COGNITIVE IMPAIRMENT AND SUBJECTIVE TIME IN JAPANESE SCHIZOPHRENICS AND NONSCHIZOPHRENICS
An important aspect of studies on time perception lies within the psychiatric realm. Accordingly temporal disintegration of the relation between past, present and future indicate a disrupted timeline and induce depersonalization. Disruption of psychological time is a central feature of many kinds of psychopathology, for instance in patients with brain lesions, in schizophrenics, in individual with Korsakow syndrome, in depressive patients, etc. Schizophrenia is in general regarded as a disorder of cognition (Bleuler, 1911). Time perception disturbances in schizophrenia have received most attention, and the research literature has often suggested that schizophrenics have a disturbed sense of time and that the schizophrenic Ìs ability to estimate time is disrupted. Minkowski stated as early as 1927 that extreme distortion of subjective time was the central symptom of schizophrenia. The present study was conducted to compare time perception of short durations, including intra- and interindividual variability of subjective duration judgments, in Japanese schizophrenic and in nonschizophrenic subjects. The psychophysical methods of reproduction, and of verbal estimation in subjective seconds, were used. It was found 1) that the means of the reproductions do not differ between the two groups, 2) the schizophrenics verbally estimated all durations longer and less veridical than the nonschizophrenic subjects, 3) the variability of the estimates between, as well as within, subjects is much greater in schizophrenics than in the nonschizophrenic group, 4) also the estimates by the schizophrenic group showed an approximately linear function of responses vs. the reference durations in log-log coordinates, in agreement with Stevens Ì power law. Schizophrenics are described in terms of distraction and of chaotic and disorganized behavior. This important aspect of schizophrenic symptomatology typically results in cognitive impairment. The impairment may be at the root of the deviant, though fairly consistent, estimations by the schizophrenics. They seem to be unable to translate perceived time into numbers (seconds), probably because of their general difficulty to quantify. The conclusion is that our result does not support the view of general time distortion as such in schizophrenia.