Hazy memories are a common post-party scenario on New Year’s Day, where the night before the crowd was alive with noise makers, silly hats and, for some, many different types of alcoholic beverages.
Indeed, New Year’s Eve parties are nearly synonymous with alcohol consumption. And while many partygoers recognize that they will be drinking more than their normal amount of alcohol and make plans to get to and from a party safely, there also is a need to recognize the challenge that alcohol places on your brain.
For example, one symptom of overwhelming your brain with alcohol is an alcohol-induced memory blackout (absence of memory for what happened while intoxicated). Most people think that only alcoholics experience blackouts during alcohol intoxication. However, blackouts can occur at blood-alcohol concentrations as low as 0.1 percent. (The legal limit to drive a vehicle is 0.08 percent.) And there is a 50 percent chance of having a partial or complete blackout at blood-alcohol concentrations of 0.22 percent. (For most people, that level would result from having more than six to eight drinks in a few hours.)
Indeed, researchers are finding that blackouts are common, especially among young people, who are most likely to binge drink (more than four drinks within two hours in females, more than five drinks within two hours in males). In one survey, nearly nine percent of college undergraduates reported one or two blackouts in the previous two weeks.
Because memory-related brain areas are very sensitive to alcohol, they can be depressed while other brain areas are active, so behavior can occur without awareness or feedback about whether it is dangerous.
The manner in which someone drinks has a large influence on blackouts. Gulping drinks (for example, in drinking games), consuming highly concentrated drinks like shots of hard liquor, or drinking on an empty stomach can all rapidly increase blood-alcohol content and the risk of blackout.
In order to remember the good times you had at a New Year’s Eve celebration, it is best to eat a full meal, limit the number and sip through each alcoholic beverage.
Kathy Grant, Ph.D.
Professor of Behavioral Neuroscience
OHSU Brain Institute