Physiological Psychology

637 Pages·1980·22.47 MB·English

by  Thomas Brown (Auth.)

p>tin yS,Wπ ϊ*l O1 g l~ Ca^ l 7 THOMAS S. BBRROO WN ACADEMIC PRESS
Λ Λ New York
DePaul University
San Francisco
PATRICIA M. WALLACE °^sidiar of
A y
psychology Clarion State College HwoJrtBÎace Jovanovich,
Publishers
Cover illustration on photograph by D. L. Cramer
Copyright ©1980, by Academic Press, Inc.
All rights reserved.
No part of this publication may be reproduced or
transmitted in any form or by any means, electronic
or mechanical, including photocopy, recording, or any
information storage and retrieval system, without
permission in writing from the publisher.
ACADEMIC PRESS, INC.
Ill Fifth Avenue, New York, New York 10003
United Kingdom Edition published by
ACADEMIC PRESS, INC. (LONDON) LTD.
24/28 Oval Road, London NW1 7DX
ISBN: 0-12-136660-X
Library of Congress Catalog Card Number: 79-52344
PRINTED IN THE UNITED STATES OF AMERICA
There is an air of enthusiasm in a field like physiological
preface
psychology that is very typical of young sciences. The excitement
even infects the general public as more and more TV specials
and magazine articles appear which deal with topics in this
field. We hope we will convey some of this enthusiasm to the
students who read this book, some of whom will continue with
their training and go on to explore the fascinating relationship
between physiology and behavior.
Our aim in writing this book was to present an introduction
to a field that is rapidly growing and changing. This area of
study combines the talents of psychologists, biologists, chem-
ists, physicists, engineers, nutritionists, and many others inter-
ested in the relationship between biology and behavior. Though
a young field, it is accumulating significant information very
rapidly, partly because of the development of new techniques
and new approaches, and partly because of the growing aware-
ness that we cannot understand human behavior without "look-
ing inside" the body. This book is intended for an undergraduate
course usually called physiological psychology, but which may
also go under such names as biological psychology, psychobiol-
ogy, brain and behavior, or physiology and behavior.
The book's organization reflects the most recent trends in the
field of physiological psychology. We begin with basic infor-
mation about the nervous system and the neuron, and then
discuss the topics about which physiological psychologists know
the most: the sensory systems. The next section examines the
physiological bases of some of the more "primitive" behaviors,
such as hunger and thirst, reproduction, sleep, and emotion.
The last section explores the topics of development, and of
learning and memory, from the standpoint of plasticity in the
nervous system. This approach acknowledges a major change in
the way scientists are viewing the nervous system. An approach
that we believe will lead to a better understanding of the way
the nervous system is able to change in response to internal and
external events. The final chapter deals with the higher processes
such as thinking, decision making, attention, and language; it
describes ground-breaking studies that are actually exploring
the physiological bases of human consciousness.
In a field as interdisciplinary as this, there will be many
students who do not have extensive backgrounds in psychology,
biology, or the other sciences that have contributed to knowl-
edge in the area. We have written the book with this in mind.
And no strong science prerequisites are necessary in order to
understand the material. Even so, we recognize that physiolog-
ical psychology is not an easy subject, and we have given much
thought and effort to designing a book that will provide students
with as much help as possible.
One simple technique we use is tightly organized chapters.
Every chapter is preceded by an outline, and within the chapter
are running summaries that review each major section. This
technique will not only improve the student's understanding of
the material, it will allow instructors to assign parts of chapters
without causing confusion. Key terms are typed in bold face,
and are listed at the end of each chapter, along with a list of
suggested readings. All key terms are defined in an extensive
glossary at the end of the book.
Another technique we employ to help the student is the use
of many human experiments and applications. The effects of
drugs on feeding behavior in a rat are certainly fascinating to
physiological psychologists, but students usually want to know
how these findings might apply to humans.
Within each chapter we emphasize the logical progression of
experiments which lead to specific conclusions in every subject
area, and we spend extra time examining the methods used to
arrive at conclusions. It is particularly important for students to
understand "how you get there from here," and to be able to
evaluate the methods scientists use to test hypotheses. No
method, whether it is a lesion, a pharmacological manipulation,
an electrical recording, or any other, is free from complications
in interpretation. Yet valid conclusions can be drawn based on
the weight of the evidence from several kinds of studies. When
a question is attacked from several angles, the experimental
results often begin to fit a pattern, and the pieces of the puzzle
gradually fall into place. TTie knowledge base of physiological
psychology has benefited from this multifaceted approach, and
we emphasize it throughout the book, explaining the advantages
and limitations of each technique. There is no separate chapter
on techniques—this material is interwoven into each of the
subject areas. We have found that students are far more likely to
appreciate methodological issues when they can see how they
affect the interpretations of specific experimental results.
It may be acceptable to understate the significance and rele-
vance of experimental findings among colleagues, but students
appreciate an explanation of why a specific experiment was
performed, and how the results fit into and support (or refute)
a general hypothetical framework. In each chapter, we empha-
size the relevance of experimental results and try to show why
each set of experiments answers some questions and raises still
more. We also frequently point out the relevance of findings in
xii preface
one chapter to issues presented in another. The division of a
book into chapters might lead a student to believe that there are
discrete subsystems of behavior, each of which has its own set
of physiological underpinnings. We tried to counteract this by
cross-referencing between chapters, without sacrificing the in-
dependence of each chapter.
A unique feature of this book is the inclusion of a brief atlas
of the human brain. Our students have frequently been exas-
perated by the numerous anatomical terms, and it seemed quite
logical to provide them with a detailed map to help them find
their way in this novel terrain.
A comprehensive study guide accompanies and parallels the
book, which contains more features to help the student. The
guide recapitulates the important points in each chapter, and
includes multiple choice, essay, and matching questions for self-
examination. There are anatomical diagrams to provide practice
in identifying and labeling those structures mentioned in the
text. The study guide also contains useful projects which can be
conducted by the student, or by the instructor as class demon-
strations. Another feature of the study guide is the section on
"Ideas for Research Topics," with suggested sources. It has been
our experience that students often have difficulty finding a topic
for a research paper, and this section was included to help
alleviate that problem.
No book is the work of its authors alone, and this one is no
exception. Our reviewers, some of whom stayed with us through
the writing of the entire manuscript, provided valuable advice,
criticism, and suggestions. We would like to thank Paul D.
Coleman, University of Rochester Medical Center; Michael Ga-
briel, University of Texas at Austin; William T. Greenough,
University of Illinois at Urbana-Champaign; John E. Kelsey,
Indiana University; Richard A. King, University of North Car-
olina at Chapel Hill; Dale W. McAdam, University of Rochester;
and Margaret White, California State University at Fullerton.
Our editors, and the people at Academic Press, deserve special
thanks. Those on the publishing end of a book rarely receive
enough credit, yet their ideas, suggestions, and long, hard hours
of work are an important component of the book's quality. We
would like to thank Raelene Seelbach and Melissa Preston for
assistance with the seemingly endless details of writing, typing,
filing, and obtaining copyright permissions. For moral support,
we thank Julian Jones and the sorely missed and lovingly
remembered Poukah.
Last, but far from least, we gratefully acknowledge the contri-
preface xiii
butions of our students, for their suggestions and advice, their
challenging questions, and their sometimes astonishing in-
sights. Some of their suggestions are worth quoting:
"More graphics, not necessarily pictures, but graphs and
diagrams."
"Less jargon . . . please."
"Write for us, not for other professors who already know it."
"Why don't you write a book on human sexuality?"
"How could anyone know enough to write an entire text-
book?"
"Give it some humanity . . . I'm not just a black box filled
with nuts and bolts."
We took most of these suggestions to heart, and especially
tried to "give it some humanity." We hope we have succeeded.
Thomas S. Brown
Patricia Wallace
xii preface
INTRODUCTION The Mind-Body Problem
Localization of Function
Nature versus Nurture 1
The Organization of this Book
KEY TERMS
SUGGESTED READINGS
introduction
introduction *n r e c et nyear/s news stories have carried titles such as "Emotional
Stress and Sudden Death" (Engel, 1977), "Mind Controllers: CIA
Testing" (Getlein, 1977), "Biorhythms: A Key to Your Ups and Downs
(Boich, 1977), and "Pain Control with Hypnosis" (Holden, 1977).
Reading through these, one feels a combination of emotions, some-
times outrage and indignity, sometimes fear, and sometimes a ner-
vous optimism about what scientists can accomplish. It is one thing to
learn that our moods and actions are related to environmental events.
But it is quite another to learn that these same moods and actions may
be related to the action of certain chemicals in specific parts of the
brain. Can our very thoughts, our most private emotions, be studied
by a detached scientist and reduced to the mere action of a few chemi-
cals in the brain? Worse, can they be controlled by simply changing
brain chemistry or neural activity? The glimmerings of a major assault
on the very nature of human beings are on the horizon.
This book is about physiological psychology—the physiological ba-
ses of behavior. In many ways, the fears and hopes that people are
developing about this field are a credit to its enormous growth and
success in learning about the brain. In this book, we will discuss what
is known about how physiological events relate to behavior, and often
how behavior can be changed, even controlled, by modifying the
physiological events. But the experiments and findings we are about to
explain will have a large impact on the way that human beings per-
ceive themselves, and their relationship to the world. So before we
begin, we will examine some of these philosophical issues.
the mind—body problem Historically, philosophers have hypothesized that the mind and the
body are two different elements. Even though the brain is highly com-
plex, and certainly has a lot to do with our behavior, it is still part of
the body, and thus merely matter. The "mind," the "consciousness,"
the "I" that thinks, decides, feels, and understands is something non-
physical—or a different element. Descartes (1596-1650) was one of
the foremost proponents of this dualistic position.
While physiologically oriented psychologists were studying simple
behaviors like reflexes, this issue remained in the background. Even
later, with the advent of behaviorism in the beginning of this century,
scientists limited themselves to the study of overt behavior, and the
issue still did not present too much of a problem. "Mind" and "con-
sciousness" were not studied by scientists because they are not overt
behaviors. They are hidden, subjective experiences. During the beha-
vioristic era, they were considered not suitable for scientific inquiry.
But in recent years, there has been an incredible burgeoning of
knowledge about how the brain works, and how its workings are re-
lated to our behavior. And very recently, scientists have dared to enter
2 physiological psychology
the previously forbidden terrain of the study of "consciousness/' As
we learn more about the brain, we find that physiological events are
related to emotions like anger, fear, love, and even to decision mak-
ing, perception, and intellect. Right now, the knowledge that we have
about the physiological correlates of the hidden thoughts and feelings
of a human being are very rudimentary. But we have enough so that
people are beginning to wonder whether "mind" is indeed something
separate. Is it possible that the workings of the brain can account for
the subjective experience of "mind?" Can physical events account for
"me?"
Scientists are very often conservative people, and do not like to take
a stand without data to back them up. There are not yet any data avail-
able to settle this issue, and some would say that there never will be.
Many scientists prefer to think of the mind-body problem as a philo-
sophical issue that does not concern scientists. But others have entered
the debate.
Wilder Penfield (1975), for example, has performed hundreds of
neurosurgical operations on epileptic patients, some of which in-
cluded electrical stimulation of brain tissue. His observations have led
him to the belief that mind and brain are intimately related, but that
the workings of the brain cannot, by themselves, explain the mind:
When I have caused a conscious patient to move his hand by applying an
electrode to the motor cortex of one hemisphere, I have often asked him about
it. Invariably his response was, "I didn't do that. You did!" When 1 caused
him to vocalize, he said, "1 didn't make that sound. You pulled it out of .
me." . . . For my own part, after years of striving to explain the mind on the
basis of brain action alone, 1 have come to the conclusion that it is simpler
(and far easier to be logical) if one adopts the hypothesis that our being does
consist of two fundamental elements. (Penfield, 1975)
Other scientists argue that the mind is not a separate element, that
the mind can be explained by the workings of the brain. Sagan (1977)
states this position quite forcefully:
My fundamental premise about the brain is that its workings—what we
sometimes call "mind"—are a consequence of its anatomy and physiology, and
nothing more. "Mind" may be a consequence of the action of the components
of the brain severally or collectively. Some processes may be a function of the
brain as a whole. Λ few students of the subject seem to have concluded that,
because they have been unable to isolate and localize all higher brain
functions, no future generation of neuro anatomists will be able to achieve this
objective. But absence of evidence is not evidence of absence. (Sagan, 1977)
Steven Rose (1973) also takes this position:
In particular, consciousness and mind are seen . . . as being an inevitable
consequence of the evolution of particular brain structures which developed in
a series of evolutionary changes in the pathway of man's own emergence. The
hypothesis is advanced that consciousness is a consequence of the evolution of
introduction 3
a particular level of complexity and degree of interaction among the nerve cells
(neurons) of the cerebral cortex, while the form it takes is profoundly modified
for each individual brain by its development in relationship with the
environment. (Rose, 1973)
Rose suggests that the mind-body problem may be one caused by
semantic difficulties. The study of mind on a mentalistic level (which
might on the surface make it seem as though there are two fundamen-
tal elements underlying mind and brain) is really simply a different
hierarchical analysis of the correlates of human behavior. Neurobi-
ology understands human behavior on one level, and psychology and
sociology understand it on quite another.
The implications of the proposition that mind and brain are one and
the same are profound. If it is true, and it becomes widely accepted,
human beings will have to change the way that they view themselves.
Perhaps even our own values have physiological roots. Wilson (1978)
argues this point in his book On Human Nature:
Figure 1.1
Innate censors and motivators exist in the brain that deeply and
An anatomical drawing by
unconsciously affect our ethical premises: from these roots, morality evolved as
Albertus Magnus (1206-1280).
instinct. If that perception is correct, science may soon be in a position to
[From Clarke and Dewhurst
investigate the very origin and meaning of human values, from which all
(1972).]
ethical pronouncements and much of political practice flow. . . .
Because the guides of human nature must be examined with a complicated
arrangement of mirrors, they are a deceptive subject, always the philosopher's
deadfall. The only way forward is to study human nature as part of the
natural sciences, in an attempt to integrate the natural sciences with the social
sciences and humanities. I can conceive of no ideological or formalistic
shortcut. Neurobiology cannot be learned at the feet of a guru. . . . (Wilson,
1978)
To many people, these are frightening, even revolutionary ideas.
They attack the very core of human philosophy and come into conflict
with ideas about religion, free will, and the concept of the human soul.
As more and more is learned about the workings of the brain, the
question of who and what we are will loom larger. A major rethinking
may be needed.
localization off unction Another issue which has been disputed throughout the centuries, and
which reflects in some ways the mind-body problem, is the issue of
localization of function. Two opposing viewpoints hold that (1) con-
sciousness and other functions of human beings cannot be localized
within particular areas of the brain, and (2) different areas within the
brain handle different kinds of behaviors.
The concept of localization of function is a very old one, and even
during the Middle Ages, people believed that different areas of the
brain served different functions. During this time, they concentrated
4 physiological psychology