This study assessed the relationship between cell phone use and actual college grade point average (GPA) after controlling for known predictors

differentiating with respect to a squared quantity rather than a single quantity

overlinetor identity

Last updated Sep 8, 2023 Save as PDF Fundamentals De Broglie thermal wavelength picture_as_pdfFull BookPageDonate /*<![CDATA[*/ window.hypothesisConfig = function () { return { "showHighlights": false }; }; //localStorage.setItem('darkMode', 'false'); window.beelineEnabled = true; document.getElementsByTagName('head')[0].prepend(document.getElementById('mt-screen-css'),document.getElementById('mt-print-css')); //$('head').prepend($('#mt-print-css')); //$('head').prepend($('#mt-screen-css'));/*]]>*/ Page ID346 /*<![CDATA[*/window.addEventListener('load', ()=>LibreTexts.TOC(undefined, undefined, true));/*]]>*/ /*<![CDATA[*/ //CORS override LibreTexts.getKeys().then(()=>{ if(!$.ajaxOld){ $.ajaxOld = $.ajax; $.ajax = (url, options)=> { if(url.url && url.url.includes('.libretexts.org/@api/deki/files')) { let [subdomain, path] = LibreTexts.parseURL(); let token = LibreTexts.getKeys.keys[subdomain]; url.headers = Object.assign(url.headers || {}, {'x-deki-token':token}); } else if (typeof url === 'string' && url.includes('.libretexts.org/@api/deki/files')){ let [subdomain, path] = LibreTexts.parseURL(); let token = LibreTexts.getKeys.keys[subdomain]; options.headers = Object.assign(options.headers || {}, {'x-deki-token':token}); } return $.ajaxOld(url, options); } } });/*]]>*/ \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }  \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \newcommand{\id}{\mathrm{id}} \newcommand{\Span}{\mathrm{span}} \newcommand{\kernel}{\mathrm{null}\,} \newcommand{\range}{\mathrm{range}\,} \newcommand{\RealPart}{\mathrm{Re}} \newcommand{\ImaginaryPart}{\mathrm{Im}} \newcommand{\Argument}{\mathrm{Arg}} \newcommand{\norm}[1]{\| #1 \|} \newcommand{\inner}[2]{\langle #1, #2 \rangle} \newcommand{\Span}{\mathrm{span}} \newcommand{\id}{\mathrm{id}} \newcommand{\Span}{\mathrm{span}} \newcommand{\kernel}{\mathrm{null}\,} \newcommand{\range}{\mathrm{range}\,} \newcommand{\RealPart}{\mathrm{Re}} \newcommand{\ImaginaryPart}{\mathrm{Im}} \newcommand{\Argument}{\mathrm{Arg}} \newcommand{\norm}[1]{\| #1 \|} \newcommand{\inner}[2]{\langle #1, #2 \rangle} \newcommand{\Span}{\mathrm{span}}\newcommand{\AA}{\unicode[.8,0]{x212B}} Table of contents IntroductionCommon Physical ChangesTextureColorTemperatureShapeChange of StatePhysical PropertiesLusterMalleabilityAbility to be drawn into a thin wireDensityViscosityCommon Chemical ChangesChange in TemperatureChange in ColorNoticeable OdorFormation of a PrecipitateFormation of BubblesExercise 11\PageIndex{1}Exercise 22\PageIndex{2}Exercise 33\PageIndex{3}Exercise 44\PageIndex{4}Exercise 55\PageIndex{5}ReferencesOutside Links

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Even if the species are orientated properly, a reaction will not take place unless the particles collide with a certain minimum energy called the activation energy of the reaction. Activation energy is the minimum energy required to make a reaction occur.

It’s important to note that an outline is different from a script. While a script contains everything that will be said, an outline includes the main content

(B1∩A),(B2∩A),(B3∩A)(B1∩A),(B2∩A),(B3∩A)(B_1 \cap A), (B_2 \cap A), (B_3 \cap A) and (B4∩A)(B4∩A)(B_4 \cap A)

The teacher’s view of student writing is but one voice among a chorus of peers.

Each of these three goals presents a helpful perspective on developing authors’ needs. An author’s ability to compose requires skill, understanding, and situational familiarity. None of those goals are met through a letter grade. Grades help label, sort, and rank students; they don’t inform students, target instruction, or encourage self-awareness.

A teacher should help students learn to assess quality fairly, to collaborate professionally, and to identify differences between their own work and model writing they wish to emulate. Writing classrooms can be laboratories in which students develop meaningful, relevant writing skills. If teachers stop grading student writing and instead focus on review and collaboration skills, each classroom would have a team of people qualified to assess the quality of writing. Teachers, then, could grade whether students provide beneficial peer review feedback and collaborate effectively—the meaningful work of writing.

if learning to work as/with peer reviewers provides insights into and feedback about writing performance, then the traditional structure of writing education is backward. If writing helps groups of people get things done, then students need to learn how to form, negotiate, and benefit from those groups. Grades get in the way, and teachers cannot guide students through their own writing, assessing, and reviewing processes if they are too distracted by issuing grades.

With all these systems of peer feedback already available to us, students need to learn to make use of them. Teachers could benefit from saved time and energy if they incorporated peer review systems of various flavors in their classes, reducing their workload and providing a variety of feedback for their students. Students, then, would learn to trust—and derive practical value from—the feedback of a real audience beyond their teacher. Writers who can peer review effectively become purposeful readers, thinking of texts, from classmates’ work to their textbooks, as devices used to achieve goals, rather than as static documents designed only to inform. The mantra that “you can’t believe everything you read on the Internet” makes rational sense but seems to fail us at crucial moments. Thinking critically about the things we read takes longer than clicking Like, retweeting, reblogging, or sharing; the efficiency of social tools discourages complex questioning that challenges and validates claims. In-class peer review helps writers think carefully about the implications of writing and the ways writing can help solve problems.

Instead, we should teach people how to improve their writing through peer review. Variations of peer review help us write in many of our day-to-day situations. We learn what sorts of text messages work best by observing how our friends text and respond to us. We learn what makes an effective email by reading the ones we get and responding or deleting as we see fit. We learn how best to craft Facebook posts by seeing what kinds of content can garner the most likes—at its heart a form of quick (and addictive) peer review. Consider, too, all of the review features available on websites such as Yelp, Amazon, LinkedIn, Angie’s List, and so on. Reviews offer feedback and critique by users/peers.

(1) determining whether students understand a concept well enough to implement it, (2) identifying elements of student writing that need improvement, and (3) helping students learn to better self-assess.

But how exactly does a letter count? How does it fit in with an overall view of a student’s ability? And more importantly, given the complexities of writing, how can one letter reflect the myriad

They learn how to write well by getting feedback from readers and from reading and analyzing examples of similar writing from other authors (such as their peers or professional authors writing the same type of material the students are writing).

Students don’t learn how to write from a grade.

but wouldn’t it be better to help writers develop the ability to independently assess the quality of writing, either theirs or other people’s? By expecting students to write so that teachers can rate, rank, and label them, we implicitly tell students that our satisfaction is more significant than their intrinsic aspirations. Writers should develop the purpose of their writing, rather than having it determined elsewhere. Students must learn that process through experience; grading will not teach them.

It puts the teacher in charge and abolishes the opportunity for students to learn how to evaluate quality. Writing in graded situations becomes writing for a grade, whereas writing in other circumstances seeks effectiveness as a standard. When students write for a grade, they come to see writing as transactional (given to someone in exchange for credit) rather than actionable (created with purpose and designed to achieve a goal).

as different graders notice different things within the same text. But when students have only one teacher in their classroom, and that one teacher’s assessment carries all the weight and authority, students learn to write for the teacher instead of expecting the writing to do anything on its own.

We need to help students become skilled reviewers of other people’s writing, a skill that is much more useful than learning to write to please the teacher.

in this text, grades are a fairly recent invention, in terms of the history of education. It would seem that grades have been imposed upon a system that had been getting along without them for hundreds of years. This imposition is a reductive one, replacing feedback, commentary, suggestions for improvement, and opportunity for discussion with merely a single letter or number. The idea of an A paper and giving numeric or alphabetic grades needs to end. Instead, we need to help students think of writing as adults do—in terms of inciting action and achieving goals.

When was the last time your writing was graded? Odds are, not since you left school. Since then, anything you’ve written had a specific purpose, and you worked on it until it met your goal. Maybe a colleague or manager decided when it was good enough, and maybe they even gave you feedback about what worked well or not, but you didn’t get a score, a letter grade, or have your writing ranked against your colleagues’ work. But for some reason, this scoring/ranking system has become the norm as a method of labeling the relative quality of student writing. The whole arrangement teaches students to write for an arbitrary measurement from an authority figure rather than for a real audience

Some people with racial identities other than white, including people who are multiracial, use the label person/people of color to indicate solidarity among groups, but it is likely that they still prefer a more specific label when referring to an individual or referencing a specific racial group.

If a Southern person thinks their accent is leading others to form unfavorable impressions, they can consciously change their accent with much practice and effort. Once their ability to speak without their Southern accent is honed, they may be able to switch very quickly between their native accent when speaking with friends and family and their modified accent when speaking in professional settings.

In some cases, swearing can be cathartic, allowing a person to release emotions that might otherwise lead to more aggressive or violent actions.

The level of clarity with which we speak varies depending on whom we talk to, the situation we’re in, and our own intentions and motives. We sometimes make a deliberate effort to speak as clearly as possible.

The same can happen with new slang terms. Most slang words also disappear quickly, and their alternative meaning fades into obscurity.

When we express observations, we report on the sensory information we are taking or have taken in. Eyewitness testimony is a good example of communicating observations. Witnesses are not supposed to make judgments or offer conclusions;

For example, the word calculate comes from the Latin word calculus, which means “pebble.”

the peppered moth had light colored wings that closely matched the color of the bark of the trees. This inherited trait provided camouflage for the moths helping to protect them from predator birds. Although most of the moths had light colored wings, a few each generation had darker wings, but without sufficient camouflage these darker colored moths had been easy prey

The trend toward smaller average bill size ceased and selection for larger beaks and body size resulted in a lasting increase in beak size.

"misprints," mutations. Self-reproduction plus mutation make possible natural selection. Natural selection makes possible evolution." We might even say that given these conditions, natural selection and evolution are not only possible, but inevitable.

Why do we have emotions and why are our emotions so similar to the emotions found in a wide range of other animal species?  Why do we have the capacity to think, why does our thinking take the forms that it does, and why are many of our thinking processes fundamentally similar to the thinking processes found in many other animal species?

example, some experts have argued that humans have an innate disposition to be territorial and to be suspicious and wary of strangers, of outsiders, and perhaps even hostile to those outside of their own group.  Although this may have been an adaptive psychological trait in our ancient Pleistocene past when humans lived in small groups of hunter-gatherers, in today's world these tendencies may dispose us toward prejudice and even dangerous and wasteful wars.

pass one's genes on to the next generation. Natural selection is similar to artificial selection, a process used by animal breeders to enhance characteristics

information overload

Visual aids

Diagrams

Aside from the human resources available in the library, you can also use electronic resources such as library databases

brainstorming

captive audience

One of the first questions you should ask yourself is “Who is my audience?”

________

Having immersed myself in these movies and the technologies that inspire them, it’s clear that, if we want to ensure these trends don’t cause more problems than they resolve, we desperately need the perspectives that movies like Ghost in the Shell and others reveal. The alternative is risking losing our own “ghosts” in the drive to innovate bigger and better, without thinking about the consequences.

Yet as the narrative unfolds, we learn that this is not a person, but an AI developed by US security services that has escaped the leash of its handlers.

In 2012, the South African athlete Oscar Pistorius made history by being the first runner to compete in the Olympic Games with two prosthetic legs. His iconic racing blades came to represent the promise of technological enhancements to overcome human limitations. Yet they stirred up fears of them giving him an unfair advantage that led to him being barred from competing in the previous Olympics. The same year that Pistorius successfully competed in the Olympics, the Canadian researcher Steve Mann was allegedly assaulted because his computer-augmented eye extension offended someone. And in 2015, patient-advocate Hugo Campos discovered he didn’t legally have access to the implanted defibrillator that kept him alive. These are all relatively small examples of the tension that’s growing between conventional thinking and human augmentation. But they illustrate how the angst that Kusanagi feels about her augmented body, and how it defines her, is already part of today’s society. And we’ve barely touched the tip of this particular iceberg.

Throughout Ghost, Major Kusanagi is plagued by doubts of who she is. Do her cybernetic augmentations make her less human, or having less worth? Is her sense of self—her “ghost”—simply an illusion of her machine programming? And what autonomy does she have when she malfunctions, or needs an upgrade? These are questions that are already beginning to tax developers and others in the real world. And as robotic and cyber technologies become increasingly advanced, they are only going to become harder to navigate.

Inspired by the neural laces of Iain M. Banks’ Culture novels, and echoing Ghost, Musk announced on Twitter that, in his opinion, “Creating a neural lace is the thing that really matters for humanity to achieve symbiosis with machines.”

doldrums

When the anime movie Ghost in the Shell was released in 1995, the world wide web was still little more than a novelty, Microsoft was just beginning to find its GUI-feet, and artificial intelligence research was in the

dopamine

suggests the “listener’s lean” demonstrates “ultimate interest.

This is the purpose of ethically appropriate research with careful oversight. The ban does not change the need for discussion. If anything, it brings the debate back to the reality of patients seeking care for diseases that currently have no cure.

These editing therapies will permanently change all the descendants of a couple. In some cases it could rid a family of a genetic disease. In others, the unintended effects may be worse than the disease itself.

The technology is here, but we know so much less about its effects than we should.

These traits are often the product of multiple genes working in tandem. The products of these genes work together throughout our lives, which makes the impact of editing at the embryonic level impossible to predict.

heritable genetic modification

Tertiary

type

Primary type (the one I identify with most closely)

The speaker shares a message with the receiver, having selected a particular method to communicate that message

When we are focused on gaining information whether from a teacher in a classroom setting, or a pastor at church, we are engaging in informational listening

addition, animal cells contain little digestive pouches, called lysosomes and peroxisomes, which break down macromolecules and destroy foreign invaders. All of the organelles are anchored in the cell’s cytoplasm via a cytoskeleton. The cell’s organelles are isolated from the surrounding environment by a plasma membrane.

One cell divides into two, which begins the creation of millions of more cells that ultimately become you. (Public Domain; National Institutes of Health).

The first of those goals is for the materials presented in this text to have clear relevance to you whether you choose to pursue a career in research or not. In addition, you’ll find that equal time and attention has been given to qualitative and quantitative research methods. Because sociological researchers use both types of methodology, it is important that sociology students gain an understanding of both approaches to research. Finally, I hope that you will find this text engaging and readable. Conducting research is a rewarding and exciting activity. Reading about research should be rewarding as well and, if not always exciting, it certainly shouldn’t put you to sleep.

There are many potential jobs out there for people with knowledge about how to conduct research. In fact, one of my very first jobs as a college graduate with a BA in sociology was at an evaluation research firm that hired me specifically because of the knowledge I’d gained in my college research methods class. While there, I worked as a data-collection coordinator, helping in the evaluation of local domestic violence shelters and transitional housing sites by administering satisfaction surveys to residents. I also helped collect data for a study on community member’s thoughts and feelings about where they lived by conducting telephone interviews with a random sample of people who lived in the area. (This last project made me much more sensitive than I’d previously been to survey researchers who do cold-calling.) Without a background in research methods, I would not have been hired for this position.

These findings, that wealth and income shape a child’s educational experiences, are probably not that shocking to any of us, even if we know someone who may be an exception to the rule. Sometimes the patterns that social scientists observe fit our commonly held beliefs about the way the world works. When this happens, we don’t tend to take issue with the fact that patterns don’t necessarily represent all people’s experiences. But what happens when the patterns disrupt our assumptions?

One of the first and most important things to keep in mind about sociology is that sociologists aim to explain patterns in society. Most of the time, a pattern will not explain every single person’s experience, a fact about sociology that is both fascinating and frustrating

Some sociologists take the position that reality is in the eye of the beholder and that our job is to understand others’ view of reality. Other sociologists feel that, while people may differ in their perception of reality, there is only one truereality. These sociologists are likely to aim to discover that true reality in their research rather than discovering a variety of realities.

This friend committed what social scientists refer to as selective observation by noticing only the pattern that she wanted to find at the time. If, on the other hand, your friend’s experience with her boyfriend had been her only experience with any man, then she would have been committing what social scientists refer to as overgeneralization, assuming that broad patterns exist based on very limited observations.

social scientific research methods. Research methods are a systematic process of inquiry applied to learn something about our social world. But before we take a closer look at research methods, let’s consider some of our other sources of knowledge.

DO NOT add more magnesium in case the flame is not completely extinguished.

First impressions are quickly formed, sometimes spontaneous, and involve little to no cognitive effort. Despite the fact that first impressions aren’t formed with much conscious effort, they form the basis of inferences and judgments about a person’s personality

Scientific studies have shown that insufficient sleep increases the risk for heart disease, Type 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a condition called sleep apnea, is also linked to an increased risk for chronic disease[7].

In addition to highly addictive nicotine, these products contain harmful and potentially harmful ingredients such as: ultrafine particles that can damage the lungs flavorings that have been linked to serious health problems heavy metals and volatile organic compounds

In the United States, smoking causes more than four hundred thousand deaths every single year

The HHS reports that there is strong evidence that increased physical activity decreases the risk of early death, heart disease, stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and falls; and improves cognitive function in the elderly

In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.

. A well established body of research links poor diet and inactivity to a wide range of preventable diseases and premature death.

The Metric and US Customary System

While vitamins, multivitamins, and supplements are a $20 billion industry in the United States, and more than 50 percent of Americans purchase and use them daily, there is no consistent evidence that they are better than food in promoting health and preventing disease.

Nutrient-dense foods are the opposite of “empty-calorie” foods such as carbonated sugary soft drinks, which provide many calories and very little, if any, other nutrients

Vitamin deficiencies can cause severe health problems and even death. For example, a deficiency in niacin causes a disease called pellagra, which was common in the early twentieth century in some parts of America. The common signs and symptoms of pellagra are known as the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists discovered that better diets relieved the signs and symptoms of pellagra, many people with the disease ended up hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent certain disorders and diseases such as scurvy (vitamin C), night blindness (vitamin A), and rickets (vitamin D).

Proteins provide the basic structure to bones, muscles and skin, enzymes and hormones and play a role in conducting most of the chemical reactions that take place in the body.

During digestion, the body breaks down digestible complex carbohydrates into simple sugars, mostly glucose. Glucose is then absorbed into the bloodstream and transported to all our cells where it is stored, used to make energy, or used to build macromolecules. Fiber is also a complex carbohydrate, but it cannot be broken down by digestive enzymes in the human intestine. As a result, it passes through the digestive tract undigested unless the bacteria that inhabit the colon or large intestine break it down.

For ease of use, food labels state the amount of energy in food in “calories,” meaning that each calorie is actually multiplied by one thousand to equal a kilocalorie.

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In short, the enterprise of grading student writing should be replaced by a combination of formative and summative evaluation.

If I don’t submit a letter grade at the end of a semester, I will not have a job. But providing end-of-semester grades doesn’t preclude providing formative assessment that can help students revise a text or project so they will better understand why they might receive an 85% as a final grade

As grades lose their power, the desire to evade punishment or failure can dissolve into the desire to seek knowledge and learn something new.

Formative evaluation—done typically by responding to in-process student writing several times during the semester—replaces the punishment or praise of student learning, typically demonstrated

Grading is a silent, one-way evaluation, where a teacher assigns a letter, rife with a set of socio-cultural significances, to a piece of student writing

Generalized DeMorgans Laws 1.1.25

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Countably Infinite Union of Events

sample space 𝑆

ℤ

where v0yv0y\displaystyle v_{0y} is the initial velocity of 70.0 m/s

sedentarism

megafauna

Reflect on your responses to the questions above and develop your career vision statement here

hat type of work environment will energize you and give you a sense of purpose?

hat level of responsibility do you desire?

hat kind of work is meaningful to you?

hat will your ideal career look like?

here do you see yourself in the next 20 years…

here do you see yourself in the next 15 years….

here do you see yourself in the next 10 years….

As you begin PHASE 1 of the career exploration process and answer the question “Who Am I?” start thinking about your personal and career vision. Where do you see yourself in the next few years? What accomplishments do you wish to achieve in your personal and professional life? Where do you see yourself in the next 5 years…. Where do you see yourself in the next 10 years…. Where do you see yourself in the next 15 years…. Where do you see yourself in the next 20 years…. What will your ideal career look like? What kind of work is meaningful to you? What level of responsibility do you desire? What type of work environment will energize you and give you a sense of purpose? Reflect on your responses to the questions above and develop your career vision statement here____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Each phase of the career exploration process will help you refine your career vision statement and solidify it by the end of this course. Enjoy the process!

Develop six affirmations related to being successful in your career and life planning. Be sure to state your affirmations in the present and use positive phrases. Make your affirmations personal and meaningful to you.

there are currently very few accurate genetic markers of good health. Rather, there are many more genetic markers for disease. However, science is evolving and nutritional genetics aims to identify what nutrients to eat to “turn on” healthy genes and “turn off” genes that cause disease. Eventually this field will progress so that a person’s diet can be tailored to their genetics. Thus, your DNA will determine your optimal diet.

P

A

p

Pr

(b)

(a)

in a “pudding” of positive charge.

most of the mass and the positive charge of an atom are located in its nucleus

Protons and neutrons are concentrated in a central region

alpha particles,

electron

neutron

proton

Subatomic

atoms to be indivisible.

Homo sapiens

Homo sapiens

Plot

Life in college usually differs in many ways from one’s previous life in high school or in the workforce. What are the biggest changes you are experiencing now or anticipate experiencing this term? __________________________________________________________________

What do you value that will you likely have less time or money to spend on while in college? __________________________________________________________________

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dienc

plot

trailer

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The arts, humanities, and English share think for oneself as a high-priority goal. In addition, the arts, of which writing (especially creative writing) might be considered a part, lists creativity as a top goal,

These terms, such as data, are not ones that writers use to describe or understand their own writing and learning. Writing instructors and administrators like me, especially those who use rubrics not only for grading but for assessing entire programs, are using tools with which we are not properly trained and that were designed for other academic disciplines and data-driven research. While rubrics may be moderately helpful in assessing a program on

A rubric suggests that the task and its goals are understood before the writing itself occurs and that writing works the same way for everyone every time

But a rubric is a set of preconceived parameters—designed before seeing the products of the task at hand— that applies across the board.

But what if you do x and y and b—and discover something you’d not known before and isn’t on the rubric? The rubric does not accommodate the unexpected.

the rubric’s simplicity implies that all writing can be fixed or corrected and that this correction can be done in the same way across pieces of written work and across students, instead of suggesting that revision—sometimes re-envisioning—is a more rewarding and fruitful step in becoming a better writer.

If one evaluates writing by looking for what’s wrong or what needs to be corrected or fixed, one misses potential and fails to point toward improvement in the future.

A rubric, then, is an odd way to simultaneously overcomplicate and oversimplify the way one looks at and judges a written text.

Instead of responding to writing in language—with oral or written feedback— many rubrics mechanize response

A Rube Goldberg machine is an overly engineered mechanism for a simple task. A rubric, by comparison, looks fancy and is often quantitative—it looks incredibly well engineered with its seemingly airtight checklist.

Did your own answers to the question of why we read touch on any of the reasons DiYanni gives?

120soda×⎛⎝6 sodassix pack⎞⎠

Our self-perceptions can and do change. Recall that we have an overall self-concept and self-esteem that are relatively stable, and we also have context-specific self-perceptions. Context-specific self-perceptions vary depending on the person with whom we are interacting, our emotional state, and the subject matter being discussed. Becoming aware of the process of self-perception and the various components of our self-concept (which you have already started to do by studying this chapter) will help you understand and improve your self-perceptions.

rawbacks of MRI scans include their much higher cost, and patient discomfort with the procedure. The MRI scanner subjects the patient to such powerful electromagnets that the scan room must be shielded. The patient must be enclosed in a metal tube-like device for the duration of the scan, sometimes as long as thirty minutes, which can be uncomfortable and impractical for ill patients

In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device, which was in use clinically by the early 1980s.

however, X-rays are capable of damaging cells and initiating changes that can lead to cancer. This danger of excessive exposure to X-rays was not fully appreciated for many years after their widespread use

What about research on human subjects? We do not have to go very far back in history to find situations where researchers behaved in unethical ways towards their human subjects. One of the most famous ethical violations in history is that many experiments were conducted using concentration camp prisoners as subjects during the holocaust. Throughout the years, psychologists have engaged in various studies that have pushed the envelope of ethical research, such as Milgram's study of obedience or Zimbardo's Stanford prison study. Studies such as these have led to the development of strict ethical guidelines for human research. As with research on nonhuman animal subjects, there is a committee known as an Institutional Review Board (IRB) whose role is to approve research proposals. These committees ensure that there is an appropriate reason for completing the research with human subjects and that the safety of the human subjects are appropriately considered. To further complicate matters, here in the United States, we have our own history of when ethical violations intersected with racial/ethnic divides. Indeed, members of some groups have historically faced more than their fair share of the risks of scientific research, including people who are institutionalized, are disabled, or belong to racial or ethnic minorities. A particularly tragic example is the Tuskegee syphilis study conducted by the US Public Health Service from 1932 to 1972 (Reverby, 2009). The participants in this study were poor African American men in the vicinity of Tuskegee, Alabama, who were told that they were being treated for “bad blood.” Although they were given some free medical care, they were not treated for their syphilis. Instead, they were observed to see how the disease developed in untreated patients. Even after the use of penicillin became the standard treatment for syphilis in the 1940s, these men continued to be denied treatment without being given an opportunity to leave the study. The study was eventually discontinued only after details were made known to the general public by journalists and activists. It is now widely recognized that researchers need to consider issues of justice and fairness at the societal level.

One area of controversy regarding research techniques is the use of nonhuman animal subjects. One of the keys to behaving in an ethical manner is to ensure that one has given informed consent to be a subject in a study. Obviously, animals are unable to give consent. For this reason, there are some who believe that researchers should not use nonhuman animal subjects in any case. There are others that advocate for using nonhuman animal subjects because nonhuman animal subjects many times will have distinct advantages over human subjects. Their nervous systems are frequently less complex than human systems, which facilitates the research. It is much easier to learn from a system with thousands of neurons compared to one with billions of neurons like humans. Also, nonhuman animals may have other desirable characteristics such as shorter life cycles, larger neurons, and translucent embryos. However, it is widely recognized that this research must proceed with explicit guidelines ensuring the safe treatment of the animals. For example, any research institution that will be conducting research using nonhuman animal subjects must have an Institutional Animal Care and Use Committee (IACUC). IACUCs review the proposed experiments to ensure an appropriate rationale for using nonhuman animals as subjects and ensure ethical treatment of those subjects. Furthermore, many researchers who work with nonhuman animal subjects adhere to the Three R's: Replacement, Reduction, and Refinement (Russell & Burch, 1959). Replacement suggests that researchers should seek to use inanimate systems as a replacement for nonhuman animal subjects whenever possible. Furthermore, replacement is also suggested to replace higher level organisms with lower level organisms whenever possible. The idea is that instead of choosing a primate to conduct the study, researchers are encouraged to use a lower level animal such as an invertebrate (a sea slug, for example) to conduct the study. Reduction refers to reducing the number of nonhuman animal subjects that will be used in the particular study. The idea here is that if a study can learn sufficient information from one nonhuman animal, then they should only use one. Finally, refinement is about how the nonhuman animals are cared for. The goal is to minimize discomfort that the subject experiences and to enhance the conditions that the subject experiences throughout their life. For a full discussion of the Three R's, see Tannenbaum and Bennett (2015). In conclusion, many researchers argue that what we have learned from nonhuman animal subjects has been invaluable. These studies have led to drug therapies for treating pain and other disorders; for instance, most drugs are studied using animals first, to ensure they are safe for humans. Animal nervous systems are used as models for the human nervous systems in many areas. Sea slugs (Aplysia californica) have been used to learn about neural networks involved in learning and memory. Cats have been studied to learn about how our brain's visual system is organized. Owls have been used to learn about sound localization in the auditory system. Indeed, research using nonhuman animal subjects has led to many important discoveries.

Sometimes when surgeons perform surgery to improve the lives of their patients, they can unintentionally create other issues. One famous example of this involves patients who were subjected to a procedure that effectively disrupts the communication between the two sides of the brain. Split-brain research refers to the study of those who received this treatment and the knowledge resulting from this work (Rosen, 2018). Under what circumstances would such a seemingly radical procedure be used - and what are its effects? In order to treat patients with severe epilepsy, doctors cut the corpus callosum in the brain, which is the main structure that connects the two hemispheres. Doing this kept the electrical activity that was causing the epileptic seizures confined to one hemisphere and helped get the epilepsy under control. However, this also disconnected the two hemispheres from each other, which led to some interesting studies, where researchers were able to study the functions of each hemisphere independently. These studies will be discussed later when we cover lateralization of functions.

Another way the brain has been studied by neuroscientists is through various techniques that are employed before or during brain surgery. One such technique, direct cortical stimulation, occurs when a researcher applies a small electrical current directly to the brain itself. This stimulation can cause excitation or inhibition depending on how much stimulation is given. In order to do direct cortical stimulation, the subject must have their brain exposed during surgery. One may reasonably ask the question, “Why would we ever do this?” Well, when someone is having brain surgery, there is likely a reason. For example, if a patient has a tumor in a medial portion of the brain, doctors may have to go through healthy brain tissue in order to reach the tumor so that they can remove it. Doctors must choose carefully which part of the healthy brain tissue they will damage in order to get to the tumor. One way of figuring out which area would do the least damage is to do a technique known as cortical mapping. During cortical mapping, direct cortical stimulation is applied to various parts of the healthy brain tissue to map out their functions. This allows doctors to choose the path of least damage. Alternatively, cortical mapping can now occur through surgically implanted subdural strip and grid electrodes that will allow the researchers/doctors to stimulate the brain areas in between surgeries, as opposed to during surgery. Additionally, in recent years, researchers have been examining whether TMS is an appropriate (and non-surgical) substitution for direct cortical stimulation.

A lesion is a site of damage in the brain. In neuroscience, we conduct lesion studies on both animals and human subjects. In animals, lesions can be made in a specific area by the researcher. Researchers are able to correlate the deficits in function with the area of damage. For example, if a researcher damages area X, and now the animal is unable to enter into REM (rapid eye movement) sleep, one can reasonably conclude that area X serves some function related to REM sleep. Although the same can be said for lesion studies of humans, accidents, or medical necessities are generally the source of human lesion subjects. You'll recall that we began this chapter by mentioning the tragic - but educational - case of Phineas Gage. Lesion studies can allow for very specific conclusions to be made about very specific brain areas. However, in human subjects, many of the lesion patients have damage to multiple areas. In general, this makes it more difficult to make conclusions about the function of the brain areas. If the person has damage to areas X, Y, and Z, and is unable to enter into REM sleep, we are uncertain whether the area that is related to REM sleep is area X, Y, or Z or some combination of them.

ne technique that is used to study animals in neuroscience, known as single cell recordings allows for us to record the activity of a cell, at least in theory. The idea of single cell recordings is that we can place a very tiny recording device, known as a microelectrode, into a single neuron and then we can try and figure out what will “activate” that particular neuron. For example, in the visual system, you may find a neuron that activates when a line moves in a certain direction in a certain location. We would then conclude that this neuron processes moving lines from a particular location. Furthermore, single cell recordings have excellent spatial and temporal resolution. The researcher can tell exactly where the activity is coming from and exactly when the activity is occurring. However, single cell recordings are usually extracellular (outside of the cell). That is, they don’t record from inside a single cell but, rather, they record from outside a few cells. Also, consider that the neuron that responds to a line in a particular location that is moving in a particular direction likely does not respond to much else. So, it is extremely difficult to determine what exactly each cell does through single cell recordings. Recording from one area ignores what is happening everywhere else in the brain.

TMS studies, as with most research techniques, can come in the form of basic research (research intended to inform our understanding) and applied research (research intended to solve a problem). Basic research in neuroscience is typically driven by research questions aimed at a general understanding of how the brain and nervous system work. Some TMS studies have used TMS to reduce brain activity in the right amygdala during the processing of faces with negative emotions (Baeken et al., 2010). Although this research wasn’t specific to autism, it is not hard to see the connection between understanding how the amygdala works and ASD. Furthermore, studies have tried to use TMS to treat ASD. Studies thus far have focused on using TMS to change activity levels and possibly stimulate neural plasticity. There was even a transcranial magnetic stimulation therapy for autism conference held in 2014 to discuss the use of the tool in the treatment of ASD. Indeed, there are myriad of possibilities for how this tool can be used in the future. (See Oberman et al. (2015) for a review of TMS treatments for ASD.)