UBPA01 13/7/06 10:54 AM Page i Understanding Biological Psychology UBPA01 13/7/06 10:54 AM Page ii Basic Psychology This series offers those new to the study of psychology comprehensive, systematic and accessible introductions to the core areas of the subject. Written by specialists in their fields, they are designed to convey something of the flavour and excitement of psychological research today. Understanding Children’s Development Fourth Edition PETER K. SMITH, HELEN COWIE AND MARK BLADES Understanding Cognition PETER J. HAMPSON AND PETER E. MORRIS Understanding Abnormal Psychology NEIL FRUDE Understanding Biological Psychology PHILIP J. CORR UBPA01 13/7/06 10:54 AM Page iii Understanding Biological Psychology Philip J. Corr Department of Psychology University of Wales Swansea UBPA01 13/7/06 10:54 AM Page iv © 2006 by Philip J. Corr blackwell publishing 350 Main Street, Malden, MA 02148-5020, USA 9600 Garsington Road, Oxford OX4 2DQ, UK 550 Swanston Street, Carlton, Victoria 3053, Australia The right of Philip J. Corr to be identified as the Author of this Work has been asserted in accordance with the UK Copyright, Designs, and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher. First published 2006 by Blackwell Publishing Ltd 1 2006 Library of Congress Cataloging-in-Publication Data Corr, Philip J. Understanding biological psychology / Philip J. Corr. p. cm. – (Basic psychology) Includes bibliographical references and index. ISBN-13: 978-0-631-21953-8 (hardcover : alk. paper) ISBN-10: 0-631-21953-6 (hardcover : alk. paper) ISBN-13: 978-0-631-21954-5 (pbk. : alk. paper) ISBN-10: 0-631-21954-4 (pbk. : alk. paper) 1. Psychobiology. I. Title. II. Series: Basic psychology (Oxford, England) QP360.C6677 2006 612.8–dc22 2005033633 A catalogue record for this title is available from the British Library. Set in 10.5/12.5pt Dante by Graphicraft Limited, Hong Kong Printed and bound in the United Kingdom by TJ International, Padstow, Cornwall The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com UBPA01 22/6/06 10:57 AM Page v Contents Preface vii Acknowledgements xii 1 Introduction 1 Part I: Foundations 17 2 Evolution and Genetics 21 3 Brain Structure and Function 66 4 Neurons and Neurotransmission 89 5 Sensory and Motor Systems 122 6 The Neuroendocrine System 169 7 Learning and Neural Plasticity 203 Part II: Approaches 245 8 Neuropsychology 249 9 Psychophysiology 278 10 Neuroimaging 304 11 Neurophysiology 324 12 Psychopharmacology 347 13 Psychogenomics 365 Part III: Applications 403 14 Clinical Disorder I: Depression 405 15 Clinical Disorder II: Anxiety 438 UBPA01 22/6/06 10:57 AM Page vi vi Contents 16 Clinical Disorder III: Schizophrenia 471 17 Personality: Emotion and Motivation 518 18 Cognition: Computation and Consciousness 563 Glossary 600 References 623 Index of Authors 662 Index of Subjects 667 UBPA01 22/6/06 10:57 AM Page vii Preface Biological psychology has entered an exciting era. Rapid advances are being made in our understanding of the biological basis of the mind, and whole new areas of investigation are being opened up by technological innovation (for example, the Human Genome Project). These advances are destined to transform our understanding of psychology and promise to lead to many practical benefits, notably innovative therapeutic approaches in medicine and psychiatry. This is indeed an exciting time to be studying biological psychology; it is certainly an exciting time to be writing about it. As a result of this rapid scientific progress, however, biological psychology is becom- ing increasingly complex (there are between 20,000 and 30,000 scientific articles on the brain published each year). This complexity poses a challenge to the student, who is bombarded with an array of new concepts, processes, systems and experimental find- ings, many of which come with their own obscure nomenclature. Biological psychology can, indeed, seem daunting. In this book the presentation of material, while not disguising this complexity, focuses on the central themes running through the subject and how these themes relate to some of the major areas of interest to the psychologist. Biological processes are at the heart of our own experiences, as well as being at the heart of psychology: they form the foundations of every thought, feeling and action we have, and they are implicated in all experimental effects reported in psychology journals. For example, there can be no cognition or social behaviour without the mediation of the brain. In clinical neurology, all too easily it is seen that brain damage (resulting from tumour, stroke, etc.) robs patients of certain aspects of their minds (e.g., long-term memory), and certain pathological brain processes (e.g., senile dementia) rob patients of their sense of self and identity. The extent to which brain processes must be considered in psychological theories of normal behaviour is, of course, open to debate – at times, heated debate – and quite rightly so, as no one approach in psychology can claim supremacy. The main theme of this book concerns understanding biological psychology, by which is meant not the learning of long lists of facts and figures about brain structure and func- tion (although some learning in this respect is unavoidable), but rather the appreciation of the central role that biological processes play in psychology. Thus, the aim of this book is to cover the core aspects of the biological perspective in psychology from a conceptual UBPA01 22/6/06 10:57 AM Page viii viii Preface viewpoint, which, it is hoped, will give a better perspective over the whole psychological landscape. This book surveys not only what is currently known, but also what is know- able and will be known in the not too distant future (e.g., the molecular basis of major psychiatric disorders); this will involve acknowledging the lack of empirical findings and theoretical agreement, but also the recognition that innovative techniques are pushing forward the boundaries of our knowledge (e.g., gene sequencing techniques). This Janus- faced approach is core to the scientific perspective: looking back to the past and published research and looking to the future with all its prospects and problems. As noted by the Nobel Prize winning chemist, Harry Kroto (2002), the key to under- standing complex phenomena is the recognition of the importance of framing the research problem clearly in the first place: first, it is important to know what we do not really understand; and second, the crucial questions in need of answer must be clarified. Some mysteries in psychology (e.g., consciousness) consist not so much in our inability to provide appropriate tools of investigation but rather in our inability to frame the crucial research questions in a sufficiently precise manner. Confucius was way ahead of us in recognizing this problem: ‘I seek not the answer, but to understand the question.’ The book is divided into three main Parts: ‘Foundations’, ‘Approaches’ and ‘Applications’. Part I covers a number of fundamental aspects of biological psychology; Part II surveys the main methodologies used and, by way of illustration, describes the types of careers open to the biologically inspired psychologist; and Part III provides a presentation of a sample of some of the implications of biological psychology in psychopathology, personality and cognition. This book is primarily aimed at undergraduate psychology students, but is also appropriate for postgraduate students without a formal background in psychology or biological aspects of psychology – some of the chapters, especially those in Part II (‘Approaches’) will be useful to psychology postgraduate students, and the chapters in Part III (‘Applications’) to clinical and health psychology students. Understanding Psychology What is meant by understanding? This involves more than merely learning theories and findings and being able to recall these in sufficient detail to pass assessment tests. Under- standing is to know the reasons for the adoption of a research approach and to appreciate the intellectual excitement and the human passions that go to make up a scientific discipline. The learning of specific theories and findings is, needless to say, important, but appreciating why these theories and findings are considered important is a necessary precondition to understanding their true significance. As noted by the famous neuropsychologist Donald Hebb (1949, p. xi), ‘the task of the psychologist, the task of understanding behavior and reducing the vagaries of human thought to a mechanical process of cause and effect, is a more difficult one than of any other scientist’. In addition to the sheer complexity of psychological phenomena, under- standing psychology is more difficult than understanding other disciplines (e.g., physics or chemistry) for a number of reasons. First, its object of study is familiar to us all: we all have first-hand experience of what it is like to have a human mind and we have UBPA01 22/6/06 10:57 AM Page ix Preface ix common-sense ideas about our own and others’ behaviour, motives, intentions, etc. These naive ideas often stand in the way of our appreciating and accepting scientific findings. Second, psychology is a fragmented discipline. This fragmentation can lead to fragmented understanding. As any student quickly learns, undergraduate degree programmes in psychology typically comprise a number of separate courses (Cognition, Social Psycho- logy, Biological Psychology, Individual Differences, Clinical Psychology, Occupational Psychology, etc.).