Redundancy-associated deficit in schizophrenic reaction time performance.

Examined the influence of information redundancy on the reaction-time performance of 3 groups of females: 36 hospitalized schizophrenics defined as process or reactive by the Elgin Prognostic Rating Scale; 18 nonschizophrenic psychiatric-patient controls; and 18 normal hospital staff controls. The influence of information redundancy was assessed by manipulating the degree of regularity in the presentation of preparatory interval (PI) durations. Runs of 2 and 4 identical PIs, defined as low and high redundant sets, respectively, were embedded in an irregular order of trials to test the influence associated with regular presentation. In contrast to previous analyses showing that the irregular vs. regular presentation condition interacts with PI duration, the interaction was found for process patients only. This interaction took the form of a "crossover" in which the regular PI trials yielded worse performance than the irregular trials at long PI durations; the opposite was true for short durations. Redundant PIs tended to show an improved performance immediately and then, for the process group only, a progressive loss on successive trials. An interpretation in light of D. Shakow's (see record 1965-08514-001) "set theory" and an inhibitory process explanation are disucssed. (25 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)