Retrieval-induced forgetting and mental imagery

In the present article, we present four experiments in which we examined whether mental imagery can initiate retrieval-induced forgetting. Participants were presented with word pairs (Experiments 1, 2, and 3) or narratives (Experiment 4) and then engaged in selective mental imagery about half of the details from half of the categories. The results indicated that mental imagery can produce the same pattern of impairment as retrieval practice (Experiment 1) and postevent questioning (Experiment 4). Additionally, mental imagery-invoked, retrievalinduced forgetting was found for category cued recall (Experiments 1, 3, and 4) and cued recall (Experiment 2); it was found to dissipate across a 24-h delay, but only when there was no pre-delay test (Experiment 3). Such retrieval-induced forgetting was also found for imagining from the first-person and third-person perspectives (Experiment 4). From these findings, we suggest that the underlying retrieval processes behind mental imagery can initiate retrieval-induced forgetting. The findings are discussed in terms of inhibitory processes.     

Neuroimaging of mental imagery: An introduction

Adaptive mechanisms to protect cognitive performance under stressors through compensation in energy investment have previously received much research attention. However, stressors have also often been found to substantially reduce both performance and investment. The mechanisms underlying this dual negative effect are still unclear. This study tested the hypothesis that stressors can immediately hamper performance, which in turn reduces energy investment in later phases. In an experiment (N=103), we compared control and stressor conditions (noise or time pressure), investigating the effects of stressors on performance and information-sampling investment (as behavioural measure of energy investment) in two phases of a judgement task. The results showed an instant negative effect of stressors on performance and a delayed negative effect on information-sampling investment. Furthermore, impaired initial performance predicted the decline in investment over time. Finally, the effects of stressors on investment decline were partially mediated through initial performance level. The present findings contribute to theories aiming to explain the relationship between hampered performance and motivational losses.     

Perception and imagination: amodal perception as mental imagery

When we see an object, we also represent those parts of it that are not visible. The question is how we represent them: this is the problem of amodal perception. I will consider three possible accounts: (a) we see them, (b) we have non-perceptual beliefs about them and (c) we have immediate perceptual access to them, and point out that all of these views face both empirical and conceptual objections. I suggest and defend a fourth account, according to which we represent the occluded parts of perceived objects by means of mental imagery. This conclusion could be thought of as a (weak) version of the Strawsonian dictum, according to which “imagination is a necessary ingredient of perception itself”.     

Representationalism and the phenomenology of mental imagery

This paper sketches a phenomenological analysis of visual mental imagery and uses it to criticize representationalism and the internalist-versus-externalist framework for understanding consciousness. Contrary to internalist views of mental imagery imagery experience is not the experience of a phenomenal mental picture inspected by the mind’s eye, but rather the mental simulation of perceptual experience. Furthermore, there are experiential differences in perceiving and imagining that are not differences in the properties represented by these experiences. Therefore, externalist representationalism, which maintains that the properties of experience are the external properties represented by experience, is an inadequate account of conscious experience.     

Positive mental imagery and mental health amongst university students in Pakistan

Mental health problems amongst university students pose a major public health challenge, and this is particularly the case in Pakistan. Alongside broader societal and cultural pressures, cognitive factors likely also play a role in the development of and resilience to mental health problems and may provide a feasible target for interventions. The current study built on previous research in primarily European samples investigating the relationship between one cognitive factor, positive future-oriented mental imagery, and mental health, extending this to a sample of university students in Pakistan (N = 1838). In a cross-sectional design, higher vividness of positive future-oriented mental imagery was associated with lower levels of depressive symptoms and higher levels of positive mental health amongst participants completing questionnaire measures on paper (N = 1430) or online (N = 408). In the sample completing the measures on paper, these relationships remained statistically significant even when controlling for socio-demographic and mental health-related variables. The results provide a foundation for further investigating positive mental imagery as a potential mechanism of mental health and intervention target amongst university students in Pakistan.     

Spontaneous imagery scanning in mental extrapolation

We report an experiment that suggests a functional application of mental-image scanning. After subjects inspected a simple dot pattern, the pattern was removed, and they were then shown an arrow at an unexpected location. Their task was to judge as quickly as possible whether the arrow pointed at any of the dots in the previously observed pattern. Although the subjects were never instructed to form or scan mental images, most of them reported having done so in order to make their judgments, and their reaction times were directly proportional to the distances separating the dots and the arrows, as typically found in image-scanning experiments. Imagery scanning may therefore serve a useful function when one must judge spatial relations between the positions of remembered objects and newly specified locations.     

Individual differences in spatial mental imagery

In this article, we report a new image-scanning paradigm that allowed us to measure objectively individual differences in spatial mental imagery—specifically, imagery for location. Participants were asked to determine whether an arrow was pointing at a dot using a visual mental image of an array of dots. The degree of precision required to discriminate “yes” from “no” trials was varied. In Experiment 1, the time to scan increasing distances, as well as the number of errors, increased when greater precision was required to make a judgement. The results in Experiment 2 replicated those results while controlling for possible biases. When greater precision is required, the accuracy of the spatial image becomes increasingly important—and hence the effect of precision in the task reflects the accuracy of the image. In Experiment 3, this measure was shown to be related to scores on the Paper Folding test, on the Paper Form Board test, and on the visuospatial items on Raven's Advanced Progressive Matrices—but not to scores on questionnaires measuring object–based mental imagery. Thus, we provide evidence that classical standardized spatial tests rely on spatial mental imagery but not object mental imagery.     

Eye movements during visual mental imagery

It has long been debated whether eye movements play a functional role in visual mental imagery. A recent paper by Laeng and Teodorescu presents new evidence that eye movements are stored as a spatial index that is used to arrange the component parts correctly when mental images are generated.     

Idioms and mental imagery: the metaphorical motivation for idiomatic meaning

We conducted three experiments to investigate the mental images associated with idiomatic phrases in English. Our hypothesis was that people should have strong conventional images for many idioms and that the regularity in people's knowledge of their images for idioms is due to the conceptual metaphors motivating the figurative meanings of idioms. In the first study, subjects were asked to form and describe their mental images for different idiomatic expressions. Subjects were then asked a series of detailed questions about their images regarding the causes and effects of different events within their images. We found high consistency in subjects' images of idioms with similar figurative meanings despite differences in their surface forms (e.g., spill the beans and let the cat out of the bag). Subjects' responses to detailed questions about their images also showed a high degree of similarity in their answers. Further examination of subjects' imagery protocols supports the idea that the conventional images and knowledge associated with idioms are constrained by the conceptual metaphors (e.g., the MIND IS A CONTAINER and IDEAS ARE ENTITIES) which motivate the figurative meanings of idioms. The results of two control studies showed that the conventional images associated with idioms are not solely based on their figurative meanings (Experiment 2) and that the images associated with literal phrases (e.g., spill the peas) were quite varied and unlikely to be constrained by conceptual metaphor (Experiment 3). These findings support the view that idioms are not "dead" metaphors with their meanings being arbitrarily determined. Rather, the meanings of many idioms are motivated by speakers' tacit knowledge of the conceptual metaphors underlying the meanings of these figurative phrases.     

Prospective and positive mental imagery deficits in dysphoria

We know less about positive mental imagery than we do about negative mental imagery in depression. This study examined the relationship between depressed mood and the subjective experience of emotion in imagined events; specifically, prospective imagery, and imagery in response to emotionally ambiguous stimuli. One hundred and twenty-six undergraduates completed measures of depression, imagery vividness for future events, and a homograph interpretation task in which they generated images and subsequently rated image pleasantness and vividness. As predicted, compared to low dysphoria, high dysphoria was associated with poorer ability to vividly imagine positive (but not negative) future events. These findings were augmented by the observation that high dysphorics provided lower pleasantness ratings of images generated in response to homographs they interpreted as positive. We suggest that an imbalance in the inability to vividly imagine positive but not negative future events may curtail the ability of high dysphorics to be optimistic. High dysphoric individuals are further disadvantaged: even when they interpret ambiguity positively, the resulting images they generate are associated with less positive affect. Therapeutic strategies that address both such positive-specific imagery biases hold promise for depression treatment innovation.     

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.     

Fantasy proneness, mental imagery and reality monitoring

Individual differences in fantasy proneness and vividness of mental imagery have been suggested to be related to source memory confusions. To test this hypothesis, two groups scoring either high or low on a measure of fantasy proneness (selected from a group of 231 subjects) were compared on measures of self report vividness of mental imagery, objective imagery ability and reality monitoring performance. The two groups differed significantly on ratings of imagery vividness (p<0.01), but not on the imagery performance tasks, nor on reality monitoring performance. Our results indicate that, although fantasy proneness is associated with experiences of vivid mental imagery, it does not necessarily lead to reality monitoring errors.     

The uses of mental imagery in athletics: An overview

This article surveys the extant literature on mental imagery as used in athletics for performance enhancement, arousal regulation, affective and cognitive modification, and rehabilitation. For each category of use, applications are discussed, an overview of the empirical and case-study research findings is presented, and the research is critiqued. A concluding section recommends directions for future research on uses of mental imagery in athletics.     

Effect of mental imagery on realizing affordances

Using a reaction time experiment, we examined whether imagining a response would lead to an increase in the frequency of its execution. During a pre-test and a post-test, participants had to respond as quickly as possible with either their left or their right hand, as they preferred, to the illumination of one of 17 target positions arrayed in front of them in a semicircle. Between these two phases, participants performed a practice condition. Each of 40 right-handed participants was assigned to one of four groups that differed in their practice condition: One group made only dominant-hand responses to all target locations, two imagery groups imagined dominant hand responses to all target locations, and the last group received a no-practice, control task. One imagery group received instructions emphasizing that imagery has a strong effect; the second group received instructions suggesting that imagery was not effective. The results showed an increased incidence of the practised response for both imagery groups during the post-test. No effect was found for the physical performance group and the control group. The change in performance for the imagery groups was not accompanied by a change in reaction time. The results are discussed in terms of imagining the realization of action possibilities and from a neuropsychological point of view.