Investigating recollection and false memory after alcohol-induced blackouts in sober young adults

Episodes of extreme alcohol binge-drinking can result in memory loss, transient anterograde amnesic experiences known as memory blackouts (MBO). The current study investigates whether recognition memory is impacted by frequency of blackout experiences, and if false memories are more likely for those who regularly experience blackouts (n = 29) in comparison to a control group (n = 24) who had never experienced an MBO. Participants completed a recognition memory paradigm (a modified DRM task: Roediger & McDermott, (1995)), with a follow-up remember/know/guess judgement, before-alcohol and after-alcohol in the same testing session, while the MBO group (n = 23) additionally completed the task in a subsequent testing session within 20-hours of a blackout, but when sober again. Both groups displayed reduced discrimination (d’) between old and new words and a more conservative response strategy after-alcohol, which remained for MBO participants after-MBO. Critical lure words elicited more false-alarms than weakly related or unrelated words, yet the overall frequency of false-alarms dropped after-alcohol and remained depressed after blackout for the MBO group. Critically, decile analysis revealed significant shifts in d’ for early deciles (1st-6th), suggesting impairment to recognition memory after-MBO; severity of individual MBO experiences may impact these results, although it is not possible to attribute them solely to blackout events. Future work should investigate whether adults with a longer history of alcohol-induced memory blackout experiences display an impairment in recollection and familiarity, or show atypical false memory acceptance rates.