Information processing in high and low redundancy schizophrenics.

Abstract

Cromwell's (1968, 1972, 1975) stimulus redundancy theory was tested on two levels: firstly, by examining the process-reactive and paranoid-nonparanoid dimensions which form the basis of identification of high and low redundancy schizophrenics; and secondly, by examining two predictions of the theory pertaining to the information processing characteristics of high and low redundancy schizophrenics. In the first part of the study, three schizophrenic groups (acute, chronic and remitted), nonschizophrenic psychiatric patients and normals were assessed on material relevant to ascertaining the basis of subdivisions such as the process-reactive dimension. It was concluded that process-reactive ratings were largely measures of extrinsic factors, such as social competence, and were of some practical use in assessments of prognosis. However, there was little basis upon which to conclude that such subdivisions of schizophrenic samples would result in the identification of groups of patients who would differ fundamentally in their cognitive functioning. In the second part of the study, two predictions of Cromwell's stimulus redundancy theory were examined: rate of processing and extensity of attention. The performance of high and low redundancy schizophrenics, nonschizophrenic psychiatric control patients and normal controls was assessed on three information processing tasks. The results offered no positive evidence for Cromwell's theory: low redundancy schizophrenics were not found to process information faster, or to have a broadened attentional field as compared to high redundancy schizophrenics. It was concluded that a more fruitful direction for future research may lie in investigations of the strategies of processing used by schizophrenic patients.