Topography of the auditory P300 in schizotypal personality

Background: Research with schizophrenic patients has demonstrated reduced amplitude of the P300b elicited with the auditory “oddball” paradigm, as well as reduced P300a amplitude following “novel” stimuli. The focus of the present study was the investigation of these components in a nonclinical sample of participants with high expressions of the schizotypal personality trait. Methods: By use of an acoustic oddball task, including the presentation of novel stimuli, the event-related brain potentials of 14 participants with “low” and 13 participants with “high” scores on the German adaptation of the “Schizotypal Personality Questionnaire” were investigated. Current source density (CSD) curves and spline-interpolated CSD maps were generated. Peak amplitudes and latencies of the N100, P200, P300a, and P300b were determined for the CSD data. Results: Results indicate no group differences with respect to N100, P200, and P300a amplitudes and latencies. By contrast, the P300b amplitude was significantly smaller in high- as compared to low-scoring participants. Left-temporal as compared to right-temporal P300b was significantly smaller in high- than in low-schizotypal participants. Conclusions: Confirming results of other researchers, this present study suggests that a reduced P300b amplitude and an altered P300b topography at temporal sites may be a trait-like “marker” of the schizophrenia spectrum.