The ‘Nijmegse Vierdagsefeesten’ just started. Thousands will enjoy many drinks but hopefully not to the point of memory loss. How does alcohol affect your memory?
Image from Wikipedia on binge drinking. A police man that tries to restore order and safety at public event with drunken individuals.
The festival season has started, and in just a few days Nijmegen will host the event of the year: Nijmeegse Vierdaagsefeesten. Great music and an enthusiastic crowd set the atmosphere for parties and drinks. Lots of drinks! And more drinks, and even more drinks… So many drinks, that some of us will wake up the next day with a shameful feeling of emptiness… an emptiness when trying to recall last night! Call it a black hole or a black-out, it feels as if someone just cut out a piece of your memory.
What are blackouts?
Alcohol-induced blackouts are a specific kind of anterograde amnesia (or memory loss) for partial or even whole events that happened after alcohol consumption. Although you can still interact with others in this drunken state, your brain fails to create memories for these events. There are two different types of blackouts: a bloc blackout, and a fragmentary blackout. In the former case, you usually have extraordinarily high blood alcohol concentrations (BACs) and suffer from a complete memory loss of the evening. In the latter case, a fragmentary blackout, you are still able to recall at least some events of the evening.
How does alcohol affect the brain and memory?
Alcohol primarily suppresses the function of the hippocampus in several ways, an area necessary for forming new memories (read previous blog on learning & memory systems). The hippocampus receives information from sensory areas on what we have just experienced. It then ties all that information together to build a “new memory”. A small region in the hippocampus called hippocampal area CA1 contains neurons known as pyramidal cells (their cell bodies have a pyramid-like shape). These cells help the communication and transfer of newly made memories back to other brain areas which, for instance, store that information for later use.
A study on rats showed that alcohol is able to suppress the activity of those pyramidal cells in the hippocampal area CA1, thereby disrupting information flow and hippocampal cell function. While the rats had to forage for food within a plus-shaped maze, high doses of alcohol (compared to low doses) suppressed pyramidal cells from firing signals, and these rats showed less systematic exploration for food compared to lower doses.
Thus, the most important thing to keep in mind for the upcoming Vierdaagsefeesten is the following: chugging drinks on an empty stomach rapidly increases the alcohol concentration in your blood, which increases the chance of blackouts. So, if you want to avoid that shameful morning awareness of your late-night (memory) unawareness, have a good meal before drinking and take it slow ;-).