Reported mediators and individual differences in mental imagery

This study concerns the use of postlearning questionnaires to discover the strategies employed by subjects in memory tasks. Experiment 1 showed that the proportion of items for which subjects reported the use of imaginal mediators was an excellent predictor of their overall performance. Experiment 2 showed that this was true for concrete material, but not for abstract material. It is suggested that mediator reports provide an effective way of investigating individual differences in the use of mental imagery.     

视觉表象眼动的变化：知识还是技能表征的差异？

以表象看到一个运动员完成三级跳远项目为实验任务,对表象任务的信息通达水平、眼动注视点的活动位置和被试对三级跳远项目的知识水平和技能水平进行系统的操纵,通过2个实验探讨了视觉表象眼动的变化是基于知识学习表征差异还是技能训练表征差异的问题。实验1以没有三级跳远运动专业技能知识且对该运动的认知水平也较低的大学生为被试,结果表明,在完成高信息通达水平的表象任务时,注视点需要较短的持续时间,但眼跳距离会增大,眼跳频率会变低;实验2对表象任务的知识学习表征水平和技能训练表征水平进行操纵,分别以对实验任务进行过知识学习和专业技能训练的人为被试,结果表明,随着被试知识习得水平和技能水平表征能力的提高,不同表象任务信息通达水平间的眼动差异将消失,但知识学习和技能表征的差异在平均眼跳时间上有差异,技能训练型的被试其平均眼跳时间要短于知识学习型被试,达到临界水平显著,注视点平均持续时间和平均眼跳距离等均没有差异。     

Verbal imagery and connotation as memory-induced mediators of aggressive behavior.

Three studies investigated the effects of an information-processing variable (imagery-concreteness) on susceptibility to aggressive stimulation. Study 1 (n=83) results indicated that subjects' rating of imagery level and aggressive connotation for words can be manipulated independently. In study 2 (n=64), manipulations of verbal connotation and verbal imagery indicated that imagery level but not aggressive connotation significantly influenced the delayed recall of the verbal material. In Study 3 (n=60), males in a 2 X 2 between-subjects factorial design first learned lists of words varying in imagery (high or low) and verbal connotation (aggressive or neutral). Next, subjects were given the opportunity to shock their partners as part of a sham learning task. To induce arousal, all subjects learning high-imagery-aggressive word lists delivered significantly more intense shock to their partners. The results were interpreted as supporting an information-processing (memory) analysis of the effects of exposure to aggressive material.     

Effects of imagery training on cognitive performance and use of physiological measures as an assessment tool of mental effort

The effectiveness of motor imagery training on cognitive performance was examined and the physiological mechanisms involved in the contribution of mental practice to motor learning were considered. The subject's mental effort during motor imagery was assessed by using psychophysiological measures and particularly eye blink activity as an 'indirect' measurement of subjects' attention. An electronic flight simulation program (Multiple Attribute Task Battery--MATB) was used to assess performance. Twenty healthy volunteers participated in the study divided in two groups: the control group and the imagery-training group. The subjects of the imagery group were asked for additional imagery training. The subjects of the actual performing group were asked additionally to passively observe the task in order to have equal time of exposure to the task. Performance scores and physiological parameters such as heart rate, respiratory rate, eye blinking activity and muscular activity were recorded during all sessions. The results revealed significantly higher performance level of the imagery-training group than the control group. Heart rate and respiratory rate significantly increased during imagery sessions compared to rest. A slight electromyographic activity was observed during the imagination of movement. Our findings support the notion that mental practice improves motor performance in a task where spatiotemporal or dynamic control of the action is highly required. The effects of mental practice on motor performance could be explained by the existence of a top-down mechanism based on the activation of a central representation of the movements, since the vegetative activation during motor imagery seems to be centrally controlled.     

Short-term memory,verbal competence,and age as predictors of imagery instructional effectiveness

Children 6 to 11 years of age heard concrete sentences that they were asked to learn. Half the subjects were instructed to construct images representing the sentence meanings. The remaining participants were provided no strategy instructions (control condition). Consistent with previous outcomes, the older children in the imagery condition learned signficantly more than did the older control subjects. There was a slight trend favoring imagery for younger children in the sample. Individual differences in short-term memory and verbal competence were more highly associated with performance in the imagery than in the control condition, such that greater short-term memory and verbal competence predicted better sentence learning in the imagery condition. In particular, short-term memory and verbal competence made unique contributions (relative to age and to each other) to prediction of sentence learning in the imagery condition, but not in the control condition. In short, imagery instruction is more effective with children who are more intellectually competent.     

Semantic and imaginal factors in learning as related to age

Sixty subjects apiece from third and sixth grade populations were given a twelve-item paired-associate list to learn under either regular or imagery instructions. The paired associates were presented in sentences or phrases which represented varying degrees of semantic correspondence between study and test trials. It was found that the semantic manipulations influenced learning similarly in the two grades, while imagery instructions produced different effects at each grade level.     

Imaginal correlates of self-reported fear and avoidance behavior

Two analogue studies explored the relationship between the content of subjects' imagery and both behavioral avoidance and self-reports of fear. In the first study, reports of aversive imagery in a fearful situation were much more frequent among high- as compared to low-avoidance subjects. Reports of aversive imagery were found significantly associated with both fear and avoidance behavior. In the second study, findings were extended, indicating that imagery content is associated with fear and avoidance when subjects imagine themselves in a fearful situation as well as when they are actually in one. This suggested some degree of functional equivalence between imagined and real situations. However, no relationship was found between image clarity and either fear or avoidance. Since imagery appears to play an important role in mediating fearful behavior, manipulation of imagery might serve as an effective treatment strategy.     

Learning and hypothesis testing in probabilistic inference tasks

The relation between learning of probabilistic inference tasks and the availability of correct hypotheses for the tasks in individual subjects was investigated in two experiments. The results showed that having the correct hypotheses as measured before learning the tasks was neither a sufficient nor a necessary condition for learning the task. It was concluded that the hypothesis measurements are not reliable enough to allow predictions on an individual level. The results also showed that subjects have not only the four basic functions: positive linear, negative linear, U-shaped and inversely U-shaped, in their hypothesis hierarchies but also J-shaped functions. That the subjects can leam such functions is thus no discodinnation of the hypotheses sampling conception of learning as assumed in earlier studies.     

A Note on State Individual Differences in Accuracy of Response Imagery: Aftereffects and Reminiscence

In two sessions, separated by 7 days, subjects imagined themselves performing a tracking task under a massed practice schedule. After conditions of interpolated rest and no-rest, which were counterbalanced across sessions, subjects actually performed the tracking task. During imagery practice, subjects verbally reported the temporal component of the task. The temporal accuracy of verbal reports varied widely across subjects, but not within subjects. Furthermore, a performance gain was demonstrated as a function of interpolated rest versus no-rest (reminiscence effect). Finally, the accuracy of verbal reports predicted imagery aftereffects, but not reminiscence effects.     

Music to the inner ears: Exploring individual differences in musical imagery

In two studies, we explored the frequency and phenomenology of musical imagery. Study 1 used retrospective reports of musical imagery to assess the contribution of individual differences to imagery characteristics. Study 2 used an experience sampling design to assess the phenomenology of musical imagery over the course of one week in a sample of musicians and non-musicians. Both studies found episodes of musical imagery to be common and positive: people rarely wanted such experiences to end and often heard music that was personally meaningful. Several variables predicted musical imagery, including personality, musical preferences, and positive mood. Musicians tended to hear musical imagery more often, but they reported less frequent episodes of deliberately-generated imagery. Taken together, the present research provides new insights into individual differences in musical imagery, and it supports the emerging view that such experiences are common, positive, and more voluntary than previously recognized.     

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.     

Short-term memory differences between children predict imagery effects when sentences are read

Children in Grades 4 through 6 read concrete sentences that they were asked to learn. Half the subjects were instructed to construct images representing the sentence meanings. The remaining participants were provided no strategy instructions (control condition). Individual differences in short-term memory were more highly associated with performance in the imagery than in the control condition. There was a clear positive effect of imagery instructions on learning efficiency among students with relatively greater short-term memory; there was no difference in learning efficiency between the imagery and control conditions among students below the median for short-term memory performance. All relevant analyses supported the conclusion that imaginal coding of sentences that are read is demanding of short-term memory capacity.     

Context availability and the recall of abstract and concrete words

Predictions of an automatic-imagery, strategic-imagery, and context-availability hypothesis of concreteness effects in free recall were examined. In each experiment, recall of abstract and concrete words controlled for rated context availability was compared with the typical situation in which context availability is confounded with imageability. In Experiment 1, a directed intentional-recall task produced concreteness effects in recall. Experiment 2 compared concreteness effects in recall following three orienting tasks: imagery rating, context-availability rating, and a directed intentional-memory task. Concreteness effects in the context-availability-controlled condition were found following the imagery-rating and the directed intentional-memory tasks, but not after the context-availability-rating task. In Experiment 3, subjects reported the strategies that they used to encode the list. Subjects reporting an imagery strategy showed concreteness effects for words controlled for rated context availability, but those not reporting it did not. These results support a strategic-imagery view of concreteness effects in free recall.     

Can People Creative in Imagery Interpret Ambiguous Figures Faster than People Less Creative in Imagery?

The purpose of the research study was to investigate whether people creative in imagery are better than people non‐creative in imagery at interpreting ambiguous figures. Creativity, in the imagery paradigm, is said to involve two processes: combinational play and discovery. Discovery plays a major role in creativity as it is the process of discerning, judging or interpreting the value of a mental construction. Furthermore, creative people have been said to be insightful thus supporting the proposition advanced here that people creative in imagery are faster at interpreting and finding alternative interpretations for ambiguous figures than people less creative in imagery. This study reports both latencies and discoveries in perception and mental imagery as measured on a figure combination task. The data support the conclusion that people creative in imagery are more capable in reinterpreting ambiguous figures and that they are quicker in their discoveries than people less creative in imagery. The analysis to the questions of how the subjects arrived at their discoveries may also illustrate the Gestalt literature on insight as a rapid pattern recognition.     

Aging, encoding fluency, and metacognitive monitoring

Encoding fluency (how rapidly one generates a mediator for a new association) may be a cue used to judge one's own learning. To evaluate age differences in utilization of this cue, older and younger adults were instructed to use interactive imagery to study paired associates, pressing a button to indicate when an image had been formed for a given pair. A judgment of learning (JOL) was also made immediately after each pair had been studied. Hence, at least two cues pertaining to encoding fluency-whether an image had been formed (a diagnostic cue) and the latency of formation (a nondiagnostic one)-were available when making JOLs. Age equivalence was found in JOL accuracy, and JOLs for both age groups were positively related to imagery formation and were negatively related to the latency of image formation. Moreover, subjectively judged latency correlated higher with JOLs than actual (objective) latency, supporting the hypothesis that perceived fluency is a cue used in constructing JOLs.     

Affective individual differences and startle reflex modulation

Potentiation of startle has been demonstrated in experimentally produced aversive emotional states, and clinical reports suggest that potentiated startle may be associated with fear or anxiety. To test the generalizability of startle potentiation across a variety of emotional states as well as its sensitivity to individual differences in fearfulness, the acoustic startle response of 17 high- and 15 low-fear adult subjects was assessed during fear, anger, joy, sadness, pleasant relaxation, and neutral imagery. Startle responses were larger in all aversive affective states than during pleasant imagery. This effect was enhanced among high fear subjects, although followup testing indicated that other affective individual differences (depression and anger) may also be related to increased potentiation of startle in negative affect. Startle latency was reduced during high- rather than low-arousal imagery but was unaffected by emotional valence.     

Fear imagery and the startle-probe reflex

Blink reflexes to acoustic probes, heart rate, and subjective reports were studied during affective memory imagery. Thirty-six undergraduates memorized 6 pairs of neutral and fearful sentences. After learning each pair, they relaxed and listened to a series of uniform tones, one every 6 s. A change in tone pitch (higher or lower) cued recall of one of the two sentences. At the first cue tone, groups (n = 12) were under different instructions: (a) ignore the sentence and relax, (b) silently articulate the sentence, and (c) imagine the sentence content as a personal experience. At the second cue tone, all subjects performed the imagery task. Startle probes (50-ms, 95-dB white noise) were presented unpredictably during relaxation and recall trials. Probe blink reflexes were larger and cardiac rate faster at fear sentence recall than at neutral sentence recall or relaxation. For probe reflexes, this effect was greater for imagery than for nonsemantic recall tasks.     

The effects of mental imagery on skin temperature and skin temperature sensation

In a series of six experimental sessions five subjects were instructed to imagine their hand in a hot and cold water stream. During the imagery period the subjects estimated with a psychophysical scale their subjective temperature sensations caused by the imagery. Skin temperature was measured from the thumb of the subjects' dominant hand. After each session the subjects were asked whether they had succeeded in producing an imagery. The skin temperature changes deviated significantly from the control level in the successful imagery experiments. Differences in the skin temperature changes between the successful and unsuccessful imagery experiments were significant. The skin temperature changes measured and the subjects' temperature sensations, produced by the imagery, were similar in the successful imagery experiments. The possible relationships between mental imagery and changes in skin temperature and skin temperature sensation are discussed.     

The process of learning from small-scale maps

Two experiments are reported that test the general hypothesis that learning from a small scale map proceeds in a global to local fashion, structured by the spatial subdivisions present in the map. In Experiment 1, a fairly simple map depicting a single fictitious country containing provinces and cities was used as the to-be-learned stimulus. Evidence for a provincial to capital to city learning process was found, with map recall best when subjects used an imagery learning strategy. In Experiment 2, a more complex map containing multiple countries, with provincial and city elements present was used. The global to local learning process was replicated, as well as the beneficial effects of an imagery study strategy. Results are discussed in terms of progressive image differentiation and total information set size.