Drink, Drink, Drink...Blackout!

Hell Week at Bryn Mawr means different things to different people, but one key activity is intricately linked to the week: drinking. While participating in Hell Week, one sees a number of students experience alcohol related “injuries,” particularly the phenomenon known as black-outs. Indeed, after-party breakfasts (or should I say lunches?) are often filled with conversations centering around events that the previously drunk person cannot recall and remember. However, black-outs are not isolated to the Bryn Mawr campus. They occur in colleges worldwide and to individuals of all ages who engage with alcohol. Hence, in relation to neurobiology, but also in relation to general background and health information, the mental and physical processes behind black-out impairments and overall alcohol usage is interesting and important to examine and comprehend.

The information on how alcohol affects the brain is plentiful. Beginning in elementary school, many students learn the effects of alcohol. “Alcohol is a depressant,” they are told, and as a depressant, it slows down one’s central nervous system. Writes Eric Chudler, “Alcohol is a very small molecule and is soluble in "lipid" and water solutions. Because of these properties, alcohol gets into the bloodstream very easily and also crosses the blood brain barrier” (3). Indeed, alcohol produces various neurochemical effects: it increases the turnover of norepinephrine and dopamine, decreases the transmission in acetylcholine systems, increases the transmission in GABA systems, and increases the production of beta-endorphin in the hypothalamus. More specifically, according to the article “Neurobiology Added to Social, Moral Debate on Teen Drinking,” drinking may make the brain less receptive to the neurotransmitter GABA. GABA works to produces feelings of calmness and sleepiness. Therefore, when people, young people especially, consume alcohol, they become less sensitive to GABA. This may explain why younger people are able to stay awake and conscious longer than older people who drink the same amount.

Still, although much is known on the overall effects of alcohol, information on how blackout episodes affect the brain is just beginning to forcefully emerge. Studies done on blackouts provide further insight into the disruptive cognitive actions that occur when an individual overindulges in alcohol consumption. Indeed, blackouts are an extremely common occurrence for those who take part in drinking. Aaron White provides a definition of a blackout writing, “They represent episodes of amnesia, during which subjects are capable of participating even in salient, emotionally charged events—as well as more mundane events—that they later cannot remember. Like milder alcohol–induced memory impairments, these periods of amnesia are primarily “anterograde,” meaning that alcohol impairs the ability to form new memories while the person is intoxicated, but does not typically erase memories formed before intoxication”(1). Additionally, Jeff Benson speaks on two different types of blackouts- en bloc and fragments (2). Specifically, blackouts that occur en bloc have a beginning and an end; they contain “lost time,” and can be recalled later as events in and of themselves. For example, a person experiencing an en bloc blackout may recall their night in pieces- they may remember partaking in a conversation, and within this conversation, they may remember a block of time gone missing, hence the blackout. In addition, “People experiencing an en bloc blackout are unable to recall any details whatsoever from events that occurred while they were intoxicated, despite all efforts by

the drinkers or others to cue recall” (1). However, a person may also have a fragment blackout, in which their memory lapses are unaware to them until a person reports them. More specifically, “fragmentary blackouts involve partial blocking of memory formation for events that occurred while the person was intoxicated…they often become aware that they are missing pieces of events only after being reminded that the events occurred” (1).

Certain conditions make blackouts more likely. One is age. States White, “There is no doubt about it now: there are long-term cognitive consequences to excessive drinking of alcohol in adolescence” (4). Indeed, in an experiment done on rats, researchers discovered that alcohol suppresses the action of chemical receptors in the hippocampus of young rats, impairing the development of new memories. Drinking affected the learning ability of young rats far more than it impaired the cognitive function of older rats. This research corresponds with the studies done on humans. Indeed, the younger one is, the more likely they are to experience a blackout. Likewise, Benson notes that binge drinking, extended drinking over long periods of time, drinking while fatigued, and drinking on an empty stomach are all factors that contribute to blackouts.

Altogether, the risks of blackouts are real and scary. Experiencing blackouts, and their accompanying neurobiological effects, are a warning sign to alcohol abuse and alcoholism. Whether or not you participate in the fun of Hell Week at Bryn Mawr or engage in drinking for various recreational purposes, this information on blackouts is too important to forget.

Sources:

1- http://pubs.niaaa.nih.gov/publications/arh27-2/186-196.htm

2- http://orient.bowdoin.edu/orient/article.php?date=2004-11-19&section=3&id=5

3- http://faculty.washington.edu/chudler/alco.html

4- http://www.jointogether.org/news/headlines/inthenews/2006/neurobiology-added-to-social.html