Topographic distribution of EEG alpha activity during ethanol-induced intoxication in women

Topographic maps of brain electrical activity from scalp EEG electrodes were obtained from healthy adult female volunteers using a Brain Electrical Activity Mapping (BEAM) system. Each woman received both ethanol (0.7 g/kg, p.o.) and placebo in a counterbalanced order under double-blind conditions at an interval of 1-6 days. Subjective reports of intoxication were obtained continuously via an instrumental joystick device. Subjects reported when they detected ethanol and qualitatively pleasant (i.e., euphoric) or unpleasant (i.e., dysphoric) effects. All subjects reliably discriminated ethanol from placebo. Pronounced increases in EEG alpha activity occurred during ethanol-induced intoxication in all subjects. Analysis of topographic maps revealed that the distribution of high-amplitude, fast-frequency EEG alpha activity extended further frontally to the central sulcus and temporally during ethanol intoxication than during control sessions or after placebo administration. Area analysis and significant probability mapping techniques were used to quantify the increased alpha activity and to monitor changes during the process of intoxication in each individual. One woman, with a positive family history of alcoholism, experienced only a mild degree of ethanol intoxication. This behavioral response was accompanied by a slight decrease or no change in both slow- and fast-frequency alpha activity. This finding in a single subject provides additional evidence that a possible genetic predisposition for ethanol-related effects on behavior may be reflected in measures of brain electrical activity. Overall, these data also suggest that ethanol induces rapid and widespread increases in EEG alpha activity which may be associated with the reinforcing properties of ethanol.