Essentials of Psychology By
Robert G. Turner Jr., Ph.D.
About the Author
Robert G. Turner Jr., Ph.D., has more than 20 years of teaching and education-related experience. He has taught seventh-grade sci- ence, worked as a curriculum developer for the Upward Bound Program, and taught sociology, social psychology, anthropology, and honors seminars at the university level. As a professional writer, he has written nonfiction books, journal and magazine arti- cles, novels, and stage plays.
Copyright © 2013 by Penn Foster, Inc.
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INSTRUCTIONS TO STUDENTS 1
LESSON ASSIGNMENTS 7
LESSON 1: PSYCHOLOGY: THE SCIENCE OF THE MIND 9
LESSON 2: THE MIND AT WORK 43
LESSON 3: MOTIVATION, EMOTION, DEVELOPMENT, AND PERSONALITY 75
ESSAY ASSIGNMENT 117
LESSON 4: PSYCHOLOGICAL DISORDERS 121
LESSON 5: PSYCHOLOGY FOR TWO OR MORE 143
CASE STUDIES ASSIGNMENT 165
SELF-CHECK ANSWERS 167
YOUR COURSE Welcome to Essentials of Psychology! You’re entering a course of study designed to help you better understand yourself and others. For that reason, you can think of this course as practical. It should be of use to you in living your life and reaching the goals you set for yourself.
You’ll use two main resources for your course work: this study guide and your textbook, Psychology and Your Life, 2nd Edition, by Robert S. Feldman.
OBJECTIVES When you complete this course, you’ll be able to
n Describe the science and methodologies of psychology in the context of its historical origins and major perspectives
n Outline the fundamental structure of the human nervous system and explain how it relates to the organization of human sensory perception
n Relate altered states of consciousness to sleep, hypnosis, meditation, sensory deprivation, and physiological responses to psychoactive drugs
n Discuss the basic concepts of behavioral psychology, including classical conditioning, operant conditioning, and cognitive learning theory
n Describe the nature of human memory in relationship to thinking processes, intelligence, creativity, and intuition
n Explain the basic concepts of human motivation in relationship to emotions
n Discuss concepts and models of personality, including psychodynamic, trait, learning, evolutionary, and humanistic approaches
n Explain concepts of intelligence and describe approaches to assessing and measuring intelligence
Instructions to Students2
n Differentiate a healthy personality from a disordered personality in the context of mental health and stress management
n Discuss basic influences of social life and how people respond to them
COURSE MATERIALS Your Essentials of Psychology course provides you with the materials listed below:
1. This study guide, which includes
n A lesson assignments page that lists the schedule of assigned readings in your textbook
n Self-checks and answers that allow you to measure your understanding of the course material
n Introductions to the lessons and assignments
2. Your course textbook, Psychology and Your Life, 2nd Edition, by Robert S. Feldman, which contains your assigned readings
YOUR TEXTBOOK Success in your course depends on your knowledge of the text. For that reason, you should take some time to look through it from front to back. Give yourself a sense of how the material is arranged. Here are some of the key features of your text:
n “About the Author” is found with the front matter of your text.
n A brief table of contents is found with the front matter of your text.
n An extended table of contents is found with the front matter of your text.
n A preface gives you an overview of chapter features.
Instructions to Students 3
n “To the Students” is a vital feature of your text. We strongly recommend that you become familiar with the author’s SQ3R method and take full advantage of tips for effective study and test-taking strategies.
n A modular format divides each chapter into related topic groups.
n “Learning Outcomes” are listed at the beginning of each module.
n “Study Alerts” are highlighted in text margins. They’ll help you stay focused on key ideas and concepts.
n “From the Perspective of…” shows you how psychology impacts different professions.
n “Becoming an Informed Consumer of Psychology” helps you think about practical applications of psychology in your everyday life.
n “Exploring Diversity” offers you opportunities for critical analysis of psychological issues across cultures and eth- nic groups.
n “Full Circle” end-of-chapter features give you a concept map for modules included in a chapter.
n A “Key Terms” summary helps you remember what you need to remember.
n “Looking Ahead/Looking Back” introduces key concepts of the next chapter and summarizes the chapter you’ve just completed to reinforce your learning.
n “Recap/Evaluate/Rethink” end-of-module activities are directly related to the module’s learning outcomes.
n “Case Studies” at the end of each chapter offer excellent opportunities to apply and analyze chapter content.
n Your text’s illustrations are captioned as figures. The information contained in these graphics should be seen as parts of your assigned text material. Assume their content will reappear in self-checks and lesson exams.
A STUDY PLAN This study guide is intended to help you achieve the maximum benefit from the time you spend on this course. It isn’t meant to replace your textbook. Instead, it serves as an introduction to material you’ll read in the text and as an aid to assist you in understanding this material.
This study guide provides your assignments in five lessons. Each lesson contains two to three chapter assignments, with Evaluate quizzes and a self-check for each assignment. A multiple-choice examination follows each lesson. Be sure to complete all work related to a lesson before moving on to the next lesson.
For each lesson, do the following:
1. Read the instructions to each assignment in this study guide. The instructions will provide you with the pages in the textbook that must be read.
2. Now read the assigned pages in this study guide.
3. Then read the assigned pages in the textbook.
4. When you’ve finished the assignment, complete the self- check, Evaluate quizzes, and discussion board posting. Note: The Evaluate quizzes and self-checks aren’t graded and are for your use only—don’t send your answers to the school.
â Self-Checks: The self-checks are designed to indi- cate how well you understand the material, so test yourself honestly. Make every effort to complete the questions before turning to the answers at the back of the study guide. If you find any weak areas, return to the text and review the relevant material until you understand it.
â Evaluate Quizzes: With the exception of Assignment 12, each assignment lists Evaluate quizzes for you to complete. Once you’ve taken the Evaluate quizzes, you’ll find the answers upside-down on the same page as the quiz. As with the self-checks, make every effort to complete the questions before turning
Instructions to Students4
to the answers. If you find any weak areas, return to the text and review the relevant material until you understand it.
â Discussion Board Posting: Each lesson has a required discussion board that’s located on your stu- dent portal. In order to receive credit for the discussion board, you must make an initial response to the question and respond to at least two other students.
5. Follow this procedure for all assignments until you’ve completed the lesson.
6. Once you’re confident that you understand all the material for the lesson, complete the multiple-choice lesson exam- ination. The examination is open-book and is based on both textbook and study guide material.
7. Repeat steps 1–6 for the remaining lessons in this study guide.
If you have any questions, email your instructor.
Now review the lesson assignments on the following pages of this study guide. Then begin your study of psychology with Lesson 1, Assignment 1.
Good luck, and enjoy your studies!
Instructions to Students 5
Instructions to Students6
Lesson 1: Psychology: The Science of the Mind For: Read in the Read in
study guide: the textbook:
Assignment 1 Pages 9–20 Chapter 1
Assignment 2 Pages 22–30 Chapter 2
Assignment 3 Pages 32–40 Chapter 3
Examination 250053 Material in Lesson 1 Discussion Board 250054
Lesson 2: The Mind at Work For: Read in the Read in
study guide: the textbook:
Assignment 4 Pages 43–51 Chapter 4
Assignment 5 Pages 52–60 Chapter 5
Assignment 6 Pages 61–73 Chapter 6
Examination 250055 Material in Lesson 2 Discussion Board 250056
Lesson 3: Motivation, Emotion, Development, and Personality For: Read in the Read in
study guide: the textbook:
Assignment 7 Pages 75–84 Chapter 7
Assignment 8 Pages 85–97 Chapter 8
Assignment 9 Pages 99–114 Chapter 9
Examination 250057 Material in Lesson 3 Discussion Board 250058
Lesson 4: Psychological Disorders For: Read in the Read in
study guide: the textbook:
Assignment 10 Pages 121–131 Chapter 10
Assignment 11 Pages 133–141 Chapter 11
Examination 250060 Material in Lesson 4 Discussion Board 250061
Lesson 5: Psychology for Two or More For: Read in the Read in
study guide: the textbook:
Assignment 12 Pages 143–149 Pages 484–501
Assignment 13 Pages 151–162 Pages 502–533
Examination 250062 Material in Lesson 5 Discussion Board 250063 Case Studies 250064
Note: To access and complete any of the examinations for this study
guide, click on the appropriate Take Exam icon on your student portal.
You shouldn’t have to enter the examination numbers. These numbers
are for reference only if you have reason to contact Student Services.
Psychology: The Science of the Mind
INTRODUCTION You’ll begin this lesson with an overview of psychology as a science. You’ll learn its goals and major perspectives. Next, you’ll get a critical discussion of the nature of science. This part of your assignment is essential for two reasons. First, getting the most out of this course requires you to take the scientific point of view. Second, you should get into the habit of critical thinking, always remembering that science isn’t about believing; it’s about investigating. The second assign- ment will introduce you to the relationship between the nervous system, the brain, and behavior. You’ll discover how hormones produced by the body’s endocrine system regulate body processes, including aspects of behavior. The final assignment introduces you to the fascinating perplexities of sensation and perception. You’ll discover how our senses, like vision, hearing, and touch, enter into psychological experi- ence. In this context, you’ll also get some insight into how sensory stimuli are organized precisely through the ways we perceive the world around us.
ASSIGNMENT 1—INTRODUCTION TO PSYCHOLOGY Read this assignment. Then read Chapter 1 in your textbook.
Psychologists at Work
What Is Psychology?
Psychologists try to describe, explain, and predict human behavior and mental processes. In this way, psychologists aim to help people live healthier, happier lives.
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What Are the Subfields of Psychology?
Because behavior and mental processes can be viewed in different ways, there are subfields of psychology. Neuroscientists attempt to understand the biological roots of behavior. Developmental psychology studies the ways in which psychological processes change throughout the human life cycle. Clinical psychologists attempt to diagnose and treat psychological problems, like depression.
By far, clinical psychologists make up the largest number of psychological specialists. Further, most are engaged in private practice, and more than half of all psychologists work in mental health services—typically helping people with their mental and emotional problems.
A Science Evolves
What Are the Roots of Psychology?
The first part of this section tells you about the main traditional schools of psychology. The term school here refers to a per- spective or point of view. The traditional schools of psychology developed as the science of psychology developed. You’ll be challenged to think about how the schools of psychology developed over time.
Structuralism developed in the late nineteenth century as one of the earliest views of human behavior. In 1879, a German researcher named Wilhelm Wundt became interested in how people respond to a stimulus. A stimulus is anything that causes a response or a reaction of some kind. (Stimuli is the plural of stimulus.) Heat, light, a pinprick, and loud noises are examples of stimuli. Wundt conducted his studies by introspection. Introspection involves paying attention to your own consciousness, thoughts, and feelings. Wundt thought that observing the effects of stimuli and then using self-observa- tion through introspection would help us understand human behavior. Basically, structuralists wanted to sort out the differ- ent parts that make up the human mind. However, because they depended so much on introspection, structuralists couldn’t agree on many things.
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Functionalism was developed mainly by William James. James broadened the concerns of psychology to include the nature of consciousness and the purposes of religion in human life, as well as the ways people respond to stimuli. Because his work was so broad and full of insight, it remains of interest today. The term functionalism refers to the attempt to understand how the human mind helps people adapt to their environments.
Gestalt psychology developed mainly in Europe (while behav- iorism was being developed in the United States). Its main contribution to psychology was to help us understand that we respond to the context of things we experience. Gestalt theorists liked to say, “The whole is greater than the sum of its parts.” For example, when you listen to a song that you like, you don’t enjoy each individual note independently of the others. Instead, you enjoy the overall melody that’s cre- ated when all of the notes are combined in a particular way.
There were founding mothers in the science of psychology. A few of them, like Karen Horney (pronounced “HORN-eye”), extended the perspectives of the school with which they were associated. In the case of Dr. Horney, that meant extending the psychoanalytic theory of Sigmund Freud to pay more attention to social and cultural factors.
The neuroscience perspective focuses on the ways in which biological processes, in humans and animals, underlie behaviors and behavioral responses of all kinds. The perspective includes studies of evolutionary biology—how behaviors have evolved as species have evolved—and the role of genetics in behavioral processes.
The psychodynamic perspective holds that our behavior is largely shaped by the nature of our personality and by unconscious forces in the psyche. In the psychoanalytic view, the mind is a layered thing, and the depths of it remain largely mysterious and unknown to us. The term psyche usually refers to the entire mystery of mind, consciousness, experience, and memory. The word itself comes from the Greek word for soul. The psychodynamic view comes
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primarily from the psychoanalytic theory developed by Sigmund Freud. Today, while many aspects of Freudian theory have lost favor, the psychodynamic perspective continues to help us understand things like prejudice and aggression. We’ll cover this perspective in some detail in Chapter 11.
The behavioral perspective became a dominant point of view in psychology as issues like the nature of consciousness lost popularity. Many decided to concentrate on observable and measurable (overt) behaviors and ignore the study of con- sciousness itself. Behaviorism is the study of how organisms, including human beings, learn behaviors by responding to stimuli. The behaviorist view emphasizes the idea that our behavior is shaped by our environment. That is, human behavior—and that of all organisms—is shaped by adaptive responses that best manage environmental stimuli.
The cognitive perspective views behavior and human nature as related mainly to our cognitive processes. Cognitive processes include both our thoughts and our emotions, but researchers tend to focus mainly on thoughts. In this context, thought processes are compared to the ways in which computers work. Overall, this view seeks to understand how we perceive and interpret stimuli, solve problems, and make judgments.
The humanistic perspective objects to the determinism of other views of human behavior, particularly as represented by behaviorism. Determinism is the idea that human behavior is determined mainly by mechanical or biological forces over which people have little personal control. By way of contrast, a central tenet of the humanistic perspective is that humans have free will and can be enabled to be “the best that they can be.” In other words, we adapt to the world through inner motivations and through selected responses to sensory stimuli in our environment.
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Key Controversies in Psychology There are five major controversies in psychology. You may recognize that the opposed views represent deep philosophi- cal questions about human nature and our species’ place in the cosmic scheme—whatever that may be.
1. Is human development mainly a result of environmental factors or of genetic inheritance? This is the so-called nature-nurture debate. As it turns out, most researchers tend to suspect that both play a hand.
2. To what extent is behavior motivated by conscious as opposed to unconscious mental processes? The issue here can be thought of as one of free will. If we do things for unconscious reasons, we do what we do without knowing why we do it; hence, our behavior is determined.
3. What should be the focus of research in psychology? Should we focus on observable behaviors or on internal mental processes? In fact, clinical researchers in particu- lar tend to feel that both frames of reference need to be taken into account.
4. How much of our behavior results from free will as opposed to conditioned behavior? Once again, some would argue that behavior is a mixture of free choice and “automated,” or reflexive, responses.
5. To what extent is our behavior a result of individual dif- ferences as opposed to social and cultural influences? And, in that context, are there universal psychological principles that apply across cultures?
Research in Psychology
The Scientific Method
Although your textbook focuses on psychology, as you would expect, the methods of scientific research are identical from physics to biology to sociology. This section introduces you to the ways psychologists use the methods and principles of scientific research.
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There are four basic steps in scientific research:
1. Identify questions of interest. You pay attention to the world around you and ask questions about it. Scientific observation depends on empirical evidence—evidence that can be observed and measured. So, the first step in the scientific method is observation that’s both active and selective. In other words, we don’t try to observe and study everything, everywhere. We try to observe things that can provide empirical evidence. However, we do that selectively because we focus on phenomena that catch our attention and spark our interest.
2. Formulate an explanation. To define a problem, we must recognize that relationships can exist among different variables (things that can be measured) that produce measurable outcomes. For example, you may observe that children who are read to by their parents are better students than those who aren’t read to by their parents. Although you might assume that the parents are making a positive impact on their children’s academic abilities by reading to them, you’ll need to conduct research to verify your observations. That is, you can pose a hypothesis. A hypothesis is a scientific question that states a problem in a way that can be measured and tested. Put another way, every hypothesis is a statement that shows how we mean to study a problem in order to answer a question. Theory building results from testing many hypotheses to come to overall conclusions that best explain our find- ings. After conducting a lot of research, we might develop a theory. Or we might test a theory through research to see if it makes sense.
3. Carry out research. For example, a hypothesis relating school performance to being read to by parents might look like this:
Children who are read to by their parents are more likely to score above average on standard first-grade achievement tests than children who aren’t read to by their parents.
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What we must do now is use a research technique to support or disprove our hypothesis. We might use a correlational study. Or, better yet, if feasible, we can perform an experiment.
4. Communicate findings. Having gathered our evidence, for- mulated a hypothesis, and tested it through research, we can write a research report. If we can get it published in a scientific journal, other researchers can check our work and advance their own. Often, other researchers may do this through replication, doing the same research to see if it yields similar results.
All of the following are forms of descriptive research.
Archival research looks at existing data. It might be found in census data, court records, or the findings’ previous studies. That is, you examine what are normally called secondary sources. Archival research nearly always precedes any kind of primary (original) research, since one is well advised to discover what’s already known.
Naturalistic observation (observing behavior in natural environments) is a good way to gather descriptive informa- tion. If you want to see how children actually behave on a playground, you could spend some time eating your lunch each day at a playground. On the other hand, it’s possible that children being watched by an adult will behave differ- ently than they would with no adult around. This change in behavior is called the observer effect. To avoid it, you might set up hidden remote cameras around the playground. However, since many feel that the cameras would violate the children’s right to privacy, you may not get funding for that kind of research.
Another option would be to show up every day, sit in the same place, and never interfere with what the children are doing. This approach might overcome the observer effect since people tend to go back to their normal behaviors when they don’t perceive a threat from a silent observer. There’s no way to be sure of this. In any case, naturalistic observation is an important way to study the behavior of animals in the wild, as well as human beings at work and play.
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In survey research, we gather information from people using questionnaires or interview schedules. Surveys are often used to get a sense of people’s attitudes on different subjects. They’re often used to gauge a candidate’s support among voters. Among psychologists, surveys can be used to estimate the frequency with which people perform certain behaviors or experience intense emotion. As a rule, since it isn’t normally feasible to interview everyone in, say, the town of Mayberry, it’s necessary to draw a representative random sample. A random sample requires that everyone in a population to be studied has an equal chance of being selected. When a sam- ple is representative, we can generalize our finding to the larger study population.
A case study is a special kind of naturalistic study. It’s an intense, in-depth study of some individual or small group. A famous example involved a woman named Eve who seemed, in the opinion of her therapist, to have a large number of separate personalities. Even today, what’s called multiple personality disorder is a controversial subject. It’s controversial because the condition is very rare and because most of the evidence is derived from individual cases. That doesn’t mean that single case studies can’t provide valuable information. However, scientists do prefer other methods of study to support their hypotheses.
Correlational research examines the relationship between two or more variables. As noted, a variable is anything we can measure. Gender, age, education, IQ score, income, or even approval- disapproval of a social policy are examples of variables. For example, let’s say we want to understand the relationship of age to height among humans. We could gather height information from specific age groups to compare age and height. More than likely, we would discover that as age increases, so does height. In other words, as people get older (up to about age 20), they generally get taller.
If, in a correlational study, one variable increases as the other increases, we can say that age and height have a positive correlation. In some situations, however, the value of one variable increases as the value of a related variable decreases. For example, in an average population of people
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over 30, as individuals get older they tend to run a 400-meter race more slowly. In this case, age and running time repre- sent a negative correlation.
Correlational studies can be very useful. However, all they can do is show us that one variable is related to another to a greater or lesser extent. In studying different groups of people, for example, we may find that the correlation between age and creativity is either positive or negative. However, in neither case does our finding prove that people get more (or less) creative simply because they get older. In fact, we may find that the correlation is positive among artists and nega- tive among musicians. That wouldn’t tell us that there aren’t highly creative 50-year-old musicians. Nor would it confirm that there are few creative artists under the age of 50. A cor- relation shows only that a relationship exists among different variables. To prove that one variable causes another, we must turn to another method—the experiment.
In science, the experiment is the king of research methods. Only through a carefully conducted experiment can we actually prove that one variable causes another. To under- stand the idea behind an experiment, let’s say we want to know if an experimental approach to studying sophomore- level history is better than the approach normally used at Jefferson High School (JHS). Here are the likely steps we’ll take to do our experiment:
1. Draw a representative sample of JHS sophomores. To make sure the sample is representative, we could get a list of all the sophomores. Let’s say there are 400 sopho- mores and we want a sample size of 40. We would use a randomizing technique that assures us that every student on the list has an equal chance of being selected, like drawing names out of a hat. (Each name we selected would then have to go back into the hat, so we could choose another name under the exact same conditions.)
2. Divide the sample of 40 into two groups of 20, using a randomizing technique like the one in step 1.
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3. Assign one group of 20 to a control group and the second group to an experimental group. The control group isn’t exposed to the independent variable, but the experimental group is.
4. Pick two classrooms that are identical. In one of these, stu- dents in the control group will receive a lesson on the Civil War. The standard lecture approach will be used. In the other classroom, the experimental group will get the same facts and ideas presented using a series of pictures and sound effects, along with the teacher’s instructions. That’s the experimental teaching approach. Again, we control for extraneous variables by making the conditions and environ- ment for the control and the experimental groups as similar as possible. In this case, for example, we would also want to run our experiment at the same time of day because performance typically varies, say, before lunch or after lunch.
5. After both groups of students have had their lesson on the Civil War, give them a test to see how well they’ve learned the material. The test for both groups will be identical. It will also be given to both groups under the same conditions and at the same time of day.
6. Compare the test scores to see if the students in the experimental group scored better or worse than those in the control group. If the scores in the experimental group are sufficiently higher than those in the control group, we’ll say we’ve shown that the experimental teaching method is superior to the standard method.
“Sufficiently higher” refers to statistical significance. That means that, under the laws of probability, the difference between scores in the control and experimental groups is great enough that it can’t be attributed to random fluctuation. In this experiment, the independent variables are the teaching methods. The dependent variable is the score each student gets on the evaluation test. If we conducted the experiment correctly, we can say that the independent variable caused the difference in the dependent variable.
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Ethics of Research
Human behavior is derived from all kinds of motives. Ethical motivations, perhaps based on religious or philosophical perspectives, persuade us that subjects of research shouldn’t be harmed, physically or psychologically, by the research pro- cedure. A common principle of ethical research is called informed consent. People should be told what the research is for and what discomforts, if any, may be involved. A basic principle of informed consent is that prospective research subjects can “just say no.”
Should Animals Be Used in Research?
In fact, quite a lot of psychological research has been based on findings derived from observing animal behavior. Behaviorist B.F. Skinner based a lot of his theoretical concepts on the behavior of lab rats and pigeons. Two main questions are raised by reliance on animals in research: To what extent can we generalize animal behavior to human behavior? What constitutes cruelty to animals? There are no simple and easy answers to either question.
Research findings may or may not be valid. As an informed information “consumer,” you should understand this. Science can’t be based on opinion; it must be based on empirical (observable and measurable) data. The purpose of the research must be clear. If it’s meant to support or refute a theory, for example, that must be made explicit. The study must be properly conducted—as in the proper procedures for conducting an experiment. The results or findings must represent the actual data, not the researcher’s opinion or bias.
Experimental bias may weaken the validity of research findings. Basically, bias means seeing what we expect to see. In the case of experimenter expectations, findings may be biased when a researcher “telegraphs” what he or she expects to see from research subjects. Since research subjects are typically
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in a “peasant-to-lord” relationship, this sort of thing may lead to participant expectations bias. That is, the subjects will tend to produce behaviors and responses that the researcher seems to favor. And this sort of thing, which results from human impulses to conform to social expectations, may happen below the level of conscious awareness.
Sometimes circumstances that we don’t expect influence the outcome of experiments. The placebo effect is one these unexpected circumstances. The placebo effect occurs mostly in medical experiments, although it has also occurred in psychotherapy. In the placebo effect, people who take a placebo (a fake medicine) experience the same benefits from the drug as the people who are taking the real medicine. In other words, people who think they’re getting a remedy (though they’re not) may still show signs of improvement.
To overcome the confusion caused by the placebo effect, subjects may not be informed as to whether they’re taking the placebo or the actual drug. This is called a single-blind experiment. In a double-blind experiment, neither the patient nor the experimenter administering the pills knows who’s getting a drug or who’s getting a placebo.
Once you’ve finished studying Assignment 1, complete Self-Check 1 and the Evaluate quizzes on pages 11, 23, 34, and 41 in your textbook.
You’ll find the answers upside-down on the same page as the Evaluate
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Self-Check 1 At the end of each section of Essentials of Psychology, you’ll be asked to pause and check
your understanding of what you’ve just read by completing a “self-check” exercise.
Answering these questions will help you review what you’ve studied so far. Please
complete Self-Check 1 now.
1. I want to study the differences in fear responses to live, harmless snakes in a population
made of roughly equal numbers of girls and boys. My research hypothesis is that boys will be
less fearful of snakes than will girls. In my research, my _______ definition of “fear” will be
2. While _______ psychology studies how our behavior is influenced by genetic inheritance from
our ancestors, behavioral _______ focuses on how our genes and the environment, working
together, influence specific behaviors.
3. While I might very well use psychological _______ while conducting a case study, I’ll certainly
have to have a properly drawn _______ of my study population while conducting a survey
4. In an experiment, a/an _______ variable can be manipulated by the experimenter such that
the experimental group and the _______ group receive different kinds of training on how to
solve a puzzle.
5. Among today’s main psychological perspectives, only the _______ perspective proposes the
dynamic role of the unconscious in human behavior.
6. In the process of conducting scientific _______, I’ll gather data and then analyze the data.
7. In the research process called _______ observation, I might decide to observe the way
patients are treated in an actual nursing home.
8. The _______ perspective holds that each of us has the potential to seek and reach our
highest goals of fulfillment.
9. In conducting survey research, I find that the ability to solve a certain kind of problem
increases as the subjects of my study vary in age from 8 years old to 12 years old.
Taking a mathematical measure of this relationship will be the extent to which age
_______ to problem-solving ability.
10. Among major controversies in psychology, the idea that people have free will is opposed by
the assumption that behavior is caused by environmental factors. So, we could say that free
will is the opposite of _______.
Check your answers with those on page 167.
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ASSIGNMENT 2—NEUROSCIENCE AND BEHAVIOR Read this assignment. Then read Chapter 2 in your textbook.
Neurons: The Basic Elements of Behavior
The Structure of the Neuron
At this moment, there are billions of cells in your body. Nearly all of them are specialized as tissues. Tissues are groups of cells that are similar in appearance and perform special tasks. Specialized cells make up your voluntary mus- cles, your heart, and other organs of the body. Neurons are the specialized cells of the nervous system. They’re designed to transmit signals—called nerve impulses—along the “wiring system” of the body that connects the nervous system to all the other body tissues. Such “wires” are called nerves.
You should understand that a string of neurons is connected so that the axon fibers of one neuron are linked to the dendrites of another. This kind of linkage continues along the fiber until we find a network of axon terminals directly con- nected from the brain to some tissue, such as a muscle that moves your arm. Be sure to pay attention to terminal buttons at the ends of axons. They send messages to other neurons. Note the myelin sheath around the length of an axon. It serves as an insulator needed for the electrical properties of nerve impulses.
How Neurons Fire
Your textbook will help you understand the complexities of nerve impulses. Here, let’s simply say that the poet Walt Whitman was correct to write of the “body electric.” Neurons are like tiny batteries. They have a resting state, a negative resting potential of about 70 millivolts, which is their normal charge. When they’re stimulated electrically—by a flow of ions from other neurons—they reach a brief, positively charged
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action potential. That means they’re ready to allow a tiny jolt of electricity to flow through them. When a neuron does this, we say it’s firing. In every nerve, a string of neurons passes impulses along at about 200 miles per hour. As your textbook points out, a neuron either fires or doesn’t fire; it follows the all-or-none rule. There’s no such thing as a partial nerve impulse. When a neuron does fire, it becomes part of a string of neuron firings from one end of a nerve to its final destination.
Different kinds of neurons are specialized. For example, some specialize in outgoing messages, while others are adept at receiving messages from our environment. A fascinating type of neuron is the mirror neuron. Mirror neurons fire when a person enacts a particular behavior. However, they’ll also fire simply from observing that behavior in another person. Mirror neurons may help us understand the human capacity for understanding other people’s intentions or feelings.
Where Neurons Connect to One Another: Bridging the Gap
Keep in mind that nerve impulses function electrically and chemically. The electrical part is neuron firing. The chemical part occurs between neurons. It works like this: A neuron passes its signal to another neuron through a connection from one of its axon terminals to a dendrite (receiver) of the next neuron. The axon terminal and the end of a dendrite are close together, but they don’t actually merge. There’s a space between them called a synaptic gap. So, again, the impulse from neuron A to neuron B isn’t transmitted by an electrical charge, but rather by different kinds of chemical neurotrans- mitters. A neurotransmitter is a complex organic molecule that goes from axon to dendrite, carrying instructions to receptor sites. Receptor sites on a dendrite are like tiny docks for neurotransmitter molecules. When they dock, the dendrite will either fire or it won’t, depending on what kind of neuro- transmitters have docked there. The space between two neurons where the chemical transmission of information occurs is called a synapse.
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Neurotransmitters: Multitalented Chemical Couriers
There are many kinds of neurotransmitters. They include molecules with peculiar names like acetylcholine, dopamine, and serotonin. Some kinds of neurotransmitters excite neurons to fire; they deliver excitatory messages. Other kinds of neuro- transmitters inhibit firing; they deliver inhibitory messages. You can begin to see why certain drugs that can act like neurotransmitters may block pain impulses, make us excited, or calm us down.
The Nervous System and the Endocrine System
The Nervous System
The nervous system is divided into several parts. The central nervous system, or CNS, includes the brain and spinal cord. The spinal cord controls some of our more basic behaviors. These are referred to as reflexes. A reflex is a simple involun- tary response to a stimulus. Automatically pulling your hand back from a hot stove is an example. Three kinds of neurons are involved in reflexes. Sensory (afferent) neurons transmit messages from the perimeter of the body to the CNS. Motor (efferent) neurons send messages from the CNS to muscles and glands. Interneurons send messages between sensory and motor neurons.
The peripheral nervous system includes nerve “wiring” throughout the body. It’s made up of a somatic division and an autonomic division. The somatic system links the brain and spinal cord to all of the parts of our bodies and to our sensory organs, such as our eyes and ears. When we use the somatic nervous system, we’re generally doing so voluntarily. We move from the hot sun into the shade, we listen to music we like, and we look at the beauty of a sunset.
The autonomic nervous system, or ANS, has two parts that are easy to remember because they both regulate our invol- untary or automatic body processes, such as digesting food,
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running away from a threat, and relaxing to take a nap. The sympathetic division of the ANS activates us for action. The parasympathetic division of the ANS reduces our level of excitement or arousal.
All parts of the nervous system work together. We may weep over the loss of a friend as we write a letter of sympathy to his or her spouse. Weeping involves the ANS because it’s a reflex that arises from our feelings or emotions, while writing a letter involves the somatic nervous system as well as the information-processing areas of the brain.
In this section, you’ll get an introduction to the progress of research linking genetic inheritance to predispositions to all kinds of personality traits, including learning ability and sexual orientation, as well as different kinds of diseases.
The Endocrine System: Of Chemicals and Glands
The endocrine system consists of a number of glands that, when working together, act as a chemical-regulating system for all of the body’s processes. These chemical regulators are complex proteins called hormones. Hormones regulate digestion, sexual and reproductive functioning, sleep, hunger, sugar levels, and all kinds of other things that keep us going.
You can think of it in this way: The body needs to carry on a number of life functions, and the brain and the rest of the nervous system help us with these functions. However, many life processes need to be regulated chemically. The cells and tissues that make up your body need “instructions” provided by hormones. For example, when you’re trying to escape a grizzly bear, your nervous system will activate the adrenal glands that lie above your kidneys. The inner part of these glands—called the adrenal medulla—releases hormones called epinephrine and norepinephrine into the bloodstream. These hormones alert the cells, muscles, and organs for action. They make your heart beat faster and allow more blood and nutrients to flow to your muscles. The thyroid gland, located in the throat, regulates the rate at which your body uses energy by releasing a hormone called thyroxin in
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specific amounts at specific times. The pineal gland (on the underside of the brain) releases a hormone called melatonin. Melatonin responds to rhythms of light and darkness. In this way, it helps regulate our sleep cycle by preparing the body for the morning rush hour or that drowsy period right before we turn out the lights at night. In this age of rapid trans- portation, travel across time zones can disturb melatonin production, resulting in what’s known as jet lag.
The master gland that controls much of the activity of the other endocrine glands is called the pituitary gland. About the size of a pea, it’s located deep inside the forebrain. The pituitary has a partner, the hypothalamus, which is located near the pituitary gland. These two tiny glands work together in complicated ways to regulate hormone production throughout the body.
Studying the Brain’s Functions: Spying on the Brain
This section introduces you to modern technologies used to explore the brain. They include the electroencephalogram (EEG), positron emission tomography (PET) scans, functional magnetic resonance imaging (fMRI) scans, and tran- scranial magnetic stimulation imaging (TMS).
The Central Core: Our “Old” Brain
The central core of the human brain is made up of pretty much the same elements found in the brains of vertebrates (animals with backbones). We call it “old” since related struc- tures are found way down the evolutionary scale in extinct species that lived millions of years before the arrival of the dinosaurs, much less our more immediate mammalian ancestors.
You can think of the central core as being divided into three sections: the hindbrain, the midbrain, and the forebrain. The spinal cord, protected by the vertebrae that run through our torso, leads to the hindbrain. Key features of the hindbrain
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include the brainstem, which includes the lowest portions of the brain and consists of the medulla and the cerebellum. The medulla is the thicker upper portion of the spinal cord. It contains centers for controlling important reflexes in your body, such as your heart and breathing rates. The cerebellum is like a mini brain that blossoms out just under the occipital lobes. It helps us with coordination, balance, and the complex movements mastered by athletes. (It’s better developed in cats than in humans.)
The pons—which comes from a Latin word meaning “bridge”—is actually a nerve bridge between the medulla and other areas of the brain. It looks like a little lump on the end of the brainstem.
The midbrain, at the end of the hindbrain, connects the spinal cord to the cerebrum. Think of the midbrain as a “switchboard” area for sorting nerve-impulse messages.
The reticular formation is an extension of the brain stem. It serves the important function of deciding which nerve impulses should go where and which should have priority. It’s a bit like a command and control center for incoming nerve messages. It extends through the midbrain into what’s called the forebrain. It includes groups of nerve cells that can prompt other parts of the brain into arousal. For example, a quick response to a loud noise is served by the reticular formation.
Within the forebrain, the thalamus is a “switchboard” for sensory messages on their way to the cerebral cortex. What you see, hear, taste, and smell is processed through the thalamus. The hypothalamus acts as a master control station for your emotions. When you laugh, cry, become sexually aroused, or just get thirsty, your hypothalamus is doing its job.
The Limbic System: Beyond the Central Core
The forebrain includes a group of structures referred to as the limbic system. The limbic system includes a group of structures related to self-preservation (as in fight or flight), learning, memory, the experience of pleasure, and fear.
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Within the forebrain and the limbic system, the amygdala is an almond-shaped body that produces our experience of fear. Fear should be a protective mechanism. However, many stim- uli that don’t pose real threats can send the amygdala into overtime, causing anxiety or phobias (discussed in detail later in this course). Damage to the amygdala can cause emotional blindness, and it may even lead to inappropriate emotional outbursts, such as laughing at a funeral.
Another major player in the limbic system is the hippocampus. It controls higher intellectual functions and helps us estab- lish long-term memories. A hippocampus structure is found in each of our temporal lobes. That may be why some of us scratch or rub that part of our head when we’re trying to remember something.
The Cerebral Cortex: Our “New Brain”
The outer layer of the cerebrum contains most (about 70%) of the neurons in the CNS and is called the cerebral cortex. You’ll notice in a picture of the cerebrum that it’s folded or wrinkled in various ways. These folds greatly increase the area of the cerebral cortex. The intelligence of humans com- pared with other animals is a result of both the size of the human cerebrum and all of those folds.
The cerebral cortex is divided into four different lobes. The occipital lobes—at the back of the skull—are vital to vision. The frontal lobes are associated with higher mental functioning, per- sonality, and complex motor behavior, like building a computer. (Damage to the frontal lobes can be quite devastating if you’re a theoretical physicist, a comedian, or a software programmer.) The parietal lobes—under the midportion of the skull—are asso- ciated mainly with sensation and sensory processing. Finally, the temporal lobes are associated with processing things we hear, called auditory stimuli. Because the left brain is associated with language, a person’s understanding of spo- ken words is usually impaired by left-temporal-lobe damage.
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Looked at in general terms, there are three general areas of the cerebral cortex:
1. The motor area is associated with voluntary movement. It has been very well mapped by brain researchers.
2. The sensory area includes three regions related to body sensations (like touch or pressure), sight, and sound.
3. The association areas are associated with higher mental functioning, memory, thinking, language, and speech.
The association areas (also called the association cortex) can be thought of as processing zones. They combine and sepa- rate sensory information and actions of the brain so that the specialized lobes can work together. In fact, the association cortex occupies all of the cerebral cortex that isn’t directly involved in processing sensory information or managing motor activities, like walking. For example, among associa- tion areas, Broca’s area is a speech-processing center of the left frontal lobe. Wernicke’s area is a speech-processing area of the left temporal lobe.
Neuroplasticity and the Brain
Not all that many years ago, it was assumed that people, having reached puberty, had a fixed number of neurons. As time passed, one would gradually run out of neurons and be reduced to inevitable senility. It now seems that was an overly dreary assessment.
In accounting for remarkable clinical cases requiring radical brain surgery, or recovery from severe head injuries, it now appears that the brain is engaged in continual reorganization. Not only are functions restored in interesting ways, but inter- connections among neurons become more complex over a lifetime. All of this is called neuroplasticity. Further, beyond the amazing facts of neuroplasticity, it’s now known that certain areas of the brain are capable of producing shiny new neurons in a process called neurogenesis. For the prospects of treating nervous system injuries and disorders—not to mention abating traditional stereotypes of older people—this is good news.
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The Specialization of the Hemispheres: Two Brains or One?
For better or worse, humans have very large brains. The largest part of the brain is called the cerebrum. An X-ray of the cerebrum reveals that it’s divided into two similar “loaves” called the cerebral hemispheres. (The two halves of the cere- brum are connected by a “bridge” of tough, fibrous tissue called the corpus callosum.) When you hear people talk about your right brain and your left brain, this is what they’re talk- ing about. The interesting thing about the two sides of the cerebrum is that they’re specialized. The right brain is nor- mally involved in applying overall patterns to objects and ideas. The left brain is more adept at linear thinking involving language. Interestingly, the main nerve pathways in the brain cross over. In other words, in most people, the left hand responds to right-brain signals, and the right hand responds to left-brain signals.
The capacity for certain cerebral activities to be “assigned” to either the left or right brain is called lateralization. The capacity for lateralization is thought to have evolved in humankind very recently in terms of the evolutionary time scale—a mere one million years ago. (The origins of Earth’s species through mutations and adaptive radiation, from simple to increasingly complex, date back about 500 million years.)
Your text properly gives you an overview of research indicat- ing typical differences in lateralization among males and females. The statistical evidence is sound. Women tend to distribute functions across hemisphere, and the female corpus callosum (connecting the two hemispheres) does contain more crossover connecting paths. However, recent research suggests that it isn’t safe to assume that females are inevitably more right-brained while males are inevitably more inclined to be left-brained. It turns out that variation in lateralization among individuals—male or female—is considerable.
Once you’ve finished studying Assignment 2, complete Self-Check 2 and the Evaluate quizzes on pages 55, 63, and 78 in your textbook.
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Self-Check 2 1. Looking at a string of neurons, we’ll see that axons are linked to dendrites across a junction
called a/an _______. This gap is bridged by biochemical nerve impulse transmitters called
2. The brain continually reorganizes itself in a process called _______.
3. The amygdala and the hippocampus are found in the _______ system of the brain.
4. The peripheral nervous system extends throughout the body. Its two major divisions include
the _______ division, which specializes in voluntary movement, and the autonomic division,
which handles involuntary functioning of organic processes like breathing.
5. An electroencephalograph (EEG) measures _______ activity in the brain, seen as wave
patterns, while positron emission tomography (PET) scans show us _______ activity within
the brain at a particular moment.
6. The _______ is referred to as the “new” part of our brain because it’s a relatively recent
development in the evolution of species.
7. In the neuron, looking a bit like linked sausages, the _______ sheath insulates and protects
8. Sensations like touch and pressure, vision, and hearing are associated with the _______ area
of the cerebral cortex.
9. A large portion of the cerebral cortex is occupied by tissues that aren’t directly related to
motor functions (movement) or sensory processing. These parts of the brain are said to serve
an “executive function.” We call these parts of the cortex _______ areas.
10. A part of the brain that’s vital to allowing us to keep our balance is the _______.
Check your answers with those on page 167.
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ASSIGNMENT 3—SENSATION AND PERCEPTION Read this assignment. Then read Chapter 3 in your textbook.
Sensing the World Around Us We experience the world because of our senses, but sometimes the senses can be deceiving. There’s an adage taught to young newspaper reporters: “Believe nothing you hear and only half of what you see.” The point is that perception is, above all, interpretation. We don’t just see color—we see bright red or sky blue. We don’t just hear sounds that we call music—we hear music we like and music we don’t like. Because perception combines sense information with inter- pretation, what we see, hear, smell, or taste can fool us. Keep in mind that we tend to see and understand what we expect to see based on our perceptual habits. We learn to screen out the things that aren’t important to us, like certain commer- cials, and pay attention to sensory stimuli that are important to us, like the sound of a coin hitting the pavement.
We experience a sensation when our sense organs (eyes, ears, and so on) respond to a stimulus. A stimulus is conveyed to us by some form of energy, such as light, sound waves, heat, and so on. Perception is the way we “read” or interpret a stimulus. Stimuli vary by energy type, frequency, and inten- sity. The science of psychophysics studies the ways in which stimuli are converted to psychological experience.
In the study of sensory perception, an absolute threshold is the smallest intensity necessary for a stimulus to be regis- tered by the senses. With respect to sound, for example, the absolute threshold for detecting a high-pitched sound is much lower in dogs than it is in people. In the context of psychophysics, noise is defined as background stimuli that can interfere with or block out a typical absolute threshold for a given stimulus.
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Psychologists are interested in how we compare stimuli. For example, at what point can we distinguish between two shades of red or notice a size difference between oranges in a produce display? In this context, a difference threshold is the minimal difference detectable in two or more related stimuli. A difference threshold is also called a just-noticeable difference.
Imagine that you want to estimate the weight difference between metal spheres—A, B, C, D, and E—each of which weighs somewhere around 100 grams. According to Weber’s law, the difference threshold ratio for weight is 1:50. That means that after you heft sphere A to get a sense of its weight, you won’t notice an increase or decrease in the next spheres you pick up unless the actual weight difference is 2 grams. (1:50 is proportional to 2:100.) Now imagine that you want to compare weights for a set of metal spheres—A, B, C, D, and E—each weighing around 800 grams. You heft sphere A first, then sphere B, and so on. How much heavier or lighter must B, C, D, or E be for you to register a weight difference? Answer: 16 grams. (1/50 = x/800; 50x = 800; x = 800/50; x = 16.) Given that 1:50 is the same proportion as 16:800, we see that the just-noticeable difference is pro- portional to the intensity of the original stimulus.
Sensory responses adapt to changes in environmental stim- uli. When you walk out of bright sunlight into the relatively dim light of a restaurant, your vision gradually adapts to the lower light level. In other instances, the senses adapt to persistent background noise. For example, moving from the relative quiet of the countryside to a city, we gradually learn to “screen out” the steady roar of traffic. We become less sensitive to it.
The visible spectrum refers to all of the light energy that we can see. The electromagnetic spectrum consists of all light frequencies—those we can see and those we can’t. And, in
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fact, the visible spectrum is a small part of the electromag- netic spectrum. The waves in the electromagnetic spectrum include radio and TV waves at the low-energy end of the spectrum and lethal gamma rays and X-rays at the high- energy end. Visible light—from red to violet—is roughly in the middle.
Your textbook explains the basic structure of the eye by comparing the eye to a camera. The iris (the colored part of your eye) acts like a shutter that widens or closes depending on light intensity. The cornea protects your eye and gathers light that goes through the opening in the iris (the pupillary opening). Light is then focused toward the back of the eye by the lens that’s just behind the iris. Layers of specialized cells on the inside of the eyeball act like film.
This “film” is actually a specialized layer of cells called the retina. There are two basic kinds of cells in the retina. Nearly one hundred million rods read light intensity. Rods can’t read color—only black and white. They’re primarily responsible for helping us see in the dark. Millions of cells called cones are responsible for interpreting color.
Color Vision and Color Blindness
According to the trichromatic theory of color vision, there are three kinds of color-reading cones in the retina. Call them A, B, and C. “A” reads blue-violet colors. “B” reads green. “C” reads yellow-red. By way of the interactive combinations possible from A + B + C, humans with normal vision can distinguish as many as 7 million different colors.
Color blindness—more common in men than in women—is a genetically related incapacity of one or more types of cones. In the most common kind of color blindness, all red and green objects appear as yellow.
There are aspects of color vision not explained by the trichro- matic model. In particular, the theory fails to explain afterimage phenomena. For example, stare at a rectangle of green for a moment, and then stare at a blank piece of paper. You’ll see a rather faint red rectangle. That’s an example of a retinal afterimage.
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The opponent-process theory of color vision can explain after- image phenomena. The basic idea is that cone receptors are linked in pairs, as in white-black or green-red. Thus, the afterimage for black will be white, while the afterimage for white will be black. The same goes for green-red.
Hearing and the Other Senses
Sound is made up of waves that are transmitted from an energy source to your ear through the air. Sound waves act like ripples in a pond. Without the water, there are no rip- ples. When you watch science-fiction movies that take place in outer space, the sounds the spaceships make wouldn’t really exist in our universe. Sound waves can’t travel through a vacuum. Outer space has no atmosphere, so an observer would actually hear nothing at all.
We hear because we have a way to detect, code, and interpret sounds that come to us through any medium made of mole- cules, such as air, water, steel, and so on. The speed of sound depends on the medium that carries the sound waves. (It’s about 500 miles per hour at sea level through air, and some aircraft travel faster than sound does.) Warm, humid air carries sound better than dry, cold air. Water carries sound faster than air because water molecules are closer together than air molecules. Sound-wave energy is trans- duced into nerve-impulse energy before we actually hear anything. The mechanism for this clever feat is the human ear.
The ear, like the eye, is part of a system that includes the brain, the structure of the ear, and the connecting auditory nerves. The exterior part of the ear is called the pinna. The external ear ends where the external auditory canal meets the tympanic membrane—also known as the eardrum. The inner ear has two major divisions, and both are encased in protective bone tissue. The ossicles consist of three tiny bones called the malleus (hammer), incus (anvil), and stapes (stirrup). When sound vibrates the eardrum, these little bones vibrate and transfer sound to the deepest part of the inner ear, called the cochlea. The cochlea is a complicated,
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fluid-filled device that looks like a snail shell. It transfers sound vibrations into nerve impulses that can be “read” by our busy brains.
The semicircular canals of the inner ear help us sort up from down and keep our balance. The fluid in these canals sloshes about when we turn our heads, basically allowing us to “read” centripetal and centrifugal gravitational forces.
Smell and Taste
How do we detect odors? In terms of the physiology of smelling, note that there are some 1,000 kinds of olfactory (smell) receptors located in the olfactory cells of the nasal cavity. As molecules related to a particular odor pass over these receptors, nerve signals go to the brain. The brain then tells us that we smell perfume, mildew, lasagna, or a mistake made by the family dog. You’ll note that women tend to have a better sense of smell than men and that one can distinguish another person’s sex by way of smell.
Four basic tastes have long been recognized: sweet, sour, salty, and bitter. Many researchers believe a fifth basic taste also exists—umami, a Japanese word that describes a brothy taste like that of chicken soup. As in the case of smell, we detect tastes by some 10,000 taste buds, most of which are found in the tongue. Taste receptors of different kinds work a little differently, but they all work together to differentiate foods like chocolate and fried potatoes.
Smell and taste are called chemical senses. They both depend on nerve receptors that can detect the presence of particular molecules. Those molecules may be in the air, or they may be released in fluids or gases as we taste or eat something. Both smell and taste are remarkably sensitive. Human olfactory receptors work together to allow us to detect up to 10,000 different odors. Further, just a few molecules from something like Swiss cheese can be easily detected. The fact that there are only five basic tastes doesn’t limit your palate. Foods we eat enable the different taste buds to work together and allow us to detect an enormous variety of tastes.
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The Skin Senses
Touch, pressure, temperature, and pain are detected by specialized nerve receptors in the largest organ in the human body—the integument, or skin.
Pain plays a special role in keeping us safe. Pain carried by large nerve fibers demands our attention. It’s sharp, hard, and dis- tinct. Warning pain is the body’s signal that there may be an acute organ malfunction or serious injury. Another kind of pain is carried by small nerve fibers and is called the reminding system. For example, a faint aching sensation around your sinuses may remind you that the prescribed antibiotic hasn’t taken full effect yet. Dull pain following an injury reminds you to take it easy and avoid reinjury.
According to the sensory gate theory of pain, some kinds of pain signals can block other pain signals from going to the brain. That’s because both signals will have to go through the same neural location in the spinal cord or brain stem. The process of sensory gating is well known to dentists. For example, before a dentist injects Novocain into your gums, he or she may gently pinch your cheek to reduce the pain of the needle. The pain caused by the pinching will block the pain from the needle because both pain signals must travel through the same neural gate. The pain signal that occurs first is the one that will be received.
The Gestalt Laws of Organization
Basic principles by which we organize bits and pieces of information (stimuli) are known as the Gestalt laws of organization. (In German, Gestalt means, roughly, “a pattern perceived as a whole.” It’s often capitalized because that’s the rule for nouns in German.) They include closure, simplicity, proximity, and similarity. The closure principle applies when we assume we’re looking at an octagonal stop sign even if part of it is concealed by tree branches. The proximity principle kicks in when we see a group of people close together and assume they’re a group, even if they
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aren’t. When things we see are similar in appearance, like geese in flight, we tend to perceive them as grouped together. The simplicity principle is the most basic Gestalt principle. It holds, for example, that in a observing a complex design, we’ll tend to perceive the simplest form it could represent. If it could be a design for a circuit board or a “Y” shape, we’ll tend to see the “Y” shape.
Top-Down and Bottom-Up Processing
Top-down processing is guided by experience, expectations, and motivations that are part of higher-level processing. It’s typically guided by understanding or being aware of a con- text. For example, if we’re familiar with what goes on at a Jewish Passover Seder or a Polish wedding, we’ll pick up the clues as to what’s going on when we come across such a social scene because we’re familiar with the contexts. Bottom- up processing complements top-down processing. Even if we’ve been to a Passover Seder or a Polish wedding, we may not be sure what’s going on until we pick up clues and “con- nect the dots.” In the first instance, the first clues might be men wearing yarmulkes and people speaking what sounds like Hebrew. In the second instance, we may recognize that we’re observing a wedding before we pick up other clues and figure out that we’re at an Eastern Orthodox Church, people are speaking in a strange tongue, and polka music starts up. The main thing to remember here is that we use both top- down and bottom-up processing to determine the context of a situation and how we should behave.
Sensory stimuli are subject to the brain’s organization. Your brain tends to group visual information together into familiar shapes or objects. For example, when you see a car pass down the street, you don’t imagine the car itself is shrinking as it moves away from you. The ability to discern size at different distances is possible because your brain maintains size constancy. Your brain can also maintain shape constancy. For example, your brain knows that a globe is spherical although it looks like a circle, even when you’re looking at
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only one part of it. The same phenomenon applies to bright- ness. At the beach, you’ll notice that a yellow bathing suit is just as eye-catching in the sunlight as it is on a cloudy day. This experience is known as brightness constancy.
Size constancy, shape constancy, and brightness constancy are all examples of perceptual constancy. Perceptual constancy means that we tend to see what we expect to see. However, perceptual constancy requires that we be familiar with our environments. Here’s an interesting illustration of that fact: An anthropologist recorded a strange event when he led some African forest people out of their normal environment onto a broad, grassy plain. The people began to point and laugh at grazing African buffalo in the distance. To them, the crea- tures seemed tiny and strange. The forest people lived in an environment where it was unusual to see ahead more than a few feet. Since their brains couldn’t interpret large animals from a distance, the people couldn’t maintain a sense of size constancy.
Depth Perception: Translating 2-D to 3-D
There’s an “angle shift” between what we see with the right eye and what we see with the left eye. You’ve probably noticed this. If you haven’t, just hold a pencil in front of your face and look at it with first one eye than the other eye. We call this perspective shift binocular disparity. Monocular cues also help us see depth, even with just one eye. In paintings, for example, we can get a sense of depth perception by the relative size of objects or by receding and converging vertical lines like those of a railroad track. We can also detect texture gradients as “closer” objects are more detailed, while more apparently remote objects are less detailed. An interesting monocular cue is called motion parallax. For example, observing the countryside from a moving car, we see objects closest to us passing by quickly while more remote objects pass by more slowly.
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Motion perception depends on a cooperative alliance between information we’ve internalized about the world to adapt to life as we know it, plus external motion cues. For example, when someone tosses you a basketball, the retina detects the sphere getting larger. In the context of motion perception, we won’t see the basketball in terms of size constancy, but in terms of an approaching object in motion. Even more fascinating, we actually catch the ball.
This final section is a fascinating discussion of visual (percep- tual) illusions. The best way to make sense of the discussion is by thinking creatively about the illustrations of these kinds of “perceptual tricks.”
Once you’ve finished studying Assignment 3, complete Self-Check 3; the Evaluate quizzes on pages 90, 99, 108, and 120 in your textbook; and the required discussion board posting.
Then review the material you’ve learned in this study guide and the assigned pages in your textbook for Assignments 1–3. When you’re sure that you completely understand the infor- mation, complete your examination for Lesson 1.
Lesson 1 41
Self-Check 3 1. The inner ear responsible for sending sound messages to the brain consists of a basilar
membrane and hair cells found within the _______.
2. Touch, pressure, temperature, and pain are all functions of our _______ senses.
3. The minimum intensity of a sensory stimulus that can be detected is what we call the
4. A bell rings. We hear it. Because the sound amounts to physical energy transmitted through
air, we can call it a/an _______. However, classifying, analyzing, and interpreting the sound of
the bell requires us to have a/an _______ of it.
5. In top-down _______, what we perceive is guided by higher-level knowledge, experience, and
motivations. We’re able to “fill in the gaps” of a puzzle or partial image by grasping their
6. The main reason we’re capable of _______ perception is because we have two eyes.
7. _______ are to light intensity as cones are to our perception of _______.
8. We see a car moving away from us on a street, but we don’t perceive the vehicle itself as
getting smaller as it gets farther away. The fact illustrates what’s called _______ constancy.
9. Moving from a house in the country to a big city, we’re exposed to constant background noise
of traffic. However, after a few days or weeks, we get used to those sounds and give them
less attention through a process called _______ adaptation.
10. Sour, sweet, salty, and _______ are to taste buds as _______ is to olfactory cells.
Check your answers with those on page 167.
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The Mind at Work
INTRODUCTION Lesson 2 begins with an exploration of the most mysterious aspect of human experience, consciousness. It then proceeds to a consideration of three major approaches to the psychol- ogy of learning. Two of these are schools of behaviorism— classical conditioning and operant (behavior) conditioning. The third approach, cognitive learning, takes account of men- tal processes in learning, such as observation and imitation. The final chapter in this lesson explores the nature of mem- ory, cognition (thinking and feeling), and the vital importance of language in human experience.
ASSIGNMENT 4—STATES OF CONSCIOUSNESS Read this assignment. Then read Chapter 4 in your textbook.
In this assignment, you’ll be challenged to think about the nature of consciousness. Consciousness can be defined as the sensations, thoughts, and feelings you’re aware of at any given moment. Alertness, attention, and clarity are characteristics of waking consciousness. We also experience dream states and other altered states of consciousness. Our conscious experience when we’re in a hypnotic trance, for example, isn’t quite the same as what we experience in ordinary waking con- sciousness. It’s an altered state. Our conscious experience during meditation is also different from that of ordinary waking consciousness. Therefore, meditation also qualifies as an altered state. Altered states are also produced by both legal and illegal drugs.