Perceptual deficits in schizophrenia and other psychotic disorders: A cognitive approach.
Item
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Title
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Perceptual deficits in schizophrenia and other psychotic disorders: A cognitive approach.
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Identifier
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AAI9207115
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identifier
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9207115
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Creator
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Rabinowicz, Esther F.
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Contributor
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Adviser: David R. Owen
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Date
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1991
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Experimental | Psychology, Clinical | Psychology, General
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Abstract
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Cognitive dysfunctions are fundamental to schizophrenia. Cognitive models illustrate that normals use dual processes--a global, perceptual process (stage one) followed by analytic and abstractive processes (STVM). Prior research found schizophrenics disregarded Gestalt properties of stimuli and outperformed controls on numerosity tasks. This suggested that schizophrenics have a specific, perceptual organization, early-information processing deficit that benefits them on analytic processing tasks. This study examines the performance of 8 acute and 16 chronic schizophrenics, 7 bipolar and 10 non-bipolar, mostly schizoaffective, psychotics, and 22 college and 16 hospital controls, via the same stimuli, in a number task (requiring analytic processing of 4, 5, or 6 dot patterns) and a form identification task (requiring holistic processing of square, rectangular or rhombic dot shapes). Three delay intervals between the stimulus offset and the cue to respond measured temporal processing. Patients were drug free and SCID diagnosed. Groups didn't differ in age, nor in number of previous hospitalizations. Four essential results confirm that our tasks tap different information processes, and patients and controls perform differentially. Delay improves controls' accuracy and decreases schizophrenics' accuracy on number processing (p {dollar}{dollar}.83), but controls' accuracy drops significantly (p {dollar}<{dollar}.03). All patients improve (p {dollar}<{dollar}.02) on perceptual form judgements, when shapes have more dots (i.e., additional cues). Schizophrenics are twice as impaired, and bipolars four-fold worse (p {dollar}<{dollar}.0001) on form than on number, relative to controls. The pattern of results support dual processing predictions for the control subjects and highlight specific deficits in each of the two stages for schizophrenics. Schizophrenics' performance both confirms and rebuts Place and Gilmore (1980). While prior literature places schizophrenics' deficits at the earliest stage, this research provides evidence for deficits at both the perceptual stage and the attentional allocation and consolidation stage. Contrary to previous findings, global processing deficits are ameliorated by enhancements and training. Affective psychotics, particularly bipolars, are both better and worse than schizophrenics on number and form processing respectively. State-trait differences may account for performance deficits in affectives. The pattern of results rebut Chapman and Chapman's (1973) generalized deficit hypothesis of attentional dysfunctions in schizophrenics.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
