Alcohol Facts: The Blackout

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Alcohol Facts: The Blackout

What Really Happens to Your Brain When You Blackout from Alcohol

half-lit up face and hand

You jolt awake and realize you’re in a strange bed. Who is lying next to you? What is that stain on your shirt? And what, in the name of all that’s good, is that awful smell?

This intro may remind you of a Sublime song about blacking out, but if it also sounds like your typical weekend, it may be time for a change.

The reason you “blackout” from alcohol is because your brain stops functioning as it should. To understand what really happens during blackouts, it’ll help to have a basic knowledge of how memories typically work.

How Memories Work

memories - photos on a mapThe inner workings of your brain can get quite complicated, so we’re just going to cover the basics here.

Imagine sitting in a quiet room and hearing a loud gunshot. When your ears hear the sound, it kicks off the encoding or sensory phase of memory.

The sound triggers sensory signals in the brain’s cortex that are then transcribed and delivered to the hippocampus, the part of the brain responsible for memory.

When the signal is received and transmitted within the hippocampus, it becomes part of your short-term memory. Short-term memory is actually much shorter than most people realize. It typically only lasts about 15 to 30 seconds. Anything you remember beyond that is considered part of your long-term memory.

Think of your short-term memory like a bucket that holds everything you’re currently using or thinking about. That bucket often contains new information, but it may also borrow tidbits from your long-term memory.

Not every short-term memory will make it to the long term. If the signal being transmitted within the hippocampus is strong or repeated, the brain is very likely to store the message in your long-term memory. This process is called Long-Term Potentiation (LTP). The stronger the connections, the more likely you are to remember something in the long term.

Why We Forget Things

There are a few reasons why we may not be able to recall memories, but it’s important to note blackouts and common forgetfulness are two entirely different things.

Most forgetfulness is caused by simple retrieval failure. Have you ever forgotten something you feel like you should know? It’s like it’s there in your memory somewhere, but you simply can’t find it. That’s retrieval failure, and it may have to do with a breakdown of the connections between memories.

Sometimes we also forget because memories compete, and sometimes we forget because we want to. However, the type of forgetting that happens with alcohol blackouts isn’t so much forgetting as it is a failure to store information.

To be clear, your brain may fail to store information at any time, not just during blackouts. A 1979 memory recall thesis taught us that people tend to store only the information that is necessary. Researchers asked participants to draw a penny based on memory and found that most people could only recall the details that distinguished the penny from other coins. What happens during a blackout is a failure to store, but there are some key differences between alcohol blackouts and everyday memory selectivity.

What Happens to Your Memory During a Blackout

Tolerance graphic of the brain

Blackouts typically happen when you consume large amounts of alcohol in a short period of time. When you’ve flooded your body with alcohol, it’s kind of like putting a stop sign between your immediate and short-term memories. What actually happens is a neurological, chemical disruption in the hippocampus.

Remember the sound of the gunshot and how the message was transmitted to the hippocampus? Once it gets there, the chemical glutamate is responsible for sending that message from neuron to neuron.

Alcohol interferes with the receptors that transmit glutamate, and it may prevent some receptors from working at all. Without adequate glutamate, LTP may be disrupted. During an alcohol blackout, the sensory message may make it to the hippocampus, but it will not become a long-term memory.

So if you were highly intoxicated when you heard that gunshot, you probably would have acknowledged it happening. You may have remembered it for a short time after, but then that memory is likely gone for good.

Types of Alcohol Blackouts

The magnitude of a blackout will increase with the amount of alcohol consumed. Drinking lots of alcohol in a short time can cause partial or complete blackouts. Partial blackouts are called fragmentary blackouts or brownouts. With brownouts, the person may have some recollection of the previous night’s events. They may even be able to recall things when prompted with details. Complete blackouts are called en bloc. When this happens, the person will remember nothing from the time they began drinking until after the alcohol left their system.

How to Spot a Blackout

It can be difficult to know when a friend is in a blackout period because they may respond to things normally as they happen. However, if you know your friend has a history of blacking out, there’s a trick to tell when it’s happening. If he or she has had a few drinks, ask about something obvious that happened 15 minutes earlier. If your friend is in a blackout, they are not likely to remember (unless they kept the event in their short-term memory through repetition).

If you’re with someone while they are blacking out, the best you can do is to keep them from harming themselves or others. This also means that they should stop drinking alcohol and start hydrating. There is a definite correlation between alcohol blackouts and alcohol poisoning, so this isn’t something to take lightly.

What to Do if You Get Blackouts

Lost in the laundry machineUnless you have experience with them, you probably won’t know at the time when you blackout off of alcohol, but you’ll definitely realize the next day.

If you are experiencing blackouts regularly, it is a sure sign that you are drinking alcohol in excess. This alone does not mean you are an alcoholic, but if you don’t know when to stop drinking, it could signal a problem.

Start by cutting back on your overall alcohol consumption and stop binge drinking. Binge drinking, or consuming five or more alcoholic beverages in an hour, is likely the reason you are experiencing blackouts.

If you find that you cannot stop or are having trouble cutting back, Recovery Connection can help. Give us a call at 866-812-8231 for confidential assistance.