Selection of relevant cues in volume discrimination by golden hamsters.
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Animals↗
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Results for “Space Perception”
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Stimulus structure in visual persistence: an examination of selective adaptation effects on phenomenal continuity.
The effects of adaptation by stimuli composed of the dimensions of color, orientation and size were measured on the visual persistence of a red vertical 3.5 c/d grating. Adaptation by the stimulus that shared an identical level on each of the three-component dimensions of the test stimulus decreased the visual persistence of the test stimulus. There was no effect of adaptation on visual persistence when the adapting stimulus and test stimulus shared an identical level on zero-, one-, or two-dimensional components. The present results extend the investigation of selective adaptation effects on visual persistence by Meyer, Lawson , Cohen, and Maquire to color, size and orientation. In addition, these results are in excellent agreement with Burns' finding that physically integral stimuli are represented in iconic memory as integral unitary wholes and not as dimensional components.
Adaptation, Ocular↗
Eye position and visual attention influence perceived auditory direction.
The singular and joint effects of eccentric visual fixation and peripheral visual attention upon the perceived auditory median plane (PAMP) of the head were examined in four subjects. They positioned a hidden, horizontally-moving sound source to the perceived median plane of the head, while fixating a light 20 degrees or 45 degrees to the right or left of the actual median plane, and attending to another light in peripheral vision. Analysis by multiple linear regression yielded a model for each subject which indicated the nature and weighting of those factors contributing to variance reduction in PAMP judgments. Three subjects showed a strong linear attention effect, resulting in shifts of the PAMP away from the locus of attention. Similarly, a strong linear fixation effect was discovered in two subjects, a weak effect in another, and a nonlinear, inverse fixation effect in the last. Additional factors were noted for some subjects. Possible explanations of the observed effects were discussed. The study indicates that both visual attention and visual fixation are critical factors in experiments on auditory space perception although inter-individual differences do exist in the nature and strength of the effects.
Adult↗
Contribution of figural proportion, figural memory, figure-ground perception and severity of hearing loss to performance on spatial tests.
348 adolescents, 176 male and 172 female, were administered six different spatial tests. Awareness of figural proportion, figural memory, and figure-ground perception contributed significantly to performance on spatial visualization tests but not to performance on spatial orientation tests. Similarly, severity of hearing loss was correlated with scores on visualization tests but not on spatial-orientation tests.
Adolescent↗
Relative size and spatial separation: effects on the parallel-lines illusion.
The parallel-lines illusion provides a prototypical example of visual-size assimilation, where the size of a test element is phenomenally skewed towards (or "averaged with") that of a context element. Most assimilation theories predict that distortion should decrease with spatial separation between context and test lengths. However, there is some disagreement about the nature of the function relating sizes of context and test elements and magnitude of assimilation. The present study tests the limits of assimilation in the parallel-lines configurations by observing the effects of a wide range of context/test size ratios, repeated over two disparate levels of spatial separation. The results replicate and extend 1979 findings by Brigell and Uhlarik, confirming that assimilation rises to a peak at midrange size ratios, only to decrease continuously as the ratios become more extreme. The functions were nonmonotonic and similar in shape for both levels of spatial separation, with an over-all decrease in distortion for configurations with the larger separation.
Adolescent↗
Symmetry in building block design for learning disabled and nonlearning disabled boys.
This study examined perceptual differences in symmetry with and without a model between 21 learning disabled boys with reading deficits and 28 learning disabled boys with deficits in mathematics. 55 nonlearning disabled boys served as controls. All boys were in Grades 3, 4, or 5. Without a model, all learning disabled boys built significantly more asymmetrical building block designs than nonlearning disabled boys. However, with a model, all learning disabled boys could imitate the model, but it took them longer to complete the task successfully. All boys appeared to have difficulty in modeling asymmetrical tasks, taking more time for task completion after seeing an asymmetrical model. This study suggests modeling perceptual tasks might be an effective teaching strategy for such children.
Attention↗
Selective adaptation to low spatial frequencies does not decrease the Mueller-Lyer illusion.
The idea that low spatial-frequency information in the Mueller-Lyer figure accounts for a major part of the illusion was tested in a series of five studies. In Study 1, subjects were selectively adapted to high or low square-wave spatial-frequency gratings with no difference in the magnitude of illusion they experienced. Similarly, adaptation to sinusoidal grating patterns with either high or low spatial frequency had no effect on the magnitude of illusion experienced (Studies 2 to 5). The failure of adaptation to low spatial-frequency gratings to affect the magnitude of illusion experienced indicates either that the illusion cannot be accounted for by the low spatial-frequency information or that adaptation of the visual system by grating patterns cannot be used to explore any effects of the low spatial frequencies in the figure.
Adult↗
Re-examination of evidence questions Christman's (1989) report of moderate experimental support for the visual spatial frequency hypothesis.
The visual spatial frequency hypothesis contends that perceptual characteristics of stimulus arrays can affect the magnitude and direction of hemispheric asymmetries in laterality experiments. In a 1989 literature review, Christman reported that 45 of 79 experimental comparisons yielded significant interactions for side of hemispheric advantage x perceptual characteristic which supported the visual spatial frequency hypothesis, a level of support he characterized as moderate. Re-examination of those 45 outcomes shows that in 20 of them either a significant interaction for side of hemispheric advantage x perceptual characteristic was not found or, if it was, the particulars do not agree fully with predictions of the visual spatial frequency hypothesis as presented by Christman in the 1989 paper. These findings suggest that experimental support for the visual spatial frequency hypothesis is weak, not moderate as characterized by Christman.
Attention↗
Pseudoneglect of males and females on a spatial short-term memory task.
The effect of sex on the phenomenon of pseudoneglect was assessed in 60 male and 61 female right-handed subjects using a modified form of Corsi's block-tapping test. A significant right-lateralized pseudoneglect for both sexes was found, and the level of pseudoneglect strongly correlated with neglect in the right hemispace. Men were significantly more accurate in the left hemispace than women, whereas no difference was seen between the sexes in the right hemispace. Although we found some indirect evidence from which to infer that the men's brain may be functionally more lateralized than the women's for this spatial task, there was no significant difference between the sexes in correct responses for the left hemispace, i.e., right pseudoneglect. Therefore, the results suggest that pseudoneglect phenomenon can be partly explained by a functional asymmetric feature of the brain, and the other factors probably play a role in producing the similar patterns of asymmetric perception of space in males and females.
Adult↗
The pictorial context dependency of savant artists: a research note.
The relative immunity of the concept of size constancy in the face of changes to the retinal image as well as the pictorial device of linear perspective were investigated with 9 savant artists and 9 controls. For drawing use of pictorial rules seemed independent of levels of intelligence; however, when a construction instead of a drawing task had to be carried out, diagnosis rather than the presence or absence of talent was the decisive factor.
Adult↗
Coactivation, pop-out, and symmetry affect line discrimination.
17 college students discriminated between vertical and horizontal target lines flanked by vertical and horizontal distractors. Large displays with 3.0-cm lines and small displays half this size were used. The distractors were positioned above and below the target or to the left and right of it, forming vertical and horizontal global orientations. The number of flankers sharing the target's orientation was varied. Vertical targets and small display sizes were processed more quickly. Speed of responding did not differ for the two global orientations. There was no advantage for target lines consistent with global orientation. The results were replicated in Exp. 2 with diagonal flankers. This supports an explanation using stimulus compatibility, since diagonal lines do not correspond to either of the response options and cannot induce a tendency to respond more to one target than another. Displays with multiple symmetry were responded to faster than those with a single symmetry which were faster than asymmetrical displays, supporting the idea that symmetrical axes parallel and perpendicular to the target orientation provide a facilitative frame of reference. Coactivation from same-oriented flankers, pop-out from differences in orientation, and symmetry all influenced responding in these patterns.
Attention↗
Effect of element size on stereoscopic apparent motion.
Spatial displacement limits in stereoscopic (cyclopean) apparent motion were measured from sequentially presented two-frame random-depth configurations. Each depth configuration was defined by stereoscopically near or far elements of various sizes. The limits were compared with those in luminance-defined apparent motion. The subject's task was 2-alternative forced-choice of the perceived motion direction of the sequentially presented two-frame random-dot stereograms. The spatial displacement limit below which correct motion perception arose with stereoscopic configurations was larger in proportion to increases in size of elements. The values were almost consistent with those measured by luminance-defined configurations with the same element sizes. This result suggests that the strategy for discrimination of motion direction of random configurations is similar in both stereoscopic and luminance-defined apparent motion.
Depth Perception↗
Perceptual training and its effect on racial preferences of kindergarten children.
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Black or African American↗
Hemisphere specialization of the animal brain for information processing principles.
The experiments were performed on white rats. Different techniques for forming conditioned reflexes were used. Hemisphere cortex inactivation was carried out by means of spreading depression. The right hemisphere was shown to dominate for space perception, simultaneous information processing, concrete characteristics perception, and deductive processing; the left hemisphere was shown to dominate for time perception, successive information processing, abstract characteristics perception, and inductive processing. A hypothesis of induction and deduction being the main factors determining function lateralization in the hemispheres of the animal brain was put forward.
Animals↗
Encoding into working memory of spatial location, color, and shape: electrophysiological investigations.
Event-related potentials (ERP) were recorded while subjects memorized either the location, the color or the shape of stimuli which could be located in 1 of 4 positions relative to a central fixation point (top, bottom, left or right), be of 1 of 4 positions relative to a central fixation point (top, bottom, left or right), be of 1 of 4 colors (white, green, red or blue), and present 1 of 4 shapes (triangle, cross, circle or square). These ERP were compared to ERP recorded while subjects looked at the same stimuli but performed other control, nonmemory tasks. Only ERP corresponding to the memorization of spatial location showed a differential pattern which could be specifically attributed to memory encoding processes. This reveals an important difference in ERP modulation between a working memory subsystem for spatial location and other subsystem (or subsystems) for color or shape, which would provide evidence supporting the existence of different working memory subsystems for visual information in the brain.
Adolescent↗
Effects of diet on the ability to drive.
Monoamine synthesis and release depend on the availability of their precursors. Thus some individual behaviors and aptitudes can be controlled by changing the dietary supply of such amino acids. In order to determine the effects of diet on skills for a correct driving attitude, such as sleep latency, attention level, arousal and differences between sexes, we designed a crossover, double-blind trial with 50 volunteers from both sexes, aged 21-30, who ingested a protein enriched product or one composed only of carbohydrates. After 3 h, psychotechnical computerized tests were performed to assess ability to calculate speed, manual skills and vision coordination and concentration capability. No differences were seen in the performance of the tests after the ingestion of both products; thus, diet does not seem to influence behaviors involved in driving. Males performed better in tests involving space perception while females obtained higher scores in the test for visual memory.
Adult↗
Perceived reachability in single- and multiple-degree-of-freedom workspaces.
In comparisons of perceived (imagined) and actual reaches, investigators consistently find a tendency to overestimate. A primary explanation for that phenomenon is that individuals reach as a "whole-body engagement" involving multiple degrees of freedom (m-df). The authors examined right-handers (N = 28) in 1-df and m-df workspaces by having them judge the reachability of targets at midline, right, and left visual fields. Response profiles were similar for total error. Both conditions reflected an overestimation bias, although the bias was significantly greater in the m-df condition. Midline responses differed (greater overestimation) from those of right and left visual fields, which were similar. Although the authors would have predicted better performance in the m-df condition, it seems plausible that if individuals think in terms of m-df, they may feel more confident in that condition and thereby exhibit greater overestimation. Furthermore, the authors speculate that the reduced bias at the side fields may be attributed to a more conservative strategy based in part on perceived reach constraints.
Adult↗
The influence of spatial context and the role of intentionality in the interpretation of animacy from motion.
We present three experiments investigating how spatial context influences the attribution of animacy to a moving target. Each of our displays contained a moving object (the target) that might, depending on the way it moved, convey the impression that it was alive (animate). We investigated the mechanisms underlying this attribution by manipulating the nature of the spatial context surrounding the target. In Experiment 1, the context consisted of a simple static dot (the foil), whose position relative to the target's trajectory was manipulated. With some foil positions--for example, when the foil was lying along the path traveled by the target--animacy judgments were elevated relative to control foil locations, apparently because this context supported the impression that the target was "reacting to" or was in some other way mentally influenced by the foil. In Experiment 2, contexts consisted of a static oriented rectangle (the "paddle"). On some trials, the target collided with the paddle in a way that seemed to physically account for the target's motion pattern (in the sense of having imparted momentum to it); this condition reduced animacy ratings. Experiment 3 was similar, except that the paddles themselves were in motion; again, animacy attribution was suppressed when the target's motion seemed to have been caused by a collision with the paddle. Hence, animacy attributions can be either elevated or suppressed by the nature of the environment and the target's interaction with it. Animacy attribution tracks intentionality attribution; contrary to some earlier proposals, we conclude that attributing animacy involves, and may even require, attributing to the target some minimal mental capacity sufficient to endow the target with intentionality.
Humans↗