The two sides of the mental clock: the Imaginal HemiSpatial Effect in the healthy brain

When subjects are asked to compare the mental images of two analog clocks telling different times (the mental clock test), they are faster to process angles formed by hands located in the right than in the left half of the dial. In the present paper, we demonstrate that this Imaginal HemiSpatial Effect (IHSE) can be also observed in two modified versions of the mental clock test: in Experiment 1 subjects had to imagine the position occupied by two numbers within a clock face and to judge if the subtended angle was smaller or greater than 90 degrees , while in Experiment 2 subjects were asked to match two imagined positions on a clock face with two visually presented locations. The finding of the IHSE in these tasks suggested that it is a genuine phenomenon related to spatial imagery tasks, and is consistent with recent neuroimaging evidence that the left parietal lobe is mainly involved in the generation of spatial mental images.     

Spatial representations elicit dual-coding effects in mental imagery

Spatial aspects of words are associated with their canonical locations in the real world. Yet little research has tested whether spatial associations denoted in language comprehension generalize to their corresponding images. We directly tested the spatial aspects of mental imagery in picture and word processing (Experiment 1). We also tested whether spatial representations of motion words produce similar perceptual-interference effects as demonstrated by object words (Experiment 2). Findings revealed that words denoting an upward spatial location produced slower responses to targets appearing at the top of the display, whereas words denoting a downward spatial location produced slower responses to targets appearing at the bottom of the display. Perceptual-interference effects did not obtain for pictures or for words lacking a spatial relation. These findings provide greater empirical support for the perceptual-symbols system theory ( Barsalou, 1999, 2008 ).     

Mental rotation is not easily cognitively penetrable

When participants take part in mental imagery experiments, are they using their “tacit knowledge” of perception to mimic what they believe should occur in the corresponding perceptual task? Two experiments were conducted to examine whether such an account can be applied to mental imagery in general. These experiments both examined tasks that required participants to “mentally rotate” stimuli. In Experiment 1, instructions led participants to believe that they could reorient shapes in one step or avoid reorienting the shapes altogether. Regardless of instruction type, response times increased linearly with increasing rotation angles. In Experiment 2, participants first observed novel objects rotating at different speeds, and then performed a mental rotation task with those objects. The speed of perceptually demonstrated rotation did not affect the speed of mental rotation. We argue that tacit knowledge cannot explain mental imagery results in general, and that in particular the mental rotation effect reflects the nature of the underlying internal representation and processes that transform it, rather than participants’ pre-existing knowledge.     

Is Complex Visual Information Implicated During Language Comprehension? The Case of Cast Shadows

Previous research showed that sensorimotor information affects the perception of properties associated with implied perceptual context during language comprehension. Three experiments addressed a novel question of whether perceptual context may contribute to a simulation of information about such out-of-sight objects as cast shadows. In Experiment 1, participants read a sentence that implied a particular shadow cast on a target (blinds vs. an open window) and then verified the picture of the object onto which a shadow was cast. Responses were faster when the shadow of blinds cast on the object matched that implied by the sentence. However, the data did not show the same matching effect for pictures with cast shadows from an open window. In Experiments 2 and 3, we found that verification times for pictures with no cast shadows were faster when preceded by an “open window” sentence, thus suggesting that reading the sentence does not elicit a visual simulation of any specific shadow. Experiment 3 showed that the objects superimposed with a cast shadow of the blinds and blinds themselves were verified faster after reading a “blinds” sentence. However, the results of an order analysis showed the temporal stability of the “blinds shadows” effect, but the disappearance of the “blinds” effect in the second half of the data. We conclude that the results are compatible, to a lesser or greater extent, with multiple accounts, and discuss our findings in the context of a mental imagery view, a mental simulation view, and an amodal representation view.     

视觉表象操作加工的眼动实验研究

本研究通过视觉表象旋转和扫描的眼动实验探讨表象的心理表征方式。实验一结果表明,眼动指标具有与反应时相类似的旋转角度效应。实验二结果显示,表象扫描的反应时和眼动指标都具有与知觉扫描加工一样的距离效应。由此可以认为,表象眼动与知觉眼动模式具有相似性;表象具有相对独立的心理表征方式并有其特殊的加工过程;表象的心理表征可以是形象表征,而非一定是抽象的命题或符号表征     

Using Real‐World and Standardized Spatial Imagery Tasks: Convergence,Imagery Realism,and Gender Differences

Can realistic spatial scenarios be used to measure spatial mental imagery? Can people accurately evaluate their spatial imagery? Does gender moderate the relationship between performance on realistic spatial imagery tasks and ratings of imagery realism? Forty‐two female and 31 male undergraduates first rated the realism of their images after reading spatial scenarios based on actual spatial tasks. In phase 2, they solved closely related spatial scenario problems, and then completed the VZ‐2 Paper Folding test. Performance on realistic spatial scenarios predicted performance on the VZ‐2. Men's evaluation of their spatial imagery realism predicted their actual spatial performance, but women's did not. More task experience was positively related to more realistic images and higher scores on the VZ‐2. These results were generally consistent with those found with more artificial stimulus materials, but also demonstrated the importance of considering gender differences in spatial problem strategy and/or rating scale interpretation. Copyright © 2014 John Wiley & Sons, Ltd.     

A simulation of visual imagery

This paper describes an operational computer simulation of visual mental imagery in humans. The structure of the simulation was motivated by results of experiments on how people represent information in, and access information from, visual images. The simulation includes a “surface representation,” which is spatial and quasi-pictorial, and an underlying “deep representation,” which contains “perceptual” information encoding appearance plus “propositional” information describing facts about an object. The simulation embodies a theory of how surface images are generated from deep representations, and how surface images are processed when one accesses information embedded in them. The simulation also offers an account of various sorts of imagery transformations.     

A PET meta‐analysis of object and spatial mental imagery

Neuroimaging studies have described the functional neuroanatomy of mental imagery. Taken separately, specific studies vary in the nature of the task used and are limited by statistical power and sensitivity. We took advantage of a multistudy PET database of 54 subjects acquired in our laboratory to reveal the neural bases of spatial versus object mental imagery tasks. Our first goal was to evaluate to what extent the activated foci elicited by both object and spatial studies overlap. A second aim was to compare activations elicited by spatial imagery tasks to those elicited by object imagery tasks. We also explored applying regression analyses to the relationships between the scores on the Mental Rotations Test (MRT) and changes in regional cerebral blood flow (rCBF) during spatial and object imagery tasks. This meta‐analysis yielded the following observations: (1) both spatial and object imagery tasks shared a common neural network composed of occipitotemporal (ventral pathway) and occipitoparietal (dorsal pathway) regions and also by a set of frontal regions (related to memory); (2) the superior parietal cortex was more strongly implicated during spatial imagery; (3) object imagery specifically engaged the anterior part of the ventral pathway, including the fusiform, parahippocampal, and hippocampal gyrus; (4) object imagery activated the early visual cortex, whereas spatial imagery induced a deactivation of the early visual cortex; (5) blood flow values in some of the regions noted above were positively correlated with scores on the MRT: the higher the subjects performed on the MRT, the more pronounced the rCBF was in these regions. These results may reconcile some of the apparent discrepancies among previous studies concerning the activation of early visual cortex in mental imagery. They also contribute to a better knowledge of the neural bases of object and spatial mental imagery.     

A lateralization of function approach to sex differences in spatial ability: a reexamination

The current study assessed the lateralization of function hypothesis (Rilea, S. L., Roskos-Ewoldsen, B., & Boles, D. (2004). Sex differences in spatial ability: A lateralization of function approach. Brain and Cognition, 56, 332–343) which suggested that it was the interaction of brain organization and the type of spatial task that led to sex differences in spatial ability. A second purpose was to evaluate explanations for their unexpected findings on the mental rotation task. In Experiment 1, participants completed the Water Level, Paper Folding, and mental rotation tasks (using an object-based or self-based perspective), presented bilaterally. Sex differences were only observed on the Water Level Task; a right hemisphere advantage was observed on Water Level and mental rotation tasks. In Experiment 2, a human stick figure or a polygon was mentally rotated. Men outperformed women when rotating polygons, but not when rotating stick figures. Men demonstrated a right hemisphere advantage when rotating polygons; women showed no hemisphere differences for either stimulus. Thus, hemisphere processing, task complexity, and stimulus type may influence performance for men and women across different spatial measures.     

Measure of the ability to rotate mental images

The aim of this study was to design an innovative test to measure the ability to rotate mental images. An unfolded cube was designed, which participants had to reassemble mentally, prior to mentally rotating the image, and answering 23 questions concerning the cube. The Measure of the Ability to Rotate Mental Images (MARMI) test was administered to 354 participants. Cronbach alpha was .90, and high correlations between this test and other image rotation and spatial image tests were found. However, poor correlations were observed between test scores and the responses to the visual imagery vividness questionnaire. Both test reliability and validity underscore that it is a good instrument for measuring the ability to rotate mental images.     

Vividness and Control of Mental Imagery and the Components of In-Depth Drawing

The aim of this study was to examine the associations of control and vividness of mental imagery on performance in several components of in-depth drawing in a sample of fine arts undergraduates. The sample consisted of 56 second-year undergraduates (44 women and 12 men, mean age = 21.18 years) from the Fine Arts Faculty of Vigo University, Pontevedra, Spain. Participants were required to undertake a plastic art assignment focusing on the pictorial representation of space. Participants scoring high on the image control test obtained higher scores on the spatial analysis and in the formal construction of a work than participants with poor image control. Further research involving spatial image performance tests and mental image rotation tests is proposed.     

Imagery perspective and source monitoring in imagination inflation

The present experiments suggest that imagery perspective—first person (own) versus third person (observer’s)—influences source-monitoring judgments. Imagination inflation (Garry, Manning, Loftus, &; Sherman, 1996) occurs when imaginary experience with events is mistaken for real experience. In Experiment 1, the perspective used to visualize real past events depended on memory test wording (“remember doing?” vs. “happened to you?”). Experiment 2 manipulated the perspective used to visually imagine counterfactual events and showed that the effect on imagination inflation depended on memory test wording. Imagination inflation was most likely when memory test wording encouraged participants to visualize real events from the same perspective as they had used to imagine counterfactual ones. Imagination inflation may result not simply from having created imaginary representations of events, but also from having created representations that match the decision criteria used in source monitoring.     

Factors of imagery and event recall

The relationships among various measures of mental imagery and childhood memory were examined using factor analysis and other correlational procedures. Forty-six subjects completed nine mental imagery measures (Marks’s VVIQ, Gordon’s Vividness Scale Forms 1 and 2, Space Relations Form of the Differential Aptitude Test, Barratt’s Visualization Forms A and B, Betts’s QMI, Cut the Cube Task, and Richardson’s VVQ), a number of memory measures, and two measures of the observer/field “point-of-view” distinction. Analysis revealed three distinct imagery factors, “vividness and control,” “spatial manipulation,” and “spontaneous elaboration,” as well as a fourth “childhood memory” factor. Childhood memory was not significantly correlated with any imagery variables, but observer perspectives were associated more often with childhood memories than with recent memories. In addition, the tendency to recall events from the field perspective was correlated with the spatial manipulation factor.     

Spatial versus object visualizers: A new characterization of visual cognitive style

The visual system processes object properties (such as shape and color) and spatial properties (such as location and spatial relations) in distinct systems, and neuropsychological evidence reveals that mental imagery respects this distinction. The findings reported in this article demonstrate that verbalizers typically perform at an intermediate level on imagery tasks, whereas visualizers can be divided into two groups. Specifically, scores on spatial and object imagery tasks, along with a visualizer-verbalizer cognitive style questionnaire, identified a group of visualizers who scored poorly on spatial imagery tasks but excelled on object imagery tasks. In contrast, a second group of visualizers scored high on spatial imagery tasks but poorly on object imagery tasks. The results also indicate that object visualizers encode and process images holistically, as a single perceptual unit, whereas spatial visualizers generate and process images analytically, part by part. In addition, we found that scientists and engineers excel in spatial imagery and prefer spatial strategies, whereas visual artists excel in object imagery and prefer object-based strategies.     

The coupling between spatial attention and other components of task-set: A task-switching investigation

Is spatial attention reconfigured independently of, or in tandem with, other task-set components when the task changes? We tracked the eyes of participants cued to perform one of three digit-classification tasks, each consistently associated with a distinct location. Previously we observed, on task switch trials, a substantial delay in orientation to the task-relevant location and tendency to fixate the location of the previously relevant task—“attentional inertia”. In the present experiments the cues specified (and instructions emphasized) the relevant location rather than the current task. In Experiment 1, with explicit spatial cues (arrows or spatial adverbs), the previously documented attentional handicaps all but disappeared, whilst the performance “switch cost” increased. Hence, attention can become decoupled from other aspects of task-set, but at a cost to the efficacy of task-set preparation. Experiment 2 used arbitrary single-letter cues with instructions and a training regime that encouraged participants to interpret the cue as indicating the relevant location rather than task. As in our previous experiments, and unlike in Experiment 1, we now observed clear switch-induced attentional delay and inertia, suggesting that the natural tendency is for spatial attention and task-set to be coupled and that only quasi-exogenous location cues decouple their reconfiguration.     

Object imagery and object identification: object imagers are better at identifying spatially-filtered visual objects

Object imagery refers to the ability to construct pictorial images of objects. Individuals with high object imagery (high-OI) produce more vivid mental images than individuals with low object imagery (low-OI), and they encode and process both mental images and visual stimuli in a more global and holistic way. In the present study, we investigated whether and how level of object imagery may affect the way in which individuals identify visual objects. High-OI and low-OI participants were asked to perform a visual identification task with spatially-filtered pictures of real objects. Each picture was presented at nine levels of filtering, starting from the most blurred (level 1: only low spatial frequencies—global configuration) and gradually adding high spatial frequencies up to the complete version (level 9: global configuration plus local and internal details). Our data showed that high-OI participants identified stimuli at a lower level of filtering than participants with low-OI, indicating that they were better able than low-OI participants to identify visual objects at lower spatial frequencies. Implications of the results and future developments are discussed.     

What is primed in priming from imagery?

Priming from imagery is typically weaker than that from perception. This has been interpreted as resulting from weaker activation of perceptual processes. However, for imagery and perception, commonality is only half the story: Each is also characterized by specific processes. If priming can be due to both unshared and shared components of imagery and perception, then it should be possible to observe greater priming from imagery than from perception. Two new priming experiments were designed to test this hypothesis, while controlling incidental task differences. In both experiments, participants studied objects by counting their parts (from a mental image or a picture). Experiment 1 used a word-picture matching test task, which was hypothesized to depend on stimulus processing specific to perception, and Experiment 2 a size judgment test task, which was hypothesized to depend on retrieval and generation processes specific to imagery. As predicted, priming for perceived objects was greater than priming for imagined objects in the word-picture matching task. Conversely, in the size judgment task, more priming from imagery than from perception was observed. These results support the conclusions that (a) imagery and perception have substantial unshared processes, and (b) these processes contribute to priming.     

On the Nature of Nonverbal Working Memory Fractionation: A Case of Selective Spatial Short-Term Memory Deficit in a Child

Several lines of research on adult subjects demonstrate a visual/spatial fractionation of nonverbal working memory (WM), while behavioral studies on normal children support the idea of a static/dynamic distinction. In the present paper, we report a child (Z.M.) who failed on nonverbal WM tasks. To verify the nature of his defect, we carried out two experiments: in Experiment 1, Z.M. failed on spatial WM tasks but not on visual WM tasks and was not affected by the static/dynamic format of stimulus presentation; in Experiment 2, this visual/spatial dissociation was extended to the imagery domain. These results are best accounted for within the visual/spatial fractionation of WM and confirmed the role of WM in mental imagery. Clinical and rehabilitative implications of the present findings are also discussed.