Picture perception: toward a theoretical model.
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Adolescent↗
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Results for “SIZE PERCEPTION”
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Perception of force and weight: theory and research.
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Adaptation, Physiological↗
High-level effects of masking on perceptual identification.
The extent to which visual form versus higher-level information is used to identify briefly flashed words is assessed in a perceptual identification task. In this task, a word is briefly flashed, post-masked, and a decision is made between two alternatives. The availability of visual (e.g., case or color) and higher-level information (e.g., abstract letter codes, phonology, and meaning) was manipulated by varying the information that discriminates the alternatives. Performance was better with higher-level than with visual information when pattern post-masks were used, but the reverse occurred without masking. The authors conclude that both higher-level and visual-form information can be used to identify words with the strategy depending on the information available at the time of the choice.
Cognition↗
Cognitive gender differences in very young children parallel biologically based cognitive gender differences in monkeys.
Infant humans were trained on 2 cognitive tests that have previously revealed, in infant monkeys, a double dissociation that was reversible by perinatal manipulations of androgens and ablations of specific brain sites. Children showed the same sex-linked behavior found with infant monkeys: young boys were superior on the object reversal task and young girls were superior on the concurrent discrimination task. As happened previously with infant monkeys, the gender difference was not apparent in older human subjects. Thus, early in ontogeny, cognitive gender differences have now been discovered in both humans and monkeys, probably a result of gender differences in androgens that influence the maturation rate of specific brain systems.
Adolescent↗
Age differences in visual search for feature, conjunction, and triple-conjunction targets.
The authors examined the ability of younger and older adults to search for targets defined by single features (feature search), conjunctions of 2 features (conjunction search), and conjunctions of 3 features (triple-conjunction search). Feature search was relatively age-invariant, with both older and younger adults displaying shallow search slopes. However, older adults did show reduced search rates for many conjunction targets. Interestingly, both older and younger adults benefited equivalently when an extra feature was available to define the conjunction target. That is, the relative amount of improvement in search performance was similar for younger and older adults when the triple-conjunction search was compared to the conjunction search. These results are discussed in terms of age-related differences in the effectiveness of bottom-up and top-down mechanisms that support visual search.
Adolescent↗
Retinal mechanisms in the perception of subjective contours: the contribution of lateral inhibition.
One mechanism frequently proposed for the creation of subjective contours and their related brightness effects involves lateral neural interactions on the retina, such as the lateral inhibitory effects that underlie brightness contrast. Subjective contour stimuli were displayed under an intermittent light source, with rapid onset and slow offset as has been shown to increase lateral inhibitory interactions by allowing summation of neural onset transients. A sample of forty subjects, using magnitude estimates, reported increased subjective contour clarity and brightness effects under these exposure conditions. The effects were larger for relative brightness differences than for contour visibility. It appears that this technique may have applications in exploring retinal contributions to other aspects of the perception of subjective contours.
Adult↗
Functional asymmetry in body perception and ocular dominance: a study of their interactions.
The relationships between ocular dominance and body perception (for the left and right body halves) were examined for 41 undergraduate female psychology students. The results indicate an interesting connection between the two phenomena. The four groups of subjects classified on the basis of ocular dominance (right, left, fluctuating and no dominance) showed statistically significant differences on one aspect of body perception, measured by the 'Difference Deviation Scores.' Also three groups of subjects classified on the basis of body perception (subjects with major perceptual error on the left or on the right, and subjects showing no difference in perception of the two body halves) showed statistically significant differences in ocular dominance.
Adult↗
Chronic users of LSD: the "acidheads".
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Adolescent↗
Perception of spatial and social density.
The effects of family size on the perception of three abstract rooms that differed in social and spatial density were studied. The rooms were rated on the dimensions, evaluation, spirituality, activity, and aesthetic appeal. Of the 48 subjects half were from large families with six or more members, and half were from smaller families. Family size had no effect on the perception of the rooms. The room low in spatial density was perceived most favorably, and there was no difference in the perception of a room high in social density and one high in spatial density.
Crowding↗
A comparison of static and dynamic presentation procedures on discrimination learning of individuals with severe or moderate mental retardation.
A dynamic presentation of stimulus materials may be more effective than a static presentation. To test this hypothesis, we taught 16 individuals with moderate or severe mental retardation to identify two comparative discriminations (more, longer) by each of two different procedures. In the static, or traditional, presentation procedure the stimuli were positioned before a trial began and not manipulated by the experimenter during the trial. In the dynamic presentation procedure the individual watched the experimenter manipulate the relevant dimension of the stimuli during a series of trials. Both procedures were used in combination with a procedure that relied on fading and on many examples of both the correct and incorrect stimuli across trials. Data were presented in four phases: training, generalization, 1-week maintenance, and 1-month maintenance. No differences in percentage of unprompted correct responses were found between the two procedures in training, generalization, or any of the four maintenance tests. Discussion included possible reasons these results differed from those of prior studies as well as the need for further investigation of the dynamic presentation procedure used with more traditional teaching procedures that rely on extrastimulus prompts.
Adolescent↗
More learned irrelevance than perseveration errors in rule shifting in healthy subjects.
The present experiments examined the extent to which two possible sources of error affect healthy subjects' performance in a rule-shift task. All 115 participants first received a discrimination learning task, in which a pair of different visual stimuli was presented on each trial, one of which had to be identified as 'correct.' Each stimulus varied in two dimensions: a task-relevant and a task-irrelevant dimension. Feedback on correctness was given after each choice. After eight successive correct choices, the nature of the task-relevant dimension changed: the post-shift learning phase. Two types of error can occur in this phase: continued responding to the former relevant, but now irrelevant, dimension, a perseverative error, and non-responding to the former irrelevant, but now relevant, dimension, an error due to learned irrelevance. Different groups received a post-shift task in which none, one, or both of these two types of error could affect performance. The number of incorrect choices in the post-shift phase was significantly affected by learned-irrelevance errors but not by perseverative errors. An associative-learning model incorporating feedback-induced changes in both associative strength and saliency of the elements comprising the stimuli can explain these results.
Adolescent↗
Object retrieval in the 1st year of life: learning effects of task exposure and box transparency.
Before 12 months of age, infants have difficulties coordinating and sequencing their movements to retrieve an object concealed in a box. This study examined (a) whether young infants can discover effective retrieval solutions and consolidate movement coordination earlier if exposed regularly to such a task and (b) whether different environments, indexed by box transparency, would impact the rate of learning and time of discovery of these solutions. Infants (N=12) were presented with an object retrieval task every week from 6 1/2 months of age until they were able to retrieve the toy from the box using coordinated two-handed patterns for 3 weeks. To reach that criterion, infants tested with an opaque box took 2 1/2 months and infants tested with a semitransparent box took 1 1/2 months. Both groups outperformed age-matched controls who received a one-time exposure to the task. Repeated exposure to the task and vision of the toy significantly enhanced this process of solution discovery.
Female↗
Mapping the developmental constraints on working memory span performance.
This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related variance in complex span. Results showed that developmental improvements in complex span were driven by 2 age-related but separable factors: 1 associated with general speed of processing and 1 associated with storage ability. In addition, there was an age-related contribution shared between working memory, processing speed, and storage ability that was important for higher level cognition. These results pose a challenge for models of complex span performance that emphasize the importance of processing speed alone.
Age Factors↗
Age-related deficits in guided search using cues.
The ability of young and older adults to engage in guided conjunction search was tested in 2 experiments. In the cued condition, a picture of the target was presented before the search. In the noncued condition, there was no picture of the target. In Experiment 1, the cue was presented for 200 ms; the magnitude of the cuing effect (noncued response time--cued response time) was greater for the young than for the older observers. In Experiment 2 (older observers only), the cue duration was doubled, and older observers had a larger magnitude of cuing effect than found in Experiment 1 but not as large as what would be expected under generalized slowing. The results indicated that older observers had difficulty with interpreting the cue and setting search parameters when the target varied across trials.
Adult↗
Basal level and reactivity in schizophrenia as a function of premorbid adjustment, chronicity, and diagnosis.
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Adult↗
Comparing effects of the horizontal-vertical illusion on grip scaling and judgment: relative versus absolute, not perception versus action.
The discovery that the prehension component of an open-loop, two-fingered reach is largely immune to certain salient pictorial illusions has been used to suggest that humans possess 2 distinct visual systems, 1 that subserves perceptual judgment and 1 that mediates visually controlled action. In this article, the authors present evidence that suggests that the critical distinction is not that of reaching and judgment but of relative and absolute perception. Experiment 1 extends the findings of S. Aglioti, J. F. X. DeSouza, and M. A. Goodale (1995) and suggests that the manual prehension component of open-loop reaching is affected by the horizontal-vertical illusion to a much smaller degree than perceptual size judgments. In Experiments 2 and 3, however, when perceptual size judgment is directed at a single element of the display, this difference vanishes. Experiment 4 demonstrates that grip scaling is strongly affected by the illusion when a single reach is scaled to both the horizontal and vertical components of a triangular figure.
Adult↗
Transfer of calibration in length perception by dynamic touch.
Earlier studies suggested that the calibration of actions is functionally, rather than anatomically, specific; thus, calibration of an action ought to transfer to actions that serve the same goal (Rieser, Pick, Ashmead, & Garing, 1995). In the present study, we investigated whether the calibration of perception also follows a functional organization: If one means of detecting an information variable is recalibrated, are other means of detection recalibrated as well? In two experiments, visual feedback was used to recalibrate perceived length of a rod wielded by the right hand; the recalibration was found to transfer to length perception with the left hand. This implies that calibration in perception is organized functionally rather than anatomically, and supports the general view that calibration applies to functional systems.
Adult↗
Cross-modal activation of visual cortex during depth perception using auditory substitution of vision.
Previous neuroimaging studies identified multimodal brain areas in the visual cortex that are specialized for processing specific information, such as visual-haptic object recognition. Here, we test whether visual brain areas are involved in depth perception when auditory substitution of vision is used. Nine sighted volunteers were trained blindfolded to use a prosthesis substituting vision with audition both to recognize two-dimensional figures and to estimate distance of an object in a real three-dimensional environment. Using positron emission tomography, regional cerebral blood flow was assessed while the prosthesis was used to explore virtual 3D images; subjects focused either on 2D features (target search) or on depth (target distance comparison). Activation foci were found in visual association areas during both the target search task, which recruited the occipito-parietal cortex, and the depth perception task, which recruited occipito-parietal and occipito-temporal areas. This indicates that some brain areas of the visual cortex are relatively multimodal and may be recruited for depth processing via a sense other than vision.
Acoustic Stimulation↗