Individual Differences in Imaging

Their Measurement, Origins, and Consequences

Alan Richardson

• Publisher: Routledge
• Year: 2020
• Print ISBN: 9780895031174
• eBook ISBN: 9780429639739
• Topic: Education
• Subtopic: Behavioural Management

Contains several suggestions for research and how it can be conducted. This book is useful for people with an interest in the nature and functions of mental imagery.

CHAPTER ONE

Nature of Imagery and of Imaging Differences

Casual introspection and everyday talk about something called mental imagery was, no doubt, the starting point for a scientific interest in this phenomenon. In the beginning its nature must have seemed self evident, and to many lay people it still does. Over one-hundred years ago, Mr. Poole administered Galton’s breakfast-table questionnaire to the boys in his science classes (Galton, 1883) and appears to have had no more difficulty in obtaining their responses than do psychologists today when administering similar questionnaires to their own students. However, as the discussion in this and the next chapter will show, the task of defining and measuring the different characteristics of mental imagery needs more careful thought and research attention than has often been given to it.

DEFINING A MENTAL IMAGE

Within the context of this volume, a mental image is viewed as a kind of percept-like event usually experienced in the complete absence of any corresponding pattern of sensory stimulation. In what way it is percept-like and how it functions to serve adaptive ends will be taken up later. For the moment, only its general character will be considered. As suggested, it is a type of experience familiar to most organically intact adult humans and occurs spontaneously under a wide variety of circumstances. For example, it appears ubiquitously (Doob, 1972); in day and night dreams (Bourguignon, 1972; Singer, 1966); for many people during the hypnagogic state (Mavromatis 1987); and after prolonged, varied, and intense visual stimulation (Hanawalt, 1954).

Its most common manifestation has been called thought imagery (Richardson, 1983) because it can be observed by most people as a spontaneous accompaniment to much of their thinking, that is, recalling past events, planning future actions, and attempting to solve problems. This kind of imagery, in all sensory modalities, can also be voluntarily produced with varying degrees of vividness and control over its content. It is with thought imagery that this volume is primarily concerned.

Few psychologists have denied that most people have these percept-like experiences, but many have doubted that such experiences have any adaptive value. In reviewing the research available to him, Spearman (1923) concluded that images were functionally useless:

thinking seems to be no more based on them, than the heat of a fire is derived from its smoke, or an electric train is impelled forward by its wake of sparks; the sensory concomitants of thought are degraded into little more than accidental waste products, (p. 192)

Had he lived today, Spearman might have used Kosslyn’s (1983) potent metaphor of the lights that flash on the outside of a computer.

If this conclusion were accepted, the only psychological problems would be to study the neuro-cognitive processes responsible for generating the different experiential qualities of thought imagery and the psycho-social processes responsible for creating stable individual differences in the ability to voluntarily generate these images. However, even these problems require data based upon witnesses who can provide reliable testimony on the characteristics of their own percept-like experiences; publicly observable outputs are not enough.

But are these problems the only ones worthy of investigation? Does imagery, as here defined, have no functional role to play? Is it no more than an epi-phenomenon, as Spearman and others have implied? These and similar questions will constantly recur, but their discussion will be deferred until some of the non-experiential definitions of imagery have been examined.

The aim of this examination is to lay bare the ambiguities and inconsistencies that can be found in these alternative definitions. As will be seen, all of them become involved in some way with experienced imagery, but have not yet come to terms with it. Consider the following examples. Richard Bugelski (1977) asserted that, “No one treats imagery as subjective experience,” (p. 40) and went on to define an image as “an action or a reaction, presumably neural that can generate other neural or motoric responses” (p. 41). Nevertheless, experienced sensory-like contents (images) were introduced into this discussion and, as such, were described as conditioned sensations (Ellson, 1941; Leuba, 1940; Leuba & Dunlap, 1951). This conditioning account of how an image of something comes to be experienced does not explain the novel content of many spontaneous imagination images, but this is of little concern, because the experienced image is not of theoretical interest. As he writes in a later paper (Bugelski, 1982):

When a Pavlovian dog hears a bell, a neural response (an image) corresponding to the sensory features of food will also occur Whether the dog has any subjective experience is not the question. Only people can talk about subjective experiences…. (p. 9)

But, in this approach, it is assumed that even people can say nothing of psychological importance about imagery because functional imagery is no more than a type of neural activity.

Because it is impossible to identify and measure these neural activities (images) directly, it may be necessary, in humans, to conceptualise the image as a hypothetical construct anchored on the stimulus side by, for example, nouns of high or low imagery value, and on the response side by, for example, rate of learning a paired-associate task. Thus, for Bugelski an image is a neural event, a conditioned sensation that may have a non-functional experiential aspect and a hypothetical construct. Many questions are raised by these multiple meanings for the concept of imagery. Not least among them are the theoretical relationship between each of these definitions, the conditions that lead to an awareness of sensory-like content, and what difference this awareness might make to any subsequent activity.

Allan Paivio (1971) proposed that the term imagery “be used to refer to a memory code or associative mediator that provides spatially parallel information that can mediate overt responses without necessarily being consciously experienced as a visual image” (pp. 135-136). The intention of this definition and of the research based upon it is to contrast the role of visual imaginal processing with that of abstract verbal processing in the explanation of many phenomena in the fields of learning and memory.

Three operational procedures are employed for the manipulation of these visual imaginal and verbal mediators, but as they do not always lead to the same results they cannot be considered as equivalent. In the first, the probability of activating a visual imaginal mediator is manipulated by varying the concreteness of the stimulus material. Thus, concrete nouns like table, which have been rated as producing more vivid experienced visual imagery than abstract nouns like truth, should, and do, serve as more effective mediators in paired-associate learning tasks.

The conceptual difficulty with this procedure relates to its introduction of the traditional experiential meaning of an image. Despite the definitional denial given above, all nouns used in these experiments have been rated for the vividness of experienced imagery that they arouse in the rater (Campos, 1991; Paivio, Yuille, & Madigan, 1968). What is the theoretical link between the vividness of consciously experienced visual imagery during noun rating and the non-conscious effectiveness of the same noun when acting as a mediator?

The second procedure for the evocation of imaginal mediators is by instructions to Visualize or to Form an image. Once again, the assumption must be made that the hearer will carry out an act of imaging, as this activity has been traditionally understood, and once again one would like to know the theoretical link between the conscious experience of imagery and the non-conscious activity of an imaginal mediator.

The third method of manipulating an imaginal mediator is by selecting individuals who score high and low on a measure of visual imaging ability. In some studies the measure has been scores on a spatial relations test (Ernest, 1977); in others it has been scores on the imagery section of the Individual Difference Questionnaire (Paivio, 1971), and in others, combined scores on both measures have been employed (Paivio, 1978). No theoretical justification is given for the adoption of any of these procedures, and empirically, Paivio (1971) was among the first to demonstrate that self-report imagery measures are psychometrically independent of spatial ability measures.

Many of the imaginal items on the Individual Difference Questionnaire (IDQ), have reference to imagery as traditionally defined, but how the traditional and non-traditional meanings (both conceptual and operational) are to be reconciled has yet to be established. That imagery, as traditionally defined, is implicated in Allan Paivio’s concept of it, is also apparent in his discussion of imaging in relation to the mental practice of perceptual-motor skills (Paivio, 1985).

Peter Lang (1979a) is another imagery theorist who has not been able to extricate himself from these conceptual and methodological dilemmas. Like Allan Paivio, Lang denies the functional significance of any experiential referent and defines an image as “a finite prepositional structure (and not the analogue representation suggested by phenomenology)” (1979a, p. 495). Depending on the characteristics of the stimulus scripts, it is assumed that a vivid or weak (non-conscious) image will be activated. Scripts containing detailed concrete stimulus and response descriptions activate vivid imagery, while scripts containing general abstract descriptions activate weak imagery.

It is argued that, “Under conditions of perfect instructional control script and image are the same” (Lang, 1979a, p. 503), but this control depends on adherence to the full set of instructions (1) to form an image of (2) the content of the described event (script), and (3) to become absorbed in these imaged events. What does the subject in an experiment or the client in a therapeutic session understand by these instructions? If any meaning is conveyed, it must surely be the traditional experiential meaning understood, in a general sense, by the great majority of people. The reintroduction of this traditional meaning occurs again when procedures for checking the effects of these instructions are employed. Among these checking procedures is the request to rate the vividness of any imagery obtained after hearing a particular script read out.

With the stress on instructional control (situation variables), little attention is paid to individual differences (person variables). As in other fields of psychology, this broad theoretical deficiency must be rectified. In the field of hypnosis, for example, it is well known that effective suggestions must contain the script and instructional control qualities advocated by Peter Lang, but to predict response outcomes more precisely, it is necessary to obtain information on individual differences in imaging abilities and in attitudes and expectations regarding hypnosis (Spanos & Barber, 1974).

Stephen Kosslyn (1983) defined a visual image as “a representation in the mind that gives rise to the experience of ‘seeing’ in the absence of the appropriate visual stimulation from the eyes” (p. 29). This representation and the mechanisms that enable it to be modified in various ways (e.g., in mental rotation or scanning tasks) was, at first, presented on the analogy of a computer programme that would simulate these processes and produce an appropriate output. More recently (Kosslyn, Van Kleeck, & Kirby, 1990; Sergent, 1990), an attempt has been made to relate these processes to the brain activity that underlies them.

The seeing that is the traditional act of visual imaging is a process akin to perceiving, but the product, in the form of traditional experienced visual images, is regarded as non-functional. The task of the imagery researcher is to uncover the mechanism (computer programme or brain circuitry) that can best explain this functionless experience and, more importantly, the differences in performance on so-called imagery tasks.

This approach assumes that if imaging is a process, in many ways analogous to perceiving, then predictable consequences should follow when, for example, the following tasks are undertaken. First, the subject is asked to form an image of an elephant standing against a blank wall; then, to image a dog standing next to the elephant. The question is asked, “Can you see the dog’s ears?” Second, the subject is asked to image a fly standing against a blank wall; then to form an image of a dog standing next to the fly. The question is then asked again, “Can you see the dog’s ears?” Kosslyn (1975) found that, on average, it takes 200 milliseconds longer to respond on the first occasion than it does on the second. This result is consistent with his theoretical expectation, though it does not demonstrate that the task involved the use of visual imagery either in its non-conscious representational form or in its conscious experiential form. It is well known (Hampson, 1986) that comparable results can be obtained with the use of congenitally blind subjects. Tacit knowledge (i.e., “just knowing”) might account for the difference in response times.

IMAGING DIFFERENCES AND THEIR FUNCTIONS

Relatively stable individual differences have been found for three conceptually and methodologically distinct qualities of thought imagery. These are the primary qualities to be discussed, and refer to: (1) the typical average level of vividness achievable, (2) the typical average degree of control that can be exercised, and (3) the typical, habitual, or preferred mode for the spontaneous conscious representation of thought content.

Before considering these qualities in more detail, there are two others that should be mentioned because they have aroused sufficient interest to produce provisional methods for their assessment. These refer to the apparent position of the imager when imaging (orientation), and to the apparent location of the image (localization).

Susan Blackmore (1986, 1987) constructed a questionnaire to assess differences in the ability to form visual images of scenes viewed from different positions, for example, a familiar room viewed imaginally from the floor or from the ceiling. Preliminary work shows that people known to have had out-of-body experiences “are better able to image a scene from different locations and to switch viewpoints if required” (Blackmore, 1986, p. 110). Since Mahoney and Avenor (1977) reported that elite male gymnasts were more likely to employ an internal orientation when using imagery for the mental practice of their routines than to employ an external orientation, a number of investigators have examined this quality in relation to a variety of different skills. For example, Epstein (1980), Highlen and Bennett (1979), and Mumford and Hall (1985) have done so, but with varying degrees of success. In these contexts, to view from an external orientation is to see oneself performing a skill from the viewpoint of an outside spectator, while to view from an internal orientation is to see the apparatus and/or other aspects of the task from one’s usual position as a performer. Adopting an internal viewpoint (position or orientation) also makes it easier to experience the imaged kinesthetic elements of a performance. Some people can switch orientations in response to instructions, but others find this difficult and appear to have strong orientation preferences. Whether or not this difficulty in switching is related to the more general quality of imagery control does not seem to have been investigated; nor have these internal/external orientation preferences been related to the forehead writing test in which, when asked to simulate printing one’s name on one’s forehead, some people will print it as if seeing it from the inside (internal) while others will print it as if written by someone outside oneself (external). However, Nigro and Neisser (1983) devised a point-of-view measure based on the position (internal/external) most frequently adopted in a sample of personal memories. Though the theoretical significance of the finding is unclear, Lorenz and Neisser (1985) report that significantly more childhood memories than recent memories place the recaller in an external position, that is, the event recalled, including the recaller, is seen (imaged) from the position of an outside observer.

Concerning the localization of a visual image, Galton (1883) wrote, “The place where the image appears to lie, differs much. Most persons see it in an indefinable sort of way, others see it in front of the eye, others at a distance corresponding to reality” (p. 69). He also believed that most people could learn to project an imaged object onto a piece of paper, although, in his study of 172 English schoolboys (Galton, 1880), he found only 18 (10% approximately) who reported that they could do this voluntarily and without training. Few investigators have studied the employment of this ability (Perky, 1910; Segal, 1972) but an interesting test, the Open Circle Test (Hatakeyama, 1974), has been constructed for its partial investigation. The subject is required to gaze at the centre of a 5 cm circle (drawn on a white or coloured card) and to think of a colour. If anything appears within the circle, its qualities, and any alterations in its appearance, are to be reported. In some respects the reports may resemble those obtained to the blank card of the TAT (Murray, 1943), or those obtained in a ganzfeld situation (Bertini, Lewis, & Witkin, 1969), but under all three condition...

Table of contents

• Cover
• Title Page
• Copyright Page
• Dedication Page
• Foreword
• Acknowledgments
• Key to Abbreviations Used for Major Imagery Tests
• Table of Contents
• Chapter 1 Nature of Imagery and of Imaging Differences
• Chapter 2 Measurement of Imaging Differences
• Chapter 3 Origins of Imaging Differences
• Chapter 4 Imaging Differences and Some Basic Processes
• Chapter 5 Imaging Differences and Some Applications
• Chapter 6 Conclusions and Future Directions
• Appendix A
• Appendix B
• Appendix C
• References
• Name Index
• Subject Index