Participants
Separate groups of 26 participants were involved in the Oddball Task (Mean age 20.77, range 18-32, 10 males, 2 left-handed) and the Regularity task (Mean age 19.62, range 18-30, 3 males, 0 left-handed). The experiments had local ethics committee approval and was conducted in accordance with the declaration of Helsinki (revised 2008).
Participants completed the Alcohol Use Disorders Identification Task (AUDIT; Babor et al., 2001) to assess chance differences in drinking behaviour and related problems between groups (Oddball Task mean = 9.65, Regularity task mean = 12.00, maximum possible score = 40).
Individuals were excluded from participation if they had a current or previous diagnosis of alcohol or other substance use disorder, assessed by self-report. Participants that met the eligibility criteria were asked to consume a low-fat meal approximately an hour before each session and to refrain from consuming caffeine. Participants also had to provide an alcohol breathalyser reading of zero mg/l upon arrival for their session.
The gap between alcohol and placebo sessions varied from 3-69 days in the Oddball task (median = 7), and 3-259 days (median = 8) in the Regularity task. Some participants did not return for their second sessions and were replaced.