Bolls, P. D. (2002). I Can Hear You, but Can I See You ... - PRIME Lab

Communication Research http://crx.sagepub.com

I Can Hear You, but Can I See You? The Use of Visual Cognition During Exposure to High-Imagery Radio Advertisements Paul D. Bolls Communication Research 2002; 29; 537 DOI: 10.1177/009365002236194 The online version of this article can be found at: http://crx.sagepub.com/cgi/content/abstract/29/5/537

Published by: http://www.sagepublications.com

Additional services and information for Communication Research can be found at: Email Alerts: http://crx.sagepub.com/cgi/alerts Subscriptions: http://crx.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav

Downloaded from http://crx.sagepub.com at University of Missouri-Columbia on February 20, 2008 © 2002 SAGE Publications. All rights reserved. Not for commercial use or unauthorized distribution.

COMMUNICATION 10.1177/009365002236194 Bolls • Use of Visual Cognition RESEARCH

• October 2002

PAUL D. BOLLS

I Can Hear You, but Can I See You? The Use of Visual Cognition During Exposure to High-Imagery Radio Advertisements This study tested the proposition that high-imagery radio advertisements engage visual cognitive resources. Participants in a within-subjects experiment were exposed to 60-second radio advertisements previously coded as either high- or low-imagery ads. During half of the ads, participants were also presented a series of pictures unrelated to the content of the ads. Dual-task interference between the cognitive tasks of listening to the radio advertisements and viewing the unrelated pictures was found in recognition data for high-imagery ads but not low-imagery ads. This pattern of results indicates listening to high-imagery radio ads competes with visual tasks for cognitive resources. Therefore, it appears listening to high-imagery radio advertisements engages visual cognitive resources despite the fact these advertisements are auditory messages. Implications for theories of communication-evoked mental imagery are discussed.

Radio has popularly been referred to as theater of the mind because of its perceived ability to paint pictures in the imagination of listeners. The Radio Advertising Bureau recently highlighted this characteristic of radio in a campaign that used the slogan “I saw it on the radio.” Radio producers intuitively believe a strength of radio is the ability to evoke visual imagery in a listener’s mind, and research has indicated high-imagery advertisements are more effective than low-imagery advertisements at producing many of the desired goals of advertising (Bolls & Potter, 1998; Miller & Marks, 1997). Researchers have focused on demonstrating the effectiveness of high-imagery advertisements but have not conducted research that would significantly advance theoretical explanations of the cognitive mechanisms involved in processing high-imagery advertisements. The purpose of this study is to expand current theoretical conceptualizations of communication-evoked imagery processing COMMUNICATION RESEARCH, Vol. 29 No. 5, October 2002 537-563 DOI: 10.1177/009365002236194 © 2002 Sage Publications

537


COMMUNICATION RESEARCH • October 2002 by testing the involvement of visual cognitive resources during exposure to high-imagery radio advertisements. Research that tests the involvement of specific cognitive mechanisms, such as visual cognition, could lead to valuable insights concerning why and when high-imagery advertisements are likely to be effective, as well as contribute much needed theoretical understanding of communication-evoked mental imagery. High-imagery radio advertisements are marked by an attempt to stimulate a target audience to “see” the advertised product by engaging the audience in visual mental imagery. Researchers have used two different conceptualizations of imagery. On one hand, imagery is conceptualized as a human cognitive process (i.e., Kosslyn, 1994). On the other hand, imagery is considered to be a characteristic of the message (i.e., Miller & Marks, 1997). Incorporating these two different conceptualizations of imagery into one study requires the use of terminology that will maintain the distinction between a cognitive process and a characteristic of media messages. This study uses the term imagery processing to refer to imagery as a cognitive process and uses the term imagery to refer to a characteristic of media messages. The fundamental proposition tested in this study is that high-imagery radio advertisements engage listeners in imagery processing requiring access to visual cognitive resources in order for the message to be thoroughly encoded into memory. Under this proposition, imagery processing is viewed as similar to visual perception because imagery processing uses at least some of the same cognitive resources as visual perception. The practical implication of this proposition is high-imagery radio advertisements could get the audience to see the advertised product in use by engaging visual cognition through imagery processing. This means radio could possibly be used to evoke similar cognitive and emotional responses to an advertised product as visual exposure to the product. The theoretical implication is researchers studying communication processes may need to take into account the possibility that the cognitive processing of messages may engage sensory modalities beyond what the obvious physical components of a message suggest. The proposition that imagery processing and visual perception share similar cognitive processes is not new. Researchers in cognitive psychology have been engaged in an imagery debate since the 1970s (Denis, 1991). The debate has focused on the degree of similarity between mental imagery and perception and has encouraged the development of theories of imagery processing.

The Functional Equivalence Perspective One theory to emerge from debate over the nature of imagery processing has been the functional equivalence perspective (Kosslyn, 1994). Researchers

538


Bolls • Use of Visual Cognition who are guided by this theory claim imagery processing and visual perception use similar areas of the brain. In other words, looking at the hands of a clock at 3 p.m. and imagining the hands of a clock at 3 p.m. use similar brain structures, specifically, visual cortex. In developing the functional equivalence perspective, Kosslyn (1991) proposed that imagery processing involves the activation of visual representations stored in long-term memory into a short-term memory visual buffer. The short-term memory visual buffer is proposed to have initially developed as part of the visual perception system (Farah, 1989). The involvement of structures in the visual perception system during imagery processing is the crux of the functional equivalence perspective; therefore, a basic understanding of visual perception is useful to understanding this view of imagery processing. Visual perception begins with retinotopic representation of an object in the occipital cortex caused by visual input through the eyes (Thompson, 1993). Visual perception then proceeds to the formation of memories at the temporal cortex (Farah, 1995). This type of cognitive processing is considered bottom-up processing because information flows from sense organs (the eyes) to lower levels of the brain such as the visual cortex and then up to higher brain areas such as the temporal cortex. A second type of cognitive processing, top down, is also involved in visual perception (Thompson, 1993). Topdown cognitive processing involves the flow of information from higher levels of the brain to lower levels of the brain. Top-down processing is believed to be used when initial visual input is unclear and information stored in long-term memory is needed to make sense of information being sent to lower brain areas from the eyes (Lowe, 1987). Kosslyn (1994) relied on the belief that both bottom-up cognitive processing and top-down cognitive processing are used by the brain during visual perception to provide a biologically based argument for the functional equivalence perspective of imagery processing. The human brain has efferent connections that allow information to flow from lower to higher brain areas (bottom-up processing) and afferent connections that enable the flow of information from higher to lower brain areas (top-down processing) (Kosslyn, 1994). This means it is biologically plausible for lower levels of the brain, which contain information about spatial and temporal properties of objects, and higher levels of the brain, which contain memories, to simultaneously participate in the receiving and sending of information during visual perception. Researchers working under the functional equivalence perspective believe if higher and lower brain areas cooperatively send information back and forth during visual perception, the same pattern of brain activation could occur during imagery processing. More specifically, they propose mental

539


COMMUNICATION RESEARCH • October 2002 images, resulting from imagery processing, include spatial and temporal characteristics that activate lower brain areas, potentially visual cortex. Activation of a mental image, which is constructed from long-term memory, leads to top-down activation of lower level visual cognitive resources. Some researchers have even proposed imagery processing developed from brain structures involved in top-down visual processing (Kosslyn, 1991; Kosslyn, Flynn, Amsterdam, & Wang, 1991). This leads to the proposition that visual perception and imagery processing are functionally equivalent in that to a certain extent they share cognitive resources. Studies that test the functional equivalence perspective have tapped into recent brain-imaging technologies such as positron-emission tomography (PET) and functional magnetic resonance imaging (FMRI). These technologies have the ability to identify specific areas of the brain that are activated during a cognitive task. In using brain-imaging technologies, cognitive psychologists have primarily organized research around questions concerning hemispheric specialization and the involvement of primary visual cortex in imagery processing (D’esposito et al., 1997). Questions concerning hemispheric specialization are relevant to imagery processing because the left hemisphere of the brain generally dominates during verbal processing; the right hemisphere tends to dominate nonverbal processing (Ley, 1983). Significantly greater right hemispheric involvement in imagery processing would offer further support for the involvement of a nonverbal code such as visual memories in imagery processing. Assessing the involvement of primary visual cortex during tasks involving imagery processing is important because it provides direct tests of the functional equivalence perspective. Research on hemispheric activation during imagery processing has produced mixed results. Some researchers have found that the left hemisphere appears to dominate during imagery processing (D’esposito et al., 1997; Goldenberg, Podreka, & Steiner, 1990). Others found either no asymmetry between the hemispheres or larger activation in the right hemisphere (Farah, Hammond, Levine, & Calvanio, 1988; Mellet, Tzourio, Denis, & Mazoyer, 1995). However, researchers have found that the occipital, temporal, and parietal cortices are selectively activated during imagery processing (Farah, Peronnet, Weisberg, & Monheit, 1989; Goldenberg et al., 1990; Kosslyn et al., 1993; Le Bihan et al., 1993). This supports the functional equivalence perspective because these are brain areas that have been found to subserve visual perception (Loverock & Modigliani, 1995). The functional equivalence perspective offers a precise description of cognitive mechanisms involved in imagery processing. However, one should keep in mind most of the experiments cited above as offering support for this view of imagery processing involved the manipulation (typically mental rotation)

540


Bolls • Use of Visual Cognition of very simple stimuli such as geometric shapes. It is likely this is in part due to the fact that the PET and FMRI environment is not very conducive to the presentation of significantly more complex stimuli such as broadcast advertisements. Therefore, the functional equivalence perspective remains relatively untested on “real-world” stimuli.

Advertising Research on Imagery Processing Advertising researchers take a somewhat different approach to investigating imagery processing compared to cognitive psychologists, such as Kosslyn. Both types of researchers are interested in the nature of imagery processing as a human cognitive activity, but the advertising researcher is also interested in imagery as a characteristic of media messages. This focus has led to the development of a body of research that offers good descriptions of media production features that evoke imagery processing and the effects of imagery on desired advertising outcomes. Advertising researchers have conceptualized imagery processing as a sensory method of encoding, processing, and evoking information that results in the representation of sensory experience in memory (MacInnis & Price, 1987). Imagery has been conceptualized in terms of the presence of specific production features of advertisements believed to evoke imagery processing (MacInnis & Price, 1987). Advertisements that include production features believed to evoke imagery processing are considered high-imagery advertisements, whereas advertisements that do not include such production features are considered low-imagery advertisements. In a study of radio advertisements, Bone and Ellen (1990) manipulated the degree of concrete wording in the copy for a fictitious brand of popcorn and found concrete language engaged imagery processing more than abstract language. More recent work by Bone and Ellen (1992) manipulated the plausibility of the mental images evoked and whether the mental images were self-related or other related. They found these additional content variables also influenced the degree of imagery processing. Not surprisingly, it has been suggested sound effects play a significant role in evoking imagery processing (Atwood, 1989). Miller and Marks (1997) produced two versions of a radio advertisement for a fictitious automobile, one with a sound effect and one without, and provided empirical evidence that sound effects increase the degree of imagery processing. It appears for radio advertising, concrete wording in the copy and the use of sound effects are the production features that most effectively evoke imagery processing. Advertisements that evoke imagery processing have been found to positively affect desired advertising outcomes. Research has demonstrated high-

541


COMMUNICATION RESEARCH • October 2002 imagery advertisements result in superior recall and learning of information contained in the advertisement (Childers & Houston, 1984; Lutz & Lutz, 1977; Unnava & Burnkrant, 1991). Not only are high-imagery advertisements more memorable, but they also tend to result in a more favorable audience response. Bone and Ellen (1990) manipulated the degree of imagery processing evoked by radio advertisements and found positive effects of highimagery advertisements on attitudes toward the advertisements and behavioral intentions (participants’ reports of how likely it was they would buy the advertised product). The positive effect of high-imagery radio advertisements on attitudes has been shown to be robust enough to affect specific dimensions of attitude toward the advertisement, such as attitude toward claim components and attitude toward nonclaim components (Bolls & Potter, 1998). Advertising researchers have documented positive effects of high-imagery advertisements but have failed to use theories of imagery processing, such as functional equivalence theory, to develop studies that take into account the nature of the human cognitive system to understand the effects of communicationevoked imagery processing. This gap in advertising research has led to the development of general rather than specific explanations of why advertisements that engage imagery processing work. Current theoretical explanations of why high-imagery advertisements work suggest they may draw on long-term memories anchored in a person’s own experiences (Burns, Biswas, & Babin, 1993). The idea is high-imagery advertisements are more effective because they are more personally relevant to the audience (MacInnis & Price, 1987). Under this theoretical description, a radio ad for Nike football shoes, produced to engage imagery processing by evoking a vivid image of a young athlete making an 80-yard run for the winning touchdown, would be effective because it engages the target audience in a form of personally relevant information processing. In this case, the personally relevant information processing would involve a member of the target audience recalling personal experiences related to playing or watching football during exposure to this highimagery Nike radio advertisement. A theory that describes imagery processing as personally relevant vaguely describes why high-imagery advertisements might work but says little about the underlying cognitive processes engaged by high-imagery radio advertisements. It is possible the nature of the cognitive processes engaged by high-imagery advertisements is behind many of the observed effects of these messages. This study attempts to advance theories of communicationevoked imagery processing by testing for the use of a specific mechanism of cognitive processing, namely visual cognition, during imagery processing of high-imagery radio advertisements.

542


Bolls • Use of Visual Cognition

High-Imagery Radio Ads and Imagery Processing The first step in testing the involvement of visual cognition during communicationevoked imagery processing is to test the premise that audience members engage in imagery processing during exposure to high-imagery advertisements. Most advertising research has not attempted to directly measure imagery processing but, when certain effects were observed, has inferred imagery processing was involved (Bone & Ellen, 1990). A select number of studies have attempted to demonstrate the occurrence of imagery processing during exposure to advertising through the use of self-report measures of imagery processing (Babin & Burns, 1998; Ellen & Bone, 1991). These scales have two primary limitations. First, self-report measures of imagery processing require respondents to engage in introspection to report the nature of a mental event. Second, these measures rely on the respondents’ ability to effectively recall mental images that were experienced during exposure to a message. Physiological measures overcome the above mentioned limitations by providing insight into a person’s cognitive/emotional state during online processing of a message without making the person engage in introspection. Research in psychophysiology has uncovered predictable response patterns in autonomic nervous system activity associated with imagery processing (Deschaumes-Molinaro, Dittmar, & Vernet-Maury, 1992). One such response is an increase in heart rate during imagery processing (Craig, 1968; Jones & Johnson, 1980; P. J. Lang, Kozak, Miller, Levin, & McLean, 1980). Craig (1968) found direct instructions to “imagine” led to an increase in heart rate over resting levels. P. J. Lang et al. (1980) measured heart rate while having participants imagine fearful stimuli and found cardiac acceleration during mental imagery. Jones and Johnson (1980) had participants imagine lowactivity scenes and high-activity scenes. They found participants’ heart rates were faster during high-activity images. These early studies demonstrated manipulations in the content and level of how imagery-processing affects cardiac responding. Despite the fact there appears to be a connection between a psychological state (imagery processing) and a physiological response (cardiac acceleration), researchers must be very careful in using physiological measures to index psychological states. There are multiple sources of variation in physiological responding. Furthermore, it is important to note that the primary purpose of physiology is to sustain life, so any variation in physiological response associated with a psychological state will be very small. However, given careful experimental design and data analysis, it is possible to infer a psychological state, such as imagery processing, from a pattern of

543


COMMUNICATION RESEARCH • October 2002 physiological responding, such as cardiac acceleration (Cacioppo, Tassinary, & Berntson, 2000). Why heart rate speeds up during more intense imagery processing is not completely understood. The heart is under the dual control of the sympathetic and parasympathetic nervous system, meaning any observed increase in heart rate could be due to an increase in sympathetic activation or a decrease in parasympathetic activation (Papillo & Shapiro, 1990). It is possible to speculate about the biological foundation of cardiac acceleration in response to imagery processing. Previous research suggests the heart tends to speed up during an internal focus of attention, as occurs with mental arithmetic, and slows down when attention is focused on an external stimulus (A. Lang, 1994). Parasympathetic activation is a biological response that serves a quieting function in the body, better preparing an organism to focus attention on an external stimulus to take in information from the environment (Papillo & Shapiro, 1990). Sympathetic activation speeds up physiological systems, preparing an organism to orchestrate a response to information (Papillo & Shapiro, 1990). Formulating a response to information involves a significant focus of attention internally as the organism evaluates the appropriateness of responses and information is exchanged between higher brain areas and motor systems. This internal focus of attention could conceivably engage the early stages of sympathetic activation. It follows that imagery processing, as a task that involves a significant focus of attention internally, could lead to sympathetic nervous system activation, resulting in the observed increase in heart rate. In examining cardiac response during imagery processing, an interesting question is, Does the cardiac acceleration associated with imagery processing extend to communication-evoked imagery processing, which could involve the allocation of attention both internally to generating mental images and externally to the media message? In an exploratory study, Bolls, Potter, and Lang (1998) found heart rate was faster during exposure to high-imagery radio advertisements compared to low-imagery radio advertisements. Furthermore, self-reports of imagery processing in this study revealed that participants also reported engaging in more imagery processing during the highimagery advertisements. The self-report data taken with the physiological data indicate heart rate responds to high-imagery messages as if imagery processing were occurring, supporting previously mentioned research that suggests heart rate can be used as a physiological measure of imagery processing even during exposure to media messages. If audience members engage in imagery processing during exposure to high-imagery radio advertisements, heart rate should increase.

544


Bolls • Use of Visual Cognition Hypothesis 1: Heart rate will be faster during exposure to high-imagery radio advertisements compared to low-imagery radio advertisements.

Imagery Processing and Visual Cognition The fundamental proposition tested in this experiment is advertisements that engage imagery processing also engage visual cognitive resources. One way of testing the above mentioned proposition is through a dual-task paradigm. This paradigm has been used to test theories of attention and investigate questions concerning the degree that two cognitive tasks compete for the same cognitive resources (Pashler, 1998). Experiments conducted under this paradigm simultaneously present two tasks for participants to perform. Researchers then look for evidence of dual-task interference in the form of a performance decrement on one or both tasks. Dual-task interference can result from competition for specific cognitive resources, such as those needed to execute a motor response, or general cognitive resources. The degree of similarity between two tasks has been found to modulate dual-task interference (Baddeley, 1966; Hirst & Kalmar, 1987; Navon & Miller, 1987). This means dual-task interference can be taken as evidence the two tasks share at least some degree of similarity. Based on the dual-task paradigm, one way to test the involvement of visual cognitive resources during imagery processing would be to have people simultaneously perform a task that engages visual perception and a second task that engages imagery processing. If dual-task interference were found in the form of a performance decrement on one of the tasks, this would be evidence the two tasks share similar cognitive resources. Of course, the nature of the tasks being presented needs to be carefully considered by researchers. In many dual-task experiments, tasks are kept very simple to avoid confounds arising from stimuli that carry some form of meaning to participants. For example, Baddeley and Andrade (2000) explored interference effects in working memory on the vividness of mental images by having participants perform either a finger-tapping task on a key board or a verbal counting task while simultaneously engaging in an imagery task. Other researchers who have specifically studied how visual tasks interfere with mental imagery have used line drawings (Logie, 1986) and irrelevant visual “noise” patterns (Quinn & McConnell, 1996). This approach of using simple tasks increases experimental control but does little to replicate the cognitive processing of real-world stimuli. Researchers interested in studying the cognitive processing of media need to balance experimental control with a need to achieve some degree of external validity. One way to do this is to use stimuli that participants are likely to encounter in the real world.

545


COMMUNICATION RESEARCH • October 2002 In this study, participants were asked to listen to and remember radio advertisements that varied on their ability to evoke mental images (imageryprocessing task). Participants were also instructed to view and remember pictures (visual task), unrelated to the content of the advertisements. The pictures were presented simultaneously with randomly selected advertisements, which created the dual-task processing condition. The pictures, as real-world stimuli, likely carried significant meaning to the participants, which introduces a potential confound in interpreting the results. However, an attempt was made to minimize the effect of this confound on the data by controlling how arousing the pictures were and by using a within-subjects experimental design where each participant serves as her or his own control group. Evidence for interference between the imagery processing and visual tasks was sought in participants’ recognition of the radio advertisements. If communication-evoked imagery processing uses visual cognition, then evidence of dual-task interference should only be found for the simultaneous processing of high-imagery radio advertisements and the unrelated pictures but not for low-imagery advertisements and unrelated pictures. This leads to a second hypothesis. Hypothesis 2: There will be an imagery by visual task interaction such that the introduction of a visual task will lower recognition of highimagery radio advertisements but will not significantly affect recognition of low-imagery radio advertisements.

Method Design The design of this experiment was a mixed 2 (imagery) × 2 (visual task) × 2 (measure) × 3 (message) × 3 (order) repeated measures design. Imagery, Visual Task, Measure, and Message were within-subjects factors. Imagery had two levels, high and low. Visual Task had two levels representing the presence or absence of the visual task. Measure also had two levels representing whether heart rate or secondary task reaction time was measured during exposure to the advertisement. Secondary task reaction time data were collected during exposure to half of the advertisements (reported in Bolls & Lang, 2000). Message was the repeated factor with three levels representing the three advertisements that were used at each level of Imagery × Visual Task × Measure. Order was the only between-subjects factor. Participants were randomly assigned to view one of three stimulus tape orders.

546


Bolls • Use of Visual Cognition Independent Variables Imagery Imagery was conceptualized as a characteristic of advertisements that evokes imagery processing. Imagery was manipulated by assessing the degree that a group of advertisements engaged imagery processing during a pretest and then selecting advertisements that scored extremely high or low on a self-reported Imagery-Processing Scale. Visual Task The visual task was to view and remember a set of still pictures that were presented simultaneously with randomly selected advertisements. Six advertisements within each level of imagery were randomly selected to include the visual task. Still pictures were selected from the International Affective Picture Show (IAPS) (P. J. Lang, Greenwald, Bradley, & Hamm, 1993; P. J. Lang, Ohman, & Vaitl, 1988). The IAPS is a collection of slides that have been coded for emotional arousal and valence. The IAPS has four categories of pictures, arousing/positive, arousing/negative, calm/positive, and calm/negative. Pictures were chosen from the IAPS, controlling for arousal. Pictures that had been coded as extremely arousing or extremely calm were excluded from this experiment. This helped ensure the pictures were arousing enough to attract attention but would not be so arousing as to overwhelm processing of the radio advertisements. After controlling for arousal, 96 pictures were randomly chosen with the requirement that an equal number of pictures from each of the four Arousal × Valence categories be chosen. The 96 pictures were randomly assigned to be presented with high- or low-imagery advertisements. The 48 pictures assigned to the high-imagery advertisements were coded for relatedness to the mental images evoked by the high-imagery advertisements. Four graduate students performed the coding, working in teams of two. Each team coded two groups of 12 pictures. The ratings given by the two graduate students to each picture were summed to obtain a single score representing how related a picture was to each of the selected high-imagery advertisements. Each advertisement selected to include the visual task was paired with eight pictures that were displayed on a television screen during the advertisement. Pictures were assigned to advertisements, with the requirement that two pictures from each Arousal × Valence category be assigned to each

547


COMMUNICATION RESEARCH • October 2002 advertisement. Pictures were randomly assigned to the low-imagery advertisements. Each high-imagery advertisement was assigned the pictures that it had the lowest possible relatedness score with.

Dependent Variables Heart Rate Heart rate was measured for six randomly selected advertisements within each level of imagery. Three of the six advertisements included the visual task, and three did not. Heart rate was collected time locked to exposure to each selected advertisement. Following guidelines laid out by Stern, Ray, and Quigley (2000), the procedure for measuring heart rate involved abrading participants’ skin with paper towels and placing three Beckman standard silver/silver chloride electrodes filled with conducting gel on participants’ forearms. One electrode was placed on each forearm approximately an inch below the elbow, and a third electrode was placed on the wrist of the participant’s dominant arm. This electrode placement presents the electrical activity of the heart as a two-dimensional geometric figure known as the electrocardiogram (ECG) waveform (Brownley, Hurwitz, & Schneiderman, 2000). The QRS complex is part of the ECG waveform of a single cardiac cycle and represents electrical stimulation of the ventricles of the heart, which is recorded by the electrodes (Brownley et al., 2000). Heart rate was obtained by measuring the length of time between R spikes in consecutive QRS complexes. The signal was passed from participants into a Coulbourn S series bioamplifier connected to a dual comparator and retriggable one-shot set to send a digitized pulse at the occurrence of an R spike. Digitized pulses were passed to the VPM physiological data collection program (Cook, 2001) that recorded milliseconds between each pulse and then converted it into beats per minute. Recognition Recognition for the advertisements was measured with a speeded recognition task. Two-second audio clips were selected from each stimulus advertisement. Audio clips were selected from the middle 30 seconds of each advertisement to test recognition during a part of the advertisement where mental images would likely have been evoked. One time point was randomly chosen from each 10-second block (16-25 seconds, 26-35 seconds, and 36-45 seconds), and 2 seconds of audio were recorded from that point. This was not meant to be a brand recognition test, so audio clips were selected to exclude any mention of the advertised brand name. In the case where a randomly selected clip

548


Bolls • Use of Visual Cognition included mention of the brand name, another time point within the same 10-second block was chosen. Three foils for each of the 24 stimulus advertisements were also recorded. Foils were selected from advertisements used in the pretest but not selected as stimulus advertisements. The audio clips were presented to participants at a rate of one every 4 seconds. Participants were instructed to indicate as quickly as they could whether the audio clip was from one of the advertisements they listened to during the experiment. Participants were warned the audio clips would be presented at a quick rate and told they should indicate their responses before the next clip began. Participants listened to four practice audio clips prior to completing the recognition test to help them become familiar with the rate the audio clips would be presented.

Stimulus Selection Stimulus messages were twenty-four 60-second radio advertisements selected from a pool of Mercury Award–winning advertisements from the years 1994–1997. Forty-seven advertisements were selected for pretesting. During the pretest, undergraduate students, enrolled in a telecommunications course at a large midwestern university, listened to each advertisement and rated it on an adapted version of the Babin and Burns (1998) Communication-Evoked Mental Imagery Scale. The adapted version used in this pretest included the 14 original scale items plus a 15th item allowing pretest participants to indicate no images came to their minds while listening to an advertisement. Each advertisement was rated by 10 students. Responses to the imagery scale were summed to give an imagery score for each pretest advertisement. An overall imagery score for each advertisement was obtained by taking an average of the individual imagery scores given the advertisement by the 10 students who rated it. Stimulus advertisements were chosen based on the overall imagery score for each advertisement. An attempt was made to use the 12 advertisements with the highest overall imagery scores and 12 advertisements with the lowest overall imagery scores. Pretest advertisements included different advertisements for the same product. In this case, the advertisement that scored at the furthest extreme of the high-imagery to low-imagery continuum was chosen. A 2 (imagery) × 12 (advertisement) repeated measures ANOVA was conducted on the pretest data. This analysis indicated the advertisements selected as high-imagery advertisements, M = 77.47, SD = 7.25, were rated significantly different from the advertisements chosen as low-imagery advertisements, M = 49.37, SD = 5.82, F(1, 9) = 164.9, p < .001. Table 1 displays the stimulus advertisements and their imagery scores.

549


COMMUNICATION RESEARCH • October 2002 Table 1 Stimulus Advertisements High Imagery Advertisement

Low Imagery Imagery Score

Staples (school supplies) Sega (video games) Logic (ant killer) Raineer (beer) Solaris (lawn chemicals) a Milk Nike Air (tennis shoes) a AT&T (long distance) a Bud Light (beer) a Mind Trap (game) a Cellular One (wireless) a Carnation (hot chocolate)

86.8 84.2 81.6 78.9 77.6 76.4 75.5 75.0 74.8 74.1 74.0 71.0

Advertisement

Imagery Score

Washington Apples a Michaels (arts and crafts) Jiffy Lube (oil change center) a Motel 6 Lotus (organizer) Prego (restaurant) a Chubb (insurance) Adams (peanut butter) a Tillamok (cheese) a Cherry Coke a Chevy’s (restaurant) Levis (jeans)

59.9 59.3 56.3 55.8 55.8 54.9 52.2 48.1 46.6 41.0 39.8 36.7

a. Designates advertisements that included the visual task.

Apparatus Videotapes containing the stimulus advertisements on the audio track and visual task on the video track were played on a 3/4-inch VCR. The VCR was connected to a 19-inch color television and medium-sized home stereo speaker, located approximately 5 feet behind participants. During the experiment, the video signal from the VCR was sent to the television while the audio signal was sent to the home stereo speaker. No audio signal was passed through the speakers of the television. Pictures in the visual task were viewed on the television screen, whereas the radio advertisements were heard through the home stereo speaker located behind participants.

Participants and Procedure Participants (N = 46) were undergraduate students enrolled in a telecommunications course at a large midwestern university. Participants completed the experiment one at a time in a psychophysiology laboratory. On arrival at the laboratory, participants were greeted by the researcher and given an informed consent form. The informed consent form stated the purpose of the study was to learn how people listen to the radio and informed participants of the procedures and risks involved in the collection of heart rate data. Participants were also told they would be listening to 24 radio advertisements and would be asked some questions about the advertisements. After informed

550


Bolls • Use of Visual Cognition consent was obtained, the researcher attached the heart rate electrodes to participants, handed them the packet containing self-report measures of imagery processing and attitude toward the advertisement (reported in Bolls, 2002), and played the first set of recorded instructions for the experiment. The first set of recorded instructions informed participants about the visual task and how to complete the self-report measures. For the visual task, participants were told that during some of the advertisements, pictures unrelated to the advertisements would appear on the television screen, and they should look at the pictures because they would be asked questions about the pictures as well as the radio advertisements. After listening to the instruction tape, participants were given the opportunity to ask questions. Once any questions had been answered, participants listened to the 24 advertisements. The researcher paused the stimulus tape in between each advertisement and waited for participants to indicate they were finished completing the self-report measures before restarting the tape. After completing the self-report measures for the last advertisement, participants were given a 5-minute distractor task that consisted of viewing part of an episode of the sitcom Friends. After the distractor task, participants were given the recognition test over the radio advertisements. Once the test was completed, participants were thanked and dismissed.

Results Manipulation Check As a manipulation check for imagery, participants completed a measure of self-reported imagery processing after exposure to each advertisement. These data were submitted to a 2 (imagery) × 2 (picture) × 6 (message) × 3 (order) repeated measures ANOVA. Data from 45 participants were submitted to this analysis. One participant’s data were lost due to the participant withdrawing from the experiment. Imagery had a significant main effect on self-reported imagery processing, F(1, 42) = 133.36, p < .001, epsilon squared = .75. Self-reported imagery processing was higher for advertisements that were judged during the pretest to be high-imagery radio advertisements (M = 5.04, SD = 0.64) compared to advertisements judged to be low-imagery advertisements (M = 4.11, SD = 0.53). This indicates the manipulation of imagery was successful.

551


COMMUNICATION RESEARCH • October 2002 Hypothesis 1 The first hypothesis predicted heart rate would be faster during exposure to high-imagery radio advertisements than during exposure to low-imagery advertisements. This hypothesis was tested by submitting the heart rate data to a 2 (imagery) × 2 (visual task) × 3 (message) × 10 (time) × 3 (order) repeated measures ANOVA. Heart rate data were averaged over 5-second intervals (i.e., first 5 seconds, second 5 seconds, etc.), yielding 10 time points per message for analysis. Data from 41 participants were submitted for analysis. Data from 5 participants were lost due to a combination of experimenter and equipment error. The main effect of imagery on heart rate over the entire message only approached statistical significance, p < .06. However, there was a significant Imagery × Time interaction, F(9, 342) = 5.24, p < .001, epsilon squared = .11. As can be seen in Figure 1, heart rate was faster during exposure to highimagery radio advertisements compared to low-imagery advertisements over the first 35 seconds of exposure. Based on examination of Figure 1, a second analysis of the heart rate data was conducted that only examined the first 35 seconds of exposure. This analysis consisted of a 2 (imagery) × 2 (visual task) × 3 (message) × 7 (time) × 3 (order) repeated measures ANOVA. This analysis revealed that imagery had a significant main effect on heart rate over the first 35 seconds of the advertisements, F(1, 38) = 7.33, p < .01, epsilon squared = .13. Heart rate was significantly faster during high-imagery advertisements (M = 73.99, SD = 8.11) compared to low-imagery advertisements (M = 72.96, SD = 8.67). Heart rate data supported Hypothesis 1. Heart rate responded as if participants engaged in imagery processing during exposure to high-imagery advertisements over the first 35 seconds of the advertisement. There were no significant effects of visual task, message, or order on heart rate.

Hypothesis 2 This experiment tested the proposition that imagery processing evoked by high-imagery radio advertisements engages visual cognition. Hypothesis 2 was derived to test this proposition and predicted there would be a significant Imagery × Visual Task interaction such that introducing the visual task would lower recognition for high-imagery radio advertisements but would not affect recognition for low-imagery radio advertisements. Recognition test data were submitted to a 2 (imagery) × 2 (visual task) × 6 (message) × 3 (item) × 3 (order) repeated measures ANOVA. Recognition data from 40 participants were analyzed.

552



78

Beats per Minute

77 76 75 74 73 72 5

10

15

20

25

30

35

40

45

50

Seconds High Imagery Figure 1.

Low Imagery

Heart Rate Averaged Over 5-Second Periods During Exposure to the Radio Advertisements

The first analysis of the recognition data for the radio advertisements examined the percentage of audio clips from the advertisements that participants correctly recognized (percentage correct). There was a significant Imagery × Visual Task interaction on percentage correct, F(1, 37) = 17.95, p < .001, epsilon squared = .30. This interaction is displayed in Figure 2. As predicted, introduction of the visual task lowered recognition for high-imagery radio advertisements. However, recognition for low-imagery radio advertisements slightly improved with introduction of the visual task. Imagery, visual task, message, and order did not have significant main effects on the percentage correct data. Means for the percentage correct data are displayed in Table 2. The same analysis used to assess percentage correct was also used to analyze response latency for recognition test audio clips. Response latency was

553


COMMUNICATION RESEARCH • October 2002

Percentage Correct

0.64 0.62 0.6 0.58 0.56 0.54 0.52

No Picture

Picture

Visual Task Condition Low Imagery

High Imagery Figure 2.

Imagery ⴛ Visual Task Interaction on Percentage of Correct Responses to the Recognition Test Clips From the Radio Advertisements

Table 2 Radio Advertisement Recognition Test Percentage Correct High Imagery Dual-Task Condition No visual task Visual task

Low Imagery

M

SD

M

SD

.63 .53

.16 .18

.57 .62

.16 .20

analyzed separately for whether participants gave a correct response by indicating the test item was from the advertisements (old) or gave an incorrect response by indicating the test item was not from the advertisements (new).

554



2160 2140

Milliseconds

2120 2100 2080 2060 2040 2020

No Picture

Picture

Visual Task Condition High Imagery Figure 3.

Low Imagery

Imagery ⴛ Visual Task Interaction on Response Latency to the Recognition Test Clips From the Radio Advertisements

For indicating the item was old, there was a significant main effect of imagery on response latency, F(1, 25) = 4.70, p < .04, epsilon squared = .12. Participants were faster at indicating the item was old for low-imagery advertisements (M = 2,068.45, SD = 322.75) compared to high-imagery advertisements (M = 2,111.36, SD = 342.62). There was also a significant Imagery × Visual Task interaction on response latency for indicating the test item was old, F(1, 25) = 20.43, p < .000, epsilon squared = .42. As Figure 3 displays, response latency for indicating the test item was old got slower with the introduction of the visual task for high-imagery advertisements. However, response latency got faster with the introduction of the visual task for low-imagery radio advertisements. Analysis of the response latency data for indicating the target was a new item uncovered a significant main effect of the visual task on response

555


COMMUNICATION RESEARCH • October 2002 latency, F(1, 9) = 10.92, p < .009, epsilon squared = .37. Response latency was faster for test items from ads that did not include the visual task (M = 2,286.87, SD = 364.31) compared to items from ads that included the visual task (M = 2,369.23, SD = 335.82). The Imagery × Visual Task interaction was not significant for response latency to indicating the test item was a new item. Hypothesis 2 was supported. The percentage correct and response latency data showed evidence of dual-task interference between listening to highimagery radio advertisements and the visual task. No evidence of dual-task interference was found during exposure to low-imagery advertisements.

Discussion The results of this study provide a starting point for building a more detailed theory of communication-evoked mental imagery, based on an understanding of the human cognitive system. Current theories of communication-evoked imagery have served advertisers fairly well by describing the effects of highimagery messages but do not describe in detail the cognitive processes evoked by high-imagery messages. Forwarding a more detailed description of the cognitive processes involved during communication-evoked imagery is the primary theoretical contribution of this study. This study involved two steps in providing data for theory building. First, the ability of a particular type of message to engage people in imagery processing was assessed. Second, the involvement of a specific cognitive mechanism, namely visual cognition, was tested. The results of this study suggest high-imagery radio advertisements are a type of message that engages imagery processing and that visual cognitive resources are used to process these messages. Evidence that listeners engage in imagery processing during exposure to high-imagery radio advertisements was found in the heart rate data. As predicted, heart rate measured during exposure to the advertisements was faster during high-imagery radio advertisements compared to low-imagery advertisements. It is important to note cardiac acceleration was found only over the first 35 seconds of high-imagery advertisements. This could be due to how many radio advertisements are produced. Much of the material in the last portion of an ad is unlikely to engage imagery processing. The last portion of many ads is dedicated to communicating some final details about product characteristics rather than further development of a story line. Results found for the heart rate data have both theoretical and practical implications. Cardiac acceleration was observed in response to high-imagery advertisements despite the fact that the task in this experiment required participants to pay attention to a stimulus in the external environment (the

556


Bolls • Use of Visual Cognition advertisements). This is interesting because the allocation of attention to a stimulus in the external environment is generally associated with cardiac deceleration, whereas cardiac acceleration is associated with an internal focus of attention (A. Lang, 1994). A finding of cardiac acceleration in response to production features of radio advertisements that increase the message’s level of imagery points to a difference between communicationevoked imagery processing and cognitive processes engaged by other production features that have been studied, such as voice changes and production effects (laser effects, etc.). Production features such as voice changes have been found to reflexively increase attention paid to the message as indexed by cardiac deceleration (Potter, 1999). One possible explanation is production features that increase the imagery level of a radio advertisement could encourage an internal focus of attention, whereas other attention-grabbing production features encourage an external focus of attention to the message. Traditionally, media researchers have conceptualized attention in terms of cognitive resources that are grabbed by features of a media message. The heart rate data in this study indicate the cognitive processing of media messages can involve a significant amount of internal mental activity. The importance of such a finding is it supports expanding the traditional conceptualization of attention to media to include the notion that cognitive resources can be allocated to internal thought processes as well as externally to message content during media exposure. A. Lang’s (2000) limited capacity model acknowledges that information stored in long-term memory is retrieved to aide the encoding of media messages into memory; however, even this recent model primarily focuses on cognitive resources allocated externally to a message. An expanded conceptualization of attention to media could lead to several interesting lines of research. Whether attention is focused primarily externally to the message or internally to mental processes during exposure could affect responses to the message. In an advertising context, an increase in internal mental activity during message exposure could have implications for the level of persuasion resulting from an advertisement. Internal mental activity during advertisement exposure could strengthen the associations between the emotions evoked by the message and the advertised product. Furthermore, an increase in the allocation of limited cognitive resources to internal mental activity could affect the ability of an audience member to encode extremely specific pieces of information from a media message into memory. The degree of internal mental activity a person engages in during media exposure could also affect responses such as perceived realism. Future studies need to be conducted that examine how different types of internal mental activity during media exposure affect audience responses.

557


COMMUNICATION RESEARCH • October 2002 This study also offers evidence that imagery processing engaged by highimagery advertisements activates visual cognition. As predicted, introduction of the visual task decreased recognition for high-imagery radio advertisements but did not significantly affect recognition for low-imagery advertisements. This indicates the high-imagery advertisements and the visual task were competing for some of the same cognitive resources. Given that highimagery advertisements are marked by their ability to evoke mental images described by people in visual-like terms, and it was a visual task that interfered with recognition, it is logical to consider the resources the two tasks were competing for as visual cognitive resources. Previous research has described communication-evoked imagery processing as a “sensory” mode of information processing (MacInnis & Price, 1987); now, descriptions of communicationevoked imagery processing can be more precise by proposing the involvement of specific sensory cognitive processes. The results of this study suggest visual mental imagery engaged by radio advertisements is indeed visual all the way down to a biological level. It appears during exposure to a high-imagery ad, the brain sees the message by activating visual cognitive resources. This has implications for the “experience” of media exposure. Intuitively, it is easy to suggest a television message is a more sensory rich message than a radio message. This study provides data that could serve as the foundation for conducting further research that demonstrates the experience of listening to well-produced radio may be as sensory rich of an experience as viewing television. Other researchers have suggested imagery processing is a highly involved, personally relevant mode of message processing (MacInnis & Price, 1987) but have not proposed a specific cognitive mechanism underlying personally relevant processing. It is possible that the act of seeing a mental image leads to greater involvement, creating a sense of personal relevance. Future research should investigate how imagery processing increases message involvement and creates a sense of personal relevance. Engaging visual cognitive resources during exposure to a radio message may also make it easier to encode the message in memory. A. Lang, Potter, and Bolls (1999) demonstrated visual encoding is easier than audio encoding of media content. If high-imagery radio ads engage audience members in a form of visual encoding by engaging visual cognitive resources, there could be plenty of cognitive resources to accurately encode the message in memory and perform the other cognitive activities that typically accompany radio listening. As a laboratory experiment, this study is subject to several limitations. The primary limitation is that the conditions that participants completed the

558


Bolls • Use of Visual Cognition study in did not replicate a more naturalistic listening environment. The purpose of this study was to investigate a specific cognitive process; therefore, the control offered in a laboratory was more important to conducting a valid study than replicating a naturalistic listening environment. Furthermore, this study did replicate the cognitive conditions of real-world radio listening. Participants were put in a dual-task cognitive-processing environment. A second limitation is that the use of visual cognition during exposure to highimagery radio advertisements was indirectly measured through the use of a dual-task paradigm. A more direct way of measuring the use of visual cognition would be to conduct this study using FMRI or PET technology. FMRI and PET are designed to directly measure brain regions activated during performance of a cognitive task such as imagery processing. Presently, these technologies are not conducive to the presentation of auditory stimuli and are extremely difficult for communication researchers to gain access to. Until FMRI and PET become more accessible to communication researchers, the dual-task paradigm can provide data useful for drawing initial conclusions regarding cognitive processes engaged by media messages, given careful experimental and task design. In conclusion, this study expands on previous theoretical descriptions of communication-evoked imagery processing by providing evidence for the involvement of visual cognition in processing media messages that engage imagery processing. Furthermore, this study demonstrates messages that engage imagery processing encourage an internal focus of attention rather then calling attention externally to the message. Based on the results of this study, a more specific theory of communication-evoked imagery processing can be proposed and tested. One part of the theory should propose that during exposure to a high-imagery message, attention is divided between the tasks of encoding the message into short-term memory and the internal task of generating the communication-evoked mental images. The theory should go on to describe the internal cognitive processes involved in imagery processing. Specifically, it should be proposed that cognitive resources are allocated to activating visual-like memories from long-term memory and that cognitive processes similar to those used in visual perception are engaged to elicit and maintain communication-evoked mental images in short-term memory during encoding of a high-imagery message. Future research that tests this theory should not only attempt to replicate the results of this study but also test the involvement of other sensory modalities that might be activated during communication-evoked imagery processing.

559


COMMUNICATION RESEARCH • October 2002

References Atwood, A. (1989). Extending imagery research to sounds: Is a sound also worth a thousand words? Advances in Consumer Research, 16, 587-594. Babin, L. A., & Burns, A. C. (1998). A modified scale for the measurement of communication evoked mental imagery. Psychology and Marketing, 15(3), 261-278. Baddeley, A. (1966). Short-term memory for word sequences as a function of acoustic, semantic and formal similarity. Quarterly Journal of Experimental Psychology, 18, 362-365. Baddeley, A. D., & Andrade, J. (2000). Working memory and the vividness of imagery. Journal of Experimental Psychology: General, 129(1), 126-145. Bolls, P. D. (2002). The effect of dual-task cognitive processing on audience response to imagery in radio advertisements. Manuscript submitted for publication. Bolls, P. D., & Lang, A. (2000, May). I saw it on the radio: The allocation of attention to high imagery radio advertisements. Paper presented to the Information Systems Division of the International Communication Association, Acapulco, Mexico. Bolls, P. D., & Potter, R. F. (1998). I saw it on the radio: The effects of imagery evoking radio commercials on listeners’ allocation of attention and attitude toward the ad. In D. D. Muehling (Ed.), Proceedings of the 1998 conference of the American Academy of Advertising (pp. 123-130). Madison, WI: Omnipress. Bolls, P. D., Potter, R. F., & Lang, A. (1998, August). I saw it on the radio: Listeners’ physiological and cognitive responses to imagery eliciting radio commercials. Psychophysiology, 35(Suppl. 1), S21. Bone, P. F., & Ellen, P. S. (1990). The effect of imagery processing and imagery content on behavioral intentions. In M. E. Goldberg, G. Gorn, & R. W. Pollay (Eds.), Advances in consumer research (Vol. 17, pp. 449-454). Provo, UT: Association for Consumer Research. Bone, P. F., & Ellen, P. S. (1992). The generation and consequences of communication-evoked images. Journal of Consumer Research, 19, 93-104. Brownley, K. A., Hurwitz, B. E., & Schneiderman, N. (2000). Cardiovascular psychophysiology. In J. T. Cacioppo, L. G. Tassinary, & G. G. Berntson (Eds.), Handbook of psychophysiology (pp. 224-264). New York: Cambridge University Press. Burns, A. C., Biswas, B., & Babin, L. A. (1993). The operation of visual imagery as a mediator of advertising effects. Journal of Advertising, 22(2), 71-85. Cacioppo, J. T., Tassinary, L. G., & Berntson, G. G. (2000). Psychophysiological science. In J. T. Cacioppo, L. G. Tassinary, & G. G. Berntson (Eds.), Handbook of psychophysiology (pp. 3-23). New York: Cambridge University Press. Childers, T. L., & Houston, M. J. (1984). Conditions for a picture superiority effect on consumer memory. Journal of Consumer Research, 11, 643-654. Cook, E. (2001). VPM reference manual. Birmingham: University of Alabama at Birmingham, Department of Psychology.

560


Bolls • Use of Visual Cognition Craig, K. D. (1968). Physiological arousal as a function of imagined, vicarious, and direct stress experiences. Journal of Abnormal Psychology, 73(6), 513520. Denis, M. (1991). Image and cognition. New York: Harverster Wheatsheaf. Deschaumes-Molinaro, C., Dittmar, A., & Vernet-Maury, E. (1992). Autonomic nervous system response patterns correlate with mental imagery. Physiology and Behavior, 51, 1021-1027. D’esposito, M., Detre, J. A., Aguirre, G. K., Stallcup, M., Alsop, D. C., Tippet, L. J., et al. (1997). A functional MRI study of mental image generation. Neuropsychologia, 35(5), 725-730. Ellen, P. S., & Bone, P. F. (1991). Measuring communication-evoked imagery processing. In R. H. Holman & M. R. Solomon (Eds.), Advances in consumer research (Vol. 18, pp. 806-812). Provo, UT: Association for Consumer Research. Farah, M. J. (1989). The neural basis of mental imagery. Trends in Neurosciences, 12, 395-399. Farah, M. J. (1995). Current issues in the neuropsychology of image generation. Neuropsychologia, 33(11), 1455-1471. Farah, M. J., Hammond, K. L., Levine, D. N., & Calvanio, R. (1988). Visual and spatial mental imagery: Disociable systems of representation. Cognitive Psychology, 20, 439-562. Farah, M. J., Peronnet, F., Weisberg, L. L., & Monheit, M. A. (1989). Brain activity underlying mental imagery: Event-related potentials during image generation. Journal of Cognitive Neuroscience, 1, 302-316. Goldenberg, G., Podreka, I., & Steiner, M. (1990). The cerebral localization of visual imagery: Evidence from emission computerized tomography of cerebral blood flow. In P. J. Hampson & D. E. Marks (Eds.), Imagery: Current developments (pp. 103-128). New York: Routledge. Hirst, W., & Kalmar, D. (1987). Characterizing attentional resources. Journal of Experimental Psychology: General, 116, 68-81. Jones, G. E., & Johnson, H. J. (1980). Heart rate and somatic concomitants of mental imagery. Psychophysiology, 17(4), 339-347. Kosslyn, S. M. (1991). A cognitive neuroscience of visual cognition: Further developments. In R. H. Logie & M. Denis (Eds.), Advances in psychology: Mental images in human cognition (pp. 351-381). New York: North Holland. Kosslyn, S. M. (1994). Image and brain. Cambridge, MA: MIT Press. Kosslyn, S. M., Alpert, N. M., Thompson, W. L., Maljkovic, V., Weise, S. B., Chabris, C. F., et al. (1993). Visual mental imagery activates topographically organized visual cortex: PET investigations. Journal of Cognitive Neuroscience, 5(3), 263-287. Kosslyn, S. M., Flynn, R. A., Amsterdam, J. B., & Wang, G. (1991). Components of high-level vision: A cognitive neuroscience analysis and accounts of neurological syndromes. Cognition, 34, 203-277. Lang, A. (1994). What can the heart tell us about thinking? In A. Lang (Ed.), Measuring psychological responses to media (pp. 99-112). Hillsdale, NJ: Lawrence Erlbaum.

561


COMMUNICATION RESEARCH • October 2002 Lang, A. (2000). The limited capacity model of mediated message processing. Journal of Communication, 50(1), 46-70. Lang, A., Potter, R. F., & Bolls, P. D. (1999). Something for nothing: Is visual encoding automatic? Media Psychology, 1(2), 145-163. Lang, P. J., Greenwald, M. K., Bradley, M., & Hamm, A. (1993). Looking at pictures: Evaluative, facial, visceral and behavioral responses. Psychophysiology, 30, 261-274. Lang, P. J., Kozak, M. J., Miller, G. A., Levin, D. N., & McLean, A. (1980). Emotional imagery: Conceptual structure and pattern of somato-visceral response. Psychophysiology, 17, 179-192. Lang, P. J., Ohman, A., & Vaitl, D. (1988). The International Affective Picture System [Slides]. Gainesville: University of Florida, Center for Research in Psychophysiology. Le Bihan, D., Turner, R., Zeffiro, T. A., Cue’nod, C. A., Jezzard, P., & Bonnerot, V. (1993). Activation of human primary visual cortex during visual recall: A magnetic resonance imaging study. Proceedings of the National Academy of Science, 90, 11802-11805. Ley, R. G. (1983). Cerebral laterality and imagery. In A. A. Sheikh (Ed.), Imagery: Current theory, research and application (pp. 252-287). New York: John Wiley. Logie, R. H. (1986). Visuo-spatial processing in working memory. Quarterly Journal of Experimental Psychology, 38A, 229-247. Loverock, D. S., & Modigliani, V. (1995). Visual imagery and the brain: A review. Journal of Mental Imagery, 19(1/2), 91-132. Lowe, D. G. (1987). Three-dimensional object recognition from single twodimensional images. Artificial Intelligence, 31, 355-395. Lutz, K. A., & Lutz, R. J. (1977, August). The effects of interactive imagery and learning: Application to advertising. Journal of Applied Psychology, 62, 493-498. MacInnis, D. J., & Price, L. L. (1987). The role of imagery information processing: Review and extensions. Journal of Consumer Research, 13, 473-491. Mellet, E., Tzourio, M., Denis, M., & Mazoyer, B. (1995). A positron emission tomography study of visual and mental spatial exploration. Journal of Cognitive Neuroscience, 7, 433-445. Miller, D. W., & Marks, L. J. (1997). The effects of imagery evoking radio advertising strategies on affective responses. Psychology and Marketing, 14(4), 337-360. Navon, D., & Miller, J. (1987). Role of outcome conflict in dual-task interference. Journal of Experimental Psychology: Human Perception & Performance, 13, 435-448. Papillo, J. F., & Shapiro, D. (1990). The cardiovascular system. In J. T. Cacioppo & L. G. Tassinary (Eds.), Principles of psychophysiology: Physical, social, and inferential elements (pp. 456-477). New York: Cambridge University Press. Pashler, H. (1998). The psychology of attention. Cambridge, MA: MIT Press. Potter, R. F. (1999, May). The effects of voice changes on orienting and immediate cognitive overload in radio listeners. Paper presented to the Information

562


Bolls • Use of Visual Cognition Systems Division of the International Communication Association, San Francisco. Quinn, J. G., & McConnell, J. (1996). Irrelevant pictures in visual working memory. Quarterly Journal of Experimental Psychology, 49A(1), 200-215. Stern, R. M., Ray, W. J., & Quigley, K. S. (2000). Psychophysiological recording. New York: Oxford University Press. Thompson, R. F. (1993). The brain: A neuroscience primer. New York: Freeman. Unnava, R. H., & Burnkrant, R. E. (1991). An imagery processing view of the role of pictures in print advertisements. Journal of Marketing Research, 28, 226-231.

563
