The effects of post-learning alcohol ingestion on motor memory consolidation


Memory consolidation refers to the ensemble of neuroplastic phenomena that take part following learning that allow newly formed memories to transform into long-term memories. However, the mechanisms of this process for human motor memories remain elusive. Interestingly, human studies on declarative memories indicate that pharmacological interventions seeking to increase GABAergic activity immediately post-learning enhance memory consolidation in a dose- dependent manner. This study sought to evaluate if such intervention can also enhance motor memory consolidation by testing the following hypothesis: post-learning alcohol consumption – a pharmacological agent known to increase GABAergic activity, amongst other actions – will dose-dependently enhance motor memory consolidation as compared to a placebo condition. To that purpose, a fully within-subject and counterbalanced design was carried out where participants (n = 24) had to adapt to a gradually introduced visual deviation and then ingest a beverage that either contained no alcohol (Placebo), a Moderate or a High dose of alcohol. The alcohol doses were sex- and body weight-adjusted to reach a peak blood alcohol concentration of 0.000%, ~0.050%, and ~0.100% for the Placebo, Moderate, and High conditions, respectively. To assess consolidation, retention was measured 24h later through reach aftereffects. Results revealed that, in absence of performance differences upon initial learning, there were no significant differences in retention, between conditions, 24h after initial learning. These results suggest that post-learning alcohol ingestion does not enhance motor memory consolidation. One possibility is that an intervention seeking to increase GABAergic activity immediately post- learning does not facilitate the neuroplastic phenomena mediating memory.