Visual selectivity in schizophrenia.

Abstract

Further information concerning the nature of selective attention processes in schizophrenia was sought by examining selectivity in the region corresponding to the normal stationary visual field. Acute schizophrenic, chronic schizophrenic, and neurotic subjects were required to discriminate pairs of vertical columns of dots that varied in confusion value and in display angle. The results indicated that chronic subjects were only able to process low confusion peripheral stimuli within a narrow display angle of 12 degrees. Accurate discrimination of high confusion stimuli was limited among chronics to a display angle of 2 degrees. Acute schizophrenics were able to discriminate peripheral stimuli to 25 degrees. Although the performance of neurotic subjects was significantly better than that of chronic subjects, accurate discrimination of high confusion stimuli for neurotic subjects was limited to a display angle of 12 degrees. Differences in performance topography were attributed to the use of different selective strategies. The spatial extensity within which more efficient grouping strategies were used was apparently constricted for chronic schizophrenics and extended for acute schizophrenics relative to neurotic controls.