REACTION TIME RESPONSES BY SCHIZOPHRENICS, MENTAL DEFECTIVES AND NORMAL ADULTS
J. TIZARD PH. D.1, and
P. H. VENABLES PH. D.1
1 The M.R.C. Unit for Research in Occupational Adaptation, Institute of Psychiatry, Maudsley Hospital, London, England.
A study carried out in a London mental hospital replicated an experiment by Rodnick and Shakow on "set in the schizophrenic as measured by a composite reaction time." Subjects were 25 chronic schizophrenics. A control group of 10 mental defectives and another of 10 colleagues of the writers were also tested. Results were similar to those obtained by Rodnick and Shakow, in that the schizophrenics were slower and more variable than the controls. Also unlike the controls, the schizophrenics tended to be quicker in response when the signals were presented at irregular intervals than when they were presented at regular ones, if the interval between a warning signal and the stimulus was greater than 4 seconds. Alternative hypotheses to account for the findings were proposed and tested but the results are held to confirm Rodnick and Shakow's hypothesis that schizophrenics suffer from defects of mental set.
