TEMPORAL INTEGRATION DEFICIT IN VISUAL INFORMATION-PROCESSING BY CHRONIC-SCHIZOPHRENICS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 18  (11) , 1311-1320
Abstract
Speed of visual information processing of chronic schizophrenics and normal subjects was evaluated. Retarded information processing by schizophrenics was attributed to a dysfunction at the earliest stage of processing. By using a backward-masking paradigm and varying target duration, whether schizophrenic and normals conform to an iconic or visual persistence theory of processing was evaluated. Also, whether schizophrenic and normal information processing is a function of the total time a stimulus is available for viewing prior to disruption (stimulus onset asynchrony, SOA), or whether it is the time following the stimulus offset prior to disruption by the mask (interstimulus interval, ISI) was evaluated. Th former conforms more closely to a visual persistence and the latter to an iconic notion of processing. Evidently, schizophrenics and normals conform to the processing of information as a fucntion of the SOA as opposed to ISI. Schizophrenic processing during the period of temporal integration (i.e., up to 130 ms) was significantly retarded when compared to normal controls. Evidently, for chronic schizophrenics, visual signals associated with target processing during the temporal integration period have either decayed at a slower rate or are more unstable than those of normals. The compatibility of these findings with a visual persistence as opposed to an iconic model of information processing is discussed.

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