ABNORMALITIES IN EVENT-RELATED POTENTIALS - N100, N200 AND P300 TOPOGRAPHY IN ALCOHOLICS

Event-related potentials were recorded in 30 abstinent alcoholics, and 30 gender- and age-matched controls during a two-tone discrimination (odd ball) task. All the subjects were free from medication and dextra l. The amplitudes of N100, N200 and P300 in the alcoholics were reduce d and the P300 latency prolonged as compared with those of the control s. A P300 amplitude reduction occurred in the left and midline frontal , and the left and midline central regions. This is the first report o f the amplitude of P300 being markedly decreased in the left hemispher es of the brains of the alcoholics. The results are discussed in terms of the cognitive dysfunctions of alcoholics.