WTF Happened Last Night?! What Really Happens When You Blackout

Your eyelids are crusted over. Something smells. There's a weird stain on your sheets. A glass of water and a pack of Advil somehow ended up next to your bed, and on the floor next to you lies your frantic attempt at disrobing last night: one shoe, a shirt, your wallet and some kind of feather boa.

Your phone, christened with a new crack in the corner, is filled with a million text messages from concerned friends and one from an ex:

Are you okay? Where did you go? Hello??? How dare you text me out of the blue like this? Do you realize how much you hurt me? F*ck you.

You blink at the screen and then at your window, which is allowing a far too brightly-lit sun to beam its awful "Good morning!" onto your bed.

There are hundreds of Ring Pops on your desk and your iTunes is playing the Bangerz album on repeat. Head pounding, breath reeking of ashtrays and limbs aching, you wonder, What the hell happened last night?

I'll tell you what happened: You blacked out. You endured an episode of amnesia during which you lost your ability to form any and all memories while you were severely intoxicated. You could have had the worst night of your life or the best and you'll never know.

You could have even participated in an emotionally-charged event -- called your ex in a fit of rage and asked what you did that was so wrong to get dumped -- and you still won't remember it, despite the fact that the memories we normally remember most vividly are those that stir up lots of emotions.

Or, you could have done nothing except play video games for hours until you fell asleep under a blanket of taquitos. You'll never know.

How We Form Memories

Memory-forming occurs in three stages and blacking out disrupts this normal, everyday flow of committing information to your brain. When you learn a new piece of information, it first enters your sensory memory, where it lasts for a few seconds.

Then it ventures to your short-term memory, where it lasts anywhere from a few seconds to a few minutes. Finally, with sufficient repetition and concentration, that piece of information enters your relatively permanent long-term memory.

For example, when a girl you meet at a bar tells you her name, it'll get stored in your short-term memory. To adequately remember her name when you later ask her to dance, you'll have to focus heavily on it throughout the evening.

This will help store it in your long-term memory. What was her name again? Ah, yes. Kayla. Wanna dance?

Alcohol consumption at any level can affect your ability to transfer information from your short-term memory to your long-term memory, which means Drunk You will have a harder time forming lasting memories throughout your night out.

If your blood alcohol concentration (BAC) rises to between a 0.14 - 0.20, you risk blacking out, which means you'll completely lose your ability to transfer information from short-term to long-term memory. While Drunk You may just have a fuzzy memory of the night, Blacked-Out You will remember absolutely nothing.

The Two Types Of Blackouts

There are two types of blackouts: en bloc and fragmentary blackouts. If you en bloc blackout, all details of your evening will be lost. This is because en bloc blackouts completely block the process of transferring information from your short-term to your long-term memory.

Therefore, no matter how much you or your friends try, you won't be able to piece together any aspect of last night's events. Your brain didn't pick up a single thing.

Interestingly enough, you likely were a normal, fully-functioning partygoer while you were en bloc blacked out: Your short-term memory was still in tact, so you were able to make your own sometimes harmless (engaging in a conversation with Kayla, ideally) and, unfortunately, sometimes harmful (vandalizing, driving, spending money or getting into a fight) decisions.

However, the amount of time you remember something while en bloc blacked out depends on how long your short-term memory is. For most people, it's no more than a few minutes, so moments after you had that conversation or bought $200 in Ring Pops, you would have forgotten that either of those things happened.

And the next morning, when you wake up with a gnarly headache and eye crusties like chip crumbs weaved into your eyelashes, all of those little short-term memory formations will have disappeared entirely because they never reached your long-term memory.

When you black out, you basically lose your mind.

Fragmentary blackouts, on the other hand, are what some of us like to call "brown outs." The most common kinds of blackouts, fragmentary blackouts are a more partial blocking of memory formation. If you experienced a fragmentary blackout, you only realize that you forgot parts of your night when people remind you that those parts occurred. In order to recall anything, you will need some kind of trigger.

A High BAC Isn't Enough To Blackout

It's important to note that a high BAC isn't enough to black out. Drinking on an empty stomach, and drinking rapidly, will dramatically increase your chances of blacking out. A variety of factors, such as your genetic makeup, physiological features and proportion of body fat also contribute to your susceptibility to blackout.

Gender plays a huge role in susceptibility as well: A woman can drink the same amount of alcohol as a man and have a much higher BAC, meaning she will experience the negative consequences, like blacking out, more frequently. Women also have lower levels of enzymes needed to help metabolize alcohol, so they can drink less than men and still blackout.

Ladies, trying to keep up with the boys really does have its risks.

Even more so, if you have a history of blacking out, you're more vulnerable to alcohol's effects on your memory compared to those who have never blacked out.

Of 772 undergraduate college students surveyed, 51 percent blacked out at least once in their lifetimes, and 40 percent blacked out within the year prior to the survey. And they'll probably black out again soon.

All in all, just check yourself before you annihilate yourself with booze. Stay hydrated, stick to one kind of alcohol, be cautious when playing drinking games and pace yourself. And don't do that thing where you purposely eat less all day to get drunker at night. Just don't do it. Seriously.

Photo Courtesy: We Heart It