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