This AEP study aims to investigate the characteristics of cerebral responsiveness in a large number of 181 schizophrenics compared with 200 normal controls. AEPs evoked by binaural click stimuli were recorded with 1024 msec of analysis time through the two derivations (3 CH: Cz→A1+2, 6 CH: Cz→T5). The differences between the two groups of each sex in latency and interpeak amplitude were estimated statistically.
The statistically significant (P<0.01 or 0.05) results were obtained as follows.
1. The schizophrenic group of both sexes showed a significant latency prolongation, middle latency components, P 2, P 3, long latency components, especially for the most prominent negative peak N 4 and prominent positive peak P 5.
2. The schizophrenic group of both sexes showed a significant interpeak amplitude reduction including the most prominent negative peak N 4 and prominent positive peak P 5, but augmentation for N 2-P 3.
3. There were no significant differences in latency and amplitude of N 4, P 5 between unmedicated and medicated schizophrenics. A few components with significant differences in latencies and amplitudes between the subjects taking antipsychotics more than 600 mg, in chlorpromazine equivalent values, or not, coincides with those also between the epileptics and healthy subjects.
Theses differences in the middle and long latency components confirmed regardless of schizphrenic subtypes, suggests the dysfunction in the primary and secondary cortex in schizphrenics
