightness can include or exclude people. This reminds me that accessibility isn't just a technical feature; it's an ethical responsibility. If design creates disability, them redesign can also remove it. It makes me wonder how many limitations in our world are actually design failures, not human ones.

  21. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. Social model of disability. November 2023. Page Version ID: 1184222120. URL: https://en.wikipedia.org/w/index.php?title=Social_model_of_disability&oldid=1184222120#Social_construction_of_disability (visited on 2023-12-07).

      This article expands on the same idea presented in Chapter 10 that disability is not caused by an individual's physical or mental condition, but by barriers built into society. What stood out to me is how the model shifts focus from fixing people to fixing environments. This connects that exclusion often comes from design choices rather than personal limitations. It also mede me think about my own digital and academic spaces; how often are they designed for neurotypical, able-bodied users by default? The social model reminds us that inclusion is not charity; it's justice through design.

    1. quietly retired to our several places of residence, without having any conversation with each other

      It’s interesting that everyone kept quiet afterward. It reminds me of how some protest groups today stay anonymous to protect themselves, kind of like the Sons of Liberty did later.

    1. many young adults also harbored ageist misperceptions and erroneous beliefs.

      Personal Connection: This statement reminds me of how people will be shocked to find out that older couples still date or hold hands. It shows how age stereotypes are still wrong.

  22. drive.google.com drive.google.com
    1. Media literacy learning provides an open environment in which both students and the teacher canconverse and respectfully give divergent opinions.

      I like how this frames media literacy as a conversation instead of just a lecture. It emphasizes collaboration and the value of multiple perspectives. Even though De Abreu is speaking to teachers, I can imagine how powerful this would feel if students heard it directly. I believe they might feel more confident sharing their own ideas and questioning what they see. It reminds me that learning media literacy is as much about dialogue and understanding others' viewpoints as it is about facts.

    2. Media literacy involves critical thinking. To think that it does not would make the study of medialiteracy a passive undertaking, rather than an engaged dynamic

      This line really captures the heart of media literacy—it’s not about memorizing facts about media, but about questioning what we see and hear. De Abreu emphasizes that without critical thinking, media literacy becomes empty. It reminds me that consuming news or social posts passively makes us more likely to be influenced by bias or misinformation. True literacy means asking who made this, why, and how it’s shaping what I believe.

    1. Disappointing Mingi, as he always did, Yunho had responded with a shrug.

      I really get that sense of determination here, fate, that the way it is is how it will always be. Yunho thinking he's always disappointing Mingi, it reminds me a lot of how in religious contextual stories the protagonist is meant to fear God, and in that fear is love. That quote:

      Love, for you, is larger than the usual romantic love. It’s like a religion. It’s terrifying. No one will ever want to sleep with you.

    1. John sinks down in his seat, afraid she is going to ask him questions as well. He pulls out his phone and looksthrough social media to keep her from bothering him. As other students enter the class, some quiet andothers talkative, John wonders if he will have to interact with them. Even though he has not met many peopleyet–and certainly has not had any deep conversations with anyone–he feels anxious about having to get toknow strangers and feels most comfortable keeping to himself at least fo

      This situation shows how easily anxiety can keep someone from connecting with others. It’s sad that John feels the need to hide behind his phone instead of giving himself a chance to meet new people. It reminds me how difficult social situations can be when fear takes over, and how important it is to slowly build confidence to open up.

    1. Intensifying

      A lot of the time, or maybe just with me, I can see myself rushing into this stage to get to the integrating stage, but usually it's because i'm so excited to be around the person and to have a 'someone.' which reminds me of how a happy dog is so excited for you to be homme they run up to you and jump on you at the door, and you're so overwhelmed you push them away.

    1. Author response:

      The following is the authors’ response to the previous reviews

      Overview of reviewer's concerns after peer review: 

      As for the initial submission, the reviewers' unanimous opinion is that the authors should perform additional controls to show that their key findings may not be affected by experimental or analysis artefacts, and clarify key aspects of their core methods, chiefly:  

      (1) The fact that their extremely high decoding accuracy is driven by frequency bands that would reflect the key press movements and that these are located bilaterally in frontal brain regions (with the task being unilateral) are seen as key concerns, 

      The above statement that decoding was driven by bilateral frontal brain regions is not entirely consistent with our results. The confusion was likely caused by the way we originally presented our data in Figure 2. We have revised that figure to make it more clear that decoding performance at both the parcel- (Figure 2B) and voxel-space (Figure 2C) level is predominantly driven by contralateral (as opposed to ipsilateral) sensorimotor regions. Figure 2D, which highlights bilateral sensorimotor and premotor regions, displays accuracy of individual regional voxel-space decoders assessed independently. This was the criteria used to determine which regional voxel-spaces were included in the hybridspace decoder. This result is not surprising given that motor and premotor regions are known to display adaptive interhemispheric interactions during motor sequence learning [1, 2], and particularly so when the skill is performed with the non-dominant hand [3-5]. We now discuss this important detail in the revised manuscript:

      Discussion (lines 348-353)

      “The whole-brain parcel-space decoder likely emphasized more stable activity patterns in contralateral frontoparietal regions that differed between individual finger movements [21,35], while the regional voxel-space decoder likely incorporated information related to adaptive interhemispheric interactions operating during motor sequence learning [32,36,37], particularly pertinent when the skill is performed with the non-dominant hand [38-40].”

      We now also include new control analyses that directly address the potential contribution of movement-related artefact to the results.  These changes are reported in the revised manuscript as follows:

      Results (lines 207-211):

      “An alternate decoder trained on ICA components labeled as movement or physiological artefacts (e.g. – head movement, ECG, eye movements and blinks; Figure 3 – figure supplement 3A, D) and removed from the original input feature set during the pre-processing stage approached chance-level performance (Figure 4 – figure supplement 3), indicating that the 4-class hybrid decoder results were not driven by task-related artefacts.”

      Results (lines 261-268):

      “As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C). Task-related eye movements did not explain these results since an alternate 5-class hybrid decoder constructed from three eye movement features (gaze position at the KeyDown event, gaze position 200ms later, and peak eye movement velocity within this window; Figure 4 – figure supplement 3A) performed at chance levels (cross-validated test accuracy = 0.2181; Figure 4 – figure supplement 3B, C). “

      Discussion (Lines 362-368):

      “Task-related movements—which also express in lower frequency ranges—did not explain these results given the near chance-level performance of alternative decoders trained on (a) artefact-related ICA components removed during MEG preprocessing (Figure 3 – figure supplement 3A-C) and on (b) task-related eye movement features (Figure 4 – figure supplement 3B, C). This explanation is also inconsistent with the minimal average head motion of 1.159 mm (± 1.077 SD) across the MEG recording (Figure 3 – figure supplement 3D).“

      (2) Relatedly, the use of a wide time window (~200 ms) for a 250-330 ms typing speed makes it hard to pinpoint the changes underpinning learning, 

      The revised manuscript now includes analyses carried out with decoding time windows ranging from 50 to 250ms in duration. These additional results are now reported in:

      Results (lines 258-261):

      “The improved decoding accuracy is supported by greater differentiation in neural representations of the index finger keypresses performed at positions 1 and 5 of the sequence (Figure 4A), and by the trial-by-trial increase in 2-class decoding accuracy over early learning (Figure 4C) across different decoder window durations (Figure 4 – figure supplement 2).”

      Results (lines 310-312):

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C).“

      Discussion (lines 382-385):

      “This was further supported by the progressive differentiation of neural representations of the index finger keypress (Figure 4A) and by the robust trial-bytrial increase in 2-class decoding accuracy across time windows ranging between 50 and 250ms (Figure 4C; Figure 4 – figure supplement 2).”

      Discussion (lines 408-9):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1).”

      (3) These concerns make it hard to conclude from their data that learning is mediated by "contextualisation" ---a key claim in the manuscript; 

      We believe the revised manuscript now addresses all concerns raised in Editor points 1 and 2.

      (4) The hybrid voxel + parcel space decoder ---a key contribution of the paper--- is not clearly explained; 

      We now provide additional details regarding the hybrid-space decoder approach in the following sections of the revised manuscript:

      Results (lines 158-172):

      “Next, given that the brain simultaneously processes information more efficiently across multiple spatial and temporal scales [28, 32, 33], we asked if the combination of lower resolution whole-brain and higher resolution regional brain activity patterns further improve keypress prediction accuracy. We constructed hybrid-space decoders (N = 1295 ± 20 features; Figure 3A) combining whole-brain parcel-space activity (n = 148 features; Figure 2B) with regional voxel-space activity from a datadriven subset of brain areas (n = 1147 ± 20 features; Figure 2D). This subset covers brain regions showing the highest regional voxel-space decoding performances (top regions across all subjects shown in Figure 2D; Methods – Hybrid Spatial Approach). 

      […]

      Note that while features from contralateral brain regions were more important for whole-brain decoding (in both parcel- and voxel-spaces), regional voxel-space decoders performed best for bilateral sensorimotor areas on average across the group. Thus, a multi-scale hybrid-space representation best characterizes the keypress action manifolds.”

      Results (lines 275-282):

      “We used a Euclidian distance measure to evaluate the differentiation of the neural representation manifold of the same action (i.e. - an index-finger keypress) executed within different local sequence contexts (i.e. - ordinal position 1 vs. ordinal position 5; Figure 5). To make these distance measures comparable across participants, a new set of classifiers was then trained with group-optimal parameters (i.e. – broadband hybrid-space MEG data with subsequent manifold extraction (Figure 3 – figure supplements 2) and LDA classifiers (Figure 3 – figure supplements 7) trained on 200ms duration windows aligned to the KeyDown event (see Methods, Figure 3 – figure supplements 5). “

      Discussion (lines 341-360):

      “The initial phase of the study focused on optimizing the accuracy of decoding individual finger keypresses from MEG brain activity. Recent work showed that the brain simultaneously processes information more efficiently across multiple—rather than a single—spatial scale(s) [28, 32]. To this effect, we developed a novel hybridspace approach designed to integrate neural representation dynamics over two different spatial scales: (1) whole-brain parcel-space (i.e. – spatial activity patterns across all cortical brain regions) and (2) regional voxel-space (i.e. – spatial activity patterns within select brain regions) activity. We found consistent spatial differences between whole-brain parcel-space feature importance (predominantly contralateral frontoparietal, Figure 2B) and regional voxel-space decoder accuracy (bilateral sensorimotor regions, Figure 2D). The whole-brain parcel-space decoder likely emphasized more stable activity patterns in contralateral frontoparietal regions that differed between individual finger movements [21, 35], while the regional voxelspace decoder likely incorporated information related to adaptive interhemispheric interactions operating during motor sequence learning [32, 36, 37], particularly pertinent when the skill is performed with the non-dominant hand [38-40]. The observation of increased cross-validated test accuracy (as shown in Figure 3 – Figure Supplement 6) indicates that the spatially overlapping information in parcel- and voxel-space time-series in the hybrid decoder was complementary, rather than redundant [41].  The hybrid-space decoder which achieved an accuracy exceeding 90%—and robustly generalized to Day 2 across trained and untrained sequences— surpassed the performance of both parcel-space and voxel-space decoders and compared favorably to other neuroimaging-based finger movement decoding strategies [6, 24, 42-44].”

      Methods (lines 636-647):

      “Hybrid Spatial Approach.  First, we evaluated the decoding performance of each individual brain region in accurately labeling finger keypresses from regional voxelspace (i.e. - all voxels within a brain region as defined by the Desikan-Killiany Atlas) activity. Brain regions were then ranked from 1 to 148 based on their decoding accuracy at the group level. In a stepwise manner, we then constructed a “hybridspace” decoder by incrementally concatenating regional voxel-space activity of brain regions—starting with the top-ranked region—with whole-brain parcel-level features and assessed decoding accuracy. Subsequently, we added the regional voxel-space features of the second-ranked brain region and continued this process until decoding accuracy reached saturation. The optimal “hybrid-space” input feature set over the group included the 148 parcel-space features and regional voxelspace features from a total of 8 brain regions (bilateral superior frontal, middle frontal, pre-central and post-central; N = 1295 ± 20 features).”

      (5) More controls are needed to show that their decoder approach is capturing a neural representation dedicated to context rather than independent representations of consecutive keypresses; 

      These controls have been implemented and are now reported in the manuscript:

      Results (lines 318-328):

      “Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or micro-offline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69). These findings were not explained by behavioral changes of typing rhythm (t = -0.03, p = 0.976; Figure 5 – figure supplement 5), adjacent keypress transition times (R2 = 0.00507, F[1,3202] = 16.3; Figure 5 – figure supplement 6), or overall typing speed (between-subject; R2 = 0.028, p \= 0.41; Figure 5 – figure supplement 7).”

      Results (lines 385-390):

      “Further, the 5-class classifier—which directly incorporated information about the sequence location context of each keypress into the decoding pipeline—improved decoding accuracy relative to the 4-class classifier (Figure 4C). Importantly, testing on Day 2 revealed specificity of this representational differentiation for the trained skill but not for the same keypresses performed during various unpracticed control sequences (Figure 5C).”

      Discussion (lines 408-423):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1). This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A). On the other hand, online contextualization did not predict learning (Figure 5 – figure supplement 3). Consistent with these results the average within-subject correlation between offline contextualization and micro-offline gains was significantly stronger than withinsubject correlations between online contextualization and either micro-online or micro-offline gains (Figure 5 – figure supplement 4). 

      Offline contextualization was not driven by trial-by-trial behavioral differences, including typing rhythm (Figure 5 – figure supplement 5) and adjacent keypress transition times (Figure 5 – figure supplement 6) nor by between-subject differences in overall typing speed (Figure 5 – figure supplement 7)—ruling out a reliance on differences in the temporal overlap of keypresses. Importantly, offline contextualization documented on Day 1 stabilized once a performance plateau was reached (trials 11-36), and was retained on Day 2, documenting overnight consolidation of the differentiated neural representations.”

      (6) The need to show more convincingly that their data is not affected by head movements, e.g., by regressing out signal components that are correlated with the fiducial signal;  

      We now include data in Figure 3 – figure supplement 3D showing that head movement was minimal in all participants (mean of 1.159 mm ± 1.077 SD).  Further, the requested additional control analyses have been carried out and are reported in the revised manuscript:

      Results (lines 204-211):

      “Testing the keypress state (4-class) hybrid decoder performance on Day 1 after randomly shupling keypress labels for held-out test data resulted in a performance drop approaching expected chance levels (22.12%± SD 9.1%; Figure 3 – figure supplement 3C). An alternate decoder trained on ICA components labeled as movement or physiological artefacts (e.g. – head movement, ECG, eye movements and blinks; Figure 3 – figure supplement 3A, D) and removed from the original input feature set during the pre-processing stage approached chance-level performance (Figure 4 – figure supplement 3), indicating that the 4-class hybrid decoder results were not driven by task-related artefacts.” Results (lines 261-268):

      “As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C). Task-related eye movements did not explain these results since an alternate 5-class hybrid decoder constructed from three eye movement features (gaze position at the KeyDown event, gaze position 200ms later, and peak eye movement velocity within this window; Figure 4 – figure supplement 3A) performed at chance levels (cross-validated test accuracy = 0.2181; Figure 4 – figure supplement 3B, C). “

      Discussion (Lines 362-368):

      “Task-related movements—which also express in lower frequency ranges—did not explain these results given the near chance-level performance of alternative decoders trained on (a) artefact-related ICA components removed during MEG preprocessing (Figure 3 – figure supplement 3A-C) and on (b) task-related eye movement features (Figure 4 – figure supplement 3B, C). This explanation is also inconsistent with the minimal average head motion of 1.159 mm (± 1.077 SD) across the MEG recording (Figure 3 – figure supplement 3D). “

      (7) The offline neural representation analysis as executed is a bit odd, since it seems to be based on comparing the last key press to the first key press of the next sequence, rather than focus on the inter-sequence interval

      While we previously evaluated replay of skill sequences during rest intervals, identification of how offline reactivation patterns of a single keypress state representation evolve with learning presents non-trivial challenges. First, replay events tend to occur in clusters with irregular temporal spacing as previously shown by our group and others.  Second, replay of experienced sequences is intermixed with replay of sequences that have never been experienced but are possible. Finally, and perhaps the most significant issue, replay is temporally compressed up to 20x with respect to the behavior [6]. That means our decoders would need to accurately evaluate spatial pattern changes related to individual keypresses over much smaller time windows (i.e. - less than 10 ms) than evaluated here. This future work, which is undoubtably of great interest to our research group, will require more substantial tool development before we can apply them to this question. We now articulate this future direction in the Discussion:

      Discussion (lines 423-427):

      “A possible neural mechanism supporting contextualization could be the emergence and stabilization of conjunctive “what–where” representations of procedural memories [64] with the corresponding modulation of neuronal population dynamics [65, 66] during early learning. Exploring the link between contextualization and neural replay could provide additional insights into this issue [6, 12, 13, 15].”

      (8) And this analysis could be confounded by the fact that they are comparing the last element in a sequence vs the first movement in a new one. 

      We have now addressed this control analysis in the revised manuscript:

      Results (Lines 310-316)

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches).”

      Discussion (lines 408-416):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1). This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A). On the other hand, online contextualization did not predict learning (Figure 5 – figure supplement 3). Consistent with these results the average within-subject correlation between offline contextualization and micro-offline gains was significantly stronger than within-subject correlations between online contextualization and either micro-online or micro-offline gains (Figure 5 – figure supplement 4).”

      It also seems to be the case that many analyses suggested by the reviewers in the first round of revisions that could have helped strengthen the manuscript have not been included (they are only in the rebuttal). Moreover, some of the control analyses mentioned in the rebuttal seem not to be described anywhere, neither in the manuscript, nor in the rebuttal itself; please double check that. 

      All suggested analyses carried out and mentioned are now in the revised manuscript.

      eLife Assessment 

      This valuable study investigates how the neural representation of individual finger movements changes during the early period of sequence learning. By combining a new method for extracting features from human magnetoencephalography data and decoding analyses, the authors provide incomplete evidence of an early, swift change in the brain regions correlated with sequence learning…

      We have now included all the requested control analyses supporting “an early, swift change in the brain regions correlated with sequence learning”:

      The addition of more control analyses to rule out that head movement artefacts influence the findings, 

      We now include data in Figure 3 – figure supplement 3D showing that head movement was minimal in all participants (mean of 1.159 mm ± 1.077 SD).  Further, we have implemented the requested additional control analyses addressing this issue:

      Results (lines 207-211):

      “An alternate decoder trained on ICA components labeled as movement or physiological artefacts (e.g. – head movement, ECG, eye movements and blinks; Figure 3 – figure supplement 3A, D) and removed from the original input feature set during the pre-processing stage approached chance-level performance (Figure 4 – figure supplement 3), indicating that the 4-class hybrid decoder results were not driven by task-related artefacts.”

      Results (lines 261-268):

      “As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C). Task-related eye movements did not explain these results since an alternate 5-class hybrid decoder constructed from three eye movement features (gaze position at the KeyDown event, gaze position 200ms later, and peak eye movement velocity within this window; Figure 4 – figure supplement 3A) performed at chance levels (cross-validated test accuracy = 0.2181; Figure 4 – figure supplement 3B, C). “

      Discussion (Lines 362-368):

      “Task-related movements—which also express in lower frequency ranges—did not explain these results given the near chance-level performance of alternative decoders trained on (a) artefact-related ICA components removed during MEG preprocessing (Figure 3 – figure supplement 3A-C) and on (b) task-related eye movement features (Figure 4 – figure supplement 3B, C). This explanation is also inconsistent with the minimal average head motion of 1.159 mm (± 1.077 SD) across the MEG recording (Figure 3 – figure supplement 3D).“

      and to further explain the proposal of offline contextualization during short rest periods as the basis for improvement performance would strengthen the manuscript. 

      We have edited the manuscript to clarify that the degree of representational differentiation (contextualization) parallels skill learning.  We have no evidence at this point to indicate that “offline contextualization during short rest periods is the basis for improvement in performance”.  The following areas of the revised manuscript now clarify this point:  

      Summary (Lines 455-458):

      “In summary, individual sequence action representations contextualize during early learning of a new skill and the degree of differentiation parallels skill gains. Differentiation of the neural representations developed during rest intervals of early learning to a larger extent than during practice in parallel with rapid consolidation of skill.”

      Additional control analyses are also provided supporting a link between offline contextualization and early learning:

      Results (lines 302-318):

      “The Euclidian distance between neural representations of Index<sub>OP1</sub> (i.e. - index finger keypress at ordinal position 1 of the sequence) and Index<sub>OP5</sub> (i.e. - index finger keypress at ordinal position 5 of the sequence) increased progressively during early learning (Figure 5A)—predominantly during rest intervals (offline contextualization) rather than during practice (online) (t = 4.84, p < 0.001, df = 25, Cohen's d = 1.2; Figure 5B; Figure 5 – figure supplement 1A). An alternative online contextualization determination equaling the time interval between online and offline comparisons (Trial-based; 10 seconds between Index<sub>OP1</sub> and Index<sub>OP5</sub> observations in both cases) rendered a similar result (Figure 5 – figure supplement 2B).

      Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches). Conversely, online contextualization (using either measurement approach) did not explain early online learning gains (i.e. – Figure 5 – figure supplement 3).”  

      Public Reviews: 

      Reviewer #1 (Public review): 

      Summary: 

      This study addresses the issue of rapid skill learning and whether individual sequence elements (here: finger presses) are differentially represented in human MEG data. The authors use a decoding approach to classify individual finger elements and accomplish an accuracy of around 94%. A relevant finding is that the neural representations of individual finger elements dynamically change over the course of learning. This would be highly relevant for any attempts to develop better brain machine interfaces - one now can decode individual elements within a sequence with high precision, but these representations are not static but develop over the course of learning. 

      Strengths: 

      The work follows a large body of work from the same group on the behavioural and neural foundations of sequence learning. The behavioural task is well established a neatly designed to allow for tracking learning and how individual sequence elements contribute. The inclusion of short offline rest periods between learning epochs has been influential because it has revealed that a lot, if not most of the gains in behaviour (ie speed of finger movements) occur in these so-called micro-offline rest periods. 

      The authors use a range of new decoding techniques, and exhaustively interrogate their data in different ways, using different decoding approaches. Regardless of the approach, impressively high decoding accuracies are observed, but when using a hybrid approach that combines the MEG data in different ways, the authors observe decoding accuracies of individual sequence elements from the MEG data of up to 94%. 

      Weaknesses:  

      A formal analysis and quantification of how head movement may have contributed to the results should be included in the paper or supplemental material. The type of correlated head movements coming from vigorous key presses aren't necessarily visible to the naked eye, and even if arms etc are restricted, this will not preclude shoulder, neck or head movement necessarily; if ICA was conducted, for example, the authors are in the position to show the components that relate to such movement; but eye-balling the data would not seem sufficient. The related issue of eye movements is addressed via classifier analysis. A formal analysis which directly accounts for finger/eye movements in the same analysis as the main result (ie any variance related to these factors) should be presented.

      We now present additional data related to head (Figure 3 – figure supplement 3; note that average measured head movement across participants was 1.159 mm ± 1.077 SD) and eye movements (Figure 4 – figure supplement 3) and have implemented the requested control analyses addressing this issue. They are reported in the revised manuscript in the following locations: Results (lines 207-211), Results (lines 261-268), Discussion (Lines 362-368).

      This reviewer recommends inclusion of a formal analysis that the intra-vs inter parcels are indeed completely independent. For example, the authors state that the inter-parcel features reflect "lower spatially resolved whole-brain activity patterns or global brain dynamics". A formal quantitative demonstration that the signals indeed show "complete independence" (as claimed by the authors) and are orthogonal would be helpful.

      Please note that we never claim in the manuscript that the parcel-space and regional voxelspace features show “complete independence”.  More importantly, input feature orthogonality is not a requirement for the machine learning-based decoding methods utilized in the present study while non-redundancy is [7] (a requirement satisfied by our data, see below). Finally, our results show that the hybrid space decoder out-performed all other methods even after input features were fully orthogonalized with LDA (the procedure used in all contextualization analyses) or PCA dimensionality reduction procedures prior to the classification step (Figure 3 – figure supplement 2).

      Relevant to this issue, please note that if spatially overlapping parcel- and voxel-space timeseries only provided redundant information, inclusion of both as input features should increase model over-fitting to the training dataset and decrease overall cross-validated test accuracy [8]. In the present study however, we see the opposite effect on decoder performance. First, Figure 3 – figure supplement 1 & 2 clearly show that decoders constructed from hybrid-space features outperform the other input feature (sensor-, wholebrain parcel- and whole-brain voxel-) spaces in every case (e.g. – wideband, all narrowband frequency ranges, and even after the input space is fully orthogonalized through dimensionality reduction procedures prior to the decoding step). Furthermore, Figure 3 – figure supplement 6 shows that hybrid-space decoder performance supers when parceltime series that spatially overlap with the included regional voxel-spaces are removed from the input feature set. 

      We state in the Discussion (lines 353-356)

      “The observation of increased cross-validated test accuracy (as shown in Figure 3 – Figure Supplement 6) indicates that the spatially overlapping information in parcel- and voxel-space time-series in the hybrid decoder was complementary, rather than redundant [41].”

      To gain insight into the complimentary information contributed by the two spatial scales to the hybrid-space decoder, we first independently computed the matrix rank for whole-brain parcel- and voxel-space input features for each participant (shown in Author response image 1). The results indicate that whole-brain parcel-space input features are full rank (rank = 148) for all participants (i.e. - MEG activity is orthogonal between all parcels). The matrix rank of voxelspace input features (rank = 267± 17 SD), exceeded the parcel-space rank for all participants and approached the number of useable MEG sensor channels (n = 272). Thus, voxel-space features provide both additional and complimentary information to representations at the parcel-space scale.  

      Author response image 1.

      Matrix rank computed for whole-brain parcel- and voxel-space time-series in individual subjects across the training run. The results indicate that whole-brain parcel-space input features are full rank (rank = 148) for all participants (i.e. - MEG activity is orthogonal between all parcels). The matrix rank of voxel-space input features (rank = 267 ± 17 SD), on the other hand, approached the number of useable MEG sensor channels (n = 272). Although not full rank, the voxel-space rank exceeded the parcel-space rank for all participants. Thus, some voxel-space features provide additional orthogonal information to representations at the parcel-space scale.  An expression of this is shown in the correlation distribution between parcel and constituent voxel time-series in Figure 2—figure Supplement 2.

      Figure 2—figure Supplement 2 in the revised manuscript now shows that the degree of dependence between the two spatial scales varies over the regional voxel-space. That is, some voxels within a given parcel correlate strongly with the time-series of the parcel they belong to, while others do not. This finding is consistent with a documented increase in correlational structure of neural activity across spatial scales that does not reflect perfect dependency or orthogonality [9]. Notably, the regional voxel-spaces included in the hybridspace decoder are significantly less correlated with the averaged parcel-space time-series than excluded voxels. We now point readers to this new figure in the results.

      Taken together, these results indicate that the multi-scale information in the hybrid feature set is complimentary rather than orthogonal.  This is consistent with the idea that hybridspace features better represent multi-scale temporospatial dynamics reported to be a fundamental characteristic of how the brain stores and adapts memories, and generates behavior across species [9].  

      Reviewer #2 (Public review): 

      Summary: 

      The current paper consists of two parts. The first part is the rigorous feature optimization of the MEG signal to decode individual finger identity performed in a sequence (4-1-3-2-4; 1~4 corresponds to little~index fingers of the left hand). By optimizing various parameters for the MEG signal, in terms of (i) reconstructed source activity in voxel- and parcel-level resolution and their combination, (ii) frequency bands, and (iii) time window relative to press onset for each finger movement, as well as the choice of decoders, the resultant "hybrid decoder" achieved extremely high decoding accuracy (~95%). This part seems driven almost by pure engineering interest in gaining as high decoding accuracy as possible. 

      In the second part of the paper, armed with the successful 'hybrid decoder,' the authors asked more scientific questions about how neural representation of individual finger movement that is embedded in a sequence, changes during a very early period of skill learning and whether and how such representational change can predict skill learning. They assessed the difference in MEG feature patterns between the first and the last press 4 in sequence 41324 at each training trial and found that the pattern differentiation progressively increased over the course of early learning trials. Additionally, they found that this pattern differentiation specifically occurred during the rest period rather than during the practice trial. With a significant correlation between the trial-by-trial profile of this pattern differentiation and that for accumulation of offline learning, the authors argue that such "contextualization" of finger movement in a sequence (e.g., what-where association) underlies the early improvement of sequential skill. This is an important and timely topic for the field of motor learning and beyond. 

      Strengths: 

      Each part has its own strength. For the first part, the use of temporally rich neural information (MEG signal) has a significant advantage over previous studies testing sequential representations using fMRI. This allowed the authors to examine the earliest period (= the first few minutes of training) of skill learning with finer temporal resolution. Through the optimization of MEG feature extraction, the current study achieved extremely high decoding accuracy (approx. 94%) compared to previous works. For the second part, the finding of the early "contextualization" of the finger movement in a sequence and its correlation to early (offline) skill improvement is interesting and important. The comparison between "online" and "offline" pattern distance is a neat idea. 

      Weaknesses: 

      Despite the strengths raised, the specific goal for each part of the current paper, i.e., achieving high decoding accuracy and answering the scientific question of early skill learning, seems not to harmonize with each other very well. In short, the current approach, which is solely optimized for achieving high decoding accuracy, does not provide enough support and interpretability for the paper's interesting scientific claim. This reminds me of the accuracy-explainability tradeoff in machine learning studies (e.g., Linardatos et al., 2020). More details follow. 

      There are a number of different neural processes occurring before and after a key press, such as planning of upcoming movement and ahead around premotor/parietal cortices, motor command generation in primary motor cortex, sensory feedback related processes in sensory cortices, and performance monitoring/evaluation around the prefrontal area. Some of these may show learning-dependent change and others may not.  

      In this paper, the focus as stated in the Introduction was to evaluate “the millisecond-level differentiation of discrete action representations during learning”, a proposal that first required the development of more accurate computational tools.  Our first step, reported here, was to develop that tool. With that in hand, we then proceeded to test if neural representations differentiated during early skill learning. Our results showed they did.  Addressing the question the Reviewer asks is part of exciting future work, now possible based on the results presented in this paper.  We acknowledge this issue in the revised Discussion:  

      Discussion (Lines 428-434):

      “In this study, classifiers were trained on MEG activity recorded during or immediately after each keypress, emphasizing neural representations related to action execution, memory consolidation and recall over those related to planning. An important direction for future research is determining whether separate decoders can be developed to distinguish the representations or networks separately supporting these processes. Ongoing work in our lab is addressing this question. The present accuracy results across varied decoding window durations and alignment with each keypress action support the feasibility of this approach (Figure 3—figure supplement 5).”

      Given the use of whole-brain MEG features with a wide time window (up to ~200 ms after each key press) under the situation of 3~4 Hz (i.e., 250~330 ms press interval) typing speed, these different processes in different brain regions could have contributed to the expression of the "contextualization," making it difficult to interpret what really contributed to the "contextualization" and whether it is learning related. Critically, the majority of data used for decoder training has the chance of such potential overlap of signal, as the typing speed almost reached a plateau already at the end of the 11th trial and stayed until the 36th trial. Thus, the decoder could have relied on such overlapping features related to the future presses. If that is the case, a gradual increase in "contextualization" (pattern separation) during earlier trials makes sense, simply because the temporal overlap of the MEG feature was insufficient for the earlier trials due to slower typing speed.  Several direct ways to address the above concern, at the cost of decoding accuracy to some degree, would be either using the shorter temporal window for the MEG feature or training the model with the early learning period data only (trials 1 through 11) to see if the main results are unaffected would be some example. 

      We now include additional analyses carried out with decoding time windows ranging from 50 to 250ms in duration, which have been added to the revised manuscript as follows: 

      Results (lines 258-261):

      “The improved decoding accuracy is supported by greater differentiation in neural representations of the index finger keypresses performed at positions 1 and 5 of the sequence (Figure 4A), and by the trial-by-trial increase in 2-class decoding accuracy over early learning (Figure 4C) across different decoder window durations (Figure 4 – figure supplement 2).”

      Results (lines 310-312):

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C).“

      Discussion (lines 382-385):

      “This was further supported by the progressive differentiation of neural representations of the index finger keypress (Figure 4A) and by the robust trial-by trial increase in 2-class decoding accuracy across time windows ranging between 50 and 250ms (Figure 4C; Figure 4 – figure supplement 2).”

      Discussion (lines 408-9):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1).”

      Several new control analyses are also provided addressing the question of overlapping keypresses:

      Reviewer #3 (Public review):

      Summary: 

      One goal of this paper is to introduce a new approach for highly accurate decoding of finger movements from human magnetoencephalography data via dimension reduction of a "multi-scale, hybrid" feature space. Following this decoding approach, the authors aim to show that early skill learning involves "contextualization" of the neural coding of individual movements, relative to their position in a sequence of consecutive movements.

      Furthermore, they aim to show that this "contextualization" develops primarily during short rest periods interspersed with skill training and correlates with a performance metric which the authors interpret as an indicator of offline learning. 

      Strengths: 

      A strength of the paper is the innovative decoding approach, which achieves impressive decoding accuracies via dimension reduction of a "multi-scale, hybrid space". This hybridspace approach follows the neurobiologically plausible idea of concurrent distribution of neural coding across local circuits as well as large-scale networks. A further strength of the study is the large number of tested dimension reduction techniques and classifiers. 

      Weaknesses: 

      A clear weakness of the paper lies in the authors' conclusions regarding "contextualization". Several potential confounds, which partly arise from the experimental design (mainly the use of a single sequence) and which are described below, question the neurobiological implications proposed by the authors and provide a simpler explanation of the results. Furthermore, the paper follows the assumption that short breaks result in offline skill learning, while recent evidence, described below, casts doubt on this assumption.  

      Please, see below for detailed response to each of these points.

      Specifically: The authors interpret the ordinal position information captured by their decoding approach as a reflection of neural coding dedicated to the local context of a movement (Figure 4). One way to dissociate ordinal position information from information about the moving effectors is to train a classifier on one sequence and test the classifier on other sequences that require the same movements, but in different positions (Kornysheva et al., Neuron 2019). In the present study, however, participants trained to repeat a single sequence (4-1-3-2-4).

      A crucial difference between our present study and the elegant study from Kornysheva et al. (2019) in Neuron highlighted by the Reviewer is that while ours is a learning study, the Kornysheva et al. study is not. Kornysheva et al. included an initial separate behavioral training session (i.e. – performed outside of the MEG) during which participants learned associations between fractal image patterns and different keypress sequences. Then in a separate, later MEG session—after the stimulus-response associations had been already learned in the first session—participants were tasked with recalling the learned sequences in response to a presented visual cue (i.e. – the paired fractal pattern). 

      Our rationale for not including multiple sequences in the same Day 1 training session of our study design was that it would lead to prominent interference effects, as widely reported in the literature [10-12].  Thus, while we had to take the issue of interference into consideration for our design, the Kornysheva et al. study did not. While Kornysheva et al. aimed to “dissociate ordinal position information from information about the moving effectors”, we tested various untrained sequences on Day 2 allowing us to determine that the contextualization result was specific to the trained sequence. By using this approach, we avoided interference effects on the learning of the primary skill caused by simultaneous acquisition of a second skill.

      The revised manuscript states our findings related to the Day 2 Control data in the following locations:

      Results (lines 117-122):

      “On the following day, participants were retested on performance of the same sequence (4-1-3-2-4) over 9 trials (Day 2 Retest), as well as on the single-trial performance of 9 different untrained control sequences (Day 2 Controls: 2-1-3-4-2, 4-2-4-3-1, 3-4-2-3-1, 1-4-3-4-2, 3-2-4-3-1, 1-4-2-3-1, 3-2-4-2-1, 3-2-1-4-2, and 4-23-1-4). As expected, an upward shift in performance of the trained sequence (0.68 ± SD 0.56 keypresses/s; t = 7.21, p < 0.001) was observed during Day 2 Retest, indicative of an overnight skill consolidation effect (Figure 1 – figure supplement 1A).”

      Results (lines 212-219):

      “Utilizing the highest performing decoders that included LDA-based manifold extraction, we assessed the robustness of hybrid-space decoding over multiple sessions by applying it to data collected on the following day during the Day 2 Retest (9-trial retest of the trained sequence) and Day 2 Control (single-trial performance of 9 different untrained sequences) blocks. The decoding accuracy for Day 2 MEG data remained high (87.11% ± SD 8.54% for the trained sequence during Retest, and 79.44% ± SD 5.54% for the untrained Control sequences; Figure 3 – figure supplement 4). Thus, index finger classifiers constructed using the hybrid decoding approach robustly generalized from Day 1 to Day 2 across trained and untrained keypress sequences.”

      Results (lines 269-273):

      “On Day 2, incorporating contextual information into the hybrid-space decoder enhanced classification accuracy for the trained sequence only (improving from 87.11% for 4-class to 90.22% for 5-class), while performing at or below-chance levels for the Control sequences (≤ 30.22% ± SD 0.44%). Thus, the accuracy improvements resulting from inclusion of contextual information in the decoding framework was specific for the trained skill sequence.”

      As a result, ordinal position information is potentially confounded by the fixed finger transitions around each of the two critical positions (first and fifth press). Across consecutive correct sequences, the first keypress in a given sequence was always preceded by a movement of the index finger (=last movement of the preceding sequence), and followed by a little finger movement. The last keypress, on the other hand, was always preceded by a ring finger movement, and followed by an index finger movement (=first movement of the next sequence). Figure 4 - supplement 2 shows that finger identity can be decoded with high accuracy (>70%) across a large time window around the time of the keypress, up to at least +/-100 ms (and likely beyond, given that decoding accuracy is still high at the boundaries of the window depicted in that figure). This time window approaches the keypress transition times in this study. Given that distinct finger transitions characterized the first and fifth keypress, the classifier could thus rely on persistent (or "lingering") information from the preceding finger movement, and/or "preparatory" information about the subsequent finger movement, in order to dissociate the first and fifth keypress. 

      Currently, the manuscript provides little evidence that the context information captured by the decoding approach is more than a by-product of temporally extended, and therefore overlapping, but independent neural representations of consecutive keypresses that are executed in close temporal proximity - rather than a neural representation dedicated to context. 

      During the review process, the authors pointed out that a "mixing" of temporally overlapping information from consecutive keypresses, as described above, should result in systematic misclassifications and therefore be detectable in the confusion matrices in Figures 3C and 4B, which indeed do not provide any evidence that consecutive keypresses are systematically confused. However, such absence of evidence (of systematic misclassification) should be interpreted with caution, and, of course, provides no evidence of absence. The authors also pointed out that such "mixing" would hamper the discriminability of the two ordinal positions of the index finger, given that "ordinal position 5" is systematically followed by "ordinal position 1". This is a valid point which, however, cannot rule out that "contextualization" nevertheless reflects the described "mixing".

      The revised manuscript contains several control analyses which rule out this potential confound.

      Results (lines 318-328):

      “Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or micro-offline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69). These findings were not explained by behavioral changes of typing rhythm (t = -0.03, p = 0.976; Figure 5 – figure supplement 5), adjacent keypress transition times (R<sup>2</sup> = 0.00507, F[1,3202] = 16.3; Figure 5 – figure supplement 6), or overall typing speed (between-subject; R<sup>2</sup> = 0.028, p \= 0.41; Figure 5 – figure supplement 7).”

      Results (lines 385-390):

      “Further, the 5-class classifier—which directly incorporated information about the sequence location context of each keypress into the decoding pipeline—improved decoding accuracy relative to the 4-class classifier (Figure 4C). Importantly, testing on Day 2 revealed specificity of this representational differentiation for the trained skill but not for the same keypresses performed during various unpracticed control sequences (Figure 5C).”

      Discussion (lines 408-423):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1). This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A). On the other hand, online contextualization did not predict learning (Figure 5 – figure supplement 3). Consistent with these results the average within-subject correlation between offline contextualization and micro-offline gains was significantly stronger than within subject correlations between online contextualization and either micro-online or micro-offline gains (Figure 5 – figure supplement 4). 

      Offline contextualization was not driven by trial-by-trial behavioral differences, including typing rhythm (Figure 5 – figure supplement 5) and adjacent keypress transition times (Figure 5 – figure supplement 6) nor by between-subject differences in overall typing speed (Figure 5 – figure supplement 7)—ruling out a reliance on differences in the temporal overlap of keypresses. Importantly, offline contextualization documented on Day 1 stabilized once a performance plateau was reached (trials 11-36), and was retained on Day 2, documenting overnight consolidation of the differentiated neural representations.”

      During the review process, the authors responded to my concern that training of a single sequence introduces the potential confound of "mixing" described above, which could have been avoided by training on several sequences, as in Kornysheva et al. (Neuron 2019), by arguing that Day 2 in their study did include control sequences. However, the authors' findings regarding these control sequences are fundamentally different from the findings in Kornysheva et al. (2019), and do not provide any indication of effector-independent ordinal information in the described contextualization - but, actually, the contrary. In Kornysheva et al. (Neuron 2019), ordinal, or positional, information refers purely to the rank of a movement in a sequence. In line with the idea of competitive queuing, Kornysheva et al. (2019) have shown that humans prepare for a motor sequence via a simultaneous representation of several of the upcoming movements, weighted by their rank in the sequence. Importantly, they could show that this gradient carries information that is largely devoid of information about the order of specific effectors involved in a sequence, or their timing, in line with competitive queuing. They showed this by training a classifier to discriminate between the five consecutive movements that constituted one specific sequence of finger movements (five classes: 1st, 2nd, 3rd, 4th, 5th movement in the sequence) and then testing whether that classifier could identify the rank (1st, 2nd, 3rd, etc) of movements in another sequence, in which the fingers moved in a different order, and with different timings. Importantly, this approach demonstrated that the graded representations observed during preparation were largely maintained after this cross decoding, indicating that the sequence was represented via ordinal position information that was largely devoid of information about the specific effectors or timings involved in sequence execution. This result differs completely from the findings in the current manuscript. Dash et al. report a drop in detected ordinal position information (degree of contextualization in figure 5C) when testing for contextualization in their novel, untrained sequences on Day 2, indicating that context and ordinal information as defined in Dash et al. is not at all devoid of information about the specific effectors involved in a sequence. In this regard, a main concern in my public review, as well as the second reviewer's public review, is that Dash et al. cannot tell apart, by design, whether there is truly contextualization in the neural representation of a sequence (which they claim), or whether their results regarding "contextualization" are explained by what they call "mixing" in their author response, i.e., an overlap of representations of consecutive movements, as suggested as an alternative explanation by Reviewer 2 and myself.

      Again, as stated in response to a related comment by the Reviewer above, it is not surprising that our results differ from the study by Kornysheva et al. (2019) . A crucial difference between the studies that the Reviewer fails to recognize is that while ours is a learning study, the Kornysheva et al. study is not. Our rationale for not including multiple sequences in the same Day 1 training session of our study design was that it would lead to prominent interference effects, as widely reported in the literature [10-12].  Thus, while we had to take the issue of interference into consideration for our design, the Kornysheva et al. study did not, since it was not concerned with learning dynamics. The strengths of the elegant Kornysheva study highlighted by the Reviewer—that the pre-planned sequence queuing gradient of sequence actions was independent of the effectors or timings used—is precisely due to the fact that participants were selecting between sequence options that had been previously—and equivalently—learned. The decoders in the Kornynsheva study were trained to classify effector- and timing-independent sequence position information— by design—so it is not surprising that this is the information they reflect.

      The questions asked in our study were different: 1) Do the neural representations of the same sequence action executed in different skill (ordinal sequence) locations differentiate (contextualize) during early learning?  and 2) Is the observed contextualization specific to the learned sequence? Thus, while Kornysheva et al. aimed to “dissociate ordinal position information from information about the moving effectors”, we tested various untrained sequences on Day 2 allowing us to determine that the contextualization result was specific to the trained sequence. By using this approach, we avoided interference effects on the learning of the primary skill caused by simultaneous acquisition of a second skill.

      Such temporal overlap of consecutive, independent finger representations may also account for the dynamics of "ordinal coding"/"contextualization", i.e., the increase in 2class decoding accuracy, across Day 1 (Figure 4C). As learning progresses, both tapping speed and the consistency of keypress transition times increase (Figure 1), i.e., consecutive keypresses are closer in time, and more consistently so. As a result, information related to a given keypress is increasingly overlapping in time with information related to the preceding and subsequent keypresses. The authors seem to argue that their regression analysis in Figure 5 - figure supplement 3 speaks against any influence of tapping speed on "ordinal coding" (even though that argument is not made explicitly in the manuscript). However, Figure 5 - figure supplement 3 shows inter-individual differences in a between-subject analysis (across trials, as in panel A, or separately for each trial, as in panel B), and, therefore, says little about the within-subject dynamics of "ordinal coding" across the experiment. A regression of trial-by-trial "ordinal coding" on trial-by-trial tapping speed (either within-subject, or at a group-level, after averaging across subjects) could address this issue. Given the highly similar dynamics of "ordinal coding" on the one hand (Figure 4C), and tapping speed on the other hand (Figure 1B), I would expect a strong relationship between the two in the suggested within-subject (or group-level) regression. 

      The aim of the between-subject regression analysis presented in the Results (see below) and in Figure 5—figure supplement 7 (previously Figure 5—figure supplement 3) of the revised manuscript, was to rule out a general effect of tapping speed on the magnitude of contextualization observed. If temporal overlap of neural representations was driving their differentiation, then participants typing at higher speeds should also show greater contextualization scores. We made the decision to use a between-subject analysis to address this issue since within-subject skill speed variance was rather small over most of the training session. 

      The Reviewer’s request that we additionally carry-out a “regression of trial-by-trial "ordinal coding" on trial-by-trial tapping speed (either within-subject, or at a group-level, after averaging across subjects)” is essentially the same request of Reviewer 2 above. That request was to perform a modified simple linear regression analysis where the predictor is the sum the 4-4 and 4-1 transition times, since these transitions are where any temporal overlaps of neural representations would occur.  A new Figure 5 – figure supplement 6 in the revised manuscript includes a scatter plot showing the sum of adjacent index finger keypress transition times (i.e. – the 4-4 transition at the conclusion of one sequence iteration and the 4-1 transition at the beginning of the next sequence iteration) versus online contextualization distances measured during practice trials. Both the keypress transition times and online contextualization scores were z-score normalized within individual subjects, and then concatenated into a single data superset. As is clear in the figure data, results of the regression analysis showed a very weak linear relationship between the two (R<sup>2</sup> = 0.00507, F[1,3202] = 16.3). Thus, contextualization score magnitudes do not reflect the amount of overlap between adjacent keypresses when assessed either within- or between-subject.

      The revised manuscript now states:

      Results (lines 318-328):

      “Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or micro-offline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69). These findings were not explained by behavioral changes of typing rhythm (t = -0.03, p = 0.976; Figure 5 – figure supplement 5), adjacent keypress transition times (R<sup>2</sup> = 0.00507, F[1,3202] = 16.3; Figure 5 – figure supplement 6), or overall typing speed (between-subject; R<sup>2</sup> = 0.028, p \= 0.41; Figure 5 – figure supplement 7).”

      Furthermore, learning should increase the number of (consecutively) correct sequences, and, thus, the consistency of finger transitions. Therefore, the increase in 2-class decoding accuracy may simply reflect an increasing overlap in time of increasingly consistent information from consecutive keypresses, which allows the classifier to dissociate the first and fifth keypress more reliably as learning progresses, simply based on the characteristic finger transitions associated with each. In other words, given that the physical context of a given keypress changes as learning progresses - keypresses move closer together in time and are more consistently correct - it seems problematic to conclude that the mental representation of that context changes. To draw that conclusion, the physical context should remain stable (or any changes to the physical context should be controlled for). 

      The revised manuscript now addresses specifically the question of mixing of temporally overlapping information:

      Results (Lines 310-328)

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches). Conversely, online contextualization (using either measurement approach) did not explain early online learning gains (i.e. – Figure 5 – figure supplement 3). Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or micro-offline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69). These findings were not explained by behavioral changes of typing rhythm (t = -0.03, p = 0.976; Figure 5 – figure supplement 5), adjacent keypress transition times (R<sup>2</sup> = 0.00507, F[1,3202] = 16.3; Figure 5 – figure supplement 6), or overall typing speed (between-subject; R<sup>2</sup> = 0.028, p \= 0.41; Figure 5 – figure supplement 7). “

      Discussion (Lines 417-423)

      “Offline contextualization was not driven by trial-by-trial behavioral differences, including typing rhythm (Figure 5 – figure supplement 5) and adjacent keypress transition times (Figure 5 – figure supplement 6) nor by between-subject differences in overall typing speed (Figure 5 – figure supplement 7)—ruling out a reliance on differences in the temporal overlap of keypresses. Importantly, offline contextualization documented on Day 1 stabilized once a performance plateau was reached (trials 11-36), and was retained on Day 2, documenting overnight consolidation of the differentiated neural representations.”

      A similar difference in physical context may explain why neural representation distances ("differentiation") differ between rest and practice (Figure 5). The authors define "offline differentiation" by comparing the hybrid space features of the last index finger movement of a trial (ordinal position 5) and the first index finger movement of the next trial (ordinal position 1). However, the latter is not only the first movement in the sequence but also the very first movement in that trial (at least in trials that started with a correct sequence), i.e., not preceded by any recent movement. In contrast, the last index finger of the last correct sequence in the preceding trial includes the characteristic finger transition from the fourth to the fifth movement. Thus, there is more overlapping information arising from the consistent, neighbouring keypresses for the last index finger movement, compared to the first index finger movement of the next trial. A strong difference (larger neural representation distance) between these two movements is, therefore, not surprising, given the task design, and this difference is also expected to increase with learning, given the increase in tapping speed, and the consequent stronger overlap in representations for consecutive keypresses. Furthermore, initiating a new sequence involves pre-planning, while ongoing practice relies on online planning (Ariani et al., eNeuro 2021), i.e., two mental operations that are dissociable at the level of neural representation (Ariani et al., bioRxiv 2023).  

      The revised manuscript now addresses specifically the question of pre-planning:

      Results (lines 310-318):

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches). Conversely, online contextualization (using either measurement approach) did not explain early online learning gains (i.e. – Figure 5 – figure supplement 3).”

      Discussion (lines 408-416):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1). This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A). On the other hand, online contextualization did not predict learning (Figure 5 – figure supplement 3). Consistent with these results the average within-subject correlation between offline contextualization and micro-offline gains was significantly stronger than within-subject correlations between online contextualization and either micro-online or micro-offline gains (Figure 5 – figure supplement 4).”

      A further complication in interpreting the results stems from the visual feedback that participants received during the task. Each keypress generated an asterisk shown above the string on the screen. It is not clear why the authors introduced this complicating visual feedback in their task, besides consistency with their previous studies. The resulting systematic link between the pattern of visual stimulation (the number of asterisks on the screen) and the ordinal position of a keypress makes the interpretation of "contextual information" that differentiates between ordinal positions difficult. During the review process, the authors reported a confusion matrix from a classification of asterisks position based on eye tracking data recorded during the task and concluded that the classifier performed at chance level and gaze was, thus, apparently not biased by the visual stimulation. However, the confusion matrix showed a huge bias that was difficult to interpret (a very strong tendency to predict one of the five asterisk positions, despite chance-level performance). Without including additional information for this analysis (or simply the gaze position as a function of the number of astersisk on the screen) in the manuscript, this important control analysis cannot be properly assessed, and is not available to the public.  

      We now include the gaze position data requested by the Reviewer alongside the confusion matrix results in Figure 4 – figure supplement 3.

      Results (lines 207-211):

      “An alternate decoder trained on ICA components labeled as movement or physiological artefacts (e.g. – head movement, ECG, eye movements and blinks; Figure 3 – figure supplement 3A, D) and removed from the original input feature set during the pre-processing stage approached chance-level performance (Figure 4 – figure supplement 3), indicating that the 4-class hybrid decoder results were not driven by task-related artefacts.” Results (lines 261-268):

      “As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C). Task-related eye movements did not explain these results since an alternate 5-class hybrid decoder constructed from three eye movement features (gaze position at the KeyDown event, gaze position 200ms later, and peak eye movement velocity within this window; Figure 4 – figure supplement 3A) performed at chance levels (cross-validated test accuracy = 0.2181; Figure 4 – figure supplement 3B, C). “

      Discussion (Lines 362-368):

      “Task-related movements—which also express in lower frequency ranges—did not explain these results given the near chance-level performance of alternative decoders trained on (a) artefact-related ICA components removed during MEG preprocessing (Figure 3 – figure supplement 3A-C) and on (b) task-related eye movement features (Figure 4 – figure supplement 3B, C). This explanation is also inconsistent with the minimal average head motion of 1.159 mm (± 1.077 SD) across the MEG recording (Figure 3 – figure supplement 3D).”

      The rationale for the task design including the asterisks is presented below:

      Methods (Lines 500-514)

      “The five-item sequence was displayed on the computer screen for the duration of each practice round and participants were directed to fix their gaze on the sequence. Small asterisks were displayed above a sequence item after each successive keypress, signaling the participants' present position within the sequence. Inclusion of this feedback minimizes working memory loads during task performance [73]. Following the completion of a full sequence iteration, the asterisk returned to the first sequence item. The asterisk did not provide error feedback as it appeared for both correct and incorrect keypresses. At the end of each practice round, the displayed number sequence was replaced by a string of five "X" symbols displayed on the computer screen, which remained for the duration of the rest break. Participants were instructed to focus their gaze on the screen during this time. The behavior in this explicit, motor learning task consists of generative action sequences rather than sequences of stimulus-induced responses as in the serial reaction time task (SRTT). A similar real-world example would be manually inputting a long password into a secure online application in which one intrinsically generates the sequence from memory and receives similar feedback about the password sequence position (also provided as asterisks), which is typically ignored by the user.”

      The authors report a significant correlation between "offline differentiation" and cumulative micro-offline gains. However, this does not address the question whether there is a trial-by-trial relation between the degree of "contextualization" and the amount of micro-offline gains - i.e., the question whether performance changes (micro-offline gains) are less pronounced across rest periods for which the change in "contextualization" is relatively low. The single-subject correlation between contextualization changes "during" rest and micro-offline gains (Figure 5 - figure supplement 4) addresses this question, however, the critical statistical test (are correlation coefficients significantly different from zero) is not included. Given the displayed distribution, it seems unlikely that correlation coefficients are significantly above zero. 

      As recommend by the Reviewer, we now include one-way right-tailed t-test results which provide further support to the previously reported finding. The mean of within-subject correlations between offline contextualization and cumulative micro-offline gains was significantly greater than zero (t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76; see Figure 5 – figure supplement 4, left), while correlations for online contextualization versus cumulative micro-online (t = -1.14, p = 0.8669, df = 25, Cohen's d = -0.22) or micro-offline gains t = -0.097, p = 0.5384, df = 25, Cohen's d = -0.019) were not. We have incorporated the significant one-way t-test for offline contextualization and cumulative micro-offline gains in the Results section of the revised manuscript (lines 313-318) and the Figure 5 – figure supplement 4 legend.

      The authors follow the assumption that micro-offline gains reflect offline learning.

      However, there is no compelling evidence in the literature, and no evidence in the present manuscript, that micro-offline gains (during any training phase) reflect offline learning. Instead, emerging evidence in the literature indicates that they do not (Das et al., bioRxiv 2024), and instead reflect transient performance benefits when participants train with breaks, compared to participants who train without breaks, however, these benefits vanish within seconds after training if both groups of participants perform under comparable conditions (Das et al., bioRxiv 2024). During the review process, the authors argued that differences in the design between Das et al. (2024) on the one hand (Experiments 1 and 2), and the study by Bönstrup et al. (2019) on the other hand, may have prevented Das et al. (2024) from finding the assumed (lasting) learning benefit by micro-offline consolidation. However, the Supplementary Material of Das et al. (2024) includes an experiment (Experiment S1) whose design closely follows the early learning phase of Bönstrup et al. (2019), and which, nevertheless, demonstrates that there is no lasting benefit of taking breaks for the acquired skill level, despite the presence of micro-offline gains. 

      We thank the Reviewer for alerting us to this new data added to the revised supplementary materials of Das et al. (2024) posted to bioRxiv. However, despite the Reviewer’s claim to the contrary, a careful comparison between the Das et al and Bönstrup et al studies reveal more substantive differences than similarities and does not “closely follows a large proportion of the early learning phase of Bönstrup et al. (2019)” as stated. 

      In the Das et al. Experiment S1, sixty-two participants were randomly assigned to “with breaks” or “no breaks” skill training groups. The “with breaks” group alternated 10 seconds of skill sequence practice with 10 seconds of rest over seven trials (2 min and 2 sec total training duration). This amounts to 66.7% of the early learning period defined by Bönstrup et al. (2019) (i.e. - eleven 10-second-long practice periods interleaved with ten 10-second-long rest breaks; 3 min 30 sec total training duration).  

      Also, please note that while no performance feedback nor reward was given in the Bönstrup et al. (2019) study, participants in the Das et al. study received explicit performance-based monetary rewards, a potentially crucial driver of differentiated behavior between the two studies:

      “Participants were incentivized with bonus money based on the total number of correct sequences completed throughout the experiment.”

      The “no breaks” group in the Das et al. study practiced the skill sequence for 70 continuous seconds. Both groups (despite one being labeled “no breaks”) follow training with a long 3-minute break (also note that since the “with breaks” group ends with 10 seconds of rest their break is actually longer), before finishing with a skill “test” over a continuous 50-second-long block. During the 70 seconds of training, the “with breaks” group shows more learning than the “no breaks” group. Interestingly, following the long 3minute break the “with breaks” group display a performance drop (relative to their performance at the end of training) that is stable over the full 50-second test, while the “no breaks” group shows an immediate performance improvement following the long break that continues to increase over the 50-second test.  

      Separately, there are important issues regarding the Das et al. study that should be considered through the lens of recent findings not referred to in the preprint. A major element of their experimental design is that both groups—“with breaks” and “no breaks”— actually receive quite a long 3-minute break just before the skill test. This long break is more than 2.5x the cumulative interleaved rest experienced by the “with breaks” group. Thus, although the design is intended to contrast the presence or absence of rest “breaks”, that difference between groups is no longer maintained at the point of the skill test. 

      The Das et al. results are most consistent with an alternative interpretation of the data— that the “no breaks” group experiences offline learning during their long 3-minute break. This is supported by the recent work of Griffin et al. (2025) where micro-array recordings from primary and premotor cortex were obtained from macaque monkeys while they performed blocks of ten continuous reaching sequences up to 81.4 seconds in duration (see source data for Extended Data Figure 1h) with 90 seconds of interleaved rest. Griffin et al. observed offline improvement in skill immediately following the rest break that was causally related to neural reactivations (i.e. – neural replay) that occurred during the rest break. Importantly, the highest density of reactivations was present in the very first 90second break between Blocks 1 and 2 (see Fig. 2f in Griffin et al., 2025). This supports the interpretation that both the “with breaks” and “no breaks” group express offline learning gains, with these gains being delayed in the “no breaks” group due to the practice schedule.

      On the other hand, if offline learning can occur during this longer break, then why would the “with breaks” group show no benefit? Again, it could be that most of the offline gains for this group were front-loaded during the seven shorter 10-second rest breaks. Another possible, though not mutually exclusive, explanation is that the observed drop in performance in the “with breaks” group is driven by contextual interference. Specifically, similar to Experiments 1 and 2 in Das et al. (2024), the skill test is conducted under very different conditions than those which the “with breaks” group practiced the skill under (short bursts of practiced alternating with equally short breaks). On the other hand, the “no breaks” group is tested (50 seconds of continuous practice) under quite similar conditions to their training schedule (70 seconds of continuous practice). Thus, it is possible that this dissimilarity between training and test could lead to reduced performance in the “with breaks” group.

      We made the following manuscript revisions related to these important issues: 

      Introduction (Lines 26-56)

      “Practicing a new motor skill elicits rapid performance improvements (early learning) [1] that precede skill performance plateaus [5]. Skill gains during early learning accumulate over rest periods (micro-offline) interspersed with practice [1, 6-10], and are up to four times larger than offline performance improvements reported following overnight sleep [1]. During this initial interval of prominent learning, retroactive interference immediately following each practice interval reduces learning rates relative to interference after passage of time, consistent with stabilization of the motor memory [11]. Micro-offline gains observed during early learning are reproducible [7, 10-13] and are similar in magnitude even when practice periods are reduced by half to 5 seconds in length, thereby confirming that they are not merely a result of recovery from performance fatigue [11]. Additionally, they are unaffected by the random termination of practice periods, which eliminates the possibility of predictive motor slowing as a contributing factor [11]. Collectively, these behavioral findings point towards the interpretation that micro offline gains during early learning represent a form of memory consolidation [1]. 

      This interpretation has been further supported by brain imaging and electrophysiological studies linking known memory-related networks and consolidation mechanisms to rapid offline performance improvements. In humans, the rate of hippocampo-neocortical neural replay predicts micro-offline gains [6]. Consistent with these findings, Chen et al. [12] and Sjøgård et al. [13] furnished direct evidence from intracranial human EEG studies, demonstrating a connection between the density of hippocampal sharp-wave ripples (80-120 Hz)—recognized markers of neural replay—and micro-offline gains during early learning. Further, Griffin et al. reported that neural replay of task-related ensembles in the motor cortex of macaques during brief rest periods— akin to those observed in humans [1, 6-8, 14]—are not merely correlated with, but are causal drivers of micro-offline learning [15]. Specifically, the same reach directions that were replayed the most during rest breaks showed the greatest reduction in path length (i.e. – more efficient movement path between two locations in the reach sequence) during subsequent trials, while stimulation applied during rest intervals preceding performance plateau reduced reactivation rates and virtually abolished micro-offline gains [15]. Thus, converging evidence in humans and non-human primates across indirect non-invasive and direct invasive recording techniques link hippocampal activity, neural replay dynamics and offline skill gains in early motor learning that precede performance plateau.”

      Next, in the Methods, we articulate important constrains formulated by Pan and Rickard and Bonstrup et al for meaningful measurements:

      Methods (Lines 493-499)

      “The study design followed specific recommendations by Pan and Rickard (2015): 1) utilizing 10-second practice trials and 2) constraining analysis of micro-offline gains to early learning trials (where performance monotonically increases and 95% of overall performance gains occur) that precede the emergence of “scalloped” performance dynamics strongly linked to reactive inhibition effects ( [29, 72]). This is precisely the portion of the learning curve Pan and Rickard referred to when they stated “…rapid learning during that period masks any reactive inhibition effect” [29].”

      We finally discuss the implications of neglecting some or all of these recommendations:

      Discussion (Lines 444-452):

      “Finally, caution should be exercised when extrapolating findings during early skill learning, a period of steep performance improvements, to findings reported after insufficient practice [67], post-plateau performance periods [68], or non-learning situations (e.g. performance of non-repeating keypress sequences in  [67]) when reactive inhibition or contextual interference effects are prominent. Ultimately, it will be important to develop new paradigms allowing one to independently estimate the different coincident or antagonistic features (e.g. - memory consolidation, planning, working memory and reactive inhibition) contributing to micro-online and micro-offline gains during and after early skill learning within a unifying framework.”

      Along these lines, the authors' claim, based on Bönstrup et al. 2020, that "retroactive interference immediately following practice periods reduces micro-offline learning", is not supported by that very reference. Citing Bönstrup et al. (2020), "Regarding early learning dynamics (trials 1-5), we found no differences in microscale learning parameters (micro online/offline) or total early learning between both interference groups." That is, contrary to Dash et al.'s current claim, Bönstrup et al. (2020) did not find any retroactive interference effect on the specific behavioral readout (micro-offline gains) that the authors assume to reflect consolidation. 

      Please, note that the Bönstrup et al. 2020 paper abstract states: 

      “Third, retroactive interference immediately after each practice period reduced the learning rate relative to interference after passage of time (N = 373), indicating stabilization of the motor memory at a microscale of several seconds.”

      which is further supported by this statement in the Results: 

      “The model comprised three parameters representing the initial performance, maximum performance and learning rate (see Eq. 1, “Methods”, “Data Analysis” section). We then statistically compared the model parameters between the interference groups (Fig. 2d). The late interference group showed a higher learning rate compared with the early interference group (late: 0.26 ± 0.23, early: 2.15 ± 0.20, P=0.04). The effect size of the group difference was small to medium (Cohen’s d 0.15)[29]. Similar differences with a stronger rise in the learning curve of a late interference groups vs. an early interference group were found in a smaller sample collected in the lab environment (Supplementary Fig. 3).”

      We have modified the statement in the revised manuscript to specify that the difference observed was between learning rates: Introduction (Lines 30-32)

      “During this initial interval of prominent learning, retroactive interference immediately following each practice interval reduces learning rates relative to interference after passage of time, consistent with stabilization of the motor memory [11].”

      The authors conclude that performance improves, and representation manifolds differentiate, "during" rest periods (see, e.g., abstract). However, micro-offline gains (as well as offline contextualization) are computed from data obtained during practice, not rest, and may, thus, just as well reflect a change that occurs "online", e.g., at the very onset of practice (like pre-planning) or throughout practice (like fatigue, or reactive inhibition).  

      The Reviewer raises again the issue of a potential confound of “pre-planning” on our contextualization measures as in the comment above: 

      “Furthermore, initiating a new sequence involves pre-planning, while ongoing practice relies on online planning (Ariani et al., eNeuro 2021), i.e., two mental operations that are dissociable at the level of neural representation (Ariani et al., bioRxiv 2023).”

      The cited studies by Ariani et al. indicate that effects of pre-planning are likely to impact the first 3 keypresses of the initial sequence iteration in each trial. As stated in the response to this comment above, we conducted a control analysis of contextualization that ignores the first sequence iteration in each trial to partial out any potential preplanning effect. This control analyses yielded comparable results, indicating that preplanning is not a major driver of our reported contextualization effects. We now report this in the revised manuscript:

      We also state in the Figure 1 legend (Lines 99-103) in the revised manuscript that preplanning has no effect on the behavioral measures of micro-offline and micro-online gains in our dataset:

      The Reviewer also raises the issue of possible effects stemming from “fatigue” and “reactive inhibition” which inhibit performance and are indeed relevant to skill learning studies. We designed our task to specifically mitigate these effects. We now more clearly articulate this rationale in the description of the task design as well as the measurement constraints essential for minimizing their impact.

      We also discuss the implications of fatigue and reactive inhibition effects in experimental designs that neglect to follow these recommendations formulated by Pan and Rickard in the Discussion section and propose how this issue can be better addressed in future investigations.

      To summarize, the results of our study indicate that: (a) offline contextualization effects are not explained by pre-planning of the first action sequence iteration in each practice trial; and (b) the task design implemented in this study purposefully minimize any possible effects of reactive inhibition or fatigue.  Circling back to the Reviewer’s proposal that “contextualization…may just as well reflect a change that occurs "online"”, we show in this paper direct empirical evidence that contextualization develops to a greater extent across rest periods rather than across practice trials, contrary to the Reviewer’s proposal.  

      That is, the definition of micro-offline gains (as well as offline contextualization) conflates online and "offline" processes. This becomes strikingly clear in the recent Nature paper by Griffin et al. (2025), who computed micro-offline gains as the difference in average performance across the first five sequences in a practice period (a block, in their terminology) and the last five sequences in the previous practice period. Averaging across sequences in this way minimises the chance to detect online performance changes and inflates changes in performance "offline". The problem that "online" gains (or contextualization) is actually computed from data entirely generated online, and therefore subject to processes that occur online, is inherent in the very definition of micro-online gains, whether, or not, they computed from averaged performance.

      We would like to make it clear that the issue raised by the Reviewer with respect to averaging across sequences done in the Griffin et al. (2025) study does not impact our study in any way. The primary skill measure used in all analyses reported in our paper is not temporally averaged. We estimated instantaneous correct sequence speed over the entire trial. Once the first sequence iteration within a trial is completed, the speed estimate is then updated at the resolution of individual keypresses. All micro-online and -offline behavioral changes are measured as the difference in instantaneous speed at the beginning and end of individual practice trials.

      Methods (lines 528-530):

      “The instantaneous correct sequence speed was calculated as the inverse of the average KTT across a single correct sequence iteration and was updated for each correct keypress.”

      The instantaneous speed measure used in our analyses, in fact, maximizes the likelihood of detecting changes in online performance, as the Reviewer indicates.  Despite this optimally sensitive measurement of online changes, our findings remained robust, consistently converging on the same outcome across our original analyses and the multiple controls recommended by the reviewers. Notably, online contextualization changes are significantly weaker than offline contextualization in all comparisons with different measurement approaches.

      Results (lines 302-309)

      “The Euclidian distance between neural representations of Index<sub>OP1</sub> (i.e. - index finger keypress at ordinal position 1 of the sequence) and Index<sub>OP5</sub> (i.e. - index finger keypress at ordinal position 5 of the sequence) increased progressively during early learning (Figure 5A)—predominantly during rest intervals (offline contextualization) rather than during practice (online) (t = 4.84, p < 0.001, df = 25, Cohen's d = 1.2; Figure 5B; Figure 5 – figure supplement 1A). An alternative online contextualization determination equalling the time interval between online and offline comparisons (Trial-based; 10 seconds between Index<sub>OP1</sub> and Index<sub>OP5</sub> observations in both cases) rendered a similar result (Figure 5 – figure supplement 2B).

      Results (lines 316-318)

      “Conversely, online contextualization (using either measurement approach) did not explain early online learning gains (i.e. – Figure 5 – figure supplement 3).”

      Results (lines 318-328)

      “Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or microoffline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69). These findings were not explained by behavioral changes of typing rhythm (t = -0.03, p = 0.976; Figure 5 – figure supplement 5), adjacent keypress transition times (R<sup>2</sup> = 0.00507, F[1,3202] = 16.3; Figure 5 – figure supplement 6), or overall typing speed (between-subject; R<sup>2</sup> = 0.028, p \= 0.41; Figure 5 – figure supplement 7).”

      We disagree with the Reviewer’s statement that “the definition of micro-offline gains (as well as offline contextualization) conflates online and "offline" processes”.  From a strictly behavioral point of view, it is obviously true that one can only measure skill (rather than the absence of it during rest) to determine how it changes over time.  While skill changes surrounding rest are used to infer offline learning processes, recovery of skill decay following intense practice is used to infer “unmeasurable” recovery from fatigue or reactive inhibition. In other words, the alternative processes proposed by the Reviewer also rely on the same inferential reasoning. 

      Importantly, inferences can be validated through the identification of mechanisms. Our experiment constrained the study to evaluation of changes in neural representations of the same action in different contexts, while minimized the impact of mechanisms related to fatigue/reactive inhibition [13, 14]. In this way, we observed that behavioral gains and neural contextualization occurs to a greater extent over rest breaks rather than during practice trials and that offline contextualization changes strongly correlate with the offline behavioral gains, while online contextualization does not. This result was supported by the results of all control analyses recommended by the Reviewers. Specifically:

      Methods (Lines 493-499)

      “The study design followed specific recommendations by Pan and Rickard (2015): 1) utilizing 10-second practice trials and 2) constraining analysis of micro-offline gains to early learning trials (where performance monotonically increases and 95% of overall performance gains occur) that precede the emergence of “scalloped” performance dynamics strongly linked to reactive inhibition effects ( [29, 72]). This is precisely the portion of the learning curve Pan and Rickard referred to when they stated “…rapid learning during that period masks any reactive inhibition effect” [29].”

      And Discussion (Lines 444-448):

      “Finally, caution should be exercised when extrapolating findings during early skill learning, a period of steep performance improvements, to findings reported after insufficient practice [67], post-plateau performance periods [68], or non-learning situations (e.g. performance of non-repeating keypress sequences in  [67]) when reactive inhibition or contextual interference effects are prominent.”

      Next, we show that offline contextualization is greater than online contextualization and predicts offline behavioral gains across all measurement approaches, including all controls suggested by the Reviewer’s comments and recommendations. 

      Results (lines 302-318):

      “The Euclidian distance between neural representations of Index<sub>OP1</sub> (i.e. - index finger keypress at ordinal position 1 of the sequence) and Index<sub>OP5</sub> (i.e. - index finger keypress at ordinal position 5 of the sequence) increased progressively during early learning (Figure 5A)—predominantly during rest intervals (offline contextualization) rather than during practice (online) (t = 4.84, p < 0.001, df = 25, Cohen's d = 1.2; Figure 5B; Figure 5 – figure supplement 1A). An alternative online contextualization determination equalling the time interval between online and offline comparisons (Trial-based; 10 seconds between Index<sub>OP1</sub> and Index<sub>OP5</sub> observations in both cases) rendered a similar result (Figure 5 – figure supplement 2B).

      Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches). Conversely, online contextualization (using either measurement approach) did not explain early online learning gains (i.e. – Figure 5 – figure supplement 3).”

      Results (lines 318-324)

      “Within-subject correlations were consistent with these group-level findings. The average correlation between offline contextualization and micro-offline gains within individuals was significantly greater than zero (Figure 5 – figure supplement 4, left; t = 3.87, p = 0.00035, df = 25, Cohen's d = 0.76) and stronger than correlations between online contextualization and either micro-online (Figure 5 – figure supplement 4, middle; t = 3.28, p = 0.0015, df = 25, Cohen's d = 1.2) or microoffline gains (Figure 5 – figure supplement 4, right; t = 3.7021, p = 5.3013e-04, df = 25, Cohen's d = 0.69).”

      Discussion (lines 408-416):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1). This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A). On the other hand, online contextualization did not predict learning (Figure 5 – figure supplement 3). Consistent with these results the average within-subject correlation between offline contextualization and micro-offline gains was significantly stronger than within subject correlations between online contextualization and either micro-online or micro-offline gains (Figure 5 – figure supplement 4).”

      We then show that offline contextualization is not explained by pre-planning of the first action sequence:

      Results (lines 310-316):

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R<sup>2</sup> = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches).”

      Discussion (lines 409-412):

      “This result remained unchanged when measuring offline contextualization between the last and second sequence of consecutive trials, inconsistent with a possible confounding effect of pre-planning [30] (Figure 5 – figure supplement 2A).”

      In summary, none of the presented evidence in this paper—including results of the multiple control analyses carried out in response to the Reviewers’ recommendations— supports the Reviewer’s position. 

      Please note that the micro-offline learning "inference" has extensive mechanistic support across species and neural recording techniques (see Introduction, lines 26-56). In contrast, the reactive inhibition "inference," which is the Reviewer's alternative interpretation, has no such support yet [15].

      Introduction (Lines 26-56)

      “Practicing a new motor skill elicits rapid performance improvements (early learning) [1] that precede skill performance plateaus [5]. Skill gains during early learning accumulate over rest periods (micro-offline) interspersed with practice [1, 6-10], and are up to four times larger than offline performance improvements reported following overnight sleep [1]. During this initial interval of prominent learning, retroactive interference immediately following each practice interval reduces learning rates relative to interference after passage of time, consistent with stabilization of the motor memory [11]. Micro-offline gains observed during early learning are reproducible [7, 10-13] and are similar in magnitude even when practice periods are reduced by half to 5 seconds in length, thereby confirming that they are not merely a result of recovery from performance fatigue [11]. Additionally, they are unaffected by the random termination of practice periods, which eliminates the possibility of predictive motor slowing as a contributing factor [11]. Collectively, these behavioral findings point towards the interpretation that microoffline gains during early learning represent a form of memory consolidation [1]. 

      This interpretation has been further supported by brain imaging and electrophysiological studies linking known memory-related networks and consolidation mechanisms to rapid offline performance improvements. In humans, the rate of hippocampo-neocortical neural replay predicts micro-offline gains [6].

      Consistent with these findings, Chen et al. [12] and Sjøgård et al. [13] furnished direct evidence from intracranial human EEG studies, demonstrating a connection between the density of hippocampal sharp-wave ripples (80-120 Hz)—recognized markers of neural replay—and micro-offline gains during early learning. Further, Griffin et al. reported that neural replay of task-related ensembles in the motor cortex of macaques during brief rest periods— akin to those observed in humans [1, 6-8, 14]—are not merely correlated with, but are causal drivers of micro-offline learning [15]. Specifically, the same reach directions that were replayed the most during rest breaks showed the greatest reduction in path length (i.e. – more efficient movement path between two locations in the reach sequence) during subsequent trials, while stimulation applied during rest intervals preceding performance plateau reduced reactivation rates and virtually abolished micro-offline gains [15]. Thus, converging evidence in humans and non-human primates across indirect non-invasive and direct invasive recording techniques link hippocampal activity, neural replay dynamics and offline skill gains in early motor learning that precede performance plateau.”

      That said, absence of evidence, is not evidence of absence and for that reason we also state in the Discussion (lines 448-452):

      A simple control analysis based on shuffled class labels could lend further support to the authors' complex decoding approach. As a control analysis that completely rules out any source of overfitting, the authors could test the decoder after shuffling class labels. Following such shuffling, decoding accuracies should drop to chance-level for all decoding approaches, including the optimized decoder. This would also provide an estimate of actual chance-level performance (which is informative over and beyond the theoretical chance level). During the review process, the authors reported this analysis to the reviewers. Given that readers may consider following the presented decoding approach in their own work, it would have been important to include that control analysis in the manuscript to convince readers of its validity. 

      As requested, the label-shuffling analysis was carried out for both 4- and 5-class decoders and is now reported in the revised manuscript.

      Results (lines 204-207):

      “Testing the keypress state (4-class) hybrid decoder performance on Day 1 after randomly shuffling keypress labels for held-out test data resulted in a performance drop approaching expected chance levels (22.12%± SD 9.1%; Figure 3 – figure supplement 3C).”

      Results (lines 261-264):

      “As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C).”

      Furthermore, the authors' approach to cortical parcellation raises questions regarding the information carried by varying dipole orientations within a parcel (which currently seems to be ignored?) and the implementation of the mean-flipping method (given that there are two dimensions - space and time - it is unclear what the authors refer to when they talk about the sign of the "average source", line 477). 

      The revised manuscript now provides a more detailed explanation of the parcellation, and sign-flipping procedures implemented:

      Methods (lines 604-611):

      “Source-space parcellation was carried out by averaging all voxel time-series located within distinct anatomical regions defined in the Desikan-Killiany Atlas [31]. Since source time-series estimated with beamforming approaches are inherently sign-ambiguous, a custom Matlab-based implementation of the mne.extract_label_time_course with “mean_flip” sign-flipping procedure in MNEPython [78] was applied prior to averaging to prevent within-parcel signal cancellation. All voxel time-series within each parcel were extracted and the timeseries sign was flipped at locations where the orientation difference was greater than 90° from the parcel mode. A mean time-series was then computed across all voxels within the parcel after sign-flipping.”

      Recommendations for the authors: 

      Reviewer #1 (Recommendations for the authors): 

      Comments on the revision: 

      The authors have made large efforts to address all concerns raised. A couple of suggestions remain: 

      - formally show if and how movement artefacts may contribute to the signal and analysis; it seems that the authors have data to allow for such an analysis  

      We have implemented the requested control analyses addressing this issue. They are reported in: Results (lines 207-211 and 261-268), Discussion (Lines 362-368):

      - formally show that the signals from the intra- and inter parcel spaces are orthogonal. 

      Please note that, despite the Reviewer’s statement above, we never claim in the manuscript that the parcel-space and regional voxel-space features show “complete independence”. 

      Furthermore, the machine learning-based decoding methods used in the present study do not require input feature orthogonality, but instead non-redundancy [7], which is a requirement satisfied by our data (see below and the new Figure 2 – figure supplement 2 in the revised manuscript). Finally, our results already show that the hybrid space decoder outperformed all other methods even after input features were fully orthogonalized with LDA or PCA dimensionality reduction procedures prior to the classification step (Figure 3 – figure supplement 2).

      We also highlight several additional results that are informative regarding this issue. For example, if spatially overlapping parcel- and voxel-space time-series only provided redundant information, inclusion of both as input features should increase model overfitting to the training dataset and decrease overall cross-validated test accuracy [8]. In the present study however, we see the opposite effect on decoder performance. First, Figure 3 – figure supplements 1 & 2 clearly show that decoders constructed from hybrid-space features outperform the other input feature (sensor-, whole-brain parcel- and whole-brain voxel-) spaces in every case (e.g. – wideband, all narrowband frequency ranges, and even after the input space is fully orthogonalized through dimensionality reduction procedures prior to the decoding step). Furthermore, Figure 3 – figure supplement 6 shows that hybridspace decoder performance supers when parcel-time series that spatially overlap with the included regional voxel-spaces are removed from the input feature set.  We state in the Discussion (lines 353-356)

      “The observation of increased cross-validated test accuracy (as shown in Figure 3 – Figure Supplement 6) indicates that the spatially overlapping information in parcel- and voxel-space time-series in the hybrid decoder was complementary, rather than redundant [41].”

      To gain insight into the complimentary information contributed by the two spatial scales to the hybrid-space decoder, we first independently computed the matrix rank for whole-brain parcel- and voxel-space input features for each participant (shown in Author response image 1). The results indicate that whole-brain parcel-space input features are full rank (rank = 148) for all participants (i.e. - MEG activity is orthogonal between all parcels). The matrix rank of voxelspace input features (rank = 267± 17 SD), exceeded the parcel-space rank for all participants and approached the number of useable MEG sensor channels (n = 272). Thus, voxel-space features provide both additional and complimentary information to representations at the parcel-space scale.  

      Figure 2—figure Supplement 2 in the revised manuscript now shows that the degree of dependence between the two spatial scales varies over the regional voxel-space. That is, some voxels within a given parcel correlate strongly with the time-series of the parcel they belong to, while others do not. This finding is consistent with a documented increase in correlational structure of neural activity across spatial scales that does not reflect perfect dependency or orthogonality [9]. Notably, the regional voxel-spaces included in the hybridspace decoder are significantly less correlated with the averaged parcel-space time-series than excluded voxels. We now point readers to this new figure in the results.

      Taken together, these results indicate that the multi-scale information in the hybrid feature set is complimentary rather than orthogonal.  This is consistent with the idea that hybridspace features better represent multi-scale temporospatial dynamics reported to be a fundamental characteristic of how the brain stores and adapts memories, and generates behavior across species [9].

      Reviewer #2 (Recommendations for the authors):  

      I appreciate the authors' efforts in addressing the concerns I raised. The responses generally made sense to me. However, I had some trouble finding several corrections/additions that the authors claim they made in the revised manuscript: 

      "We addressed this question by conducting a new multivariate regression analysis to directly assess whether the neural representation distance score could be predicted by the 4-1, 2-4, and 4-4 keypress transition times observed for each complete correct sequence (both predictor and response variables were z-score normalized within-subject). The results of this analysis also affirmed that the possible alternative explanation that contextualization effects are simple reflections of increased mixing is not supported by the data (Adjusted R<sup>2</sup> = 0.00431; F = 5.62).  We now include this new negative control analysis in the revised manuscript."  

      This approach is now reported in the manuscript in the Results (Lines 324-328 and Figure 5-Figure Supplement 6 legend.

      "We strongly agree with the Reviewer that the issue of generalizability is extremely important and have added a new paragraph to the Discussion in the revised manuscript highlighting the strengths and weaknesses of our study with respect to this issue." 

      Discussion (Lines 436-441)

      “One limitation of this study is that contextualization was investigated for only one finger movement (index finger or digit 4) embedded within a relatively short 5-item skill sequence. Determining if representational contextualization is exhibited across multiple finger movements embedded within for example longer sequences (e.g. – two index finger and two little finger keypresses performed within a short piece of piano music) will be an important extension to the present results.”

      "We strongly agree with the Reviewer that any intended clinical application must carefully consider the specific input feature constraints dictated by the clinical cohort, and in turn impose appropriate and complimentary constraints on classifier parameters that may differ from the ones used in the present study. We now highlight this issue in the Discussion of the revised manuscript and relate our present findings to published clinical BCI work within this context."  

      Discussion (Lines 441-444)

      “While a supervised manifold learning approach (LDA) was used here because it optimized hybrid-space decoder performance, unsupervised strategies (e.g. - PCA and MDS, which also substantially improved decoding accuracy in the present study; Figure 3 – figure supplement 2) are likely more suitable for real-time BCI applications.”

      and 

      "The Reviewer makes a good point. We have now implemented the suggested normalization procedure in the analysis provided in the revised manuscript." 

      Results (lines 275-282)

      “We used a Euclidian distance measure to evaluate the differentiation of the neural representation manifold of the same action (i.e. - an index-finger keypress) executed within different local sequence contexts (i.e. - ordinal position 1 vs. ordinal position 5; Figure 5). To make these distance measures comparable across participants, a new set of classifiers was then trained with group-optimal parameters (i.e. – broadband hybrid-space MEG data with subsequent manifold extraction (Figure 3 – figure supplements 2) and LDA classifiers (Figure 3 – figure supplements 7) trained on 200ms duration windows aligned to the KeyDown event (see Methods, Figure 3 – figure supplements 5). “

      Where are they in the manuscript? Did I read the wrong version? It would be more helpful to specify with page/line numbers. Please also add the detailed procedure of the control/additional analyses in the Method. 

      As requested, we now refer to all manuscript revisions with specific line numbers. We have also included all detailed procedures related to any additional analyses requested by reviewers.

      I also have a few other comments back to the authors' following responses: 

      "Thus, increased overlap between the "4" and "1" keypresses (at the start of the sequence) and "2" and "4" keypresses (at the end of the sequence) could artefactually increase contextualization distances even if the underlying neural representations for the individual keypresses remain unchanged. One must also keep in mind that since participants repeat the sequence multiple times within the same trial, a majority of the index finger keypresses are performed adjacent to one another (i.e. - the "4-4" transition marking the end of one sequence and the beginning of the next). Thus, increased overlap between consecutive index finger keypresses as typing speed increased should increase their similarity and mask contextualization- related changes to the underlying neural representations."  "We also re-examined our previously reported classification results with respect to this issue. 

      We reasoned that if mixing effects reflecting the ordinal sequence structure is an important driver of the contextualization finding, these effects should be observable in the distribution of decoder misclassifications. For example, "4" keypresses would be more likely to be misclassified as "1" or "2" keypresses (or vice versa) than as "3" keypresses. The confusion matrices presented in Figures 3C and 4B and Figure 3-figure supplement 3A display a distribution of misclassifications that is inconsistent with an alternative mixing effect explanation of contextualization." 

      "Based upon the increased overlap between adjacent index finger keypresses (i.e. - "4-4" transition), we also reasoned that the decoder tasked with separating individual index finger keypresses into two distinct classes based upon sequence position, should show decreased performance as typing speed increases. However, Figure 4C in our manuscript shows that this is not the case. The 2-class hybrid classifier actually displays improved classification performance over early practice trials despite greater temporal overlap. Again, this is inconsistent with the idea that the contextualization effect simply reflects increased mixing of individual keypress features."  

      As the time window for MEG feature is defined after the onset of each press, it is more likely that the feature overlap is the current and the future presses, rather than the current and the past presses (of course the three will overlap at very fast typing speed). Therefore, for sequence 41324, if we note the planning-related processes by a Roman numeral, the overlapping features would be '4i', '1iii', '3ii', '2iv', and '4iv'. Assuming execution-related process (e.g., 1) and planning-related process (e.g., i) are not necessarily similar, especially in finer temporal resolution, the patterns for '4i' and '4iv' are well separated in terms of process 'i' and 'iv,' and this advantage will be larger in faster typing speed. This also applies to the other presses. Thus, the author's arguments about the masking of contextualization and misclassification due to pattern overlap seem odd. The most direct and probably easiest way to resolve this would be to use a shorter time window for the MEG feature. Some decrease in decoding accuracy in this case is totally acceptable for the science purpose.  

      The revised manuscript now includes analyses carried out with decoding time windows ranging from 50 to 250ms in duration. These additional results are now reported in:

      Results (lines 258-268):

      “The improved decoding accuracy is supported by greater differentiation in neural representations of the index finger keypresses performed at positions 1 and 5 of the sequence (Figure 4A), and by the trial-by-trial increase in 2-class decoding accuracy over early learning (Figure 4C) across different decoder window durations (Figure 4 – figure supplement 2). As expected, the 5-class hybrid-space decoder performance approached chance levels when tested with randomly shuffled keypress labels (18.41%± SD 7.4% for Day 1 data; Figure 4 – figure supplement 3C). Task-related eye movements did not explain these results since an alternate 5-class hybrid decoder constructed from three eye movement features (gaze position at the KeyDown event, gaze position 200ms later, and peak eye movement velocity within this window; Figure 4 – figure supplement 3A) performed at chance levels (crossvalidated test accuracy = 0.2181; Figure 4 – figure supplement 3B, C).”

      Results (lines 310-316):

      “Offline contextualization strongly correlated with cumulative micro-offline gains (r = 0.903, R² = 0.816, p < 0.001; Figure 5 – figure supplement 1A, inset) across decoder window durations ranging from 50 to 250ms (Figure 5 – figure supplement 1B, C). The offline contextualization between the final sequence of each trial and the second sequence of the subsequent trial (excluding the first sequence) yielded comparable results. This indicates that pre-planning at the start of each practice trial did not directly influence the offline contextualization measure [30] (Figure 5 – figure supplement 2A, 1st vs. 2nd Sequence approaches). “

      Discussion (lines 380-385):

      “The first hint of representational differentiation was the highest false-negative and lowest false-positive misclassification rates for index finger keypresses performed at different locations in the sequence compared with all other digits (Figure 3C). This was further supported by the progressive differentiation of neural representations of the index finger keypress (Figure 4A) and by the robust trial-by-trial increase in 2class decoding accuracy across time windows ranging between 50 and 250ms (Figure 4C; Figure 4 – figure supplement 2).”

      Discussion (lines 408-9):

      “Offline contextualization consistently correlated with early learning gains across a range of decoding windows (50–250ms; Figure 5 – figure supplement 1).”

      "We addressed this question by conducting a new multivariate regression analysis to directly assess whether the neural representation distance score could be predicted by the 4-1, 2-4 and 4-4 keypress transition times observed for each complete correct sequence" 

      For regression analysis, I recommend to use total keypress time per a sequence (or sum of 4-1 and 4-4) instead of specific transition intervals, because there likely exist specific correlational structure across the transition intervals. Using correlated regressors may distort the result.  

      This approach is now reported in the manuscript:

      Results (Lines 324-328) and Figure  5-Figure Supplement 6 legend.

      "We do agree with the Reviewer that the naturalistic, generative, self-paced task employed in the present study results in overlapping brain processes related to planning, execution, evaluation and memory of the action sequence. We also agree that there are several tradeoffs to consider in the construction of the classifiers depending on the study aim. Given our aim of optimizing keypress decoder accuracy in the present study, the set of tradeoffs resulted in representations reflecting more the latter three processes, and less so the planning component. Whether separate decoders can be constructed to tease apart the representations or networks supporting these overlapping processes is an important future direction of research in this area. For example, work presently underway in our lab constrains the selection of windowing parameters in a manner that allows individual classifiers to be temporally linked to specific planning, execution, evaluation or memoryrelated processes to discern which brain networks are involved and how they adaptively reorganize with learning. Results from the present study (Figure 4-figure supplement 2) showing hybrid-space decoder prediction accuracies exceeding 74% for temporal windows spanning as little as 25ms and located up to 100ms prior to the KeyDown event strongly support the feasibility of such an approach." 

      I recommend that the authors add this paragraph or a paragraph like this to the Discussion. This perspective is very important and still missing in the revised manuscript. 

      We now included in the manuscript the following sections addressing this point:

      Discussion (lines 334-338)

      “The main findings of this study during which subjects engaged in a naturalistic, self-paced task were that individual sequence action representations differentiate during early skill learning in a manner reflecting the local sequence context in which they were performed, and that the degree of representational differentiation— particularly prominent over rest intervals—correlated with skill gains. “

      Discussion (lines 428-434)

      “In this study, classifiers were trained on MEG activity recorded during or immediately after each keypress, emphasizing neural representations related to action execution, memory consolidation and recall over those related to planning. An important direction for future research is determining whether separate decoders can be developed to distinguish the representations or networks separately supporting these processes. Ongoing work in our lab is addressing this question. The present accuracy results across varied decoding window durations and alignment with each keypress action support the feasibility of this approach (Figure 3—figure supplement 5).”

      "The rapid initial skill gains that characterize early learning are followed by micro-scale fluctuations around skill plateau levels (i.e. following trial 11 in Figure 1B)"  Is this a mention of Figure 1 Supplement 1 A?  

      The sentence was replaced with the following: Results (lines 108-110)

      “Participants reached 95% of maximal skill (i.e. - Early Learning) within the initial 11 practice trials (Figure 1B), with improvements developing over inter-practice rest periods (micro-offline gains) accounting for almost all total learning across participants (Figure 1B, inset) [1].”

      The citation below seems to have been selected by mistake; 

      "9. Chen, S. & Epps, J. Using task-induced pupil diameter and blink rate to infer cognitive load. Hum Comput Interact 29, 390-413 (2014)." 

      We thank the Reviewer for bringing this mistake to our attention. This citation has now been corrected.

      Reviewer #3 (Recommendations for the authors):  

      The authors write in their response that "We now provide additional details in the Methods of the revised manuscript pertaining to the parcellation procedure and how the sign ambiguity problem was addressed in our analysis." I could not find anything along these lines in the (redlined) version of the manuscript and therefore did not change the corresponding comment in the public review.  

      The revised manuscript now provides a more detailed explanation of the parcellation, and sign-flipping procedure implemented:

      Methods (lines 604-611):

      “Source-space parcellation was carried out by averaging all voxel time-series located within distinct anatomical regions defined in the Desikan-Killiany Atlas [31]. Since source time-series estimated with beamforming approaches are inherently sign-ambiguous, a custom Matlab-based implementation of the mne.extract_label_time_course with “mean_flip” sign-flipping procedure in MNEPython [78] was applied prior to averaging to prevent within-parcel signal cancellation. All voxel time-series within each parcel were extracted and the timeseries sign was flipped at locations where the orientation difference was greater than 90° from the parcel mode. A mean time-series was then computed across all voxels within the parcel after sign-flipping.”

      The control analysis based on a multivariate regression that assessed whether the neural representation distance score could be predicted by the 4-1, 2-4 and 4-4 keypress transition times, as briefly mentioned in the authors' responses to Reviewer 2 and myself, was not included in the manuscript and could not be sufficiently evaluated. 

      This approach is now reported in the manuscript: Results (Lines 324-328) and Figure  5-Figure Supplement 6 legend.

      The authors argue that differences in the design between Das et al. (2024) on the one hand (Experiments 1 and 2), and the study by Bönstrup et al. (2019) on the other hand, may have prevented Das et al. (2024) from finding the assumed learning benefit by micro-offline consolidation. However, the Supplementary Material of Das et al. (2024) includes an experiment (Experiment S1) whose design closely follows a large proportion of the early learning phase of Bönstrup et al. (2019), and which, nevertheless, demonstrates that there is no lasting benefit of taking breaks with respect to the acquired skill level, despite the presence of micro-offline gains.  

      We thank the Reviewer for alerting us to this new data added to the revised supplementary materials of Das et al. (2024) posted to bioRxiv. However, despite the Reviewer’s claim to the contrary, a careful comparison between the Das et al and Bönstrup et al studies reveal more substantive differences than similarities and does not “closely follows a large proportion of the early learning phase of Bönstrup et al. (2019)” as stated. 

      In the Das et al. Experiment S1, sixty-two participants were randomly assigned to “with breaks” or “no breaks” skill training groups. The “with breaks” group alternated 10 seconds of skill sequence practice with 10 seconds of rest over seven trials (2 min and 2 sec total training duration). This amounts to 66.7% of the early learning period defined by Bönstrup et al. (2019) (i.e. - eleven 10-second long practice periods interleaved with ten 10-second long rest breaks; 3 min 30 sec total training duration). Also, please note that while no performance feedback nor reward was given in the Bönstrup et al. (2019) study, participants in the Das et al. study received explicit performance-based monetary rewards, a potentially crucial driver of differentiated behavior between the two studies:

      “Participants were incentivized with bonus money based on the total number of correct sequences completed throughout the experiment.”

      The “no breaks” group in the Das et al. study practiced the skill sequence for 70 continuous seconds. Both groups (despite one being labeled “no breaks”) follow training with a long 3-minute break (also note that since the “with breaks” group ends with 10 seconds of rest their break is actually longer), before finishing with a skill “test” over a continuous 50-second-long block. During the 70 seconds of training, the “with breaks” group shows more learning than the “no breaks” group. Interestingly, following the long 3minute break the “with breaks” group display a performance drop (relative to their performance at the end of training) that is stable over the full 50-second test, while the “no breaks” group shows an immediate performance improvement following the long break that continues to increase over the 50-second test.  

      Separately, there are important issues regarding the Das et al study that should be considered through the lens of recent findings not referred to in the preprint. A major element of their experimental design is that both groups—“with breaks” and “no breaks”— actually receive quite a long 3-minute break just before the skill test. This long break is more than 2.5x the cumulative interleaved rest experienced by the “with breaks” group. Thus, although the design is intended to contrast the presence or absence of rest “breaks”, that difference between groups is no longer maintained at the point of the skill test. 

      The Das et al results are most consistent with an alternative interpretation of the data— that the “no breaks” group experiences offline learning during their long 3-minute break. This is supported by the recent work of Griffin et al. (2025) where micro-array recordings from primary and premotor cortex were obtained from macaque monkeys while they performed blocks of ten continuous reaching sequences up to 81.4 seconds in duration (see source data for Extended Data Figure 1h) with 90 seconds of interleaved rest. Griffin et al. observed offline improvement in skill immediately following the rest break that was causally related to neural reactivations (i.e. – neural replay) that occurred during the rest break. Importantly, the highest density of reactivations was present in the very first 90second break between Blocks 1 and 2 (see Fig. 2f in Griffin et al., 2025). This supports the interpretation that both the “with breaks” and “no breaks” group express offline learning gains, with these gains being delayed in the “no breaks” group due to the practice schedule.

      On the other hand, if offline learning can occur during this longer break, then why would the “with breaks” group show no benefit? Again, it could be that most of the offline gains for this group were front-loaded during the seven shorter 10-second rest breaks. Another possible, though not mutually exclusive, explanation is that the observed drop in performance in the “with breaks” group is driven by contextual interference. Specifically, similar to Experiments 1 and 2 in Das et al. (2024), the skill test is conducted under very different conditions than those which the “with breaks” group practiced the skill under (short bursts of practiced alternating with equally short breaks). On the other hand, the “no breaks” group is tested (50 seconds of continuous practice) under quite similar conditions to their training schedule (70 seconds of continuous practice). Thus, it is possible that this dissimilarity between training and test could lead to reduced performance in the “with breaks” group.

      We made the following manuscript revisions related to these important issues: 

      Introduction (Lines 26-56)

      “Practicing a new motor skill elicits rapid performance improvements (early learning) [1] that precede skill performance plateaus [5]. Skill gains during early learning accumulate over rest periods (micro-offline) interspersed with practice [1, 6-10], and are up to four times larger than offline performance improvements reported following overnight sleep [1]. During this initial interval of prominent learning, retroactive interference immediately following each practice interval reduces learning rates relative to interference after passage of time, consistent with stabilization of the motor memory [11]. Micro-offline gains observed during early learning are reproducible [7, 10-13] and are similar in magnitude even when practice periods are reduced by half to 5 seconds in length, thereby confirming that they are not merely a result of recovery from performance fatigue [11]. Additionally, they are unaffected by the random termination of practice periods, which eliminates the possibility of predictive motor slowing as a contributing factor [11]. Collectively, these behavioral findings point towards the interpretation that microoffline gains during early learning represent a form of memory consolidation [1]. 

      This interpretation has been further supported by brain imaging and electrophysiological studies linking known memory-related networks and consolidation mechanisms to rapid offline performance improvements. In humans, the rate of hippocampo-neocortical neural replay predicts micro-offline gains [6]. Consistent with these findings, Chen et al. [12] and Sjøgård et al. [13] furnished direct evidence from intracranial human EEG studies, demonstrating a connection between the density of hippocampal sharp-wave ripples (80-120 Hz)—recognized markers of neural replay—and micro-offline gains during early learning. Further, Griffin et al. reported that neural replay of task-related ensembles in the motor cortex of macaques during brief rest periods— akin to those observed in humans [1, 6-8, 14]—are not merely correlated with, but are causal drivers of micro-offline learning [15]. Specifically, the same reach directions that were replayed the most during rest breaks showed the greatest reduction in path length (i.e. – more efficient movement path between two locations in the reach sequence) during subsequent trials, while stimulation applied during rest intervals preceding performance plateau reduced reactivation rates and virtually abolished micro-offline gains [15]. Thus, converging evidence in humans and non-human primates across indirect non-invasive and direct invasive recording techniques link hippocampal activity, neural replay dynamics and offline skill gains in early motor learning that precede performance plateau.”

      Next, in the Methods, we articulate important constraints formulated by Pan and Rickard (2015) and Bönstrup et al. (2019) for meaningful measurements:

      Methods (Lines 493-499)

      “The study design followed specific recommendations by Pan and Rickard (2015): 1) utilizing 10-second practice trials and 2) constraining analysis of micro-offline gains to early learning trials (where performance monotonically increases and 95% of overall performance gains occur) that precede the emergence of “scalloped” performance dynamics strongly linked to reactive inhibition effects ([29, 72]). This is precisely the portion of the learning curve Pan and Rickard referred to when they stated “…rapid learning during that period masks any reactive inhibition effect” [29].”

      We finally discuss the implications of neglecting some or all of these recommendations:

      Discussion (Lines 444-452):

      “Finally, caution should be exercised when extrapolating findings during early skill learning, a period of steep performance improvements, to findings reported after insufficient practice [67], post-plateau performance periods [68], or non-learning situations (e.g. performance of non-repeating keypress sequences in  [67]) when reactive inhibition or contextual interference effects are prominent. Ultimately, it will be important to develop new paradigms allowing one to independently estimate the different coincident or antagonistic features (e.g. - memory consolidation, planning, working memory and reactive inhibition) contributing to micro-online and micro-offline gains during and after early skill learning within a unifying framework.”

      Personally, given that the idea of (micro-offline) consolidation seems to attract a lot of interest (and therefore cause a lot of future effort/cost public money) in the scientific community, I would find it extremely important to be cautious in interpreting results in this field. For me, this would include abstaining from the claim that processes occur "during" a rest period (see abstract, for example), given that micro-offline gains (as well as offline contextualization) are computed from data obtained during practice, not rest, and may, thus, just as well reflect a change that occurs "online", e.g., at the very onset of practice (like pre-planning) or throughout practice (like fatigue, or reactive inhibition). In addition, I would suggest to discuss in more depth the actual evidence not only in favour, but also against, the assumption of micro-offline gains as a phenomenon of learning.  

      We agree with the reviewer that caution is warranted. Based upon these suggestions, we have now expanded the manuscript to very clearly define the experimental constraints under which different groups have successfully studied micro-offline learning and its mechanisms, the impact of fatigue/reactive inhibition on micro-offline performance changes unrelated to learning, as well as the interpretation problems that emerge when those recommendations are not followed. 

      We clearly articulate the crucial constrains recommended by Pan and Rickard (2015) and Bönstrup et al. (2019) for meaningful measurements and interpretation of offline gains in the revised manuscript. 

      Methods (Lines 493-499)

      “The study design followed specific recommendations by Pan and Rickard (2015): 1) utilizing 10-second practice trials and 2) constraining analysis of micro-offline gains to early learning trials (where performance monotonically increases and 95% of overall performance gains occur) that precede the emergence of “scalloped” performance dynamics strongly linked to reactive inhibition effects ( [29, 72]). This is precisely the portion of the learning curve Pan and Rickard referred to when they stated “…rapid learning during that period masks any reactive inhibition effect” [29].”

      In the Introduction, we review the extensive evidence emerging from LFP and microelectrode recordings in humans and monkeys (including causality of neural replay with respect to micro-offline gains and early learning in the Griffin et al. Nature 2025 publication):

      Introduction (Lines 26-56)

      “Practicing a new motor skill elicits rapid performance improvements (early learning) [1] that precede skill performance plateaus [5]. Skill gains during early learning accumulate over rest periods (micro-offline) interspersed with practice [1, 6-10], and are up to four times larger than offline performance improvements reported following overnight sleep [1]. During this initial interval of prominent learning, retroactive interference immediately following each practice interval reduces learning rates relative to interference after passage of time, consistent with stabilization of the motor memory [11]. Micro-offline gains observed during early learning are reproducible [7, 10-13] and are similar in magnitude even when practice periods are reduced by half to 5 seconds in length, thereby confirming that they are not merely a result of recovery from performance fatigue [11]. Additionally, they are unaffected by the random termination of practice periods, which eliminates the possibility of predictive motor slowing as a contributing factor [11]. Collectively, these behavioral findings point towards the interpretation that microoffline gains during early learning represent a form of memory consolidation [1]. 

      This interpretation has been further supported by brain imaging and electrophysiological studies linking known memory-related networks and consolidation mechanisms to rapid offline performance improvements. In humans, the rate of hippocampo-neocortical neural replay predicts micro-offline gains [6]. Consistent with these findings, Chen et al. [12] and Sjøgård et al. [13] furnished direct evidence from intracranial human EEG studies, demonstrating a connection between the density of hippocampal sharp-wave ripples (80-120 Hz)—recognized markers of neural replay—and micro-offline gains during early learning. Further, Griffin et al. reported that neural replay of task-related ensembles in the motor cortex of macaques during brief rest periods— akin to those observed in humans [1, 6-8, 14]—are not merely correlated with, but are causal drivers of micro-offline learning [15]. Specifically, the same reach directions that were replayed the most during rest breaks showed the greatest reduction in path length (i.e. – more efficient movement path between two locations in the reach sequence) during subsequent trials, while stimulation applied during rest intervals preceding performance plateau reduced reactivation rates and virtually abolished micro-offline gains [15]. Thus, converging evidence in humans and non-human primates across indirect non-invasive and direct invasive recording techniques link hippocampal activity, neural replay dynamics and offline skill gains in early motor learning that precede performance plateau.”

      Following the reviewer’s advice, we have expanded our discussion in the revised manuscript of alternative hypotheses put forward in the literature and call for caution when extrapolating results across studies with fundamental differences in design (e.g. – different practice and rest durations, or presence/absence of extrinsic reward, etc). 

      Discussion (Lines 444-452):

      “Finally, caution should be exercised when extrapolating findings during early skill learning, a period of steep performance improvements, to findings reported after insufficient practice [67], post-plateau performance periods [68], or non-learning situations (e.g. performance of non-repeating keypress sequences in  [67]) when reactive inhibition or contextual interference effects are prominent. Ultimately, it will be important to develop new paradigms allowing one to independently estimate the different coincident or antagonistic features (e.g. - memory consolidation, planning, working memory and reactive inhibition) contributing to micro-online and micro-offline gains during and after early skill learning within a unifying framework.”

      References

      (1) Zimerman, M., et al., Disrupting the Ipsilateral Motor Cortex Interferes with Training of a Complex Motor Task in Older Adults. Cereb Cortex, 2012.

      (2) Waters, S., T. Wiestler, and J. Diedrichsen, Cooperation Not Competition: Bihemispheric tDCS and fMRI Show Role for Ipsilateral Hemisphere in Motor Learning. J Neurosci, 2017. 37(31): p. 7500-7512.

      (3) Sawamura, D., et al., Acquisition of chopstick-operation skills with the nondominant hand and concomitant changes in brain activity. Sci Rep, 2019. 9(1): p. 20397.

      (4) Lee, S.H., S.H. Jin, and J. An, The dieerence in cortical activation pattern for complex motor skills: A functional near- infrared spectroscopy study. Sci Rep, 2019. 9(1): p. 14066.

      (5) Grafton, S.T., E. Hazeltine, and R.B. Ivry, Motor sequence learning with the nondominant left hand. A PET functional imaging study. Exp Brain Res, 2002. 146(3): p. 369-78.

      (6) Buch, E.R., et al., Consolidation of human skill linked to waking hippocamponeocortical replay. Cell Rep, 2021. 35(10): p. 109193.

      (7) Wang, L. and S. Jiang, A feature selection method via analysis of relevance, redundancy, and interaction, in Expert Systems with Applications, Elsevier, Editor. 2021.

      (8) Yu, L. and H. Liu, Eeicient feature selection via analysis of relevance and redundancy. Journal of Machine Learning Research, 2004. 5: p. 1205-1224.

      (9) Munn, B.R., et al., Multiscale organization of neuronal activity unifies scaledependent theories of brain function. Cell, 2024.

      (10) Borragan, G., et al., Sleep and memory consolidation: motor performance and proactive interference eeects in sequence learning. Brain Cogn, 2015. 95: p. 54-61.

      (11) Landry, S., C. Anderson, and R. Conduit, The eeects of sleep, wake activity and timeon-task on oeline motor sequence learning. Neurobiol Learn Mem, 2016. 127: p. 5663.

      (12) Gabitov, E., et al., Susceptibility of consolidated procedural memory to interference is independent of its active task-based retrieval. PLoS One, 2019. 14(1): p. e0210876.

      (13) Pan, S.C. and T.C. Rickard, Sleep and motor learning: Is there room for consolidation? Psychol Bull, 2015. 141(4): p. 812-34.

      (14) , M., et al., A Rapid Form of Oeline Consolidation in Skill Learning. Curr Biol, 2019. 29(8): p. 1346-1351 e4.

      (15) Gupta, M.W. and T.C. Rickard, Comparison of online, oeline, and hybrid hypotheses of motor sequence learning using a quantitative model that incorporate reactive inhibition. Sci Rep, 2024. 14(1): p. 4661.

    1. Author response:

      The following is the authors’ response to the original reviews.

      Public Reviews:

      Reviewer #1 (Public review):

      Summary:

      Here, the authors propose that changes in m6A levels may be predictable via a simple model that is based exclusively on mRNA metabolic events. Under this model, m6A mRNAs are "passive" victims of RNA metabolic events with no "active" regulatory events needed to modulate their levels by m6A writers, readers, or erasers; looking at changes in RNA transcription, RNA export, and RNA degradation dynamics is enough to explain how m6A levels change over time.

      The relevance of this study is extremely high at this stage of the epi transcriptome field. This compelling paper is in line with more and more recent studies showing how m6A is a constitutive mark reflecting overall RNA redistribution events. At the same time, it reminds every reader to carefully evaluate changes in m6A levels if observed in their experimental setup. It highlights the importance of performing extensive evaluations on how much RNA metabolic events could explain an observed m6A change.

      Weaknesses:

      It is essential to notice that m6ADyn does not exactly recapitulate the observed m6A changes. First, this can be due to m6ADyn's limitations. The authors do a great job in the Discussion highlighting these limitations. Indeed, they mention how m6ADyn cannot interpret m6A's implications on nuclear degradation or splicing and cannot model more complex scenario predictions (i.e., a scenario in which m6A both impacts export and degradation) or the contribution of single sites within a gene.

      Secondly, since predictions do not exactly recapitulate the observed m6A changes, "active" regulatory events may still play a partial role in regulating m6A changes. The authors themselves highlight situations in which data do not support m6ADyn predictions. Active mechanisms to control m6A degradation levels or mRNA export levels could exist and may still play an essential role.

      We are grateful for the reviewer’s appreciation of our findings and their implications, and are in full agreement with the reviewer regarding the limitations of our model, and the discrepancies in some cases - with our experimental measurements, potentially pointing at more complex biology than is captured by m6ADyn. We certainly cannot dismiss the possibility that active mechanisms may play a role in shaping m6A dynamics at some sites, or in some contexts. Our study aims to broaden the discussion in the field, and to introduce the possibility that passive models can explain a substantial extent of the variability observed in m6A levels.

      (1) "We next sought to assess whether alternative models could readily predict the positive correlation between m6A and nuclear localization and the negative correlations between m6A and mRNA stability. We assessed how nuclear decay might impact these associations by introducing nuclear decay as an additional rate, δ. We found that both associations were robust to this additional rate (Supplementary Figure 2a-c)."

      Based on the data, I would say that model 2 (m6A-dep + nuclear degradation) is better than model 1. The discussion of these findings in the Discussion could help clarify how to interpret this prediction. Is nuclear degradation playing a significant role, more than expected by previous studies?

      This is an important point, which we’ve now clarified in the discussion. Including nonspecific nuclear degradation in the m6ADyn framework provides a model that better aligns with the observed data, particularly by mitigating unrealistic predictions such as excessive nuclear accumulation for genes with very low sampled export rates. This adjustment addresses potential artifacts in nuclear abundance and half-life estimations. However, we continued to use the simpler version of m6ADyn for most analyses, as it captures the key dynamics and relationships effectively without introducing additional complexity. While including nuclear degradation enhances the model's robustness, it does not fundamentally alter the primary conclusions or outcomes. This balance allows for a more straightforward interpretation of the results.

      (2) The authors classify m6A levels as "low" or "high," and it is unclear how "low" differs from unmethylated mRNAs.

      We thank the reviewer for this observation. We analyzed gene methylation levels using the m6A-GI (m6A gene index) metric, which reflects the enrichment of the IP fraction across the entire gene body (CDS + 3UTR). While some genes may have minimal or no methylation, most genes likely exist along a spectrum from low to high methylation levels. Unlike earlier analyses that relied on arbitrary thresholds to classify sites as methylated, GLORI data highlight the presence of many low-stoichiometry sites that are typically overlooked. To capture this spectrum, we binned genes into equal-sized groups based on their m6A-GI values, allowing a more nuanced interpretation of methylation patterns as a continuum rather than a binary or discrete classification (e.g. no- , low- , high methylation).

      (3) The authors explore whether m6A changes could be linked with differences in mRNA subcellular localization. They tested this hypothesis by looking at mRNA changes during heat stress, a complex scenario to predict with m6ADyn. According to the collected data, heat shock is not associated with dramatic changes in m6A levels. However, the authors observe a redistribution of m6A mRNAs during the treatment and recovery time, with highly methylated mRNAs getting retained in the nucleus being associated with a shorter half-life, and being transcriptional induced by HSF1. Based on this observation, the authors use m6Adyn to predict the contribution of RNA export, RNA degradation, and RNA transcription to the observed m6A changes. However:

      (a) Do the authors have a comparison of m6ADyn predictions based on the assumption that RNA export and RNA transcription may change at the same time?

      We thank the reviewer for this point. Under the simple framework of m6ADyn in which RNA transcription and RNA export are independent of each other, the effect of simultaneously modulating two rates is additive. In Author response image 1, we simulate some scenarios wherein we simultaneously modulate two rates. For example, transcriptional upregulation and decreased export during heat shock could reinforce m6A increases, whereas transcriptional downregulation might counteract the effects of reduced export. Note that while production and export can act in similar or opposing directions, the former can only lead to temporary changes in m6A levels but without impacting steady-state levels, whereas the latter (changes in export) can alter steady-state levels. We have clarified this in the manuscript results to better contextualize how these dynamics interact.

      Author response image 1.

      m6ADyn predictions of m6A gene levels (left) and Nuc to Cyt ratio (right) upon varying perturbations of a sampled gene. The left panel depicts the simulated dynamics of log2-transformed m6A gene levels under varying conditions. The lines represent the following perturbations: (1) export is reduced to 10% (β), (2) production is increased 10-fold (α) while export is reduced to 10% (β), (3) export is reduced to 10% (β) and production is reduced to 10% (α), and (4) export is only decreased for methylated transcripts (β^m6A) to 10%. The right panel shows the corresponding nuclear:cytoplasmic (log2 Nuc:Cyt) ratios for perturbations 1 and 4.

      (b) They arbitrarily set the global reduction of export to 10%, but I'm not sure we can completely rule out whether m6A mRNAs have an export rate during heat shock similar to the non-methylated mRNAs. What happens if the authors simulate that the block in export could be preferential for m6A mRNAs only?

      We thank the reviewer for this interesting suggestion. While we cannot fully rule out such a scenario, we can identify arguments against it being an exclusive explanation. Specifically, an exclusive reduction in the export rate of methylated transcripts would be expected to increase the relationship between steady-state m6A levels (the ratio of methylated to unmethylated transcripts) and changes in localization, such that genes with higher m6A levels would exhibit a greater relative increase in the nuclear-to-cytoplasmic (Nuc:Cyt) ratio. However, the attached analysis shows only a weak association during heat stress, where genes with higher m6A-GI levels tend to increase just a little more in the Nuc:Cyt ratio, likely due to cytoplasmic depletion. A global reduction of export (β 10%) produces a similar association, while a scenario where only the export of methylated transcripts is reduced (β^m6A 10%) results in a significantly stronger association (Author response image 2). This supports the plausibility of a global export reduction. Additionally, genes with very low methylation levels in control conditions also show a significant increase in the Nuc:Cyt ratio, which is inconsistent with a scenario of preferential export reduction for methylated transcripts (data not shown).

      Author response image 2.

      Wild-type MEFs m6A-GIs (x-axis) vs. fold change nuclear:cytoplasmic localization heat shock 1.5 h and control (y-axis), Pearson’s correlation indicated (left panel). m6ADyn, rates sampled for 100 genes based on gamma distributions and simulation based on reducing the global export rate (β) to 10% (middle panel). m6ADyn simulation for reducing the export rate for m6A methylated transcripts (β^m6A) to 10% (right panel).

      (c) The dramatic increase in the nucleus: cytoplasmic ratio of mRNA upon heat stress may not reflect the overall m6A mRNA distribution upon heat stress. It would be interesting to repeat the same experiment in METTL3 KO cells. Of note, m6A mRNA granules have been observed within 30 minutes of heat shock. Thus, some m6A mRNAs may still be preferentially enriched in these granules for storage rather than being directly degraded. Overall, it would be interesting to understand the authors' position relative to previous studies of m6A during heat stress.

      The reviewer suggests that methylation is actively driving localization during heat shock, rather than being passively regulated. To address this question, we have now knocked down WTAP, an essential component of the methylation machinery, and monitored nuclear:cytoplasmic localization over the course of a heat shock response. Even with reduced m6A levels, high PC1 genes exhibit increased nuclear abundance during heat shock. Notably, the dynamics of this trend are altered, with the peak effect delayed from 1.5h heat shock in siCTRL samples to 4 hours in siWTAP samples (Supplementary Figure 4). This finding underscores that m6A is not the primary driver of these mRNA localization changes but rather reflects broader mRNA metabolic shifts during heat shock. These findings have been added as a panel e) to Supplementary Figure 4.

      (d) Gene Ontology analysis based on the top 1000 PC1 genes shows an enrichment of GOs involved in post-translational protein modification more than GOs involved in cellular response to stress, which is highlighted by the authors and used as justification to study RNA transcriptional events upon heat shock. How do the authors think that GOs involved in post-translational protein modification may contribute to the observed data?

      High PC1 genes exhibit increased methylation and a shift in nuclear-to-cytoplasmic localization during heat stress. While the enriched GO terms for these genes are not exclusively related to stress-response proteins, one could speculate that their nuclear retention reduces translation during heat stress. The heat stress response genes are of particular interest, which are massively transcriptionally induced and display increased methylation. This observation supports m6ADyn predictions that elevated methylation levels in these genes are driven by transcriptional induction rather than solely by decreased export rates.

      (e) Additionally, the authors first mention that there is no dramatic change in m6A levels upon heat shock, "subtle quantitative differences were apparent," but then mention a "systematic increase in m6A levels observed in heat stress". It is unclear to which systematic increase they are referring to. Are the authors referring to previous studies? It is confusing in the field what exactly is going on after heat stress. For instance, in some papers, a preferential increase of 5'UTR m6A has been proposed rather than a systematic and general increase.

      We thank the reviewer for raising this point. In our manuscript, we sought to emphasize, on the one hand, the fact that m6A profiles are - at first approximation - “constitutive”, as indicated by high Pearson correlations between conditions (Supplementary Figure 4a). On the other hand, we sought to emphasize that the above notwithstanding, subtle quantitative differences are apparent in heat shock, encompassing large numbers of genes, and these differences are coherent with time following heat shock (and in this sense ‘systematic’), rather than randomly fluctuating across time points. Based on our analysis, these changes do not appear to be preferentially enriched at 5′UTR sites but occur more broadly across gene bodies (potentially a slight 3’ bias). A quick analysis of the HSF1-induced heat stress response genes, focusing on their relative enrichment of methylation upon heat shock, shows that the 5'UTR regions exhibit a roughly similar increase in methylation after 1.5 hours of heat stress compared to the rest of the gene body (Author response image 3). A prominent previous publication (Zhou et al. 2015) suggested that m6A levels specifically increase in the 5'UTR of HSPA1A in a YTHDF2- and HSF1-dependent manner, and highlighted the role of 5'UTR m6A methylation in regulating cap-independent translation, our findings do not support a 5'UTR-specific enrichment. However, we do observe that the methylation changes are still HSF1-dependent. Off note, the m6A-GI (m6A gene level) as a metric that captures the m6A enrichment of gene body excluding the 5’UTR, due to an overlap of transcription start site associated m6Am derived signal.

      Author response image 3.

      Fold change of m6A enrichment (m6A-IP / input) comparing 1.5 h heat shock and control conditions for 5UTR region and the rest of the gene body (CDS and 3UTR) in the 10 HSF! dependent stress response genes.

      Reviewer #2 (Public review):

      Dierks et al. investigate the impact of m6A RNA modifications on the mRNA life cycle, exploring the links between transcription, cytoplasmic RNA degradation, and subcellular RNA localization. Using transcriptome-wide data and mechanistic modelling of RNA metabolism, the authors demonstrate that a simplified model of m6A primarily affecting cytoplasmic RNA stability is sufficient to explain the nuclear-cytoplasmic distribution of methylated RNAs and the dynamic changes in m6A levels upon perturbation. Based on multiple lines of evidence, they propose that passive mechanisms based on the restricted decay of methylated transcripts in the cytoplasm play a primary role in shaping condition-specific m6A patterns and m6A dynamics. The authors support their hypothesis with multiple large-scale datasets and targeted perturbation experiments. Overall, the authors present compelling evidence for their model which has the potential to explain and consolidate previous observations on different m6A functions, including m6A-mediated RNA export.

      We thank the reviewer for the spot-on suggestions and comments on this manuscript.

      Reviewer #3 (Public review):

      Summary:

      This manuscript works with a hypothesis where the overall m6A methylation levels in cells are influenced by mRNA metabolism (sub-cellular localization and decay). The basic assumption is that m6A causes mRNA decay and this happens in the cytoplasm. They go on to experimentally test their model to confirm its predictions. This is confirmed by sub-cellular fractionation experiments which show high m6A levels in the nuclear RNA. Nuclear localized RNAs have higher methylation. Using a heat shock model, they demonstrate that RNAs with increased nuclear localization or transcription, are methylated at higher levels. Their overall argument is that changes in m6A levels are rather determined by passive processes that are influenced by RNA processing/metabolism. However, it should be considered that erasers have their roles under specific environments (early embryos or germline) and are not modelled by the cell culture systems used here.

      Strengths:

      This is a thought-provoking series of experiments that challenge the idea that active mechanisms of recruitment or erasure are major determinants for m6A distribution and levels.

      We sincerely thank the reviewer for their thoughtful evaluation and constructive feedback.

      Recommendations for the authors:

      Reviewer #1 (Recommendations for the authors):

      (1) Supplementary Figure 5A Data: Please double-check the label of the y-axis and the matching legend.

      We corrected this.

      (2) A better description of how the nuclear: cytoplasmic fractionation is performed.

      We added missing information to the Material & Methods section.

      (3) Rec 1hr or Rec 4hr instead of r1 and r4 to indicate the recovery.

      For brevity in Figure panels, we have chosen to stick with r1 and r4.

      (4) Figure 2D: are hours plotted?

      Plotted is the fold change (FC) of the calculated half-lives in hours (right). For the model (left) hours are the fold change of a dimension-less time-unit of the conditions with m6A facilitated degradation vs without. We have now clarified this in the legend.

      (5) How many genes do we have in each category? How many genes are you investigating each time?

      We thank the reviewer for this question. In all cases where we binned genes, we used equal-sized bins of genes that met the required coverage thresholds. We have reviewed the manuscript to ensure that the number of genes included in each analysis or the specific coverage thresholds used are clearly stated throughout the text.

      (6) Simulations on 1000 genes or 2000 genes?

      We thank the reviewer for this question and went over the text to correct for cases in which this was not clearly stated.

      Reviewer #2 (Recommendations for the authors):

      Specific comments:

      (1) The manuscript is very clear and well-written. However, some arguments are a bit difficult to understand. It would be helpful to clearly discriminate between active and passive events. For example, in the sentence: "For example, increasing the m6A deposition rate (⍺m6A) results in increased nuclear localization of a transcript, due to the increased cytoplasmic decay to which m6A-containing transcripts are subjected", I would directly write "increased relative nuclear localization" or "apparent increase in nuclear localization".

      We thank the reviewer for this careful observation. We have modified the quoted sentence, and also sought to correct additional instances of ambiguity in the text.

      Also, it is important to ensure that all relationships are described correctly. For example, in the sentence: "This model recovers the positive association between m6A and nuclear localization but gives rise to a positive association between m6A and decay", I think "decay" should be replaced with "stability". Similarly, the sentence: "Both the decrease in mRNA production rates and the reduction in export are predicted by m6ADyn to result in increasing m6A levels, ..." should it be "Both the increase in mRNA production and..."?

      We have corrected this.

      This sentence was difficult for me to understand: "Our findings raise the possibility that such changes could, at least in part, also be indirect and be mediated by the redistribution of mRNAs secondary to loss of cytoplasmic m6A-dependent decay." Please consider rephrasing it.

      We rephrased this sentence as suggested.

      (2) Figure 2d: "A final set of predictions of m6ADyn concerns m6A-dependent decay. m6ADyn predicts that (a) cytoplasmic genes will be more susceptible to increased m6A mediated decay, independent of their m6A levels, and (b) more methylated genes will undergo increased decay, independently of their relative localization (Figure 2d left) ... Strikingly, the experimental data supported the dual, independent impact of m6A levels and localization on mRNA stability (Figure 2d, right)."

      I do not understand, either from the text or from the figure, why the authors claim that m6A levels and localization independently affect mRNA stability. It is clear that "cytoplasmic genes will be more susceptible to increased m6A mediated decay", as they always show shorter half-lives (top-to-bottom perspective in Figure 2d). Nonetheless, as I understand it, the effect is not "independent of their m6A levels", as half-lives are clearly the shortest with the highest m6A levels (left-to-right perspective in each row).

      The two-dimensional heatmaps allow for exploring conditional independence between conditions. If an effect (in this case delta half-life) is a function of the X axis (in this case m6A levels), continuous increases should be seen going from one column to another. Conversely, if it is a function of the Y axis (in this case localization), a continuous effect should be observed from one row to another. Given that effects are generally observed both across rows and across columns, we concluded that the two act independently. The fact that half-life is shortest when genes are most cytoplasmic and have the highest m6A levels is therefore not necessarily inconsistent with two effects acting independently, but instead interpreted by us as the additive outcome of two independent effects. Having said this, a close inspection of this plot does reveal a very low impact of localization in contexts where m6A levels are very low, which could point at some degree of synergism between m6A levels and localization. We have therefore now revised the text to avoid describing the effects as "independent."

      (3) The methods part should be extended. For example, the description of the mRNA half-life estimation is far too short and lacks details. Also, information on the PCA analysis (Figure 4e & f) is completely missing. The code should be made available, at least for the differential model.

      We thank the reviewer for this point and expanded the methods section on mRNA stability analysis and PCA. Additionally, we added a supplementary file, providing R code for a basic m6ADyn simulation of m6A depleted to normal conditions (added Source Code 1).

      https://docs.google.com/spreadsheets/d/1Wy42QGDEPdfT-OAnmH01Bzq83hWVrYLsjy_B4n CJGFA/edit?usp=sharing

      (4) Figure 4e, f: The authors use a PCA analysis to achieve an unbiased ranking of genes based on their m6A level changes. From the present text and figures, it is unclear how this PCA was performed. Besides a description in the methods sections, the authors could show additional evidence that the PCA results in a meaningful clustering and that PC1 indeed captures induced/reduced m6A level changes for high/low-PC1 genes.

      We have added passages to the text, hoping to clarify the analysis approach.

      (5) In Figure 4i, I was surprised about the m6A dynamics for the HSF1-independent genes, with two clusters of increasing or decreasing m6A levels across the time course. Can the model explain these changes? Since expression does not seem to be systematically altered, are there differences in subcellular localization between the two clusters after heat shock?

      A general aspect of our manuscript is attributing changes in m6A levels during heat stress to alterations in mRNA metabolism, such as production or export. As shown in Supplementary Figure 4d, even in WT conditions, m6A level changes are not strictly associated with apparent changes in expression, but we try to show that these are a reflection of the decreased export rate. In the specific context of HSF1-dependent stress response genes, we observe a clear co-occurrence of increased m6A levels with increased expression levels, which we propose to be attributed to enhanced production rates during heat stress. This suggests that transcriptional induction can drive the apparent rise in m6A levels. We try to control this with the HSF1 KO cells, in which the m6A level changes, as the increased production rates are absent for the specific cluster of stress-induced genes, further supporting the role of transcriptional activation in shaping m6A levels for these genes. For HSF1-independent genes, the HSF-KO cells mirror the behavior of WT conditions when looking at 500 highest and lowest PC1 (based on the prior analysis in WT cells), suggesting that changes in m6A levels are primarily driven by altered export rates rather than changes in production.

      Among the HSF1 targets, Hspa1a seems to show an inverse behaviour, with the highest methylation in ctrl, even though expression strongly goes up after heat shock. Is this related to the subcellular localization of this particular transcript before and after heat shock?

      Upon reviewing the heat stress target genes, we identified an issue with the proper labeling of the gene symbols, which has now been corrected (Figure 4 panel i). The inverse behavior observed for Hspb1 and partially for Hsp90aa1 is not accounted for by the m6ADyn model, and is indeed an interesting exception with respect to all other induced genes. Further investigation will be required to understand the methylation dynamics of Hspb1 during the response to heat stress.

      Reviewer #3 (Recommendations for the authors):

      Page 4. Indicate reference for "a more recent study finding reduced m6A levels in chromatin-associated RNA.".

      We thank the reviewer for this point and added two publications with a very recent one, both showing that chromatin-associated nascent RNA has less m6A methylation

      The manuscript is perhaps a bit too long. It took me a long time to get to the end. The findings can be clearly presented in a more concise manner and that will ensure that anyone starting to read will finish it. This is not a weakness, but a hope that the authors can reduce the text.

      We have respectfully chosen to maintain the length of the manuscript. The model, its predictions and their relationship to experimental observations are somewhat complex, and we felt that further reduction of the text would come at the expense of clarity.

    1. Author response:

      The following is the authors’ response to the original reviews.

      We would like to thank all the reviewers for their positive evaluation of our paper, as described in the Strengths section. We are also grateful for their helpful comments and suggestions, which we have addressed below. We believe that the manuscript has been significantly improved as a result of these suggestions. In addition to these changes, we also corrected some inconsistencies (statistical values in the last sentence of a Figure 5 caption) and sentences in the main text (lines 155, 452, 522) (these corrections did not affect the results).

      Fig. 5e: R=0.599, P<0.001 -> R=0.601, P=0.007

      L150: "the angle of stick tilt angle" -> "the angle of stick tilt"

      L437: "no such" -> "such"

      L522: "?" -> "."

      Reviewer #1 (Public Review):

      Summary/Strengths:

      This manuscript describes a stimulating contribution to the field of human motor control. The complexity of control and learning is studied with a new task offering a myriad of possible coordination patterns. Findings are original and exemplify how baseline relationships determine learning.

      Weaknesses:

      A new task is presented: it is a thoughtful one, but because it is a new one, the manuscript section is filled with relatively new terms and acronyms that are not necessarily easy to rapidly understand.

      First, some more thoughts may be devoted to the take-home message. In the title, I am not sure manipulating a stick with both hands is a key piece of information. Also, the authors appear to insist on the term ‘implicit’, and I wonder if it is a big deal in this manuscript and if all the necessary evidence appears in this study that control and adaptation are exclusively implicit. As there is no clear comparison between gradual and abrupt sessions, the authors may consider removing at least from the title and abstract the words ‘implicit’ and ‘implicitly’. Most importantly, the authors may consider modifying the last sentence of the abstract to clearly provide the most substantial theoretical advance from this study.

      Thank you for your positive comment on our paper. We agree with the reviewer that our paper used a lot of acronyms that might confuse the readers. As we have addressed below (in the rebuttal to the Results section), we have reduced the number of acronyms.

      Regarding the comment on the use of the word “implicit” in the title and the abstract, we believe that its use in this paper is very important and indispensable. One of our main findings was that the pattern of adaptation between the tip-movement direction and the stick-tilt angle largely followed that in the baseline condition when aiming at different target directions. This adaptation was largely implicit because participants were not aware of the presence of the perturbation as the amount of perturbation was gradually increased. This implicitness suggests that the adaptation pattern of how the movement should be corrected is embedded in the motor learning system. On the other hand, if this adaptation pattern was achieved on the basis of the explicit strategy of changing the direction of the tip-movement, the adaptation pattern that follows the baseline pattern is not at all surprising. For these reasons, we will continue to use the word "implicit".

      It seems that a substantial finding is the ‘constraint’ imposed by baseline control laws on sensorimotor adaptation. This seems to echo and extend previous work of Wu, Smith et al. (Nat Neurosci, 2014): their findings, which were not necessarily always replicated, suggested that the more participants were variable in baseline, the better they adapted to a systematic perturbation. The authors may study whether residual errors are smaller or adaptation is faster for individuals with larger motor variability in baseline. Unfortunately, the authors do not present the classic time course of sensorimotor adaptation in any experiment. The adaptation is not described as typically done: the authors should thus show the changes in tip movement direction and stick-tilt angle across trials, and highlight any significant difference between baseline, early adaptation, and late adaptation, for instance. I also wonder why the authors did not include a few noperturbation trials after the exposure phase to study after-effects in the study design: it looks like a missed opportunity here. Overall, I think that showing the time course of adaptation is necessary for the present study to provide a more comprehensive understanding of that new task, and to re-explore the role of motor variability during baseline for sensorimotor adaptation.

      We appreciate the reviewer for raising these important issues.

      Regarding the learning curve, because the amount of perturbation was gradually increased except for Exp.1B, we were not able to obtain typical learning curves (i.e., the curve showing errors decaying exponentially with trials). However, it may still be useful to show how the movement changed with trials during adaptation. Therefore, following the reviewer's suggestion, we have added the figures of the time course of adaptation in the supplementary data (Figures S1, S2, S4, and S5).

      There are two reasons why our experiments did not include aftereffect quantification trials (i.e., probe trials). First, in the case of adaptation to a visual perturbation (e.g., visual rotation), probe trials are not necessary because the degree of adaptation can be easily quantified by the amount of compensation in the perturbation trials (however, in the case of dynamic perturbations such as force fields, the use of probe trials is necessary). Second, the inclusion of probe trials allows participants to be aware of the presence of the perturbation, which we would like to avoid.

      We also appreciate the interesting additional questions regarding the relevance of our work to the relationship between baseline motor variability and adaptation performance. As this topic, although interesting, is outside the scope of this paper, we concluded that we would not address it in the manuscript. In fact, the experiments were not ideal for quantifying motor variability in the baseline phase because participants had to aim at different targets, which could change the characteristics of motor variability. In addition, we gradually increased the size of the perturbation except for Exp.1B (see Author response image 1, upper panel), which could make it difficult to assess the speed of adaptation. Nevertheless, we think it is worth mentioning this point in this rebuttal. Specifically, we examined the correlation between baseline motor variability when aiming the 0 deg target (tip-movement direction or stick-tilt angle) and adaptation speed in Exp 1A and Exp 1B (Author response image 1 and Author response image 2). To assess adaptation speed in Exp.1A, we quantified the slope of the tip-movement direction to a gradually increasing perturbation (Author response image 1, upper panel). The adaptation speed in Exp.1B was obtained by fitting the exponential function to the data (Author response image 2, upper panel). Although the statistical results were not completely consistent, we found that the participants with greater the motor variability at baseline tended to show faster adaptation, as shown in a previous study (Wu et al., Nat Neurosci, 2014).

      Author response image 1.

      Correlation between the baseline variability and learning speed (Experiment 1A). In Exp 1A, the rotation of the tip-movement direction was gradually increased by 1 degree per trial up to 30 degrees. The learning speed was quantified by calculating how quickly the direction of movement followed the perturbation (upper panel). The lower left panel shows the variability of the tip-movement direction versus learning speed, while the lower right panel shows the variability of the stick-tilt angle versus learning speed. Baseline variability was calculated as a standard deviation across trials (trials in which a target appeared in a 0-degree direction).

      Author response image 2.

      Correlation between the baseline variability and learning speed (Experiment 1B). In Exp 1B, the rotation of the tip-movement direction was abruptly applied from the first trial (30 degrees). The learning speed was calculated as a time constant obtained by exponential curve fitting. The lower left panel shows the variability of the tip-movement direction versus learning speed, while the lower right panel shows the variability of the stick-tilt angle versus learning speed. Baseline variability was calculated as a standard deviation across trials (trials in which a target appeared in a 0-degree direction).

      The distance between hands was fixed at 15 cm with the Kinarm instead of a mechanical constraint. I wonder how much this distance varied and more importantly whether from that analysis or a force analysis, the authors could determine whether one hand led the other one in the adaptation.

      Thank you very much for this important comment. Since the distance between the two hands was maintained by the stiff virtual spring (2000 N/m), it was kept almost constant throughout the experiments as shown in Author response image 3 (the averaged distance during a movement). The distance was also maintained during reaching movements (Author response image 4).

      We also thank the reviewer for the suggestion regarding the force analysis. As shown in Author response image 5, we did not find a role for a specific hand for motor adaptation from the handle force data. Specifically, Author response image 5 shows the force applied to each handle along and orthogonal to the stick. If one hand led the other in adaptation, we should have observed a phase shift as adaptation progressed. However, no such hand specific phase shift was observed. It should be noted, however, that it was theoretically difficult to know from the force sensors which hand produced the force first, because the force exerted by the right handle was transmitted to the left handle and vice versa due to the connection by the stiff spring. 

      Author response image 3.

      The distance between hands during the task. We show the average distance between hands for each trial. The shaded area indicates the standard deviation across participants.

      Author response image 4.

      Time course changes in the distance between hands during the movement. The color means the trial epoch shown in the right legend.

      Author response image 5.

      The force profile during the movement (Exp 1A). We decomposed the force of each handle into the component along (upper panels) and orthogonal to the stick (lower panels). Changes in the force profiles in the adaptation phase are shown (left: left hand force, right: right hand force). The colors (magenta to cyan) mean trial epoch shown in the right legend.

      I understand the distinction between task- and end-effector irrelevant perturbation, and at the same time results show that the nervous system reacts to both types of perturbation, indicating that they both seem relevant or important. In line 32, the errors mentioned at the end of the sentence suggest that adaptation is in fact maladaptive. I think the authors may extend the Discussion on why adaptation was found in the experiments with end-effector irrelevant and especially how an internal (forward) model or a pair of internal (forward) models may be used to predict both the visual and the somatosensory consequences of the motor commands.

      Thank you very much for your comment. As we already described in the discussion of the original manuscript (Lines 519-538 in the revised manuscript), two potential explanations exist for the motor system’s response to the end-effector irrelevant perturbation (i.e., stick rotation). First, the motor system predicts the sensory information associated with the action and attempts to correct any discrepancies between the prediction and the actual sensory consequences, regardless of whether the error information is end-effector relevant or end-effector irrelevant. Second, given the close coupling between the tip-movement direction and stick-tilt angle, the motor system can estimate the presence of end-effector relevant error (i.e., tip-movement direction) by the presence of end-effector irrelevant error (i.e., stick-tilt angle). This estimation should lead to the change in the tip-movement direction. As the reviewer pointed out, the mismatch between visual and proprioceptive information is another possibility, we have added the description of this point in Discussion (Lines 523-526).

      Reviewer #1 (Recommendations For The Authors):

      Minor

      Line 16: “it remains poorly understood” is quite subjective and I would suggest reformulating this statement.

      We have reformulated this statement as “This limitation prevents the study of how….”  (Line 16).

      Introduction

      Line 49: the authors may be more specific than just saying ‘this task’. In particular, they need to clarify that there is no redundancy in studies where the shoulder is fixed and all movement is limited to a plane ... which turns out to truly happen in a limited set of experimental setups (for example: Kinarm exoskeleton, but not endpoint; Kinereach system...).

      We have changed this to “such a planar arm-reaching task” (Line 49).

      Line 61: large, not infinite because of biomechanical constraints.

      We have changed “an infinite” to “a large” (Line 61) and “infinite” to “a large number of” (legend in Fig. 1f).

      Lines 67-69: consider clarifying.

      We have tried to clarify the sentence (Lines 67-69).

      Results

      TMD and STA, and TMD-STA plane, are new terms with new acronyms that are not easy to immediately understand. Consider avoiding acronyms.

      We have reduced the use of these acronyms as much as possible. 

      “visual TMD–STA plane” -> “plane representing visual movement patterns” (Lines 179180)

      “TMD axis” -> “x-axis” (Line 181, Line 190)

      “physical TMD–STA plane” -> “plane representing physical movement patterns” (Lines 182-187)

      “physical TMD–STA plane” -> “physical plane” (Line 191, Line 201, Lines 216-217, Line 254, Line 301, Line 315, Line 422, Line 511, and captions of Figures 4-9, S3)

      “visual TMD–STA plane” -> “visual plane” (Line 193, Line 241, Line 248, Line 300, Lines

      313-314, and captions of Figures 4-9, S3)

      “STA axis” -> “y-axis” (Line 241)

      Line 169: please clarify the mismatch(es) that are created when the tip-movement direction is visually rotated in the CCW direction around the starting position (tip perturbation), whereas the stick-tilt angle remains unchanged.

      Thank you for your pointing this out. We have clarified that the stick-tilt angle remains identical to the tilt of both hands (Lines 171-172).

      Discussion

      I understand the physical constraint imposed between the 2 hands with the robotic device, but I am not sure I understand the physical constraint imposed by the TMD-STA relationship.

      The phrase “physical constraint” meant the constraint of the movement on the physical space. However, as the reviewer pointed out, this phrase could confuse the constraint between the two hands. Therefore, we have avoided using the phrase “physical constraint” throughout the manuscript.

      Some work looking at 3-D movements should be used for Discussion (e.g. Lacquaniti & Soechting 1982; work by d’Avella A or Jarrasse N).

      Thank you for sharing this important information. We have cited these studies in Discussion (Lines 380-382). 

      Reviewer #2 (Public Review):

      Summary:

      The authors have developed a novel bimanual task that allows them to study how the sensorimotor control system deals with redundancy within our body. Specifically, the two hands control two robot handles that control the position and orientation of a virtual stick, where the end of the stick is moved into a target. This task has infinite solutions to any movement, where the two hands influence both tip-movement direction and stick-tilt angle. When moving to different targets in the baseline phase, participants change the tilt angle of the stick in a specific pattern that produces close to the minimum movement of the two hands to produce the task. In a series of experiments, the authors then apply perturbations to the stick angle and stick movement direction to examine how either tipmovement (task-relevant) or stick-angle (task-irrelevant) perturbations affect adaptation. Both types of perturbations affect adaptation, but this adaptation follows the baseline pattern of tip-movement and stick angle relation such that even task-irrelevant perturbations drive adaptation in a manner that results in task-relevant errors. Overall, the authors suggest that these baseline relations affect how we adapt to changes in our tasks. This work provides an important demonstration that underlying solutions/relations can affect the manner in which we adapt. I think one major contribution of this work will also be the task itself, which provides a very fruitful and important framework for studying more complex motor control tasks.

      Strengths:

      Overall, I find this a very interesting and well-written paper. Beyond providing a new motor task that could be influential in the field, I think it also contributes to studying a very important question - how we can solve redundancy in the sensorimotor control system, as there are many possible mechanisms or methods that could be used - each of which produces different solutions and might affect the manner in which we adapt.

      Weaknesses:

      I would like to see further discussion of what the particular chosen solution implies in terms of optimality.

      The underlying baseline strategy used by the participants appears to match the path of minimum movement of the two hands. This suggests that participants are simultaneously optimizing accuracy and minimizing some metabolic cost or effort to solve the redundancy problem. However, once the perturbations are applied, participants still use this strategy for driving adaptation. I assume that this means that the solution that participants end up with after adaptation actually produces larger movements of the two hands than required. That is - they no longer fall onto the minimum hand movement strategy - which was used to solve the problem. Can the authors demonstrate that this is either the case or not clearly? These two possibilities produce very different implications in terms of the results.

      If my interpretation is correct, such a result (using a previously found solution that no longer is optimal) reminds me of the work of Selinger et al., 2015 (Current Biology), where participants continue to walk at a non-optimal speed after perturbations unless they get trained on multiple conditions to learn the new landscape of solutions. Perhaps the authors could discuss their work within this kind of interpretation. Do the authors predict that this relation would change with extensive practice either within the current conditions or with further exploration of the new task landscape? For example, if more than one target was used in the adaptation phase of the experiment?

      On the other hand, if the adaptation follows the solution of minimum hand movement and therefore potentially effort, this provides a completely different interpretation.

      Overall, I would find the results even more compelling if the same perturbations applied to movements to all of the targets and produced similar adaptation profiles. The question is to what degree the results derive from only providing a small subset of the environment to explore.

      Thank you very much for pointing out this significant issue. As the reviewer correctly interprets, the physical movement patterns deviated from the baseline relationship as exemplified in Exp.2. However, this deviation is not surprising for the following reason. Under the perturbation that creates the dissociation between the hands and the stick, the motor system cannot simultaneously return both the visual stick motion and physical hands motion to the original motions: When the motor system tries to return the visual stick motion to the original visual motion, then the physical hands motion inevitably deviates from the original physical hands motion, and vice versa.  

      Our interpretation of this result is that the motor system corrects the movement to reduce the visual dissociation of the visual stick motion from the baseline motion (i.e., sensory prediction error), but this movement correction is biased by the baseline physical hands motion. In other words, the motor system attempts to balance the minimization of sensory prediction error and the minimization of motor cost. Thus, our results do not indicate that the final adaptation pattern is non-optimal, but rather reflect the attempts for optimization.

      In the revised manuscript, we have added the description of this interpretation (Lines 515-517).

      Reviewer #2 (Recommendations For The Authors):

      The authors have suggested that the only study (line 472) that has also examined an end-effector irrelevant perturbation is the bimanual study of Omrani et al., 2013, which only examined reflex activity rather than adaptation. To clarify this issue - exactly what is considered end-effector irrelevant perturbations - I was wondering about the bimanual perturbations in Dimitriou et al., 2012 (J Neurophysiol) and the simultaneous equal perturbations in Franklin et al., 2016 (J Neurosci), as well as other recent papers studying task-irrelevant disturbances which aren’t discussed. I would consider these both to also be end-effector irrelevant perturbations, although again they only used these to study reflex activity and not adaptation as in the current paper. Regardless, further explanation of exactly what is the difference between task-irrelevant and end-effector irrelevant would be useful to clarify the exact difference between the current manuscript and previous work.

      Thank you for your helpful comments. We have included as references the study by Dimitriou et al. (Line 490) and Franklin et al. (Lines 486-487), which use an endeffector irrelevant perturbation and the task-irrelevant perturbation condition, respectively. We have also added further explanation of what is the difference between task-irrelevant and end-effector irrelevant (Lines 344-352). 

      Line 575: I assume that you mean peak movement speed

      We have added “peak”. (Line 597).

      Reviewer #3 (Public Review):

      Summary:

      This study explored how the motor system adapts to new environments by modifying redundant body movements. Using a novel bimanual stick manipulation task, participants manipulated a virtual stick to reach targets, focusing on how tip-movement direction perturbations affected both tip movement and stick-tilt adaptation. The findings indicated a consistent strategy among participants who flexibly adjusted the tilt angle of the stick in response to errors. The adaptation patterns are influenced by physical space relationships, guiding the motor system’s choice of movement patterns. Overall, this study highlights the adaptability of the motor system through changes in redundant body movement patterns.

      Strengths:

      This paper introduces a novel bimanual stick manipulation task to investigate how the motor system adapts to novel environments by altering the movement patterns of our redundant body.

      Weaknesses:

      The generalizability of the findings is quite limited. It would have been interesting to see if the same relationships were held for different stick lengths (i.e., the hands positioned at different start locations along the virtual stick) or when reaching targets to the left and right of a start position, not just at varying angles along one side. Alternatively, this study would have benefited from a more thorough investigation of the existing literature on redundant systems instead of primarily focusing on the lack of redundancy in endpointreaching tasks. Although the novel task expands the use of endpoint robots in motor control studies, the utility of this task for exploring motor control and learning may be limited.

      Thank you very much for the important comment. Given that there are many parameters (e.g., stick length, locations of hands, target position etc), one may wonder how the findings obtained from only one combination can be generalized to other configurations. In the revised manuscript, we have explicitly described this point (Lines 356-359). 

      Thus, the generalizability needs to be investigated in future studies, but we believe that the main results also apply to other configurations. Regarding the baseline stick movement pattern, the control with tilting the stick was observed regardless of the stick-tip positions (Author response image 6). Regarding the finding that the adapted stick movement patterns follow the baseline movement patterns, we confirmed the same results even when the other targets were used as the target for the adaptation (Author response image 7). 

      Author response image 6.

      Stick-tip manipulation patterns when the length of the stick varied. Top: 10 naïve participants moved the stick with different lengths. A target appeared on one of five directions represented by a color of each tip position. Regardless of the length of the stick and laterality, a similar relationship between tip-movement direction and stick-tilt angle was observed. (middle: at peak velocity, bottom: at movement offset).

      Author response image 7.

      Patterns of adaptation when using the other targets. In the baseline phase, 40 naïve participants moved a stick tip to a peripheral target (24 directions). They showed a stereotypical relationship between the tip-movement direction and the stick-tilt angle (a bold gray curve). In the adaptation phase, participants were divided into four groups, each with a different target training direction (lower left, lower right, upper right, or upper left), and visual rotation was gradually imposed on the tip-movement direction. Irrespective of the target direction, the adaptation pattern of the tipmovement and stick-tilt followed with the baseline relationship.

      We also thank you for your comment about studying the existing redundant systems. We can understand the reviewer's concern about the usefulness of our task, but we believe that we have proposed the novel framework for motor adaptation in the redundant system. The future studies will be able to clarify how the knowledge gained from our task can be generally applied to understand the control and learning of the redundant system.

      Reviewer #3 (Recommendations For The Authors):

      Line 49: replace “uniquely” with primarily. A number of features of the task setup could affect the joint angles, from if/how the arm is supported, whether the wrist is fixed, alignment of the target in relation to the midline of the participant, duration of the task, and whether fatigue is an issue, etc. Your statement relates to fixed limb lengths of a participant, rather than standard reaching tasks as a whole. Not to mention the degree of inter- and intra-subject variability that does exist in point-to-point reaching tasks.

      Thank you for your helpful point. We have replaced “uniquely” with “primarily”. (Line 49).

      Line 72: the cursor is not an end-effector - it represents the end-effector.

      We have changed the expression as “the perturbation to the cursor representing the position of the end-effector (Line 72).

      Lines 73 – 78: it would benefit the authors to consider the role of intersegmental dynamics.

      Thank you for your suggestion. We are not sure if we understand this suggestion correctly, but we interpret that this suggestion to mean that the end-effector perturbation can be implemented by using the perturbation that considers the intersegmental dynamics. However, the implementation is not so straightforward, and the panels in Figure 1j,k are only conceptual for the end-effector irrelevant perturbation. Therefore, we have not described the contribution of intersegmental dynamics here.

      Lines 90 – 92: “cannot” should be “did not”, as the studies being referenced are already completed. This statement should be further unpacked to explain what they did do, and how that does not meet the requirement of redundancy in movement patterns.

      We have changed “cannot” to “did not” (Line 91). We have also added the description of what the previous studies had demonstrated (Line 88-90).

      Figure text could be enlarged for easier viewing.

      We have enlarged texts in all figures. 

      Lines 41 - 47: Interesting selection of supporting references. For the introduction of a novel environment, I would recommend adding the support of Shadmehr and MussaIvaldi 1994.

      Thank you for your suggestion. We have added Shadmehr and Mussa-Ivaldi 1994 as a reference (Line 45).

      Line 49: “this task” is vague - the above references relate to a number of different tasks. For example, the authors could replace it with a reaching task involving an end-point robot.

      Thank you very much for your suggestion. As per the suggestion by Reviewer #1, we have changed this to “such a planar arm-reaching task” (Line 49).

      Line 60: “hypothetical limb with three joints” - in Figure 1a, the human subject, holding the handle of a robotic manipulandum does have flexibility around the wrist.

      Previous studies using planar arm-reaching task have constrained the wrist joint (e.g., Flash & Hogan, 1985; Gordon et al., 1994; Nozaki et al., 2006). We tried to emphasize this point as “participants manipulate a visual cursor with their hands primarily by moving their shoulder and elbow joints” (Line 42). In the revised manuscript, we have also emphasized this point in the legend of Figure 1a.

      Lines 93-108: this paragraph could be cleaned up more clearly stating that while the use of task-irrelevant perturbations has been used in the domain of reaching tasks, the focus of these tasks has not been specifically to address “In our task, we aim to exploit this feature by doing”

      Thank you very much for your helpful comments. To make this paragraph clear, we have modified some sentences (Line 100-104).

      Line 109: “coordinates to adapt” is redundant.

      We have changed this to “adapts” (Line 110).

      Lines 109-112: these sentences could be combined to have better flow.

      Thank you very much for your valuable suggestion. We have combined these two sentences for the better flow (Line 110-112).

      Line 113-114: consider rewording - “This is a redundant task because ...” to something like “Redundancy in the task is achieved by acknowledging that ....“.

      We have changed the expression according to the reviewer’s suggestion (Line 114).

      Line 118: Consider changing “changes” to “makes use of”.

      We have changed the expression (Line 119).

      Lines 346 - 348: grammar and clarity - “This redundant motor task enables the investigation of adaptation patterns in the redundant system following the introduction of perturbations that are either end-effector relevant, end-effector irrelevant, or both.“.

      Thank you very much again for your helpful suggestion of English expression. We have adopted the sentence you suggested (Line 354-356).

    1. Dear editors and reviewers, Thank you for your careful reading of my manuscript and the detailed and insightful feedback. It has contributed significantly to the improvements in the revised version. Please find my detailed responses below.

      1 Reviewer 1

      Thank you for this helpful review, and in particular for pointing out the need for more references, illustrations, and examples in various places of my manuscript. In the case of the section on experimental software, the search for examples made clear to me that the label was in fact badly chosen. I have relabeled the dimension as “stable vs. evolving software”, and rewritten the section almost entirely. Another major change motivated by your feedback is the addition of a figure showing the structure of a typical scientific software stack (Fig. 2), and of three case studies (section 2.7) in which I evaluate scientific software packages according to my five dimensions of reviewability. The discussion of conviviality (section 2.4), a concept that is indeed not widely known yet, has been much expanded. I have followed the advice to add references in many places. I have been more hesitant to follow the requests for additional examples and illustrations, because of the inevitable conflict with the equally understandable request to make the paper more compact. In many cases, I have preferred to refer to examples discussed in the literature. A few comments deserve a more detailed reply:

      Introduction

      Highlight [page 3]: In fact, we do not even have established processes for performing such reviews

      and Note [page 3]: I disagree, there is the Journal of Open Source Software: https://joss.theoj.org/, rOpenSci has a guide for development of peer review of statistical software: https://github.com/ropensci/statistical software-review-book, and also maintain a very clear process of software review: https://ropensci.org/software-review/

      As I say in the section “Review the reviewable”, these reviews are not independent critical examination of the software as I define it. Reviewers are not asked to evaluate the software’s correctness or appropriateness for any specific purpose. They are expected to comment only on formal characteristics of the software publication process (e.g. “is there a license?”), and on a few software engineering quality indicators (“is there a test suite?”).

      Highlight [page 3]: This means that reviewing the use of scientific software requires particular attention to potential mismatches between the software’s behavior and its users’ expectations, in particular concerning edge cases and tacit assumptions made by the software developers. They are necessarily expressed somewhere in the software’s source code, but users are often not aware of them.

      and Note [page 3]: The same can be said of assumptions for equations and mathematics- the problem here is dealing with abstraction of complexity and the potential unintended consequences.

      Indeed. That’s why we need someone other than the authors to go through mathematical reasoning and verify it. Which we do.

      Reviewability of automated reasoning systems

      Wide-spectrum vs. situated software

      Highlight [page 6]: Situated software is smaller and simpler, which makes it easier to understand and thus to review.

      and Note [page 6]: I’m not sure I agree it is always smaller and simpler- the custom code for a new method could be incredibly complicated.

      The comparison is between situated software and more generic software performing the same operation. For example, a script reading one specific CSV file compared to a subroutine reading arbitrary CSV files. I have yet to see a case in which abstraction from a concrete to a generic function makes code smaller or simpler.

      Convivial vs. proprietary software

      Highlight [page 8]: most of the software they produced and used was placed in the public domain

      and Note [page 8]: Can you provide an example of this? I’m also curious how the software was placed in the public domain if there was no way to distribute it via the internet.

      Software distribution in science was well organized long before the Internet, it was just slower and more expensive. Both decks of punched cards and magnetic tapes were routinely sent by mail. The earliest organized software distribution for science I am aware of was the DECUS Software Library in the early 1960s.

      Size of the minimal execution environment

      Note [page 11]: Could you provide an example of what it might look like if they were in mainstream computational science? For example, https://github.com/ropensci/rix implements using reproducible environments for R with NIX. What makes this not mainstream? Are you talking about mainstream in the sense of MS Excel? SPSS/SAS/STATA?

      I have looked for quantitative studies on software use in science that would allow to give a precise meaning to “mainstream”, but I have not been able to find any. Based on my personal experience, mostly with teaching MOOCs on computational science in which students are asked about the software they use, the most widely used platform is Microsoft Windows. Linux is already a minority platform (though overrepresented in computer science), and Nix users are again a small minority among Linux users.

      Analogies in experimental and theoretical science

      Highlight [page 13]: which an experienced microscopist will recognize. Soft ware with a small defect, on the other hand, can introduce unpredictable errors in both kind and magnitude, which neither a domain expert nor a professional programmer or computer scientist can diag- nose easily.

      and Note [page 13]: I don’t think this is a fair comparison. Surely there must be instances of experiences microscopists not identifying defects? Similarly, why can’t there be examples of domain expert or professional program mer/computer scientist identifying errors. Don’t unit tests help protect us against some of our errors? Granted, they aren’t bullet proof, and perhaps act more like guard rails.

      There are probably cases of microscopists not noticing defects, but my point is that if you ask them to look for defects, they know what to do (and I have made this clearer in my text). For contrast, take GROMACS (one of my case studies in the revised manuscript) and ask either an expert programmer or an experienced computational biophysicist if it correctly implements, say, the AMBER force field. They wouldn’t know what to do to answer that question, both because it is ill-defined (there is no precise definition of the AMBER force field) and because the number of possible mistakes and symptoms of mistakes is enormous. I have seen a protein simulation program fail for proteins whose number of atoms was in a narrow interval, defined by the size that a compiler attributed to a specific data structure. I was able to catch and track down this failure only because a result was obviously wrong for my use case. I have never heard of similar issues with microscopes.

      Improving the reviewability of automated reasoning systems

      Review the reviewable

      Highlight [page 15]: The main difficulty in achieving such audits is that none of today’s scientific institutions consider them part of their mission.

      and Note [page 15]: I disagree. Monash provides an example here where they view software as a first class research output: https://robjhyndman.com/files/EBS_research_software.pdf

      This example is about superficial reviews in the context of career evaluation. Other institutions have similar processes. As far as I know, none of them ask reviewers to look at the actual code and comment on its correctness or its suitability for some specific purpose.

      Science vs. the software industry

      Highlight [page 15]: few customers (e.g. banks, or medical equipment manufacturers) are willing to pay for

      and Note [page 15]: What about software like SPSS/STATA/SAS- surely many many industries, and also researchers will pay for software like this that is considered mature?

      I could indeed extend the list of examples to include various industries. Compared to the huge number of individuals using PCs and smartphones, that’s still few customers.

      Emphasize situated and convivial software

      Note [page 16]: Could the author provide a diagram or schematic to more clearly show how such a system would work with forks etc?

      I have decided the contrary: I have significantly shortened this section, removing all speculation about how the ideas could be turned into concrete technology. The reason is that I have been working on this topic since I wrote the reviewed version of this manuscript, and I have a lot more to say about it than would be reasonable to include in this work. This will become a separate article.

      Make scientific software explainable

      Note [page 18]: I think it would be very beneficial to show screenshots of what the author means- while I can follow the link to Glamorous Toolkit, bitrot is a thing, and that might go away, so it would good to see exactly what the author means when they discuss these examples.

      Unfortunately, static screenshots can only convey a limited impression of Glamorous Toolkit, but I agree that they have are a more stable support than the software itself. Rather than adding my own screenshots, I refer to a recent paper by the authors of Glamorous Toolkit that includes many screenshots for illustration.

      Use Digital Scientific Notations

      Highlight [page 19]: formal specifications and Note [page 19]: It would be really helpful if you could demonstrate an example of a formal specification so we can understand how they could be considered constraints.

      Highlight [page 19]: Moreover, specifications are usually more modular than algorithms, which also helps human readers to better understand what the software does [Hinsen 2023]

      and Note [page 19]: A tight example of this would be really useful to make this point clear. Perhaps with a figure of a specification alongside an algorithm.

      I do give an example: sorting a list. To write down an actual formalized version, I’d have to introduce a formal specification language and explain it, which I think goes well beyond the scope of this article. Illustrating modularity requires an even larger example. This is, however, an interesting challenge which I’d be happy to take up in a future article.

      Highlight [page 19]: In software engineering, specifications are written to formalize the expected behavior of the software before it is written. The software is considered correct if it conforms to the specification.

      and Note [page 19]: Is an example of this test drive development?

      Not exactly, though the underlying idea is similar: provide a condition that a result must satisfy as evidence for being correct. With testing, the condition is spelt out for one specific input. In a formal specification, the condition is written down for all possible inputs.

      2 Reviewer 2

      First of all, I would like to thank the reviewer for this thoughtful review. It addresses many points that require clarifications in the my article, which I hope to have done adequately in the revised version.

      One such point is the role and form of reviewing processes for software. I have made it clearer that I take “review” to mean “critical independent inspection”. It could be performed by the user of a piece of software, but the standard case should be a review performed by experts at the request of some institution that then publishes the reviewer’s findings. There is no notion of gatekeeping attached to such reviews. Users are free to ignore them. Given that today, we publish and use scientific software without any review at all, the risk of shifting to the opposite extreme of having reviewers become gatekeepers seems unlikely to me.

      Your comment on users being software developers addresses another important point that I had failed to make clear: conviviality is all about diminishing the distinction between developers and users. Users gain agency over their computations at the price of taking on more of a developer role. This is now stated explicitly in the revised article. Your hypothesis that I want scientific software to be convivial is only partially true. I want convivially structured software to be an option for scientists, with adequate infrastructure and tooling support, but I do not consider it to be the best approach for all scientific software.

      The paragraph on the relevance and importance of reviewing in your comment is a valid point of view but, unsurprisingly, not mine. In the grand scheme of science, no specific quality assurance measure is strictly necessary. There is always another layer above that will catch mistakes that weren’t detected in the layer below. It is thus unlikely that unreliable software will cause all of science to crumble. But from many perspectives, including overall efficiency, personal satisfaction of practitioners, and insight derived from the process, it is preferable to catch mistakes as closely as possible to their source. Pre-digital theoreticians have always double-checked their manual calculations before submitting their papers, rather than sending off unchecked results and count on confrontation with experiment for finding mistakes. I believe that we should follow this same approach with software. The cost of mistakes can be quite high. Consider the story of the five retracted protein structures that I cite in my article (Miller, 2006, 10.1126/science.314.5807.1856). The five publications that were retracted involved years of work by researchers, reviewers, and editors. In between their publication and their retraction, other protein crystallographers saw their work rejected because it was in contradiction with the high-profile articles that later turned out to be wrong. The whole story has probably involved a few ruined careers in addition to its monetary cost. In contrast, independent critical examination of the software and the research processes in which it was used would likely have spotted the problem rather quickly (Matthews, 2007).

      You point out that reviewability is also a criterion in choosing software to build on, and I agree. Building on other people’s software requires trusting it. Incorporating it into one’s own work (the core principle of convivial software) requires understanding it. This is in fact what motivated my reflections on this topic. I am not much interested in neatly separating epistemic and practical issues. I am a practitioner, my interest in epistemology comes from a desire for improving practices.

      Review holism is something I have not thought about before. I consider it both impossible to apply in practice and of little practical value. What I am suggesting, and I hope to have made this clearer in my revision, is that reviewing must take into account the dependency graph. Reviewing software X requires a prior review of its dependencies (possibly already done by someone else), and a consideration of how each dependency influences the software under consideration. However, I do not consider Donoho’s “frictionless reproducibility” a sufficient basis for trust. It has the same problem as the widespread practice of tacitly assuming a piece of software to be correct because it is widely used. This reasoning is valid only if mistakes have a high chance of being noticed, and that’s in my experience not true for many kinds of research software. “It works”, when pronounced by a computational scientist, really means “There is no evidence that it doesn’t work”.

      This is also why I point out the chaotic nature of computation. It is not about Humphreys’ “strange errors”, for which I have no solution to offer. It is about the fact that looking for mistakes requires some prior idea of what the symptoms of a mistake might be. Experienced researchers do have such prior ideas for scientific instruments, and also e.g. for numerical algorithms. They come from an understanding of the instruments and their use, including in particular a knowledge of how they can go wrong. But once your substrate is a Turing-complete language, no such understanding is possible any more. Every programmer has made the experience of chasing down some bug that at first sight seems impossible. My long-term hope is that scientific computing will move towards domain-specific languages that are explicitly not Turing-complete, and offer useful guarantees in exchange. Unfortunately, I am not aware of any research in this space.

      I fully agree with you that internalist justifications are preferable to reliabilistic ones. But being fundamentally a pragmatist, I don’t care much about that distinction. Indisputable justification doesn’t really exist anywhere in science. I am fine with trust that has a solid basis, even if there remains a chance of failure. I’d already be happy if every researcher could answer the question “why do you trust your computational results?” in a way that shows signs of critical reflection.

      What I care about ultimately is improving practices in computational science. Over the last 30 years, I have seen numerous mistakes being discovered by chance, often leading to abandoned research projects. Some of these mistakes were due to software bugs, but the most common cause was an incorrect mental model of what the software does. I believe that the best technique we have found so far to spot mistakes in science is critical independent inspection. That’s why I am hoping to see it applied more widely to computation.

      2.1 References

      Miller, G. (2006) A Scientist’s Nightmare: Software Problem Leads to Five Retractions. Science 314, 1856. https://doi.org/10.1126/science.314.5807.1856

      Matthews, B.W. (2007) Five retracted structure reports: Inverted or incorrect? Protein Science 16, 1013. https://doi.org/10.1110/ps.072888607

      3 Editor

      Bayesian methods often use MCMC, which is often slow and creates long chains of estimates; however, the chains will show if the likelihood does not have a clear maximum, which is usually from a badly specified model...

      That is an interesting observation I haven’t seen mentioned bedore. I agree that Bayesian inference is particularly amenable to inspection. One more reason to normalize inspection and inspectability in computational science.

      Some reflection on the growing use of AI to write software may be worthwhile.

      The use of AI in writing and reviewing software is a topic I have considered for this review, since the technology has evolved enormously since I wrote the current version of the manuscript. However, in view of reviewer 1’s constant admonition to back up statements with citations, I refrained from delving into this topic. We all know it’s happening, but it’s too early to observe a clear impact on research software. I have therefore limited myself to a short comment in the Conclusion section.

      I wondered if highly-used software should get more scrutiny.

      This is an interesting suggestion. If and when we get serious about reviewing code, resource allocation will become an important topic. For getting started, it’s probably more productive to review newly published code than heavily used code, because there is a better chance that authors actually act on the feedback and improve their code before it has many users. That in turn will help improve the reviewing process, which is what matters most right now, in my opinion.

      “supercomputers are rare”, should this be “relatively rare” or am I speaking from a privileged university where I’ve always had access to supercomputers.

      If you have easy access to supercomputer, you should indeed consider yourself privileged. But did you ever use supercomputer time for reviewing someone else’s work? I have relatively easy access to supercomputers as well, but I do have to make a re quest and promise to do innovative research with the allocated resources.

      I did think about “testthat” at multiple points whilst reading the paper (https://testthat.r-lib.org/)

      I hadn’t seen “testthat” before, not being much of a user of R. It looks interesting, and reminds me of similar test support features in Smalltalk which I found very helpful. Improving testing culture is definitely a valuable contribution to improving computational practices.

      Can badges on github about downloads and maturity help (page 7)?

      Badges can help, on GitHub or elsewhere, e.g. in scientific software catalogs. I see them as a coarse-grained output of reviewing. The right balance to find is between the visibility of a badge and the precision of a carefully written review report. One risk with badges is the temptation to automate the evaluation that leads to it. This is fine for quantitative measures such as test coverage, but what we mostly lack today is human expert judgement on software.

  23. inst-fs-iad-prod.inscloudgate.net inst-fs-iad-prod.inscloudgate.net
    1. nstead, poor children often feel isolated and unloved, feelings that kick off a downward spiral of unhappy life events, including poor academic performance, behavioral problems, dropping out of school, and drug abuse. These events tend to rule out col-lege as an option and perpetuate the cycle of poverty

      This section demonstrates the profound emotional and social difficulties that impoverished children face. It's heartbreaking to see how a child's confidence and hope may be destroyed by a lack of support and ongoing stress. It reminds me how unfair it is that circumstances beyond of their control mold their future.

    2. eel if your son or daughter were a student in Mr. Hawkins’s class? Only two short generations ago, policymakers, school lead-ers, and teachers commonly thought of children raised in poverty with sym-pathy but without an understanding of how profoundly their chances for success were diminished by their situation. Today, we have a broad research base that clearly outlines the ramifi cations of living in poverty as well as evi-dence of schools that do succeed with economically disadvantaged students. We can safely say that we have no excuse to let any child fail. Poverty calls for key information and smarter strategie

      I find this passage powerful because it shows how much progress education has made in understanding the effects of poverty, and it reminds me that teachers can truly change the path of disadvantaged students. I agree that knowing the challenges of poverty should lead to better strategies instead of lower expectations, since every child deserves a fair chance to succeed. My question is how schools can prepare teachers to recognize and respond to poverty in a way that empowers students rather than making them feel pitied.

  24. inst-fs-iad-prod.inscloudgate.net inst-fs-iad-prod.inscloudgate.net
    1. high-poverty secondary schools for over a dozen years woke meup to the educational injustices that arc forged by economic injustice and howthose injustices trickle up and out of high school and into college. My student

      This text made me think about things deeper than I did before. The teacher realizing here that many of her students did not attend community college or any college at all gave her a deep sense of frustration. From her experience, many kids were already uninterested in learning, but many times it seems as if they were set up that way, and the system failed them. This reminds me that many times the way the educational system is not fair; what may seem fair and achievable for some may not for others, which is the most upsetting part to me. Relating to one of our first texts, this reminds me of how school is supposed to be an equalizer for all people, but it seems like it actually does the opposite.

      When the teacher realizes all of the educational justices, it reminds me of when I was young and my mom was a high school teacher in Detroit, Michigan. Detroit is a very diverse area with low income. She was furious with the injustices of the school system, and I was exposed to much of the truth at a young age. I was still very young at this time, and fortunate enough to go to a private school at this time, but I felt for these kids.

    1. Mark Johanson. Can your boss read your work messages? BBC, February 2022. URL:

      This reminds me of how nearly everything on school laptops are usually monitored. I feel like people shouldn't use work/school technology for anything personal or private because it is definitely not private. The article stated that companies usually monitor employees for security reasons, especialy when they deal with sensitive materials.

    2. Rachel Quigley. First picture of the American builder ‘shot dead by McAfee software tycoon who went on the run’ (and he’s posing with Michael Jordan). Mail Online, November 2012. URL: https://www.dailymail.co.uk/news/article-2231953/John-McAfee-US-builder-shot-dead-software-tycoon-went-run-poses-Michael-Jordan.html (visited on 2023-12-06). [i23] Alex Wilhelm. Vice leaves metadata in photo of John McAfee, pinpointing him to a location in Guatemala. The Next Web, December 2012. URL: https://thenextweb.com/news/vice-leaves-metadata-in-photo-of-john-mcafee-pinpointing-him-to-a-location-in-guatemala (visited on 2023-12-06).

      This story is absolutely absurd. McAffee has excuse after excuse and contingency plan after contingency plan. He provides nothing about why he was in Belize to begin with. Reminds me of Alfred Inglethorp from Agatha Christie's The Mysterious affair at Styles, except Inglethorp had a very good reason to behave extremely suspicious. McAffee just sounds like hes in pure panic mode, but still has time for Vice to boost his ego? Again, its just absurd.

  25. social-media-ethics-automation.github.io social-media-ethics-automation.github.io
    1. We might want to avoid the consequences of something we’ve done (whether ethically good or bad), so we keep the action or our identity private

      This reminds me about a recent online controversy in my community where a very famous hijab brand's owner had a previous racist picture resurface online. Even though she had apologized for it multiple times the people of the black muslim community don't feel comfortable buying from her because of her previous actions. Which brings me to my point that digital footprint doesn't ever leave no matter how private it may seem.

    2. When we use social media platforms though, we at least partially give up some of our privacy.

      I found how users often feel they’ve lost control over their data interesting — it reminds me of the moments when I accept a “Cookie/Privacy” pop-up without really reading it, then later wonder how much the platform knows about my interests.

    3. For example, a social media application might offer us a way of “Private Messaging” [i1] (also called Direct Messaging) with another user. But in most cases those “private” messages are stored in the computers at those companies, and the company might have computer programs that automatically search through the messages, and people with the right permissions might be able to view them directly.

      I find this section very relatable because it captures how fragile our sense of privacy really online. The example of private messaging makes me think about how I often assume my DMs are confidential, even though they are stored and possibly analyzes by the platform itself. What feels private to users is often just conveniently invisible. I think this blurring between private and public spaces is what makes digital privacy so psychologically complex. It's not only about hiding information but about controlling context and audience. The idea that company can read what I write to a friend reminds me that privacy online is less of a right and more of a temporary permission.

    1. For example, social media data about who you are friends with might be used to infer your sexual orientation [h9]. Social media data might also be used to infer people’s: Race Political leanings Interests Susceptibility to financial scams Being prone to addiction (e.g., gambling) Additionally, groups keep trying to re-invent old debunked pseudo-scientific (and racist) methods of judging people based on facial features (size of nose, chin, forehead, etc.), but now using artificial intelligence [h10]. Social media data can also be used to infer information about larger social trends like the spread of misinformation [h11].

      I found this section both fascinating and unsettling. It shows how data that seems harmless, like who our friends are or what we buy, can be mined to infer extremely private information about us. As someone who often shares content online without much thought, it's alarming to realize how easily patterns can reveal aspects of our identity that we never explicitly disclose. The example of groups reviving racist pseudoscience through AI is especially disturbing. It reminds me that technological innovation can still recycle old forms of discrimination. It makes me question whether data mining is truly about knowledge discovery or if it's pften about reinforcing existing power and bias under a new technical name.

  26. sk-sagepub-com.offcampus.lib.washington.edu sk-sagepub-com.offcampus.lib.washington.edu
    1. One of the main goals of social media sites is to increase the time users are spending on their social media sites. The more time users spend, the more money the site can get from ads, and also the more power and influence those social media sites have over those users. So social media sites use the data they collect to try and figure out what keeps people using their site, and what can they do to convince those users they need to open it again later.

      This reminds me of the saying "if you're not paying for the product, you are the product". I feel like it's a little disturbing to realize how much data social media takes from you. I wonder if theres an ethical way to do this that limits privacy infringement because I feel like targeted ads could be useful in some cases, for both consumers and business owners.