LATE ENDOGENOUS POTENTIALS IN 3-TONE EXPERIMENT IN SHORT-TERM 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 wit h sustained abstinence. However, some specific components of ERPs appe ar 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-to ne paradigm, which results in a two-stage process for evaluating and c lassifying stimuli. The amplitude of P300 in short-term abstinent alco holics was reduced significantly and recovered with time of abstinence at least partly. In alcoholics abstinent for eight months the mean am plitude was lower than of the control group, but this difference faile d to be significant. The long latency of the positive peak at about 60 0 ms seems to reflect delayed information processing in alcoholics, re vealed by two-stage processing. This component arises later in alcohol ics whether they stay abstinent or not.