Previous studies in the laboratory have found that alcohol can facilitate memory if given after learning information. A study from Exeter University investigated whether this effect existed when alcohol is consumed in a naturalistic setting.
88 social drinkers (31 men and 57 women, aged 18 to 53) were given a word-learning task and were then randomly allocated to one of two groups and were told either to drink as much as they liked – the mean amount of alcohol consumed was 82.59 grams over the evening - or not to drink at all. The study assessed both retrograde facilitation and alcohol induced memory impairment using two independent tasks. In the retrograde task, participants learnt information in their own homes, and then consumed alcohol ad libitum. Participants then undertook an anterograde memory task, of alcohol impairment when intoxicated.
Both memory tasks were completed again the following day. For the retrograde task, as predicted, both conditions exhibited similar performance on the memory task immediately following learning (before intoxication) yet performance was better when tested the morning after encoding in the alcohol condition only. Units of alcohol drunk were positively correlated with the amount of retrograde facilitation the following morning.The anterograde task did not reveal significant differences in memory performance post-drinking.
The researchers say that their findings demonstrate the retrograde facilitation effect in a naturalistic setting, and found it to be related to the selfadministered grams of alcohol.
Professor Celia Morgan said: “Our research not only showed that those who drank alcohol did better when repeating the word-learning task, but that this effect was stronger among those who drank more. “The causes of this effect are not fully understood, but the leading explanation is that alcohol blocks the learning of new information and therefore the brain has more resources available to lay down other recently learned information into long-term memory. “The theory is that the hippocampus - the brain area really important in memory - switches to ‘consolidating’ memories, transferring from short into longer-term memory”
The researchers stressed this limited positive effect should be considered alongside the well-established negative effects of excessive alcohol on memory and mental and physical health.