Analysis of Stimuli Discrimination in Indian Patients with Chronic Schizophrenia

Abstract

Event-Related Potentials (ERPs) components are widely studied to understand brain response associated with cognitive processes in terms of amplitude, latency, and brain topography. Schizophrenia is a psychiatric illness which is characterized by reduced amplitude and increased latency of P300 ERP component. In this work, we have analyzed the attributes of P300 component involved during discrimination of visual stimuli (frequent, infrequent, and rare) at midline frontal and parietal sites in 14 schizophrenic patients who were receiving remediation in psychiatric setup for a long time. The key findings include increase in P300 amplitude when infrequent and rare stimuli were presented which reflected better contribution of attentional resources toward discrimination of stimuli. The P300 latency was found to be increased at same measurement sites for standards and rares for which the responses have to be ignored. The latencies were reduced in the case of infrequent stimuli (targets) which reflected better speed of cognitive processes involved during the identification of the stimuli.