AUDITORY P300 TOPOGRAPHY AND NEUROPSYCHOLOGICAL TEST-PERFORMANCE - EVIDENCE FOR LEFT HEMISPHERIC DYSFUNCTION IN SCHIZOPHRENIA

Asymmetrical topography of the auditory P300 with reduced left hemisph eric amplitudes and, consequently, a right-lateralized peak of the P30 0 electrical field has been repeatedly reported in schizophrenia. This was interpreted as an indication of reduced left-hemispheric activity during the simple cognitive P300 cask, Since generator locations calc ulated from the surface potentials are ambiguous, further evidence is required to support this conclusion. In the present study, 13 stabiliz ed DSM-III-R schizophrenic patients were studied with an auditory P300 paradigm and neuropsychological methods sensitive to functional brain asymmetries. The tests included the verbal paired associates test (Go ldstein et al 1988, Cortex 24:41-52) and the nonspatial conditional as sociative learning rest (Petrides 1985, Neuropsychologia 23:601-614), A significant correlation was found between right-sided lateralization of the P300 maximal positivity and neuropsychological evidence for le ft hemispheric temporal hippocampal dysfunction. Attentional performan ce was correlated with P300 amplitudes. The results of this study prov ide further evidence that right-sided lateralization of the P300 peaks results from dysfunction of left-hemispheric neuronal generators. (C) 1997 Society of Biological Psychiatry.