The Role of Individual Differences and Multiple Senses in Consumer Imagery Processing: Theoretical Perspectives

Evelyn Gutman, Boston University
ABSTRACT - An important marketing issue concerns how consumers evaluate information. Imagery processing can influence how consumers respond to marketing stimuli. Understanding how consumer, use imagery in their multiple senses will allow us to realize the benefits that effective use of imagery offers. This paper discusses individual differences in imagery ability, single sensory vis-a-vis multisensory stimulation and neuroscience perspectives on processing in various senses to provide background for testing marketing issues.
[ to cite ]:
Evelyn Gutman (1988) ,"The Role of Individual Differences and Multiple Senses in Consumer Imagery Processing: Theoretical Perspectives", in NA - Advances in Consumer Research Volume 15, eds. Micheal J. Houston, Provo, UT : Association for Consumer Research, Pages: 191-196.

Advances in Consumer Research Volume 15, 1988      Pages 191-196

THE ROLE OF INDIVIDUAL DIFFERENCES AND MULTIPLE SENSES IN CONSUMER IMAGERY PROCESSING: THEORETICAL PERSPECTIVES

Evelyn Gutman, Boston University

ABSTRACT -

An important marketing issue concerns how consumers evaluate information. Imagery processing can influence how consumers respond to marketing stimuli. Understanding how consumer, use imagery in their multiple senses will allow us to realize the benefits that effective use of imagery offers. This paper discusses individual differences in imagery ability, single sensory vis-a-vis multisensory stimulation and neuroscience perspectives on processing in various senses to provide background for testing marketing issues.

INTRODUCTION

Consider ways that you recall, perceive, and evaluate consumer products and services. For example, when choosing bakery products, what is expected? Should the baked bread smell fresh? Must the croissant feel crunchy? How should it look? Does it sound crispy?

How about the last exercise program you adopted? Did the music you heard or the appearance of the instructor influence you? What odors do you remember? Do you exercise with a videotape or audiotape, or do you prefer a direct experience at a facility? Furthermore, how are recall, perception, and evaluation affected by whether you can image your experience by either seeing, hearing, touching, tasting, feeling, or smelling it? Marketing stimuli can appeal to a variety of consumer senses. Consumers often use imagery in multiple senses to experience marketing stimuli. Understanding how consumers use imagery through their senses can substantially improve marketing effectiveness.

Marketers have a wide choice about how to present their products and services. New opportunities have arisen with the advent of widespread ownership of videocassette recorders, tele-shopping, talking point of purchase displays, smell strips and powder strips. Some marketing tools are more vivid than others. Consumer responses to marketing stimuli are, in part, determined by how vivid these experiences become in imagery processing.

How can an understanding of imagery be used most effectively to market a service or product? Several questions that arise include:

- Is imagery more effective when stimulated in one sense or in multiple senses?

- Do the effects of imagery processing vary according to type of product or service?

- How do consumers differ in their abilities and tendencies to perform imagery processing in various senses?

- How can we extend our understanding of imagery processing to improve marketing effectiveness?

The information processing paradigm has shown that different consumers use different skills and strategies to evaluate information (e.g., Bettman, 1979). This research has been extended to compare verbal versus imagery processing (Childers et al., 1985; MacInnis and Price, 1987). While there is recognition that imagery occurs in multiple senses, the role of the various senses has not been explored. Since consumers often use their auditory, visual, kinesthetic, tactile, taste, and olfactory senses to interact with their environments, and imagery can be a strong mediator of individual experience, it becomes important for consumer researchers to understand how imagery operates in these senses.

To begin an inquiry into the role of imagery in the various senses for consumer processing, a review of the theoretical underpinnings and evidence regarding how people use their senses is useful. An excellent review of psychological and marketing research perspectives of imagery processing is available (MacInnis and Price, 1987), and thus will not be repeated here. This paper will add to the literature by introducing some new background that relates to imagery. Following a brief introduction on mental imagery, this paper will discuss evidence on individual differences in imagery ability, single vis-a-vis multisensory stimulation and neuroscience perspectives on processing through various senses.

RESEARCH ON MENTAL IMAGERY

Individual Differences

It is generally accepted that there are individual differences in imagery ability (Marks, 1972,1973). For example, using a test that measures clearness of concrete images, Griffitts (1927) tested for the dominance of imagery type and found that among 87 subjects, approximately 9096 had images of greatest clarity of vividness in the visual mode, 5% in the auditory mode, and 5% in the kinesthetic mode. Among those cases where visual ranked first, auditory was ranked second by 76% and kinesthetic was ranked second by 24%. In every case where auditory ranked first, visual was a close second. In 5 cases where kinesthetic was ranked first, visual was ranked second in 3 and auditory was second in 2.

In another study, Natazde suggested that the incidence of illusions [Illusions are the mental representations generated as a result of asking subjects to imagine a specific stimulus.] aroused by imagination was correlated with individual differences in imagery ability, and in particular, with differences in dramatic talent (as described by Uzandze, 1966, p.131). Illusions attributed to verbally aroused images were experienced by professional actors 87.8% of the time, by drama students 80% of the time and by nonactors 31.1% of the time. Actors experienced vivid images of "scenes" while ordinary subjects experienced more abstract mental activity. This was attributed to the "figurative imagination" possessed by the actors and not the ordinary subjects. The possibility of demand effects indicates that this type of experiment should be replicated using more objective tests to differentiate subjects on imagery ability.

In a study of 64 scientists, Roe (1951) attempted to show that individual differences in "symbolic habits" are related to differences in occupation. She found a pattern of relationships between habitual type of "symbolic" activity and scientific field. Biologists and experimental physicists were predominantly in the visual imagers group, while theoretical physicists, psychologists, and anthropologists were concentrated in the group that reported habitual use of verbal -symbolization. She also investigated the profession of the fathers of these scientists and found that the fathers of most verbalizers were in "verbal professions" (e.g., lawyer, clergyman) and that the fathers of visualizers were primarily in nonverbal professions (e.g., physician, engineer). While Roe speculated about whether the relationships found reflect heredity or training and experience, the role of either factor cannot be determined from Roe's data.

Additional studies have investigated individual differences in imagery ability and how they affect learning and memory. Davis (1932) found positive correlations between recall and individual differences in imagery as measured by subjective reports. Sheehan (1966a, 1966b, 1967) found accuracy of visual memory was related to individual differences as measured by his shortened version of the Betts' questionnaire on imagery or by subjects' ratings of the vividness of imagery in the experimental setting. Sheehan concluded that vivid imagers perceive literally, while poor imagers use semantic coding devices to organize their perceptions.

Several studies that measure imagery ability have shown that good visualizers recall pictures more accurately than poor visualizers. Using the Vividness of Visual Imagery scale (WIQ) to assess imagery vividness, Marks (1972, 1973) found a positive correlation between WIQ scores and recall accuracy. McKelvie and Demers (1979) studied good visualizers' and poor visualizers' ability to recall pictures, abstract words, and concrete words. Good visualizers produced a significantly higher short term recall for all types of material, especially with concrete words. In a long term task, good visualizers produced significantly higher recall for both concrete words and pictures, but not for abstract words.

Differences in imagery ability have also been correlated with voluntary control of autonomic processes. For example, White (1978) found that ability to control salivary flow through voluntary imaging is related to reported vividness of imagery across all sensory modalities. Another study showed ability to increase heart rate through voluntary imaging is positively correlated with reported vividness of visual imagery (Carroll et al., 1979). Hirschman and Favaro (1977) also found a positive correlation between ability to increase heart rate through biofeedback training and reported vividness of auditory and visual images.

Multiple Versus Single Sensory Stimulation

Studying the role of multisensory versus single sensory message stimuli can help elucidate the role of imagery ability in various senses in influencing consumer processing. There are two possibilities: 1) conflict among multiple channels which would interfere with message transmission, or 2) complementarily among multiple channels which would enhance message transmission. Some theorists suggest that there is a central processing system that all incoming stimuli pass through before continuing on to the next specialized sensory system. This would suggest that multisensory activation, an overload of stimulation, or perhaps only certain types of conflicting multiple sensory activation, may cause interference in the central processing system. In this case, processing may be more efficient for a single sensory vis-a-vis multisensory stimulation.

Given the complex interaction among the senses, the question is not whether complementarity among multiple channels or conflict among multiple channels occurs at all times, but under what conditions each mechanism operates. This is probably a function of characteristics, such as, the nature of the stimuli and how information processing occurs among the multisensory processing system.

For example, for complex unfamiliar stimuli, imaginal processing that results from stimulation of a single sense may enhance the needed concentration for effective processing. Multisensory stimulation of complex unfamiliar material could be expected to create a great deal of noise and thus, interfere with the clarity of imaginal processing, causing an overload phenomenon. Therefore, one may hypothesize that:

Hypothesis 1: For complex, unfamiliar stimuli, single sensory stimulation is more memorable as compared with multiple sensory stimulation.

Similarly, when simple familiar stimuli are processed, imaginal processing in multiple senses may -be well coordinated. Thus, in this situation, multisensory imagery may enhance the vividness of the imagery experience. Therefore:

Hypothesis 2: For simple, familiar stimuli, multisensory stimulation is more memorable as compared with single sensory stimulation.

Ahsen (1981) discusses the possibility that, in certain people, visual imagery can be so powerful that it prevails strongly and curbs other senses. A strong visual image can create resistance to the recall of other sensory images and causes distortion in the perceptual system. Segal and Fusella (1970) showed that generating irrelevant visual images impairs visual signal detection more than irrelevant auditory images, while auditory images produced more interference in an auditory detection task than did visual images. Segal and Fusella (1971) demonstrated similar modality-specific interference in a total of six different sensory modalities (vision, audition, touch, smell, taste, and kinesthesis). In reviewing this data, Marks (in Sheikh, 1983, p.101) discusses that the result that images interfere with perception suggests that channel space is taken up by images which are in competition with processing of perceptual signals.

In contrast, research on opinion change indicates that audiovisual messages induce greater opinion change than auditory (i.e., audiotaped) messages (Frandsen, 1963). Understanding the effects of individual differences and studying the results of processing stimuli directed to various senses should help resolve these questions about when multiple sensory and when single sensory stimulation is most effective.

A related concept is vividness of the stimulus. Marketing researchers have explored the effects of vividness on memorability and cognitive structure. Kisielius and Sternthal (1984) presented brand information to subjects using either sentences alone (low vividness condition) or sentences and drawings in combination (high vividness condition). A subsequent recall test showed that more brand information was recalled when sentences and drawings were presented in combination. They postulated that vivid stimuli enhance cognitive elaboration, resulting in the development of more storage in memory, and hence a greater likelihood of the information being available for subsequent recall tasks.

The effect of the composition of visual stimuli on recall has also been explored. Lutz and Lutz (1977) .compared interactive stimuli (pictures integrating brand name and product class) with noninteractive stimuli (pictures depicting brand name or the product separately from the written form of the other member of the pair). In a paired-associate learning task, they found that the integration of the information into a single image increased recall of that stimulus.

It is interesting to note that in these studies the "multiple" stimuli, i.e., print (or verbal) and pictorial, enter the subject's mind through the same channel, i.e., visual. Enhancement may occur because when stimuli enter through the same channel and they are synchronized, they reinforce each other. This should be distinguished from stimuli entering the mind through two different channels, i.e., visual and auditory, or stimuli that present the print and picture in a disjointed manner, where incoming stimuli may not be well synchronized, and therefore create interference.

One additional perspective on the effects of multisensory imagery derives from experience in clinical settings. The role of multisensory stimuli in clinical patients may provide clues for predicting processing by non-clinical individuals. In particular, clinical patients' responses to imagery experiences vary according to how many different sensory channels are activated. Brown (1977) explains that the multisensory nature of some hallucinations may be important to the veridicality of the image experience. For example, dream hallucinations are accepted as real when the visual image is supported by other senses, such as when we feel, hear, smell, and/or touch the dream image. A hallucination which involves only one perceptual modality can be disconfirmed by the other senses. A hallucination which shares elements of two or more modalities reduces the effects of the objective world for informing the viewer that his hallucinations are false. An anecdotal example is a patient reported by Hecaen and Robert (Brown 1977). An auditory hallucination was recognized as false until the visual component of the hallucination appeared, at which point it was taken for a real perception. It is possible that multisensory stimulation may affect the believability of an imagery experience in nonclinical individuals as well, particularly for individuals who are strong imagers.

Clinical settings provide other background that may be useful to understanding consumer behavior. A large amount of research has been conducted in the neurosciences on how the brain functions and malfunctions in clinical patients. While the wide range of normal brain function is not the main focus of clinical studies, concepts gleaned from normal subjects, who are observed in this type of research, can provide useful insights for studying consumer behavior. Therefore, neuroscience perspectives are presented next so that they can be used to address marketing issues.

NEUROSCIENCE PERSPECTIVES

Introduction

Separate systems in the brain are responsible for different types of thought processes. For example, there are specific pleasure centers. (When an electrode is placed in a cat's pleasure center, and attached for autostimulation, the cat will continue stimulating itself incessantly, for days, without taking time to eat, drink or sleep.) Other regions of the brain are, in large part, responsible for auditory, visual and kinesthetic sensory activities. Furthermore, different regions are responsible for different levels of processing, i.e., primary, secondary, and tertiary regions. An enervated primary region fires electrically and sends impulses to the secondary region which begins to "develop" the nature of the stimuli. The secondary region then fires electrically and stimulates the tertiary region which makes a final interpretation and further integrates the stimuli.

The existence of separate regions and pathways r the various sensory processes implies that, in some respects, sensory systems function separately. Individual differences in sensory abilities, e.g., musical ability, keenness of observation, verbal skills, are observed often. These differences suggest that the pathways and connecting fibers that serve to integrate sensory activity differ among individuals. The existence of separate sensory systems and numerous interconnecting fibers allows for the specialization we observe. Thus, a violinist who needs to hear, and perhaps feel, his or her music may possess superb connections in the temporal lobe, which is responsible for audition, but weaker connections in the occipital cortex, which is responsible for vision. A boxer or football player, on the other hand, who must perceive the moves by the opposition and mobilize responses, requires excellent visual and kinesthetic connections. Although instruments are not yet precise enough to document these phenomena and differences among individuals, the following section is offered to explain the work in neuroscience that supports this view of the mind.

Specialization In the Brain

Anatomical measurements, recordings of electrical activity, blood-flow studies and metabolic studies have allowed us to explore relationships between mental processes, behavior, brain function and brain activity. Such techniques offer partial validation of theories about brain function and activity in normal subjects.

Attempts to map brain activity have demonstrated that different areas of specialization exist. For example, areas of sensory and motor specialization in the cerebral cortex have been demonstrated. Direct electrical stimulation of specific areas of the brain permits identification of centers that control speech and language, and activation of elementary sensations of seeing, hearing, smelling, and feeling (Penfield and Roberts, 1959). Also, experimental probing has shown that specific brain locations receive stimuli for and send signals to different body parts (e.g. toes, foot, leg, hip, etc.).

Further, studies on clinical patients indicate that images correspond in a general way with certain brain areas. Brown (1985) suggests that the sequence of image types in patients developing from a vague image to a vivid complete image, maps onto levels in the microstructure of brain regions. He identified studying the neural substrates of various stages of image development as important goals for future research.

It is generally accepted that in the brain, specialized functional regions are interconnected by multiple, complex groups of interconnecting fibers that serve to integrate sensory input. While some researchers question the existence of functionally specialized sites under certain conditions (Lashley, 1950), most agree that under normal conditions, functional specialization occurs.

Evidence of Systems of Specialization

Based on existing data and scientific judgment, two theories of neural message transmission have been proposed by neurological scientists (Patton et al., 1976). These are pattern-coding and place-coding. Each may be useful to describe different brain properties. Pattern-coding postulates that each signaled piece of information is represented as a distinctive pattern of cell discharge in sensory receiving areas. Pattern-coding is economical in the sense that each transmission line is used on different occasions to signal different types of information, and thus, is only limited by the number of distinctive patterns. Morse code is a simple example of pattern-coding. Intensity discrimination is traditionally believed to be pattern-coded.

Place-coding postulates that discharge of a unique set of centrally located neurons underlies each discriminable sensory event. Although the mechanism for modality discrimination is controversial, traditionally, it is believed to be place-coded. For the place-coding view to be valid, the existence of "private paths" from the periphery to the central receiving area must be demonstrated for each modality. The fact that many receptors respond selectively to a specific type of physical energy has been used as evidence to support modality specificity. However, support for the place-coding theory does not require that all pathways are modality specific; it merely requires the presence of some specific pathways. Burgess and Perl presented convincing evidence for modality specificity of secondary neurons when they found that certain areas and relay sites respond selectively to peripheral stimuli (e.g., mechanical stimuli). Patton concludes that for most modalities, there appears to be satisfactory evidence for the existence of some private pathways.

Another phenomenon that validates the place-coding theory is when the specificity of a sensory response is independent of the kind of physical stimulation that causes the specific central cells to discharge. This phenomenon was first noted by Muller in the 19th century who states in his law of specific nerve energies that the quality of sensory experience depends on which receptors are excited and not how they are excited. Muller found that specific cutaneous [Cutaneous means relating to the skin.] sites yield cold sensations from both cold and warm stimuli-often called "paradoxical cold".

For visual and auditory sensations, the evidence for place coding is stronger. Electrical stimulation of cells in the visual cortical receiving area in human subjects produces sensations of flashing lights. Similarly, stimulation in the auditory receiving cortex produces auditory sensations. It was this concept of place-coding that prompted DuBois Raymond to whimsically predict that if the auditory pathways were connected to the visual cortex and the optic pathways to the auditory cortex, we would see thunder and hear lightening!

Another source of evidence substantiating place-coding is the loss of modality ability when particular areas of central neurons have been destroyed. For vision, damage to the visual cortex in the occipital lobe in humans produces complete and irreversible blindness. This is the basis for concluding that the discharge of specific cells underlie conscious sensation of vision. This has not been decisively demonstrated for other senses.

The place coding theory and modality specificity suggest that processing varies according to which sense is stimulated. Assimilation and rehearsal of information should be better, when processed though a stronger sensory system than a weaker one. Therefore:

Hypothesis 3: Individuals who possess strong imagery ability in a particular channel more accurately recall the stimulus information processed through that channel than individuals who possess weaker imagery ability in that channel.

Similarly, individuals tend to have more experience and often favor certain sensory modalities, e.g. a violinist versus a football player. As a result, greater confidence may ensue from processing information through a well developed imagery channel than a less developed imagery channel. Therefore:

Hypothesis 4: Individuals who possess stronger imagery in a particular channel are more confident about stimulus information processed through that channel than individuals who possess weaker imagery ability in that channel.

Evidence from Cerebral Blood Flow Studies

Regional cerebral blood flow (rCBF) techniques have been used to reveal different areas of cortical [Cortical refers to the outer portion of an organ. In the cerebrum, this the layer of gray matter covering the hemispheres of the cerebrum and is where the nerve cell bodies are located. The cerebrum is the portion of the brain responsible for intelligence and memory, i.e., the place where we perceive, remember, think, image and make decisions.] brain stimulation during sensory stimulation. Lassen et al., (1977) found that auditory input, in the form of music, increased activity in one brain region while other regions were activated as a result of visual input in the form of looking at a cross-shaped figure. Simple tactile stimulation of the hand, mouth, and foot activated yet other regions. Larsen et al., (1977) conducted a listening test where subjects were instructed to listen to simple words, onomatopoeia such as "splash" and "crack", and found that increased activity was induced in the left hemisphere and to a lesser degree in the right hemisphere. By contrast, in a speech test, where subjects counted to twenty or mentioned days of the week at a rate of one per second, increased activity was induced in the left and right hemispheres, but in regions that are different from those activated by the listening test. It is interesting to note that the regions activated in the left and right hemispheres are often different.

The relevance of these findings is the implication that perceptual tasks involving different senses appear to activate different regions of the brain. These phenomena lend support to the concept that individual processing and responses vary according to which sensory system is activated. Sensory processing vis-a-vis imagery may activate in a similar way.

CONCLUSION

The neuroscience evidence points towards specialization in brain activity. Regardless of whether these results are from variations in genetic and/or environmental factors, it seems reasonable to expect differences in types of specialization and abilities among individuals. Differences in mental imagery and separation of sensory activities mean that people can be reached in different ways. While precise identification of differences in brain activity among individuals is difficult to demonstrate with technology generally available today [Sophisticated innovations such as the PETT scanner, i.e., positron emission transaxial tomography, which identifies locations of the brain activity by tracking utilization of radioactively tagged glucose in the brain, holds the promise of relating brain activity to behavior more precisely. Since there are fewer than 20 PETT scanners around the world, and they are quite costly, most researchers rely on less precise measurements.], the preceding background and rationale for individual differences provide insights about why people differ in recall, perception, evaluation, and behavioral responses, and suggest that individuals can be expected to vary their responses to different types of sensory stimulation. Future research that correlates brain activity with various responses would be illuminating.

This paper emphasizes the multisensory nature of imagery and presents perspectives from the neurosciences that support specialization in brain function. The abilities or preferences of different individuals in imagery processing are, in part, a function of which sense is stimulated and how well that sense is developed in imagery processing. Understanding how individuals differ in their abilities to process imagery in various senses, and how use of imagery influences the way consumers interpret their environment, can help identify more effective ways to reach the consumer.

Possible relationships to explore include:

- How individual differences in imagery ability influence recall and believability of marketing stimuli.

- How processing varies according to which sensory modality is stimulated, e.g., auditory, visual, audiovisual, kinesthetic, etc.

- How vividness of imagery in one sense affects consumer responses, as compared with responses to vivid versus unvivid imagery in another sense or in multiple senses.

- How imagery effects vary according to product or service type, i.e., are some products better represented through visual imagery while others through auditory, kinesthetic or olfactory imagery?

Imagery processing is often used by consumers to evaluate marketing stimuli, and consumers differ with respect to their ability and desire to invoke imagery processes. Imagery can potentially improve the believability and memorability of a communication and influence consumer processing and responses. A multisensory approach to imagery processing offers the possibility of realizing the substantial benefits that proper use of imagery can provide.

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