more information - www.cambridge.org/9780521762656 The Psychology of Fatigue Fatigue can have a major impact on an individual’s performance and wellbeing, yet is poorly understood, even within the scientific com- munity. There is no developed theory of its origins or functions, and different types of fatigue (mental, physical, sleepiness) are routinely confused. The widespread interpretation of fatigue as a negative consequence of work may be true only for externally imposed goals; meaningful or self-initiated work is rarely tiring and often invigorat- ing. In the first book dedicated to the systematic treatment of fatigue for over sixty years, Robert Hockey examines its many aspects – social history, neuroscience, energetics, exercise physiology, sleep and clini- cal implications – and develops a new motivational control theory, in which fatigue is treated as an emotion having a fundamental adaptive role in the management of goals. He then uses this new perspective to explore the role of fatigue in relation to individual motivation, work- ing life and wellbeing. robert hockey is Emeritus Professor of Human Factors and Cognitive Engineering in the Department of Psychology at Sheffield University. His research on human attention and performance, work- load, stress and fatigue has emphasized the adaptive nature of human regulatory activity in task performance, and he has acted as a con- sultant in the maritime, rail, nuclear and space industries. He has published over 170 research articles and edited or written five books, including Stress and Fatigue in Human Performance (1983). The Psychology of Fatigue Work, Effort and Control Robert Hockey University of Sheffield CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo, Delhi, Mexico City Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521762656 © Robert Hockey 2013 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2013 Printed and bound in the United Kingdom by the MPG Books Group A catalogue record for this publication is available from the British Library Library of Congress Cataloguing in Publication data Hockey, Robert. The psychology of fatigue : work, effort and control / Robert Hockey. pages cm Includes bibliographical references. ISBN 978-0-521-76265-6 (hardback) 1. Fatigue. I. Title. BF482.H63 2013 152.1′886–dc23 2012048497 ISBN 978-0-521-76265-6 Hardback Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. To the memory of my teachers, colleagues and friends: D. Roy Davies, Donald Broadbent, Peter Hamilton and Bert Mulder Contents List of figures page xi List of tables xii Preface xiii 1 The problem of fatigue 1 Background 1 Rationale and focus of the book: the adaptive role of fatigue 4 The failure of classical fatigue theory 6 Limitations of the energy account of fatigue 7 Fatigue is not (just) a negative state 8 A motivational perspective 10 Defining the field: what is fatigue? 11 A working definition 13 Fatigue and related feelings 15 The conceptual status of fatigue 18 Some questions for a scientific theory of fatigue 21 Plan of the book 23 2 Changing experiences of fatigue: the social-historical context 25 Background 25 Roots of the energy metaphor of fatigue 26 The pre-modern experience of work and fatigue 29 Fatigue, idleness and volition 32 Work as a benign experience 34 The loss of control over work 35 Work and fatigue in the post-industrial period 37 The intensification of work 38 Changes in leisure and recreation 39 A demands-control analysis of changes in the experience of work 40 The link between fatigue and energy 43 The medicalization of fatigue 45 Fatigue as a subject for scientific study 47 Summary 50 3 The work–fatigue hypothesis 51 Background 51 The golden age of fatigue research 54 vii viii Contents The early research agenda 54 The work curve 56 Early research on the work decrement 58 Is fatigue general or specific? 62 Recovery from fatigue: effects of rest and change 63 After-effects of fatigue 66 Vigilance and sustained attention 67 What causes the vigilance decrement? 69 Habituation and executive control 71 The sensitive task 72 Work intensity, effort and executive control 73 Workload, capacity and resources 73 Effort and executive control 74 A reappraisal of the work curve 77 Rapid onset of decrement 77 Interruptions of control: blocks, gaps and lapses 80 Three sources of performance decrement 82 Summary 85 4 Stress, coping and fatigue 86 Background 86 Stress, homeostasis and allostatic load 86 The response to stress 88 Adaptive physiological systems 89 Psychological stress and coping 91 Fatigue and the costs of coping 92 Task performance under stress 93 Early research on stress and performance 94 The modal stress pattern 95 Theoretical perspectives on stress and fatigue 96 Distraction and arousal 96 Limitations of general arousal 97 Stress and emotion as distractors 99 Emotional states and feelings 100 Specific emotions and general feelings 101 The adaptive value of feelings 101 Fatigue as an emotion 102 Summary 105 5 Effort, strain and fatigue 107 Background 107 A systems perspective on performance decrement 107 Assessing the costs of task management: effectiveness and efficiency 108 Goal competition in task performance 109 Varieties of goal: have to, want to and need to 110 The vulnerability of task goals 112 Protection of performance under stress: effort, strain and fatigue 113 Indirect effects of stressors on performance 115 Secondary task decrements 115 Strategy changes 116