Time estimation by healthy subjects and schizophrenic patients: a methodological study.

Three different methods were used to investigate the perception of short time intervals by 60 healthy subjects and a pilot group of 15 schizophrenic patients. The usefulness of metronome adjustment, verbal estimation, and operative estimation was evaluated. Estimation of longer time intervals was also studied. The influence of age, sex, oral temperature, and pulse rate was assessed. Earlier findings that schizophrenic subjects tend to overestimate short time intervals were supported by data from all three methods. Operative estimation--the subject's production of a requested time interval--could possibly best discriminate between the two groups. Estimation of longer time intervals did not differ significantly for the two groups.