Here's What Happens When You Black Out: 'Transient Amnesia' Blocks Short-Term Memory Formation

Hyperbole in the 2010s comes in clinical terms: Today, we are paranoid about bills, addicted to espresso, and schizophrenic about life choices.

Usually, this usage is a sure way of telling that the person talking does not suffer from any of these afflictions. The hallmark of paranoia, after all, is a refusal to acknowledge that one is being, well, paranoid. But there is one instance that appears to be just as commonplace as the rhetoric would have you believe.

Blacking Out

People say they black out all the time: at parties, during arguments, while taking tests, and under distress in general. Some blame alcohol. Others claim to be overcome by something they cannot quite pin down. Either way, it raises the question: What really happens?

For your reference, here’s a picture of the human brain. We’ll be talking quite a bit about it, so make sure you familiarize yourself with it.

As you can see from all the arrows, Latin nomenclature, and tubular stuff, this organ is no picnic. Once this is clear, it should come as no surprise that any meaningful answer about this system requires a very precise question. In other words, we need to be perfectly clear about what we are asking.

Personally, I had to learn this the hard way: last week, I emailed a dozen neurologists asking them to define unconsciousness for me. While those who got back to me brimmed with enthusiasm about the topic, everyone seemed to tread lightly, citing a limited scientific consensus. Put simply, unconsciousness is the temporary or permanent absence of consciousness — and without a clear definition of consciousness, we can’t really talk about either in a meaningful way.

The Right Question

But that’s OK, because according to Dr. Ausim Azizi, a chair of neurology at Temple University School of Medicine, blacking out doesn’t necessarily involve loss of consciousness at all. Instead, black outs have more in common with a condition we’re much less inclined to throw around. And that is amnesia.

“Alcoholic black-out is different from loss of consciousness,” says Azizi. “Technically, a drunk individual may lose or may not lose consciousness for a brief time, but they do not form event memories for long periods of time during inebriation.”

Amnesia is much less fun to talk about. It is the mark of old age and illness, of mental unfitness, of losing it all piece by piece, like that guy in that movie. Unfortunately, this is the closest we’ll get to a definition of blacking out.

Here’s how it all works: In order to think, talk, act, and react in a manner we consider meaningful, we need to have a pretty firm handle on the precise context in which we’re going to perform. We do this by deploying our short-term memory, or working memory. The working memory is very useful — it will, among other things, tell you where you are, where you were before, what you were going to do, and why you were going to do it.

Most of this is thought to take place in an area no bigger than your fist — the pre-frontal lobe, which is located in at the front of the cerebral cortex, right behind your forehead. Here, useful and useless information is stored for quick and immediate access. This information is also passed on to an area called the hippocampus, which decides whether the memory should be committed to long-term storage.

Whether it’s the outcome of stress, trauma, or alcohol, blacking out can be understood as a momentary shutdown of this storaging process. It is, according to Dr. Carl W. Bazil of Columbia University’s Department of Neurology, a type of transient amnesia. “While much of the brain works fairly normally — walking, talking (well, maybe slurring) — that period of time isn't recorded in memory,” he wrote in an email to Medical Daily.

It is at this point that things start to get a little abstract. Keep asking questions, and you’ll soon enter an entirely different realm of inquiry: If something doesn’t stick, have I really experienced it? Is my experience of the world all memory and no immediate stimulation? Is experience itself indirect? Is this how a Golden Retriever sees the world?

In the interest of concluding before things get weird: Blacking out is always bad news, because it is more or less synonymous with losing your mind for a substantial period of time. During a black out, you approach every new context as a blank, inaccessible slate, incapable of forming any hard memories. And without that, who are you?