J Korean Soc Biol Psychiatry.  2004 Jun;11(1):40-48.

A Study of Visual Event-Related Potential P300 in Schizophrenia

• Oh DH
• Nam JH
• Ahn DH
• Kim SH
• Choi JH

Abstract

OBJECTIVE
Event-related potentials(ERPs) are electrical changes recorded at the surface of the scalp in response to stimulus presentation, and their latency and amplitude change according to cognitive processes. Through past studies of the auditory ERP in schizophrenia, the P300 has been reported to be statistically smaller and delayed in schizophrenia than comparison groups. However, studies of the visual ERP have not been systematically examined. The present study was designed to investigate the visual P300 in patients with schizophrenia and normal controls and to compare the pattern of P300 between them.
METHODS
The subjects were composed of patients(N=22) with schizophrenia by DSM-IV and normal controls(N=22). The visual ERPs were measured by the visual continuous performance test. P300 amplitude and latency measured on 5 scalp electrodes(Fz, Cz, Pz, T7, T8) were compared between patients and controls.
RESULTS
The P300 latencies measured on Fz, Cz, Pz, and T7 electrodes were significantly longer in patients than controls(p<0.05). The P300 amplitudes in patients were smaller than controls. However, the difference between them was not statistically significant.
CONCLUSION
Analysis of the visual ERPs showed that the P300 latency is significantly delayed and the P300 amplitude is slightly smaller in patients than controls. These results are similar to established studies of the auditory P300 in schizophrenia.

MeSH Terms

Diagnostic and Statistical Manual of Mental Disorders
Electrodes
Evoked Potentials*
Humans
Scalp
Schizophrenia*