Chapter 1

Question 1

The human brain is a
squishy, wrinkled, walnut-shaped hunk of tissue
weighing about

Answer 1

1.3

kilograms.

Question 2

Despite its disagreeable external appearance, the human
brain is an amazingly intricate network of neurons (cells that receive
and transmit electrochemical signals). Contemplate for a moment
the complexity of your own brain s
neural circuits. Consider the [how many]
billion neurons in complex array, the estimated [how many] trillion connections among
them, and the almost infinite number of
paths that neural signals can follow
through this morass.

Answer 2

100
billion neurons

estimated 100 trillion connections

Question 3

neuroscience

Answer 3

(the scientific

study of the nervous system)

Question 4

Jimmie G. was tested by eminent neurologist Oliver
Sacks, and a few simple questions revealed a curious
fact:

Answer 4

The 49-year-old patient believed that he was 19.

Question 5

Thinking Creatively about Biopsychology, Clinical Implications

Answer 5

The Evolutionary Perspective, Neuroplasticity

Question 6

The study of the biology of behavior has a long history, but biopsychology did not develop into a major
neuroscientific discipline until the

Answer 6

20th century.

Question 7

Although it is not possible to specify the exact date of
biopsychology s birth, the publication of

Answer 7

The Organization of Behavior in 1949 by D. O. Hebb played a key role
in its emergence

Question 8

Biopsychologists are neuroscientists who bring to their

research a knowledge of

Answer 8

behavior and of the methods of

behavioral research.

Question 9

Neuroanatomy

Answer 9

The study of the structure of the

nervous system

Question 10

Neurochemistry

Answer 10

The study of the chemical bases of

neural activity

Question 11

Neuroendocrinology

Answer 11

The study of interactions between the nervous system and the endocrine system

Question 12

Neuropathology

Answer 12

The study of nervous system disorders

Question 13

Neuropharmacology

Answer 13

The study of the effects of drugs

on neural activity

Question 14

Neurophysiology

Answer 14

The study of the functions and activities of the nervous system

Question 15

Both human and nonhuman animals are the subject of
biopsychological research. Of the nonhumans, ! are
the most common subjects; however, !, !, !, and
! are also widely studied.

Answer 15

rats, mice, cats, dogs, and

nonhuman primates

Question 16

Humans have several advantages over other animals as
experimental subjects of biopsychological research: They
can

Answer 16

follow instructions, they can report their subjective

experiences

Question 17

In other words, the differences
between the brains of humans and those of related
species are more

Answer 17

quantitative than qualitative and thus
many of the principles of human brain function can be
clarified by the study of nonhumans

Question 18

Conversely, nonhuman animals have three advantages
over humans as subjects in biopsychological research. The
first is that

Answer 18

the brains and behavior of nonhuman subjects
are simpler than those of human subjects. Hence, the
study of nonhuman species is more likely to reveal fundamental brain behavior interactions.

Question 19

The second advantage is that insights frequently arise from the comparative
approach,

Answer 19

the study of biological processes by comparing
different species. For example, comparing the behavior of
species that do not have a cerebral cortex with the behavior of species that do can provide valuable clues about
cortical function.

Question 20

The third advantage is that it is possible

to conduct research on laboratory animals that, for ethical reasons, is not possible with human subjects.

Answer 20

This is

not to say that the study of nonhuman animals is not governed by a strict code of ethics

Question 21

Experiments

Answer 21

The experiment is the method used by
scientists to study causation, that is, to find out what
causes what.

Question 22

Usually, a different group of subjects is tested under each condition (between-subjects
design),

Answer 22

but sometimes it is possible to test the same
group of subjects under each condition (within-subjects
design).

Question 23

This difference between the conditions is called the
independent variable. The variable that is measured by
the experimenter to assess the effect of the independent
variable is called the

Answer 23

dependent variable. If the experiment is done correctly, any differences in the dependent
variable between the conditions must have been caused
by the independent variable.

Question 24

Why is it critical that there be no differences between
conditions other than the independent variable? The reason is that when there is more than one difference that
could affect the dependent variable, it is difficult to determine whether it was the independent variable or the unintended difference called a

Answer 24

confounded variable that
led to the observed effects on the dependent variable. Although the experimental method is conceptually simple,
eliminating all confounded variables can be quite difficult. Readers of research papers must be constantly on the
alert for confounded variables that have gone unnoticed
by the experimenters themselves.

Question 25

An experiment by Lester and Gorzalka (1988) illustrates the experimental method in action. The experiment was a demonstration of the Coolidge effect. The Coolidge effect is

Answer 25

the fact that a copulating male who becomes incapable of continuing to copulate with one sex partner can often recommence copulating with a new sex partner (see Figure 1.2). Before your imagination starts running wild, I should mention that the subjects in Lester and Gorzalka s experiment were hamsters, not students from the undergraduate subject pool. Lester and Gorzalka argued that the Coolidge effect had not been demonstrated in females because it is more difficult to conduct well-controlled Coolidge-effect experiments with females not because females do not display a Coolidge effect. The confusion, according to Lester and Gorzalka, stemmed from the fact that the males of most mammalian species become sexually fatigued more readily than do the females. As a result, attempts to demonstrate the Coolidge effect in females are often confounded by the fatigue of the males. When, in the midst of copulation, a female is provided with a new sex partner, the increase in her sexual receptivity could be either a legitimate Coolidge effect or a reaction to the greater vigor of the new male. Because female mammals usually display little sexual fatigue, this confounded variable is not a serious problem in demonstrations of the Coolidge effect in males.

Question 26

The dependent variable was the amount of time that the female displayed lordosis (the arched-back, rump-up, tail-diverted posture of female rodent sexual receptivity) during each sex test.

Answer 26

As Figure 1.3 illustrates, the females responded more vigorously to the unfamiliar males than they did to the familiar males during the third test, despite the fact that both the unfamiliar and familiar males were equally fatigued and both mounted the females with equal vigor.

Question 27

Quasiexperimental Studies It is not possible for biopsychologists to bring the experimental method to bear on all problems of interest to them. There are frequently physical or ethical impediments that make it impossible to assign subjects to particular conditions or to administer the conditions once the subjects have been assigned to them. For example, experiments on the causes of brain damage in human alcoholics are

Answer 27

not feasible because it would not be ethical to assign a subject to a condition that involves years of alcohol consumption. (Some of you may be more concerned about the ethics of assigning subjects to a control condition that involves years of sobriety.)

Question 28

In such prohibitive situations, biopsychologists sometimes conduct

Answer 28

quasiexperimental studies studies of groups of subjects who have been exposed to the conditions of interest in the real world. These studies have the appearance of experiments, but they are not true experiments because potential confounded variables have not been controlled for example, by the random assignment of subjects to conditions.

Question 29

In one quasiexperimental study, a team of researchers compared 100 detoxified male alcoholics from an alcoholism treatment unit with 50 male nondrinkers obtained from various sources (Acker et al., 1984). The alcoholics as a group performed more poorly on various tests of perceptual, motor, and cognitive ability, and their brain scans revealed extensive

Answer 29

brain damage. Although this quasiexperimental study seems like an experiment, it is not. Because the participants themselves decided which group they would be in by drinking alcohol or not the researchers had no means of ensuring that exposure to alcohol was the only variable that distinguished the two groups. Can you think of differences other than exposure to alcohol that could reasonably be expected to exist between a group of alcoholics and a group of abstainers differences that could have contributed to the neuroanatomical or intellectual differences that were observed between them? There are several. For example, alcoholics as a group tend to be more poorly educated, more prone to accidental head injury, more likely to use other drugs, and more likely to have poor diets. Accordingly, quasiexperimental studies have revealed that alcoholics tend to have more brain damage than nonalcoholics, but such studies have not indicated why

Question 30

Studies that focus on a single case or subject are called

Answer 30

case studies. Because they focus on a single case, they often provide a more in-depth picture than that provided by an experiment or a quasiexperimental study, and they are an excellent source of testable hypotheses.

Question 31

However, there is a major problem with all case studies: | their

Answer 31

generalizability the degree to which their results can be applied to other cases. Because humans differ from one another in both brain function and behavior, it is important to be skeptical of any biopsychological theory based entirely on a few case studies.

Question 32

It is not possible for biopsychologists to bring the experimental method to bear on all problems of interest to them. There are frequently physical or ethical impediments that make it impossible to assign subjects to particular conditions or to administer the conditions once the subjects have been assigned to them. For example, experiments on the causes of brain damage in human alcoholics are not feasible because it would not be ethical to assign a subject to a condition that involves years of alcohol consumption. (Some of you may be more concerned about the ethics of assigning subjects to a control condition that involves years of sobriety.) In such prohibitive situations, biopsychologists sometimes conduct

Answer 32

quasiexperimental studies studies of groups of subjects who have been exposed to the conditions of interest in the real world. These studies have the appearance of experiments, but they are not true experiments because potential confounded variables have not been controlled for example, by the random assignment of subjects to conditions.

Question 33

Pure research is research motivated primarily by

Answer 33

by the curiosity of the researcher it is done solely for | the purpose of acquiring knowledge.

Question 34

In contrast, applied | research is

Answer 34

is research intended to bring about some direct | benefit to humankind.

Question 35

The purpose of this section of the chapter is to give you a clearer sense of biopsychology and its diversity by describing six of its major divisions:

Answer 35

(1) physiological psychology, (2) psychopharmacology, (3) neuropsychology, (4) psychophysiology, (5) cognitive neuroscience, and (6) comparative psychology.

Question 36

Physiological psychology is

Answer 36

the division of biopsychology that studies the neural mechanisms of behavior through the direct manipulation of the brain in controlled experiments surgical and electrical methods of brain manipulation are most common. The subjects of physiological psychology research are almost always laboratory animals, because the focus on direct brain manipulation and controlled experiments precludes the use of human subjects in most instances. There is also a tradition of pure research in physiological psychology; the emphasis is usually on research that contributes to the development of theories of the neural control of behavior rather than on research that is of immediate practical benefit.

Question 37

Psychopharmacology is

Answer 37

similar to physiological psychology, except that it focuses on the manipulation of neural activity and behavior with drugs. In fact, many of the early psychopharmacologists were simply physiological psychologists who moved into drug research, and many of today s biopsychologists identify closely with both approaches. However, the study of the effects of drugs on the brain and behavior has become so specialized that psychopharmacology is regarded as a separate discipline. A substantial portion of psychopharmacological research is applied. Although drugs are sometimes used by psychopharmacologists to study the basic principles of brain behavior interaction, the purpose of many psychopharmacological experiments is to develop therapeutic drugs (see Chapter 18) or to reduce drug abuse (see Chapter 15). Psychopharmacologists study the effects of drugs on laboratory species and on humans, if the ethics of the situation permits it.

Question 38

Neuropsychology is

Answer 38

the study of the psychological effects of brain damage in human patients. Obviously, human subjects cannot ethically be exposed to experimental treatments that endanger normal brain function. Consequently, neuropsychology deals almost exclusively with case studies and quasiexperimental studies of patients with brain damage resulting from disease, accident, or neurosurgery. The outer layer of the cerebral hemispheres the cerebral cortex is most likely to be damaged by accident or surgery; this is one reason why neuropsychology has focused on this important part of the human brain. Neuropsychology is the most applied of the biopsychological subdisciplines; the neuropsychological assessment of human patients, even when part of a program of pure research, is always done with an eye toward benefiting them in some way. Neuropsychological tests facilitate diagnosis and thus help the attending physician prescribe effective treatment (see Benton, 1994). They can also be an important basis for patient care and counseling; Kolb and Whishaw (1990) described such an application.

Question 39

Psychophysiology is the division of biopsychology that | studies the relation between

Answer 39

hysiological activity and psychological processes in human subjects. Because the subjects of psychophysiological research are human, psychophysiological recording procedures are typically noninvasive; that is, the physiological activity is recorded from the surface of the body

Question 40

The usual measure of brain activity is the scalp

Answer 40

electroencephalogram (EEG)

Question 41

``` The autonomic nervous system (ANS) is the division of the nervous system that regulates ```

Answer 41

the body s inner environment

Question 42

Cognitive neuroscience is the youngest division of biopsychology, but it is currently among the most active and exciting. Cognitive neuroscientists study the

Answer 42

neural bases of cognition, a term that generally refers to higher intellectual processes such as thought, memory, attention, and complex perceptual processe

Question 43

Because of its focus on cognition, most cognitive neuroscience research involves human subjects; and because of its focus on human subjects, its methods tend to be

Answer 43

noninvasive, | rather than involving penetration or direct manipulation of the brain.

Question 44

The division of biopsychology that deals generally with the biology of behavior, rather than specifically with the neural mechanisms of behavior, is

Answer 44

comparative psychology. Comparative psychologists compare the behavior of different species in order to understand the evolution, genetics, and adaptiveness of behavior.

Question 45

ome comparative psychologists study behavior in the laboratory; others engage in

Answer 45

ethological research the study of animal behavior in | its natural environment.

Question 46

Physiological psychology: study of the neural mechanisms of behavior by manipulating the nervous systems of nonhuman animals in controlled experiments.

Answer 46

Physiological psychologists have studied the contributions of the hippocampus to memory by surgically removing the hippocampus in rats and assessing their ability to perform various memory tasks.

Question 47

Psychopharmacology: study of the effects of drugs on the | brain and behavior.

Answer 47

Psychopharmacologists have tried to improve the memory of Alzheimer s patients by administering drugs that increase the levels of the neurotransmitter acetylcholine.

Question 48

Neuropsychology: study of the psychological effects of brain damage in human patients.

Answer 48

Neuropsychologists have shown that patients with alcohol produced brain damage have particular difficulty in remembering recent events.

Question 49

Psychophysiology: study of the relation between physiological activity and psychological processes in human subjects by noninvasive physiological recording.

Answer 49

Psychophysiologists have shown that familiar faces elicit the usual changes in autonomic nervous system activity even when patients with brain damage report that they do not recognize a face.

Question 50

Cognitive neuroscience: study of the neural mechanisms of human cognition, largely through the use of functional brain imaging.

Answer 50

Cognitive neuroscientists have used brain-imaging technology to observe the changes that occur in various parts of the brain while human volunteers perform memory tasks.

Question 51

Comparative psychology: study of the evolution, genetics, and adaptiveness of behavior, largely through the use of the comparative method.

Answer 51

Comparative psychologists have shown that species of birds that cache their seeds tend to have big hippocampi, confirming that the hippocampus is involved in memory for location

Question 52

A biopsychologist who studies the memory deficits of | human patients with brain damage would likely identify with the division of biopsychology termed ______.

Answer 52

rs: (1) neuropsychology,

Question 53

Biopsychologists who study the physiological correlates of psychological processes by recording physiological signals from the surface of the human body are often referred to as ______.

Answer 53

y, (2) psychophysiologists,

Question 54

The biopsychological research of ______ frequently involves the direct manipulation or recording of the neural activity of laboratory animals by various invasive surgical, electrical, and chemical means.

Answer 54

(3) physiological psychologists

Question 55

The division of biopsychology that focuses on the | study of the effects of drugs on behavior is often referred to as ______.

Answer 55

s, (4) psychopharmacology

Question 56

______ is a division of biopsychology that investigates the neural bases of human cognition; its major method is functional brain imaging.

Answer 56

y, (5) Cognitive | neuroscience,

Question 57

______ are biopsychologists who study the genetics, evolution, and adaptiveness of behavior, often by using the comparative approach.

Answer 57

e, (6) Comparative psychologists

Question 58

rogress is most likely when different approaches are focused on a single problem in such a way that the strengths of one approach compensate for the weaknesses of the others; this combined approach is called

Answer 58

converging operations

Question 59

Korsakoff s | syndrome

Answer 59

The primary symptom of Korsakoff s syndrome is severe memory loss, which is made all the more heartbreaking as you have seen in Jimmie G. s case by the fact that its sufferers are often otherwise quite capable. Because Korsakoff s syndrome commonly occurs in alcoholics, it was initially believed to be a direct consequence of the toxic effects of alcohol on the brain. This conclusion proved to be a good illustration of the inadvisability of basing causal conclusions on quasiexperimental research. Subsequent research showed that Korsakoff s syndrome is largely caused by the brain damage associated with thiamine (vitamin B 1 ) deficiency.

Question 60

The empirical method that biopsychologists and other | scientists use to study the unobservable is called

Answer 60

scientific inference. The scientists carefully measure key events that they can observe and then use these measures as a basis for logically inferring the nature of events that they cannot observe. Like a detective carefully gathering clues from which to recreate an unwitnessed crime, a biopsychologist carefully gathers relevant measures of behavior and neural activity from which to infer the nature of the neural processes that regulate behavior.

Question 61

Often the first step in creative thinking is spotting the weaknesses of existing ideas and the evidence on which they are based the process by which these weaknesses are recognized is called

Answer 61

critical thinking. The identification of weaknesses in existing beliefs is one of the major stimuli for scientists to adopt creative new approaches.

Question 62

naggressive; or the stimulation could have been painful. Clearly, any observation that can be interpreted in so many different ways provides little support for any one interpretation. When there are several possible interpretations for a behavioral observation, the rule is to give precedence to the simplest one; this rule is called

Answer 62

Morgan s Canon.

Question 63

In 1949, Dr. Egas Moniz was awarded the Nobel Prize in | Physiology and Medicine for the development of

Answer 63

prefrontal lobotomy a surgical procedure in which the connections between the prefrontal lobes and the rest of the brain are cut as a treatment for mental illness. The prefrontal lobes are the large areas, left and right, at the very front of the brain (see Figure 1.7 on page 16). Moniz s discovery was based on the report that Becky, a chimpanzee that frequently became upset when she made errors during the performance of a food-rewarded task, did not do so following the creation of a large bilateral lesion (an area of damage to both sides of the brain) of her prefrontal lobes.

Question 64

cut out six large cores of prefrontal tissue with a surgical device called a

Answer 64

leucotome

Question 65

One such variation was transorbital lobotomy, which was developed in Italy and then popularized in the United States by Walter Freeman in the late 1940s. It involved

Answer 65

inserting an ice-pick-like device under the eyelid, driving it through the orbit (the eye socket) with a few taps of a mallet, and pushing it into the frontal lobes, where it was waved back and forth to sever the connections between the prefrontal lobes and the rest of the brain