Human Performance

Cognition, Stress and Individual Differences

D. Roy Davies, Gerald Matthews, Rob B. Stammers, Steve J. Westerman

• Publisher: Psychology Press
• Year: 2013
• ISBN:
  9781317799634
• Edition: 1
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

Human Performance provides the student and researcher with a comprehensive and accessible review of performance, in the real world and essential cognitive science theory.
Four main sections cover both theoretical and practical issues: Section One outlines the perspectives on performance offered by contemporary cognitive science, including information processing and neuroscience perspectives.
Section Two presents a multi-level view of the performer as biological organism, information-processor and intentional agent. It reviews the development of the cognitive theory of performance through experimental studies and also looks at practical issues such as human error.
Section Three reviews the impact of stress factors such as noise, fatigue and illness on performance. Section Four assesses individual and group differences in performance with accounts of ability, personality and aging.

1
Introduction

1.1 What is Performance Psychology?

Human beings are born to perform. Many integral parts of our culture, such as education, work and sport, explicitly value successful performance. In a broader sense, we perform every time we engage in a goal-directed activity, from making a point in discussion with our friends to executing successfully the instructions on a cooking recipe. In contemporary Western society at least, the urge to perform successfully has been seen as a basic drive. The philosopher Marcuse (1955) dignified these strivings as “The Performance Principle”, a drive similar to the pleasure principle of psychoanalysis. Similarly, motivation theorists have proposed a basic drive for behavioural competence, mastery over the environment, or need achievement, which may fuel our urges to perform (McClelland, 1961; Murray, 1938).

The psychology of performance seeks to understand the behaviours initiated by these strivings for competence, or even excellence. The primary aim is to understand the psychological processes that allow people to drive cars, pass examinations, carry out tasks at work and so forth. A focus on applications is more central to performance research than to many disciplines of psychology. We wish to understand how people perform not only on contrived laboratory tasks, but also on the often complex tasks of the real world. Hence, a particular concern is the breakdown and failure of performance, illustrated most dramatically by the role of human error in car and plane crashes, and in industrial disasters such as Chernobyl. In addition, the accumulation of small inefficiencies in work performance may significantly influence national productivity and economic success. McClelland (1961) presented extensive evidence suggesting that the economic success of nations reflects the degree to which cultures value need achievement.

Performance psychology is directed towards real-life behaviour, but it is concerned with more than just a disconnected set of specific applications. As a branch of psychological science, it aims to understand the behaviour of people in the real world on the basis of rigorous, empirically testable psychological theory. The most useful theories have proved to be those of cognitive psychology, which describe how task performance depends on information processing. However, real-life performance depends not just on the task, but also on the influence of stress factors such as noise, heat and fatigue. Furthermore, individuals differ in their abilities and motivations when called upon to perform. Hence, performance psychology requires an integration of the formal models of cognitive psychology with an understanding of stress and individual difference factors.

Performance psychology overlaps to a considerable degree with both cognitive psychology and applied subjects such as ergonomics and human factors. However, it may also be seen as a distinct discipline. In this book, we envisage performance studies as supporting a distinct branch of psychological theory although, in many cases, it is theory with fairly direct application. The theory of human performance derives primarily from cognitive psychology, which is based on the computational metaphor for performance, discussed further in 1.3. The brain is considered to function like a computer, with groups of neurons performing logical operations or computations. Cognitive models use the computer metaphor to describe the encoding of incoming stimuli, the computations performed on the internal codes, and the eventual selection of a motor response. Modelling is fundamental to cognitive psychology, with the testing of models against empirical data providing the fundamental step in theory development. Performance psychologists often build and test such models. However, performance psychology may be distinguished from cognitive psychology in at least four respects: research aims, concern with “context”, use of multiple levels of explanation, and applied relevance.

1.1.1 Aims of performance psychology

Both cognitive psychology and performance psychology investigate objective, measurable qualities of behaviour such as speed and accuracy of response. However, researchers have different motives for measuring reaction times and counting up errors in performance. For the cognitive psychologist, these indices of performance are a means to the end of understanding information processing, not an end in themselves. Speed and accuracy of response are relevant only in so far as they are informative about basic cognitive science questions such as the nature of mental representation or the relationship between language and thought. In contrast, the performance psychologist is interested in reaction time, for example, because speed of response is important in everyday life—in working productively, in completing tests in a set time, and in reacting to hazards during driving. Of course, understanding the factors which control reaction time requires extensive laboratory work, and an understanding of cognitive models of response. The distinction between performance psychology and mainstream cognitive psychology is subtle and, in some respects, a matter of emphasis.

The difference in research aims relates to the distinction sometimes made between competence and performance. Competence refers to the fundamental capacity of the mind to perform some task or set of computations: cognitive psychology is concerned with what the mind can compute or, put differently, the limitations on processing (Pylyshyn, 1984). Performance, in this sense, refers to what the mind does compute in a given set of circumstances. Performance may fall short of competence if the person is tired or unmotivated, for example. Explaining performance requires both a model of competence (provided by cognitive psychology), and an understanding of how the expression of that competence in observable behaviour varies with factors such as stress and voluntary intentions.

1.1.2 Contextualisation of performance

Performance psychology is concerned especially with various “contextual” factors which may influence response. By contextual factors we mean factors additional to the task itself, which may be features of the external environment, or internal qualities of the person, such as their emotional state. In standard cognitive psychology, models are typically concerned with performance of specific tasks under laboratory conditions, but performance psychology requires a wider focus that takes in stress factors and individual differences. This approach entails more emphasis on emotional and motivational factors than is usual in cognitive psychology, to explain the effects of factors such as anxiety, fatigue and interest in the task. It may also be necessary to model biologically-based influences on performance, such as the caffeine, nicotine and alcohol that people consume in everyday life. Extending cognitive models in this way is challenging, as it is not always immediately obvious how the computer metaphor of cognitive psychology can be applied to real-world factors. One of the main themes of this book is that we need the wider perspective provided by contemporary cognitive science to organise our knowledge of influences on performance. A second theme is that the person is an active agent whose wishes and strategies shape their objective performance and subjective experience of task environments. Modelling voluntary control and strategy use is a further challenge for performance psychology, discussed further in 2.5.

1.1.3 Multiple levels of explanation

Performance psychology tends to place more emphasis on the use of several distinct levels of description or abstraction than does standard cognitive psychology, because of the requirement to understand contextual factors. Suppose we aim to understand why drivers commit errors. Cognitive psychology suggests that we should construct a model of how drivers encode stimuli such as traffic signs and other vehicles, and how they select steering and speed-control responses on the basis of this information. Such models can tell us which processes are error-prone in a given traffic situation, but they do not provide the full story. On the one hand, we may need to consider more abstract issues such as the driver’s motivations to maintain safety, the extent to which “correct” driving is culturally valued, and so forth. Cognitions operate within a wider context, including the physical and social external environment, and intra-personal factors such as emotion, motivation and personality. On the other hand, we may need to understand the neural processes which support cognition; neuropsychological methods may provide a more fine-grained understanding of, say, attention to traffic signs or the stress imposed by the driving task. More generally, human performance psychology recognises that it is often valuable to investigate cognitive activity at more than one level of abstraction (Aleksander & Morton, 1993; Parasuraman, 1998a). Cognitive science provides a formal framework for distinguishing levels of description of cognitive phenomena, which we describe in section 1.3. Performance psychology often uses the “standard” information-processing models of cognitive psychology, but it seeks also to place these models within the larger perspective of real-world performance contexts.

1.1.4 Applied relevance

The wide scope of performance psychology lends itself to more direct practical application than much of cognitive psychology. Indeed, performance studies help to bridge the gap between the theoretical concerns of cognitive psychology and practical problems. Performance research overlaps with applied psychology, but here too there are significant differences in emphasis. Human performance psychology is not restricted to the study of applied settings, and draws evidence from both applied and laboratory-based studies. The search for basic principles that govern behaviour is central to the discipline, and human performance psychology considers applied evidence in parallel with controlled laboratory studies. Performance psychology can also be distinguished from the applied disciplines of human factors and ergonomics (see 1.4.1) because it maintains primary focus on the cognition of the individual, as opposed to the interface between the individual and technology.

In this chapter we first present a brief history of psychology as it relates to the study of human cognitive performance (1.2). We then introduce and evaluate the computer metaphor which provides the basis for cognitive psychology and cognitive science, and hence the theoretical basis for performance psychology (1.3). In section 1.4 we turn from theory to practice, and survey some of the applied disciplines to which performance psychology is allied. We conclude (1.5) by emphasising the multilevelled nature of performance psychology and outlining the topics covered by this book.

1.2 The Historical Roots of Human Performance Psychology

1.2.1 Pre-scientific conceptions of performance

Human performance psychology is not a new area of scientific enquiry. This section outlines its multidisciplinary heritage. The description of cognitive activity, including the development of models speculating covert cognitive processes, certainly dates back to ancient Greek times. For example, Hippocrates (460–377 BC) proposed physiological bases for personality and mental illness, involving the comparative predominance of four humours of the body (blood, black bile, yellow bile, and phlegm); Plato philosophised about the nature of knowledge and Aristotle (384–322 BC) developed hypothetical descriptions of many aspects of human cognitive activity, relating perception and understanding of the world to specific mental faculties. Although a rise in religiosity led to a decline in scientific thinking about cognitive processing during medieval times (Leahey, 1997), some continuation of the Aristotlean tradition persisted. The Persian physician and administrator, Avicenna (Ibn Sina) (980–1037), and St Thomas Aquinas (1225–1274) independently developed models of mental faculties, with Avicenna hypothesising a physiological basis for these faculties, believing (inaccurately) that they were housed in the ventricles of the brain.

In the late 17th century, Locke, the “father of empiricism”, set the scene for the rise of behaviourism more than two centuries later, proposing that the human mind begins life as a “tabula rasa” and that knowledge is derived from experience. At this time, the philosophy of Descartes, although advocating the mind–body divide required by contemporary religious thinking, provided the basis for more mechanistic approaches to cognition. For example, Descartes’ representational theory of mind proposed that we do not have direct access to reality but, instead, our understanding of the world depends on immaterial mental objects which the mind manipulates. This approach was extended by Hobbes’ dictum that “all reasoning is but reckoning”, that expressed the view that thought is a form of calculation. From the eighteenth century, notable advances were made with respect to models of human memory. Hartley (1705–1757), influenced by Newton’s theory that nerve impulses were generated by the vibration of submicroscopic particles, proposed a theory akin to the notion of a “memory trace”, suggesting that repeated sensory activation would lead to a stored copy (of reduced magnitude) of the associated nerve impulse. Hume (1711–1776), influenced by Newtonian theories of attraction of objects (Leahey, 1997), proposed principles describing how ideas may become associated (see 2.3.1). “Lockean” empiricism and the concepts of association were extended successively by James Mill (1773–1836), and his son John Mill (1806–1873), with the latter proposing theories of the composition of ideas that resemble modern-day notions of automatic processing (see 3.3.1).

1.2.2 The origins of psychological science

Early in the 19th century, a more empirical approach was taken to the study of psychology. This change of direction was largely in response to scientific activity in other fields (e.g. physics, physiology), but later owed much to the development of university-based psychological laboratories, initially in Germany and subsequently in America. For example, Helmholtz (ca. 1850) designed techniques for assessing response time that allowed nerve conductance velocity to be determined, and proposed theories relating to the conservation of energy. Based on Helmholtz’s work, F.C. Donders (1868) invented methods for the decomposition of cognition processes, using measures of reaction time. Weber, and subsequently Fechner, examined sensory discrimination at Leipzig University, and Weber’s Law was developed, indicating that human cognition was concerned with relative rather than absolute sensory differences. In the latter part of the 19th century, the discipline of psychology became formally recognised with the establishment of the first psychological laboratory by Wundt, also at Leipzig. The brand of psychology pursued by Wundt and his students became known as the structuralist school, a term coined by one such student, E.B. Tichener. The structuralists aimed to discover elementary constituents of the mind through introspection of inner experiences. In America, structuralism was superseded by functionalism, in part due to the work of William James at Harvard, which was more concerned with action, and relationships between mental life and functioning in the outside world. Notable developments in experimental psychology towards the end of the 19th century included Herman Ebbinghaus’ studies of memory and forgetting, using nonsense syllables, and Sir Francis Galton’s studies of individual differences in ability to perform.

During the early part of the 20th century, especially in America, the behaviourist movement gathered momentum, becoming the dominant psychological paradigm. The behaviourists regarded the investigation of “mentalistic behaviour” as unnecessary and unscientific, taking the view that psychology should restrict itself to the study of observable patterns of stimulus and response (although as Leary (1990) points out, these are two of the most loosely interpreted terms in psychology). Introspection was replaced with rigorous experimental data, often from animal studies. Cognitive research continued to a limited degree: Bartlett’s (1932) studies of memory showed that information is actively structured in the mind, for example.

Also important, during the early part of the 20th century, was the development of branches of applied psychology concerned with performance (Kanfer, Ackerman, Murtha, & Goff, 1995), and the application of scientific principles to the management of industrial workforces, notably by the industrial engineer, Fredrick Taylor (1856–1915). This eventually included the use of time-and-motion studies and psychometric testing of intelligence and job proficiencies, facilitated by large-scale military testi...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of tables
• List of figures
• Prologue
• 1. Introduction
• 2. Modelling the cognitive architecture
• 3. Key subsystems of the cognitive architecture
• 4. Selective attention
• 5. Divided attention and workload
• 6. Vigilance and sustained attention
• 7. Skilled performance
• 8. Human error
• 9. Stress, arousal and performance: An introduction
• 10. Noise and irrelevant speech
• 11. Thermal stress and other physical stressors
• 12. Fatigue and the energetics of performance
• 13. Lifestyle and performance: Health, diet and drugs
• 14. Individual differences in ability and performance
• 15. Individual differences: Personality and mood
• 16. Ageing and human performance
• Epilogue
• References
• Author Index
• Subject Index