Redundancy deficit in the reaction time of normal subjects under standard and meprobamate-impaired conditions

Assessed latency and redundancy deficit, which reliably show impairment in process schizophrenics, using 20 normal Ss (mean age 30.4 yrs) with no psychiatric history. Ss were tested under standard/optimal and drug-impaired conditions to evaluate whether an expected increase in latency would be accompanied by a correlated increase in redundancy deficit. Ss completed RT trials in which they depressed and released a key in response to slides and a buzzer. Meprobamate was administered for the 2nd series of trials. In other research, the redundancy deficit index has been found to be independent of latency and has shown promise as a marker of schizophrenic information processing difficulty. The present findings confirm the independence of these 2 markers in that no increased redundancy deficit was observed despite a significant increase in latency. Findings also reveal a greater degree of redundancy deficit in normals under the optimal conditions than had been expected. A methodological problem with trial arrangements is discussed, and a review of studies that tested redundancy deficit in normal Ss is presented. (French abstract) (33 ref)