The property of contingent negative variation (CNV) in psychiatric patients: schizophrenia and neurosis.

Abstract

The CNV parameters (amplitude and morphology) and the relationship between CNV parameters and performances (motor response time) were studied on schizophrenics (15 subjects), neurotics (15 subjects) and normal controls (30 subjects divided into 2 groups) in order to clarify the property of CNV in psychiatric patients. Also, the relationship between CNV and personality traits was investigated in neurotics. Since it has been known that age, sex and psychoactive drugs influence the CNV genesis in normal subjects, the control group method was used for these factors in this study. The results obtained were as follows: 1) Mean amplitudes of CNV's for schizophrenics and neurotics in each session of control, nonresponse and recovery tended to be lower than those for normal controls. Significant differences were found between schizophrenics and normal controls. 2) Correlations between CNV amplitude and response time in schizophrenics tended to be positive, while normal controls showed significantly high negative correlations. These findings were discussed from the viewpoint of the arousal theory of CNV genesis. 3) For the neurotic patients, the personality variables appeared to influence CNV amplitude. 4) Type B-CNV was most frequently seen in all sessions for normal controls. Schizophrenics and neurotics tended to show the increment of type P-CNV in nonresponse sessions without a motor response. 5) "Field Dependency" type-CNV was not found in psychiatric patients. This result did not correspond with the data reported by other investigators. 6) Type III- and type IV-prolonged CNV's appeared almost especially in schizophrenics although type II-CNV was observed in all groups. The mechanism of genesis of the prolonged CNV's was discussed.