Perceptual closure in schizophrenia.

S, Snyder; Rosenthal, David; Ia, Taylor

doi:10.1037/h0040704

Cited by 27 publications

(9 citation statements)

References 13 publications

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“…On three rarely used psychophysical tasks (Galton liar; Sander parallelogram; Kunnapas squares) Cooper (1960) found chronic schizophrenics significantly less accurate and more variable. Johannsen, Friedman & Liccione (1964) showed that schizophrenics have dificulty in achieving percep-Dnta-Processing Levels and Schizophrenia '0.5 tual closure, a finding in agreement with that of Snyder, Rosenthal & Taylor (1961). Three studies agreed in finding differences between acute schizophrenics and controls on the reproduction of visual figures (Bernstein, 1963;Burton & Sjoberg, 1964;Taylor, Rosenthal & Snyder, 1963).…”

Section: Iieceptor Ieveimentioning

confidence: 80%

Data‐processing levels and thought disorder in schizophrenia

Yates¹

1966

Australian Journal of Psychology

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It is argued that most experimental studies purporting to demonstrate “thought disorder” in schizophrenia are ambiguous as to interpretation since they fail to distinguish between the various levels of information‐processing at which break‐down can occur. Evidence from various sources is presented which suggests that thought disorder is secondary to a primary slowness in processing information, which in turn leads to continuous loss of information from the short‐term memory system. A technique for testing the theory is suggested. Other theories of thought‐disorder are discussed and it is suggested that these theories relate to phenomena which result from the primary defect.

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Section: Iieceptor Ieveimentioning

confidence: 80%

Data‐processing levels and thought disorder in schizophrenia

Yates¹

1966

Australian Journal of Psychology

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“…Patients with schizophrenia have impaired visual integration abilities that have been documented in more than 50 studies, spanning over 50 years, as demonstrated by several different research groups, using varied tasks, and in different cultures (Snyder et al, 1961; Izawa and Yamamoto, 2002; Chen et al, 2005; Sehatpour et al, 2010; Silverstein and Keane, 2011). The present study used a contour integration task that was used previously by Silverstein and colleagues (Silverstein et al, 2006, 2009, 2012) to investigate visual integration deficits in schizophrenia.…”

Section: Discussionmentioning

confidence: 99%

An event-related potential examination of contour integration deficits in schizophrenia

Butler¹,

Abeles²,

Silverstein³

et al. 2013

Front. Psychol.

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Perceptual organization, which refers to the ability to integrate fragments of stimuli to form a representation of a whole edge, part, or object, is impaired in schizophrenia. A contour integration paradigm, involving detection of a set of Gabor patches forming an oval contour pointing to the right or left embedded in a field of randomly oriented Gabors, has been developed for use in clinical trials of schizophrenia. The purpose of the present study was to assess contributions of early and later stages of processing to deficits in contour integration, as well as to develop an event-related potential (ERP) analog of this task. Twenty-one patients with schizophrenia and 28 controls participated. The Gabor elements forming the contours were given a low or high degree of orientational jitter, making it either easy or difficult to identify the direction in which the contour was pointing. ERP results showed greater negative peaks at ~165 (N1 component) and ~270 ms for the low-jitter versus the high-jitter contours, with a much greater difference between jitter conditions at 270 ms. This later ERP component was previously termed Ncl for closure negativity. Source localization identified the Ncl in the lateral occipital object recognition area. Patients showed a significant decrease in the Ncl, but not N1, compared to controls, and this was associated with impaired behavioral ability to identify contours. In addition, an earlier negative peak was found at ~120 ms (termed N120) that differentiated jitter conditions, had a dorsal stream source, and differed between patients and controls. Patients also showed a deficit in the dorsal stream sensory P1 component. These results are in accord with impairments in distributed circuitry contributing to perceptual organization deficits and provide an ERP analog to the behavioral contour integration task.

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“…There are many paradigms for studying such grouping, with contour integration being an example that is often used because it can be rigorously controlled. Since 1961, many of these paradigms have been used to study visual grouping in schizophrenia (Snyder, 1961; Snyder et al, 1961), with the general conclusion being that it is impaired, as reviewed by Silverstein and Keane (2011). Impaired grouping in schizophrenia has been demonstrated in studies of perceptual organization of static forms, fragmented forms, completion of occluded objects, illusory correlations, and coherent motion.…”

Section: The Functions and Mechanisms Of Context-sensitive Gain-contrmentioning

confidence: 99%

The coherent organization of mental life depends on mechanisms for context-sensitive gain-control that are impaired in schizophrenia

Phillips¹,

Silverstein²

2013

Front. Psychol.

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There is rapidly growing evidence that schizophrenia involves changes in context-sensitive gain-control and probabilistic inference. In addition to the well-known cognitive disorganization to which these changes lead, basic aspects of vision are also impaired, as discussed by other papers on this Frontiers Research Topic. The aim of this paper is to contribute to our understanding of such findings by examining five central hypotheses. First, context-sensitive gain-control is fundamental to brain function and mental life. Second, it occurs in many different regions of the cerebral cortex of many different mammalian species. Third, it has several computational functions, each with wide generality. Fourth, it is implemented by several neural mechanisms at cellular and circuit levels. Fifth, impairments of context-sensitive gain-control produce many of the well-known symptoms of schizophrenia and change basic processes of visual perception. These hypotheses suggest why disorders of vision in schizophrenia may provide insights into the nature and mechanisms of impaired reality testing and thought disorder in psychosis. They may also cast light on normal mental function and its neural bases. Limitations of these hypotheses, and ways in which they need further testing and development, are outlined.

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Perceptual closure in schizophrenia.

Cited by 27 publications

References 13 publications

Data‐processing levels and thought disorder in schizophrenia

Data‐processing levels and thought disorder in schizophrenia

An event-related potential examination of contour integration deficits in schizophrenia

The coherent organization of mental life depends on mechanisms for context-sensitive gain-control that are impaired in schizophrenia

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