Alcohol and retrograde memory effects: role of individual differences

OBJECTIVE: When alcohol is consumed following learning, the effect on delayed, sober memory can vary from person to person. We examined a range of individual differences to look for predictors of this variability. METHOD: Male social drinkers (N = 65; average age 23.3 years) were exposed to emotionally charged verbal stimulus materials while sober. Participants consumed 1.0 ml/kg alcohol immediately afterward and remained in an environment designed to minimize retrograde interference. Stimulus recall and recognition were tested 24 hours later, when participants had breath-alcohol concentrations of zero. Relationship between memory scores and individual differences (in age, education, alcohol consumption, vocabulary, verbal learning, emotionality, mood state 24 hours after learning, response to alcohol, personality and alcohol expectancies) were determined. RESULTS: Only age and vocabulary were significantly associated with memory score following drinking, probably because they constrained initial understanding of the statements and mediated the effects of alcohol on memory consolidation. CONCLUSIONS: The effects of a given dose of alcohol on emotionally charged verbal memory are similar for men of equal age and verbal skill, but independent of other individual differences. It is most likely that alcohol affects incidental memory by nonspecific enhancement or interference processes.