Anyone who’s ever woken up bewildered after a night of hard drinking is well aware of alcohol’s relationship with memory. The usual questions — Where am I? How did I get here? Where are my pants? — corroborate the hypothesis that booze causes blackouts. While this has been scientifically shown to be true, an observation recently made by a team of researchers has left psychologists scratching their heads: In certain situations, alcohol can make our memories better.
This puzzling discovery, written up in a new article in the journal Psychopharmacology, investigated alcohol’s influence on the “misinformation effect.” Psychologists use this term to describe what happens when a person is fed incorrect information about an event they’ve already experienced — say, an eyewitness hearing an account that’s inconsistent with what they observed. The misinformation effect predicts that, because the brain is so open to suggestions, false memories will form. And this is true in most cases — except, the researchers hypothesized, something blocks the memory-forming process from letting false memories take root in the first place.
They tested their hypothesis — that booze can “protect” the brain from making false memories — by having 83 study participants watch a staged theft, getting some of them drunk without telling them (this was all done ethically, they insist), planting some false memories in their brains, then asking them what they remembered. Volunteers were divided into three groups: People who were aware they were getting drunk, people who knew they would be sober and stay that way, and people who received booze without knowing it. Those who did get drunk had just enough booze in their systems that they wouldn’t exceed the English drink-drive limit of 80 milligrams of alcohol per 100 milliliters of blood.
Dishing out misinformation consisted mostly of telling participants, after they watched the theft, that the thief had brown, not black, hair, or that the victim’s sweater was green, not blue. The next day, after the participants sobered up, they returned to the lab and recounted what they remembered.
The results were puzzling, to say the least: Of all of the participants, the sober ones turned out to be the most likely to remember false memories, while those who got drunk afterward most often remembered what actually happened. As counterintuitive as these findings may be, the researchers explain that they’re actually consistent with what we know about memory. “We think this is because alcohol blocks new incoming information, including misinformation, so it is less likely to have a negative impact on what was witnessed,” they wrote in The Conversation.
Booze, researchers hypothesize, interferes with the way our brains form memories, and it doesn’t discriminate between true and false ones. In 2004, research from the U.S. National Institutes of Alcohol Abuse and Addiction concluded that “Alcohol primarily disrupts the ability to form new long–term memories.” Still, the review also mentions that the magnitude of memory impairment was correlated to the amount of alcohol consumed, and the researchers behind the current study point out that more research is needed to see whether there’s an upper limit to how much alcohol can “protect” the brain for misinformation. After all, a person could drink so much alcohol they forget having watched the video in the first place.
The researchers are hoping that their initial findings will give lawyers and judges pause when assessing a witness’s ability to give a trustworthy testimony: Sober witnesses, they found, were not only “more suggestible to misinformation than our alcohol consumers” but were also more willing to “testify these incorrect responses in a court of law.” For those of us not involved in court cases, however, this research asks us to second-guess just how badly we remember our nights of boozing: It’s possible our memories aren’t nearly as faulty as our hungover selves expect them to be.