Individual differences in imagery vividness and voluntary heart rate control

Dispositional differences in imagery vividness may account partially for the large individual differences in learning heart rate control. Based upon scores on the Betts QMI Vividness of Imagery Scale, 10 subjects were defined as a high imagery group and 10 subjects were defined as a low imagery group. All subjects were instructed to try to alter their heart rate as indicated by appropriately labeled lights. Six increasing, six decreasing and six rest, 45-sec trials were presented. During the trials, visual heart rate feedback was provided by a digital voltmeter. The dependent measure was computed by subtracting the mean of the last 5 beats of a 15-sec intertrial interval from the mean rate per trial. Results indicated that subjects were able to significantly raise and lower heart rate relative to rest trials. Furthermore, high imagery subjects demonstrated significantly larger changes than low imagery subjects on increase trials but not on decrease trials. Subjects in both groups typically reported using more specific images for increasing heart rate than for decreasing heart rate. These data suggest that dispositional differences in imagery vividness may have contributed to the differential performance of the two groups during the increase task.     

Self-report and physiological changes accompanying repeated imagining of a phobic scene.

Twenty female subjects were selected from a larger subject pool on the basis of their scores to the ‘snakes’ item on the Geer (1965) Fear Survey Schedule. Ten of the subjects were selected as phobic; the other ten were non-phobic controls. Heart rate, skin conductance and self-reports of fear and imagery vividness were continuously monitored while subjects repeatedly imagined a prescribed snake scene for a total of 15 trials. The phobic group reported more overall fear to the images. Further, while the nonphobic subjects reported progressively less fear over trials, the phobic subjects reported progressively more fear. The groups did not differ in rated imagery vividness. However, heart rate responses to the image differentiated the two groups. The non-phobic subjects showed a progression from cardiac acceleration in the early trials to a biphasic response pattern, deceleration preceding acceleration, in the later trials. In contrast, the phobic subjects demonstrated sustained acceleration in the later trials. The groups did not differ in skin conductance response amplitude.     

Evaluating the mind's eye: the metacognition of visual imagery

Can people evaluate phenomenal qualities of internally generated experiences, such as whether a mental image is vivid or detailed? This question exemplifies a problem of metacognition: How well do people know their own thoughts? In the study reported here, participants were instructed to imagine a specific visual pattern and rate its vividness, after which they were presented with an ambiguous rivalry display that consisted of the previously imagined pattern plus an orthogonal pattern. On individual trials, higher ratings of vividness predicted a greater likelihood that the imagined pattern would appear dominant when the participant was subsequently presented with the binocular rivalry display. Off-line self-report questionnaires measuring imagery vividness also predicted individual differences in the strength of imagery bias over the entire study. Perceptual bias due to mental imagery could not be attributed to demand characteristics, as no bias was observed on catch-trial presentations of mock rivalry displays. Our findings provide novel evidence that people have a good metacognitive understanding of their own mental imagery and can reliably evaluate the vividness of single episodes of imagination.     

Multisensory cortical processing of object shape and its relation to mental imagery

Here, we used functional magnetic resonance imaging to investigate the multisensory processing of object shape in the human cerebral cortex and explored the role of mental imagery in such processing. Regions active bilaterally during both visual and haptic shape perception, relative to texture perception in the respective modality, included parts of the superior parietal gyrus, the anterior intraparietal sulcus, and the lateral occipital complex. Of these bimodal regions, the lateral occipital complexes preferred visual over haptic stimuli, whereas the parietal areas preferred haptic over visual stimuli. Whereas most subjects reported little haptic imagery during visual shape perception, experiences of visual imagery during haptic shape perception were common. Across subjects, ratings of the vividness of visual imagery strongly predicted the amount of haptic shape-selective activity in the right, but not in the left, lateral occipital complex. Thus, visual imagery appears to contribute to activation of some, but not all, visual cortical areas during haptic perception.     

Effects of Applying the PETTLEP Model on Vividness and Ease of Imaging Movement

This study investigated the effects of applying elements of the PETTLEP model on vividness and ease of imaging movement. Forty participants (M age = 23.47 years, SD = 4.11) completed the Vividness of Movement Imagery Questionnaire when using PETTLEP imagery or traditional imagery. Results revealed significantly higher ease and vividness ratings for internal visual imagery (IVI) and kinesthetic imagery (KI) during the PETTLEP imagery condition compared to the more traditional imagery. No significant difference between conditions for external visual imagery emerged. Findings imply that incorporating PETTLEP elements during imagery enables greater ease and vividness of movement when using IVI and KI.     

Mental image generation and the contrast sensitivity function

In one experiment, observers were instructed to generate small and large visual mental images in a light-adapted or a dark-adapted viewing condition, and to rate the vividness of each image. In light-adapted viewing, small images were generated faster than large images. However, the pattern of results was reversed in dark-adapted viewing. Furthermore, the dark-adapted images were more vivid than the light-adapted images. The results show that mental images can be mapped onto some regions of the contrast sensitivity function (CSF), so that the latency (and vividness) of a particular image can be predicted. Since the CSF reflects visual processes occurring mainly in V1, the results agree with functional magnetic resonance imaging data in indicating that early visual pathways participate in imagery. Nonetheless, imagery and perception may involve different processes hosted by the same neural structures as indicated by the direct relationship between image latency and contrast sensitivity.     

Reading and visual memory: remembering scenes that were never seen.

In Experiment 1 (N = 16), under conditions of high memory load (60 pictures and 50 paragraphs) and a 1-week retention interval, undergraduate subjects reported their memory for photographs of scenes (cued recall and free-recall tasks). Subjects frequently reported memory for photographs that they had actually never seen, but had read about in a brief paragraph. In Experiment 2 (N = 40), the same pattern of results was obtained with immediate testing. Experiment 2 also demonstrated that the likelihood of subjects falsely attributing scene memory (based on reading) to actually having viewed a photograph was reduced when metacognitive awareness of imaging during reading was made salient. Awareness of image creation was induced by requiring subjects to rate the paragraphs with respect to imagery vividness. Although other measures of memory remained the same, subjects in the induced-imagery condition made 50% fewer confusion errors than subjects who read the paragraphs without imagery instructions. The results are discussed in the context of Johnson and Raye's (1981) reality monitoring model.     

Visual imagery and dream recall

Research in dream recall frequency has failed to isolate psychological variables which clearly and reliably differentiate frequent dream recallers from infrequent recallers. The present study tested the hypothesis that frequent recallers have a greater capacity for visual imagery than infrequent recallers. Subjects selected on the basis of reported dream recall frequency were administered a Paired-Associate Learning task designed to measure visual imagery, a rating scale of imagery clarity and vividness, and a subjective measure of imagery controllability. The results provide support for the hypothesis and, together with other evidence, suggest that a generalized capacity for visualization may contribute to the quality of the dreaming experience and, consequently, to its recallability.     

The functional equivalence of mental images and errors of movement.

Four experiments are reported demonstrating that mental images are functionally equivalent to physical errors of movement in producing changes in visual-motor coordination, at both central and peripheral levels of the visual-motor system. In the first experiment, subjects in one condition pointed at a target seen through laterally displacing prisms and were instructed to imagine pointing errors identical to those recorded previously for subjects in a separate condition who actually observed their pointing errors. Changes in pointing accuracy during adaptation procedures and visual-motor aftereffects following these procedures for subjects who imagined their errors were proportional to visual-motor shifts and aftereffects for subjects who observed their errors. In the second experiment, these same imagery instructions resulted in identical pointing shifts and aftereffects even in the case where prisms did not displace the target. The third experiment showed that when subjects believe that their mental images of pointing errors do not correspond to their actual pointing errors, pointing aftereffects result that are characteristic of the processing of error information at peripheral, but not central, levels of the visual motor system. The final experiment showed that when subjects do believe that their images of pointing errors correspond to actual pointing errors, but imagine the pointing movement itself in addition to their errors, pointing aftereffects result that are characteristic of the processing of error information at central, but not peripheral, levels of the visual-motor system. Contributions to visual-motor aftereffects from these two levels appear to be additive. Another significant result was that, in the imagery feedback conditions of each experiment, subjects who gave high ratings of vividness to their mental imagery showed the greatest magnitude of pointing aftereffects. These findings establish that mental images for errors of movement can produce stable visual-motor changes that cannot be accounted for simply by subjects' expectations regarding the actual consequences of their actions.     

The Role of Vividness of Visual Mental Imagery on Different Dimensions of Creativity

Although research demonstrated that people can mentally manipulate and synthesize visual elements into a creative object, the role that vividness of visual imagery plays on creative imagery is still unclear. This study explored the relationships between vividness of visual imagery and 3 dimensions of creative imagery: originality, practicality, and mental spatial transformations of visual elements. Fifty-three participants performed the creative mental synthesis task and completed the Vividness of Visual Imagery Questionnaire (VVIQ). Results revealed a positive relationship between vividness and the practicality dimension of objects. No relationship was found either between vividness and originality or between vividness and transformational complexity. The association vividness–practicality seems to reflect the ability to use pictorial information of imagery when people generate functional objects that belong to specific categories. Future research directions are discussed.     

The brain mechanism that reduces the vividness of negative imagery

The present study attempts to locate brain regions that are related to vividness control, a hypothesized mechanism that reduces the vividness of negative imagery by controlling memory retrieval and emotion processing. The results showed that BOLD response in the left posterior cingulate gyrus in the negative imagery condition, in which activation of vividness control mechanisms was considered to be strong, was greater than that in the positive imagery condition, in which the activation of control mechanisms was considered to be weak. Moreover, the activation of this region negatively correlated with the subjective vividness of negative imagery. These results support the idea that the posterior cingulate gyrus may be involved in the suppression of imagery generation. Several previous studies have suggested that the posterior cingulate cortex is involved in both memory and emotion processing. Therefore, the current results indicate that the posterior cingulate gyrus may function as the vividness control mechanism.     

An fMRI investigation on image generation in different sensory modalities: The influence of vividness

In the present fMRI study the issue of the specific cortices activation during imagery generation in different sensory modalities is addressed. In particular, we tested whether the vividness variability of imagery was reflected in the BOLD signal within specific sensory cortices. Subjects were asked to generate a mental image for each auditory presented sentence. Each imagery modality was contrasted with an abstract sentence condition. In addition, subjects were asked to fill the Italian version of the Questionnaire Upon Mental Imagery (QMI) prior to each neuroimaging session. In general, greater involvement of sensory specific cortices in high-vivid versus low-vivid subjects was found for visual (occipital), gustatory (anterior insula), kinaesthetic (pre-motor), and tactile and for somatic (post-central parietal) imagery modalities. These results support the hypothesis that vividness is related to image format: high-vivid subjects would create more analogical representations relying on the same specific neural substrates active during perception with respect to low-vivid subjects. Results are also discussed according to the simulation perspective.     

Category-specific naming and modality-specific imagery

Some attempts to explain category-specific disorders have stressed how different modality knowledge bases (i.e., visual knowledge vs motoric/functional knowledge) may underlie the distinction between living and nonliving things. This study examined 60 normal subjects for the relationship between picture naming in four subcategories (animals, fruit/vegetables, praxic and nonpraxic objects) and imagery vividness in seven modalities. Participants made more nonliving than living errors; and females made more nonliving errors than males. There was a significant correlation between naming of animals and fruits/vegetables and visual imagery vividness; however, this association was also significant for praxic and nonpraxic object naming. There was no evidence of associations between kinesthetic imagery and praxic object naming or gustatory/olfactory imagery and fruit/vegetable naming. These findings accord with the notion of a general association between visual imagery and picture naming, but provide no support for more specific links between modality-specific imagery vividness and naming in different categories.     

Problems in assessment of vividness and control of imagery.

Difficulties in assessing individual differences in vividness and control of mental imagery hinder understanding of the role of of imagery in various phenomena. This study examined the relationships among the Gordon test of imagery control, the Betts questionnaire on imagery vividness, and a research questionnaire on control of imagery developed for this study. The research questionnaire demonstrated satisfactory internal consistency and scores were more widely distributed than were those on the Gordon test. Correlations among the instruments ranged from .47 to .57, suggesting that vividness and control of imagery are not clearly differentiated in practice. Discussion of these results suggests that further empirical work is needed to establish the differential validity of the two constructs.     

Hallucinatory predisposition and vividness of auditory imagery: self-report and behavioral indices.

This study examined the relation between a subjective and a behavioral measure of the vividness of auditory imagery as well as the disposition towards hallucination in normal subjects. In addition to the Launay-Slade Hallucination Scale, subjects (57 university students) completed the Betts questionnaire in which they rated the vividness of their experienced mental images and performed a behavioral task aimed at measuring auditory imagery. The task consisted of a perception and an imagery condition in which subjects had to indicate the odd one of three everyday sounds. Performance on the behavioral task did not correlate with the auditory or scores on the Visual subscale of the Betts. In addition, neither scores on the behavioral measure nor the Auditory subscale of the Betts correlated significantly with hallucinatory predisposition as rated on the Launay-Slade Hallucination Scale. In contrast, the Visual subscale of the Betts did correlate with scores on the Launay-Slade Hallucination Scale, consistent with previous research. We conclude that there is no straightforward relationship between imagery vividness and hallucinatory experiences and that subjective and objective indices of imagery vividness measure different aspects of mental function.     

误导信息干扰引发的错误记忆研究

本研究借鉴GSS的测验程序,以学习材料视觉呈现、团体实验的形式,在人工条件下模拟了目击者记忆过程．通过操纵材料呈现时间（20秒、40秒）与测验次数（初测、重测）两个变量,考察了该情境下错误记忆的内在机制及其动态变化特点。并进一步研究该情境下受暗示性与社会期望、自尊、心理控制源以及视觉想象生动性的关系。实验发现,40秒比20秒条件下,真实记忆效果更好,错误记忆效果更少;重测比初测时错误记忆更多。可见,真实记忆量的差异是影响错误记忆的主要因素：错误记忆较为顽固,产生后呈增加趋势。相关分析还发现,受暗示性的各种指标（yiddl、yidd2、yidd3和shift）与社会期望、自尊、心理控制源、视觉想象生动性等因素均无显著相关．与桔试的自由回忆成绩成显著负相关。     

Heart rate variability and respiratory concomitants of visual and nonvisual “imagery” and cognitive style

Attention to visual and nonvisual imagery, elicited by an imagery questionnaire, was studied using both within and between subjects analyses of cardiac and respiratory parameters. Visual imagery was accompanied by more regular interbeat heart rate (HR) and shorter, more stable respiratory cycles than nonvisual imagery. “Visually-oriented” thinkers (visualizers), identified by a word association test, manifested less overall variability in HR than “verbally-oriented” thinkers (verbalizers), as well as less variable HR and respiratory period during visual imagery. Visual and nonvisual imagery differed in HR variability for verbalizers and in respiration period for visualizers. The results are discussed in terms of the concepts of attention deployment, “mental load”, cerebral asymmetry, and stylistic personality differences in cognitive functioning.     

The stability of visual perspective and vividness during mental time travel

When remembering or imagining, people can experience an event from their own eyes, or as an outside observer, with differing levels of vividness. The perspective from, and vividness with, which a person remembers or imagines has been related to numerous individual difference characteristics. These findings require that phenomenology during mental time travel be trait-like—that people consistently experience similar perspectives and levels of vividness. This assumption remains untested. Across two studies (combined N = 295), we examined the stability of visual perspective and vividness across multiple trials and timepoints. Perspective and vividness showed weak within-session stability when reported across just a few trials but showed strong within-session stability when sufficient trials were collected. Importantly, both visual perspective and vividness demonstrated good-to-excellent across-session stability across different delay intervals (two days to six weeks). Overall, our results suggest that people dependably experience similar visual phenomenology across occurrences of mental time travel.     

Evaluation of a Mental Skills Training Program for Musicians

This study explored the effects of a 9-week music-specific mental skills training program delivered to students at a music conservatoire in England (n = 14). Pre- and post-testing involved a battery of questionnaires, public performances, and participant feedback. In comparison with a control group (n = 9), the experimental group demonstrated significant changes in their views toward practice activities and specific practicing behaviors, a significant increase in self-efficacy for performing, and an increase in imagery vividness. Comments from participants in the experimental group revealed greater levels of self-awareness, confidence, facilitative views toward and heightened control over anxiety, and healthier perspectives toward music-making.