Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Perceptual Closure”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2006

Groups as epistemic providers: need for closure and the unfolding of group-centrism.

Theory and research are presented relating the need for cognitive closure to major facets of group behavior. It is suggested that a high need for closure, whether it is based on members' disposition or the situation, contributes to the emergence of a behavioral syndrome describable as group-centrism--a pattern that includes pressures to opinion uniformity, encouragement of autocratic leadership, in-group favoritism, rejection of deviates, resistance to change, conservatism, and the perpetuation of group norms. These theoretical predictions are borne out by laboratory and field research in diverse settings.

Cognition↗
PubMed1993

A closed curve is much more than an incomplete one: effect of closure in figure-ground segmentation.

Detection of fragmented closed contours against a cluttered background occurs much beyond the local coherence distance (maximal separation between segments) of nonclosed contours. This implies that the extent of interaction between locally connected detectors is boosted according to the global stimulus structure. We further show that detection of a target probe is facilitated when the probe is positioned inside a closed circle. To explain the striking contour segregation ability found here, and performance enhancement inside closed boundaries, we propose the existence of a synergetic process in early vision.

Discrimination, Psychological↗
PubMed1995

Sex and familial sinistrality differences in cognitive abilities.

Cognitive functioning was assessed in 69 left-handed males and females with a positive family history of left-handedness and in 77 left-handed and 55 right-handed males and females without familial left-handedness. Compared to females, males performed better on numerical reasoning and on two visuospatial tasks involving spatial manipulations (Figure Rotation and Surface Development). Within the group of left-handers, the multivariate effect for Familial Sinistrality was significant. Left-handers with familial left-handedness exhibited better scores on numerical reasoning, on verbal reasoning, and on two visuospatial tasks involving visual closure (Hidden Figures, Picture Completion) than did left-handers without left-handed relatives. The nonfamilial left-handers also exhibited lower scores on both inductive reasoning tasks when they were compared to their right-handed counterparts. The outcome runs contrary to the prevalent conclusion that left-handers with left-handed relatives are more likely to exhibit lower performances on visuospatial tasks than left-handers without such relatives.

Adolescent↗
PubMed1991

Parallel computation of primitive shape descriptions.

This article reports evidence that parallel search functions can occur when heterogeneous conjunction elements configure into a single object description. Experiment 1 demonstrates parallel search for form conjunctions presented in displays of heterogeneous nontargets when closure and good continuation between display elements are exhibited. When closure and good continuation are absent, reaction times increase linearly with set size (Experiment 2). Experiment 3 demonstrates a halfway stage between these two extremes, in which displays have closure but not good continuation. Finally, selection of object descriptions is shown to be temporally limited to one object at a time (Experiment 4). The data are incompatible with both local feature-based and distractor similarity-based accounts of visual search; however, they are compatible with there being an important role for preattentive feature combinations forming primitive object descriptions. Parallel search functions can occur when heterogeneous conjunctions configure into a single object description.

Adult↗
PubMed2004

Handedness and spatial ability: differential patterns of relationships.

The purpose of this exploratory study was to add to our understanding of hemispheric specialisation by examining the relationships between functional laterality (as measured by handedness, eyedness, earedness, and footedness) and spatial tests. A total of 55 males and 170 females were tested for laterality preferences and spatial test performance using a range of six spatial tests. There was a statistically significant relationship between each of the laterality measures employed, with handedness and footedness demonstrating the most robust association. Multiple regression analyses highlighted that once potential confounds were statistically controlled (age, sex, and other types of functional laterality), 3-D rotation/visualisation and speeded visual exploration task performance showed small, but significant, relations with a tendency towards left-handedness over right-handedness in total and secondary (two-handed) scale scores. Flexibility of closure performance was associated with a tendency towards left-handedness in the total and one-handed scale scores. Spatial location memory was the lone spatial ability relating with a tendency towards right-handedness. Overall, these findings offer new insights into the interplay of handedness with alternative measures of laterality as well as with spatial abilities.

Adult↗
PubMed1989

Prosopagnosia: a defect in visual configural processing.

A patient with severe, lasting prosopagnosia could not get an immediate overview of a face sufficiently specific for successful identification. He also failed completely in tasks of visual closure despite adequate performances on numerous other tests of visual perception and memory. We conclude that prosopagnosia represents a loss of visual "configural processing"--a learned skill enabling immediate identification of individual members of a class without conscious visuospatial analysis or remembering. Prosopagnosia and agnosic alexia represent two distinct defects of configural processing: Alexics cannot identify items with distinctive features that are themselves identifiable. Prosopagnosics cannot identify objects whose critical distinguishing features have no independent identities.

Adult↗
PubMed1993

Influences of closure, occlusion, and size on the perception of fragmented pictures.

Two experiments examined the ability to recognize a repeated figure in stimuli where only fragments of the figures were presented. Fragments were either closed or open regions presented either with or without an occluder that filled the spaces between the fragments (Experiment 1). Recognition performance was significantly better for open fragments, with or without an occluder, contrary to previous assertions that the occluder is the important factor for recognition. When stimulus size was varied, an occluder hindered recognition performance in the smallest size condition relative to unoccluded stimuli, which were equally easy to recognize across all size conditions (Experiment 2). The size results support the idea of size invariance in object naming. The difficulty in the smallest occluded condition is discussed in terms of differences in global and local processing depending on visual angle and sparsity.

Adult↗
PubMed2003

The watercolor effect: a new principle of grouping and figure-ground organization.

The watercolor effect is perceived when a dark (e.g., purple) contour is flanked by a lighter chromatic contour (e.g., orange). Under these conditions, the lighter color will assimilate over the entire enclosed area. This filling-in determines figure-ground organization when it is pitted against the classical Gestalt factors of proximity, good continuation, closure, symmetry, convexity, as well as amodal completion, and past experience. When it is combined with a given Gestalt factor, the resulting effect on figure-ground organization is stronger than for each factor alone. When the watercolor effect is induced by a dark red edge instead of an orange edge, its figural strength is reduced, but still stronger than without it. Finally, when a uniform surface is filled physically using the color of the orange fringe, figure-ground organization is not different from that for the purple contour only. These findings show that the watercolor effect induced by the edge could be an independent factor, different from the classical Gestalt factors of figure-ground organization.

Adult↗
PubMed1979

The effects of personality traits on Memory-For-Designs performance.

Examined 241 Memory-For-Designs protocols for the drawing styles of closure difficulty, figure-size expansion, and figure-size constriction. Chi squares then were employed to compare those data with the personality traits of the Ss. Personality traits were assessed through use of the Sixteen Personality Factor Questionnaire. The major conclusion drawn from the data analysis was that regardless of his or her personality trait, a S will perform like most other Ss in relation to Memory-For-Designs test behavior. The Ss were university students between the ages of 18 and 23, male or female, who were U. S. citizens attending Emporia State University. Initially, Ss were given the Sixteen Personality Factor Questionnaire in groups. Ss who met sample qualifications on the personality test were asked to return for an individual follow-up test with the Memory-For-Design.

Adolescent↗
PubMed1979

Acceptance of lack of closure: is it an index of advanced reasoning?

Lunzer reported data suggestive of a stage of cognitive development manifest between 9 and 11 years of age characterized by the ability to avoid drawing premature inferences when faced with ambiguity (i.e., accept lack of closure [ALC]). The present study sought to test this hypothesis. Inference tasks emphasizing ALC, memory, and hypothetico-deductive reasoning were administered to 67 males and 74 females (5-12 years in age). Although use of ALC increased with age, considerable use was evidenced on a simple task among 7-8-year-olds. On tasks hypothesized to place increasing demands on working memory, longer tasks were found to be more difficult. Marked improvement due to memory aids suggested that task difficulty results from limitations in working memory as predicted by Pascual-Leone's theory. Tasks requiring hypothetico-deductive reasoning were found to be most difficult. Performance was related to subject's spontaneous use of ALC. Lack of appropriate strategies was hypothesized to prevent solution rather than lack of logical competence. In conclusion, the relationship of ALC to age appears to be mediated by memory development rather than logical development.

Child↗
PubMed2002

A cross-cultural study of the Need for Cognitive Closure Scale: comparing its structure in Croatia, Italy, USA and The Netherlands.

This study was designed to compare the factor structure of Need for Closure Scale (NFCS) as it emerges from three European samples (Croatia, Italy and The Netherlands) to the structure emerging from a USA sample, and to test the invariance of the structure of the scale both across three European contexts and across European and US samples. This comparison was conducted to examine the generalizability of results obtained with the NFCS across cultures. The sample sizes employed in this study range from 201 (Croatia) to 418 (Italy) participants. First- and second-order confirmatory factor analysis and multiple-group measurement invariance tests were performed using the LISREL-8 program (Jöreskog and Sörbom, 1993). The analyses revealed that the factor structure of the scale was invariant across all samples, and that the best fitting model was one with two latent second-order factors, thus confirming results of previous studies (Kruglanski et al., 1997; Neuberg, Judice, & West, 1997).

Adult↗
PubMed1991

Influence of physical and semantic information in a categorisation task of fragmented forms.

Two experiments were carried out to investigate the influence of structural and semantic information in the categorisation of visual forms. In experiment 1 the stimuli were pairs of 'well structured' or 'poorly structured' fragmented forms differing in structural properties including convexity, collinearity, and closure of the elements, and in their 'nameability'. The influence of structural and semantic information was tested by means of a task involving the presentation to both visual hemifields separately of stimuli having within-category physical similarity. For well structured forms, subjects were asked to judge if two sequentially presented forms belonged to the same semantic category. For poorly structured forms, subjects were required to decide if two stimuli belonged to the same previously learnt category of forms. For the two types of stimuli, one category was composed of physically similar items, and the other was composed of physically dissimilar items. The results show a marked advantage for the category composed of physically similar forms when the stimuli are well structured but no differences between the two categories when the stimuli are poorly structured. This suggests a facilitation in the computation of global shape information for forms having collinear and closed elements. The only effect of semantic information was a tendency towards a right visual field advantage for same-category pairs of well structured forms. The pattern of results for well structured fragmented forms (experiment 1) and forms in which fragments had been joined in order to complete the contour (experiment 2) were similar, suggesting that structured incomplete forms can be processed in the same way as forms having a continuous contour. Hypotheses about the organisational processes of forms are proposed in the discussion.

Adult↗
PubMed1988

Verbal and figural Gestalt Completion Tests with lateralized occipital area brain damage.

Verbal and figural forms of the Gestalt Completion Test were administered to 8 subjects with left or near left occipital, 12 with right or near right occipital, 12 with left anterior-lateral and 9 with right anterior-lateral lesions. Z score indices of verbal vs. figural scores were constructed. The indices for these groups were compared. Damage to the left occipital area did not impair the figural score more than the verbal, while damage to the right occipital area impaired the figural considerably more than the verbal. The anterior-lateral groups had no lateralized impairment. This supports the concept that the left occipital area perceptually transforms verbal visual data, while the right occipital area transforms figural visual data.

Brain Damage, Chronic↗
PubMed1989

Gifted and nongifted race and gender effects on item functioning on the Kaufman Assessment Battery for Children.

This study examined differential item function on the K-ABC for gifted and nongifted subjects on the basis of race and gender using the technique for partial correlation proposed by Stricker (1982) and Reynolds, Willson, and Chatman (1984). It was determined that there were no items biased against gifted Black children and that 8 items were biased against gifted White children. Three items were found to be biased against nongifted Black children, while 4 items were biased against nongifted White children. When gender was considered, 2 items were found to be biased against gifted males, and 2 items also were found to be biased against gifted females. There were 10 items that were biased against nongifted Black males and 6 items biased against nongifted females. Systematic bias against race or gender was not found. It appears that the K-ABC is a relatively nonbiased test suitable for the evaluation of both gifted and nongifted children regardless of race or gender.

Achievement↗
PubMed1994

Procedural and declarative memory: a developmental study.

Measures of procedural and declarative memory were administered to 88 children forming two groups, aged 8 and 12. Two measures of priming, Gollin Figures and Degraded Words, were compared to declarative measures of recall. Strong support for a developmental dissociation between priming tasks and declarative memory was found. Both age groups showed a similar amount of priming facilitation, yet a significant age effect was observed for the declarative recall tasks. Current findings demonstrate that the level of procedural memory performance stabilizes during a period of development when declarative memory continues to improve.

Association Learning↗
PubMed1999

Volume completion.

The visual system completes image fragments into larger regions when those fragments are taken to be the visible portions of an occluded object. Kellman and Shipley (1991) argued that this "amodal" completion is based on the way that the contours of image fragments "relate." Contours relate when their imaginary extensions intersect at an obtuse or right angle. However, it is shown here that contour relatability is neither necessary nor sufficient for completion to take place. Demonstrations that go beyond traditional examples of overlapping flat surfaces reveal that "mergeable" volumes, rather than relatable contours, are the critical elements in completion phenomena. A volume is defined as a 3-D enclosure. Typically, this refers to a surface plus the inside that it encloses. Two volumes are mergeable when their unbounded visible surfaces are relatable or the insides enclosed by those surfaces can completely merge. Two surfaces are relatable when their visible portions can be extended into occluded space along the trajectories defined by their respective curvatures so that they merge into a common surface. A volume-based account of amodal completion subsumes surface completion as a special case and explains examples that neither a contour- nor a surface-based account can explain.

Attention↗
PubMed2002

The interpolation of object and surface structure.

One of the main theoretical challenges of vision science is to explain how the visual system interpolates missing structure. Two forms of visual completion have been distinguished on the basis of the phenomenological states that they induce. Modal completion refers to the formation of visible surfaces and/or contours in image regions where these properties are not specified locally. Amodal completion refers to the perceived unity of objects that are partially obscured by occluding surfaces. Although these two forms of completion elicit very different phenomenological states, it has been argued that a common mechanism underlies modal and amodal boundary and surface interpolation (the "identity hypothesis"; Kellman & Shipley, 1991; Kellman, 2001). Here, we provide new data, demonstrations, and theoretical principles that challenge this view. We show that modal boundary and surface completion processes exhibit a strong dependence on the prevailing luminance relationships of a scene, whereas amodal completion processes do not. We also demonstrate that the shape of interpolated contours can change when a figure undergoes a transition from a modal to an amodal appearance, in direct contrast to the identity hypothesis. We argue that these and previous results demonstrate that modal and amodal completion do not result from a common interpolation mechanism.

Depth Perception↗