“I did what?” Most of us will have had that post-booze discussion with friends and family, trying to piece together just what happened the night before. Hell, they even made a movie franchise out of that very idea. But what causes the memory loss associated with boozing?
There has been considerable research into alcohol-related memory loss in recent decades but the effectiveness of the research has often been questionable as it relies heavily on anecdotal evidence and individuals reporting honestly. The answers to questions such as “have you ever had booze-related memory loss?” will vary depending on the culture in which you ask them.
In a culture where drunkenness is celebrated, such as our own, the answers might be skewed towards over-reporting. Similarly, in cultures where drunkenness is a source of embarrassment, such as in Japan, there is the potential for gross underreporting.
Indeed, in a study of over 2000 Finnish men it was found that 35 per cent had experienced alcohol-related blackouts in the year leading up to the survey. If you’ve ever been to Finland, you’d know those statistics are hugely underreported in a country that drinks so much mint vodka that even Russians tell them to slow down.
But recent work from the United States’ National Institute on Alcohol Abuse and Alcoholism has collated a variety of different research and found that not only are alcohol-related blackouts exceedingly common around the world, both in social drinkers and in heavy drinkers, the reason for it is all in the chemical effect alcohol has on your brain.
Alcohol affects a part of the brain called the hippocampus, which is hugely important in memory retention – specifically the conversion of short-term memories into longer-term ones.
The memory loss experienced due to alcohol is classified as ‘anterograde’, meaning it impairs the formation of new memories in the moment but does not damage already recorded memories.
So, when you have a memory blackout, you don’t actually lose memory – rather you never had it in the first place.
The experience is similar to the way in which we remember or don’t remember dreams. When you are asleep, you are constantly dreaming – kinda the body’s way of storing and collating the memories for the day via the subconscious – but your brain’s record button hasn’t been pressed, meaning you only remember your dreams in certain situations (such as if you have been woken up during a dream or if someone says your name to you as you are sleeping).
Much like the experience of when you dream, your body doesn’t actually record memories when you are on the sauce. The booze has turned off the record button, meaning that whatever you do you are likely to remember only snippets of it – or none at all – the next day.
The National Institute on Alcohol Abuse and Alcoholism gives us the lowdown on alcohol-related blackouts:
“Blackouts are much more common among social drinkers — including college drinkers — than was previously assumed, and have been found to encompass events ranging from conversations to intercourse [our emphasis].”
The effect on the brain is different for everyone, meaning that some people don’t need that many drinks to experience significant memory loss. Effects can be felt after just one or two drinks in some people.
Furthermore – and this had confused researchers previously, due to people wanting to underreport embarrassing memories – the memories lost don’t always need to relate to bad sex or raising a shopping trolley up a flagpole. Everyday, mundane tasks such as talking to someone or sending a text will also be easily forgotten, adding to the confusion.
Some drinkers may appear relatively sober, but the impact of alcohol on their brain is such that they are not recording memories when they talk to you. Nothing personal, it’s just a chemical reaction.
Finally, if you think this information is a green light to hit the booze, know that there are also long-term effects. While the extent of the long-term damage to the brain’s hippocampus due to drinking isn’t completely understood, researchers know that some damage does take place, and this can lead to other problems with brain function – particularly the way the different parts of the brain communicate.
So, if your life is a never-ending fact-finding mission into what you got up to the night before, just know that it isn’t all as fun as the Hangover movies suggest. Actually, it is probably about as fun – and as necessary – as The Hangover Part III.