Effects of alcohol on the performance of the Tower of London task in relation to the menstrual cycle: an electroencephalographic study.

It is well known that the metabolism of alcohol and cognitive functions can vary during the menstrual cycle. Also, both alcohol ingestion and hormonal variations during menstruation have been associated with characteristic changes in electroencephalographic (EEG) activity. The aim of the present study was to determine whether EEG activity during the performance of the Tower of London (TOL) task is affected by previous ingestion of alcohol and whether these EEG patterns vary in relation to different phases of the menstrual cycle. For this purpose, female participants consumed a moderate dose of alcohol or placebo during the follicular and early luteal phases of the menstrual cycle and then, 35 min after liquid ingestion, EEG activity was recorded during the performance of TOL. A deleterious effect of alcohol on TOL performance was potentiated in the follicular phase, related to a higher α1 relative power, probably as a result of the low progesterone levels characteristic of this menstrual phase. These data show the feasibility of examining the interaction of alcohol and menstrual cycle phases on cognitive performance by means of EEG recording, and contribute toward a better understanding of the brain mechanisms that underlie the cognitive changes that occur during the menstrual cycle under the effects of alcohol.