Selective attention differentially affects brainstem auditory evoked potentials of electrodermal responders and nonresponders.

Brainstem auditory evoked potentials (BAEPs) were recorded in adult male chronic schizophrenics on maintenance neuroleptic therapy, drug-free alcoholics, and normal subjects. Subjects were subdivided into electrodermal responders (Rs) and nonresponders (NRs). Attention was directed toward auditory or visual stimuli. Independent of diagnosis, latencies of BAEP wave V were longer in NRs when visual rather than auditory stimuli were attended to, while there was no task effect for Rs. This finding is interpreted as a sign of excessive selective filtering of auditory stimuli in NRs. In the alcoholic NRs, wave I-V conduction times were longer than those in any other subgroup, possibly indicating retarded neural transmission.