Ereigniskorrelierte Oszillationen nach Präsentation alkoholbezogener Hinweisreize in der visuellen Modalität bei alkoholabhängigen Patienten

Abstract

New models of alcohol dependence postulate an attentional bias for alcohol-related cues in abstinent alcoholics that is associated with the motivation to drink alcohol. An understanding of the underlying neurophysiological mechanisms is important for an effective treatment of alcohol dependence. Aim of this study was to analyze whether event-related delta, theta and alpha oscillations elicited by alcohol-related pictures reflect such an attentional bias in abstinent alcoholics. Furthermore the influence of subacute abstinence phenomenon and the effect of stimulus repetition were investigated. Nine controls and nine abstinent patients with alcohol dependence viewed alcohol-related and neutral pictures while EEG was recorded one week after start of detoxification as well as six weeks later. One week after detoxification, 60 alcohol-related pictures and 60 neutral pictures were presented pseudo-randomized (condition 1). Six weeks later, the EEG session consisted of three conditions: 60 new alcohol-related and neutral pictures (condition 2), 25 alcohol-related and 25 neutral pictures chosen from condition 2 (condition 3, habituation-session) which were presented four times, and 60 new alcohol-related and 60 neutral pictures (condition 4, transfer-session). Repeated measures ANOVAs revealed an enhanced alpha activity elicited by alcohol-related stimuli compared to those elicited by neutral pictures in the patients with alcohol dependence during condition 2 and 4 whereas there was no alpha band enhancement in condition 1 and 3. Patients also showed enhanced alpha activity in contrast to controls elicited by alcohol-related pictures in condition 2 and 4. No significant differences were found for delta and theta oscillations. Taken together the alpha enhancement in condition 2 and 4 could reflect an early attentional bias in alcoholics toward the alcohol-related stimuli. However, this alpha enhancement merely occurs after termination of detoxification. The repetition of the alcohol-related stimuli in session 3 apparently leads to a habituation effect in the patients whereas there is no transfer effect for new the alcohol-related pictures: in session 4 the alpha band enhancement elicited by the alcohol-related pictures points to the early attentional bias for the new alcohol-related pictures again.