Late endogenous potentials in three-tone experiment in short- and long-term abstinent alcoholics.

Information processing (and cognitive ERPs as their concomitants) has been observed to be disturbed in chronic alcoholics and to recover with sustained abstinence. However, some specific components of ERPs appear to remain significantly decreased in long-term abstinent alcoholics. Using a longitudinal design we investigated the effect of abstinence and relapse on P300 and Late Slow Wave. P300 was evoked by a three-tone paradigm, which results in a two-stage process for evaluating and classifying stimuli. The amplitude of P300 in short-term abstinent alcoholics was reduced significantly and recovered with time of abstinence at least partly. In alcoholics abstinent for eight months the mean amplitude was lower than of the control group, but this difference failed to be significant. The long latency of the positive peak at about 600 ms seems to reflect delayed information processing in alcoholics, revealed by two-stage processing. This component arises later in alcoholics whether they stay abstinent or not.