Event-related potential correlates of impaired selective attention in children at high risk for schizophrenia.

Auditory event-related potentials (ERPs) associated with selective attention were recorded in 21 children at high-risk for schizophrenia and in 21 matched controls. The subjects performed a selective listening task. For behavioral evaluation, target counts on the selective listening task and on cognitive performance were assessed. Group-specific differences of ERP components could be demonstrated, as reflected by significant amplitude reductions of the frontally located negative difference wave (Nd) and of the P3 component, following selectively attended stimuli, in the high-risk children. P3 latencies tended to be prolonged in the high-risk group. Reduced Nd was found in 14 and reduced P3 in 16 high-risk children among the 21 matched pairs. Significant correlations between the ERP reductions and psychometric deficit (counting accuracy) were observed. Mismatch negativity (MMN), an ERP component associated with automatic processing of physically deviant stimuli, did not differentiate significantly between groups, but was distinctly reduced in the high-risk group. The Nd and P3 reductions suggest deficits of selective attention in a considerable number of the subjects genetically at risk for schizophrenia. The present findings are discussed with respect to their relevance as indicators of a predisposition to schizophrenia.