ABSTRACT
OBJECTIVE: Results from various methodological modalities indicate laterality of brain function and information processing abnormalities in patients with schizophrenia. In neurophysiological field, there is particular interest in the P300 component of event related potentials, being recorded during discriminative information processing. A wide literatures documented reduction of P300 amplitudes in schizophrenic patients. The present study was designed to investigate the topographic pattern of amplitudes of P300 in the patients with schizophrenia. METHOD: The subjects were composed of patients (N=20) with schizophrenia by DSM-VI and normal controls (N=20). The Auditory event related potential P300 were measured by "oddball paradigm", which known as a standard method. P300 latency was determined by Global Field Power and amplitudes measured on 5 electrodes (Fz, Cz, Pz, T3, T4) were compared between controls and patients. RESULTS: There were reduction of P300 amplitudes on all 5 cortical areas in patients with schizophrenia compared with normal controls. There is no anterior to posterior effect but also left to right effect in the both groups. CONCLUSION: P300 amplitudes reduction without localization were founded in patients with schizophrenia.