The peculiarities of brain electric activity in mentally normal parents of schizophrenics (52 subjects) as compared to the control group of mentally normal subjects without family history of manifest psychosis (22 subjects). In both groups, EEG spectral densities and auditory evoked potentials (AEP) characteristics were compared. The parents of schizophrenics appeared to differ from controls by decrease of N1 amplitude and prolongation of N2, P3 which was similar to that observed in patients with schizophrenia. The findings are discussed as evidence of heritability of deviations in cognitive processes.