Aims: Prospective memory (PM; or memory for delayed intentions) can predict relapse. The presence of alcohol has been found to lower PM performance in between-subjects designs. However, this effect has not been demonstrated using a within-subjects design. Moreover, it has yet to be established whether individual differences in executive functioning (EF) act as mediators in alcohol-related PM failure.
Design: A single blind placebo controlled experiment was used. A placebo and a moderate dose of alcohol (0.06g/kg) were administered in counterbalanced sessions.
Setting: EF and PM tasks were administered under laboratory conditions.
Participants: Forty-eight native English-speaking males aged 18-36 years, regular moderate drinkers (with AUDIT scores of 1-20), and no history of alcohol or drug abuse.
Measurements: Tests of EF (inhibition, set shifting, updating, and verbal fluency) were presented at the beginning of testing. Two equivalent versions of the Memory for Intentions Screening Test (MIST; e.g., Raskin, Buckheit & Sherrod, 2010) were then administered on separate occasions.
Findings and conclusions: A moderate dose of alcohol reduced PM performance, especially when time-based cues were presented or verbal responses were required. Retrospective recall of the PM instructions was also reduced by alcohol. Stronger phonemic fluency and inhibition abilities predicted a reduced decline in time-based PM abilities under alcohol. Better task switching and phonemic fluency skills predicted reduced alcohol-related PM deficits in verbal responses. This is the first within-subjects study to show the acute effects of alcohol upon PM and indicate how EFs mediate these effects. The influence of alcohol on PM may limit the effectiveness of prevention campaigns designed to reduce alcohol-related harms.
