- Effects of Alcohol on Memory
- What Causes an Alcohol Blackout?
- The 86-Proof Bourbon Experiment
- Do Women Black Out More Easily?
- Drug Use
- Blackout Symptoms
- Risky Behavior
- Long-Term Effects of Blacking Out
- Preventing an Alcohol Blackout
- Getting blackout drunk: how alcohol can leave you with no memory of the night before
- How memory works
- Where alcohol comes in
- Long-term potentiation
- How much is too much?
Drinking can make us feel excited, spontaneous and euphoric. But we all know that as blood alcohol content goes up, our judgment and coordination go down. Alcohol also affects a person’s ability to make memories but not in the same way that it affects other cognitive functions.
Ever drink slowly throughout a day or night? The next day, you probably woke up dehydrated with a headache and a hangover. But you could probably remember everything you did, with a little effort and reminders.
If you start the night by taking shots, chugging beer or playing drinking games, the odds of remembering everything the next day drop drastically.
That’s because the brain’s ability to create long-term memories isn’t affected as much by blood alcohol content as it is by rapid rises in that level. Binge drinking — consuming numerous drinks in a short period— is more ly to cause alcohol blackouts, amnesia and memory loss than slow, heavy drinking, according to numerous studies.
Blacking out is different from passing out. A blackout is a loss of the ability to make memories, but people are still conscious when they’re blackout drunk. They can still walk and talk, although they may do so drunkenly.
It happens quite often, too. Despite advice from experts and beer commercials, most people do not drink responsibly. More than 50 percent of adults have blacked out at least once in their lives. The number isn’t surprising considering almost 25 percent of adults binge-drink every month, according to stats from the National Institute on Alcohol Abuse and Alcoholism.
Effects of Alcohol on Memory
Scientists debate the exact way a memory is formed, but most agree that memories are made in three stages.
- Sensory memory — which includes information about everything we see, hear, smell, taste and touch — lasts for one to two seconds.
- If a person thinks about sensory information, it moves to short-term memory, which can last several minutes and depends on how long a person focuses on the information.
- When enough attention is given to information, or the information is rehearsed, it is transferred into long-term memory.
Several factors affect the lihood that information will be transferred into long-term memory. For decades, researchers have known that alcohol disrupts the brain’s ability to transfer memories from short-term to long-term memory, but they didn’t know how. The common consensus was that alcohol killed brain cells, causing memory loss and other cognitive impairments.
“You still process information. You’re not anesthetized. You haven’t passed out. But you’re not forming new memories.”
— Dr. Charles F. Zorumski, Washington University School of Medicine in St. Louis
However, scientists at the Washington University School of Medicine found in a 2011 study that alcohol didn’t kill brain cells. Instead, they found that alcohol interfered with receptors in the brain, making them produce steroids that interrupted the learning and memory-building process.
“Alcohol isn’t damaging the cells in any way that we can detect,” lead author Dr. Charles F. Zorumski said in a news release. “As a matter of fact, even at the high levels we used here, we don’t see any changes in how the brain cells communicate. You still process information. You’re not anesthetized. You haven’t passed out. But you’re not forming new memories.”
That is why people experience a range of memory loss symptoms when they binge-drink. Alcohol can cause minor memory loss, such as being unable to remember details of a conversation after a few drinks, or major memory loss, such as forgetting hours of time after taking shots.
Fragmentary blackoutsA partial blocking of memory.En bloc blackoutsA complete loss of memory during intoxication.
During en bloc blackouts, what most people refer to as being blacked out, someone can’t remember anything after a specific period of time. The brain’s ability to create long-term memories is completely blocked. However, sensory and short-term memories continue to function. The person can continue to drink and socialize, order drinks at a bar, dance and so on.
People who experience a fragmentary blackout may think they can’t remember what happened the night before, but their memory comes back when someone or something reminds them. Researchers believe a person may be unable to access the memory unless a reminder triggers it.
What Causes an Alcohol Blackout?
For most people, binge-drinking large amounts of alcohol causes them to black out. Studies seem to agree that heavy drinking alone doesn’t cause blackouts. A person has to drink a lot in a short period of time. Thus, the main cause of a blackout is a rapid rise in blood alcohol, which can be propelled by drinking on an empty stomach or while dehydrated.
The 86-Proof Bourbon Experiment
In a 1970 experiment, researchers in the Washington University School of Medicine’s psychiatry department gave 10 men with a history of alcohol addiction 16 to 18 ounces of 86-proof bourbon in a four-hour period.
The researchers tested their memories after the first hour by showing them images and asking them to recall the details two minutes, 30 minutes and 24 hours later. Most men were able to remember the images two minutes after seeing them, but half of the men could not remember them 30 minutes or 24 hours later.
The authors concluded that the blackouts were caused by an inability to transfer information from short-term to long-term memory when blood alcohol levels were rising. The results were published in the Quarterly Journal of Studies on Alcohol. Studies with similar designs have produced similar results.
Alcohol affects people differently. Research suggests that some people’s brains are more apt to blacking out than others. The reverse is also true: Some brains may be resistant to blacking out.
In a study of 100 alcoholics published in the American Journal of Psychiatry, 36 participants said they had never experienced a blackout despite a history of heavy alcohol use.
Research also indicates that a person who has experienced one blackout is more ly to have blackouts in the future. The long-term effects of a blackout are unknown, but they may cause the brain to be more susceptible to memory losses in the future.
Studies also suggest that prenatal exposure to alcohol increases a person’s chance of experiencing blackouts in the future, and certain genes may increase a person’s lihood to black out.
Do Women Black Out More Easily?
Similar numbers of men and women report blacking out, but men drink much more often and more heavily than women. The logical conclusion is that women are at a greater risk for blacking out than men. Researchers theorize that women may black out more easily because of differences in the ways the bodies of men and women metabolize alcoholic drinks, but more research is needed to be sure.
We do know that women are more ly to experience other effects of alcohol, such as liver cirrhosis, heart damage, nerve damage and other diseases caused by alcohol. Research on brain damage isn’t as conclusive.
A pair of studies — one published in Psychological Medicine and the other in Alcoholism, Clinical and Experimental Research — found that men and women both experienced brain shrinkage and memory problems after heavy alcohol consumption. The latter study found that women experienced the side effects after drinking only half as much as men.
People who are drunk or blacked out are more ly to try illicit drugs than they would be sober. In a 2004 study published in the American Journal of Alcohol and Drug Abuse, only one 50 college students who had experienced a blackout said they blacked out after drinking beer alone.
Other studies have found using benzodiazepines such as Valium and Rohypnol alongside alcohol greatly increase the chances of a blackout. Abusing these drugs without alcohol can cause memory loss, but alcohol enhances the effects of the drugs. Research also indicates that smoking marijuanawhile drinking increases the lihood of blacking out.
Popular media and some celebrities with drug problems glamorize blacking out, and not being able to remember what happened the night before is the topic of many fun-filled tales. But blackouts are no laughing matter, according to expert researcher Dr. Marc Schuckit.
“Some people think that blackouts, very bad hangovers, and outrageous behaviour at parties are very funny,” Schuckit said in a press release for a study on college students who blacked out. “This does not represent ‘fun.’ People don’t understand how dangerous blackouts are. In fact, people have oodles of misconceptions about drinking.”
People who are experiencing being blackout drunk often feel similar symptoms to being drunk. They feel carefree, are overly friendly or overly aggressive, have slurred speech and can’t walk straight. Signs that they may be blacking out or are blackout drunk include losing their train of thought, not understanding normal speech and getting confused about recent events.
Schuckit’s study and several others have found that people who black out from drinking risk a number of negative consequences.
Alcohol poisoning and death from alcohol overdose are direct consequences of drinking too much alcohol.
People who are blacked out are ly to continue drinking because the substance jeopardizes their judgment. They may not remember how much they have consumed, so they continue drinking excessively.
They’re also more ly to engage in other risky behavior. People report driving cars, having unprotected sex, vandalizing property, getting into fights and abusing illicit drugs when blacked out.
“People don’t understand how dangerous blackouts are. In fact, people have oodles of misconceptions about drinking.”
— Dr. Marc Schuckit, University of California, San Diego
Long-Term Effects of Blacking Out
The long-term effects of a blackout are unknown. Short-term effects of alcohol abuse — such as coordination problems, slurred speech and blurry vision — fade when alcohol is metabolized, which can take hours or days.
Heavy alcohol use contributes to a shrinkage of the brain similar to Alzheimer’s disease, which is characterized by memory loss.
However, long-term effects of chronic alcohol abuse — such as liver damage, nerve damage and increased cancer risk — do not always go away. For example, people with minor liver problems can recover from heavy drinking if they stop drinking. But the liver can’t recover from severe damage or scarring.
Heavy alcohol use contributes to a shrinkage of the brain similar to Alzheimer’s disease, which is characterized by memory loss. However, studies do not support alcohol as a cause of Alzheimer’s disease.
Still, several studies link heavy alcohol use to learning and memory problems. It’s unclear whether blacking out causes serious long-term damage, but heavy alcohol use and risky behaviors while blacked out can have serious long-term health effects.
Preventing an Alcohol Blackout
The easiest way to avoid blacking out is to limit how much you drink. If you’re committed to drinking heavily or for long periods of time, then pacing yourself throughout the day or night will prevent your blood alcohol from rising too quickly.
- Drink slowly
- Avoid shots or drinking games
- Eat food before drinking
- Eat more food if you’re drinking for a long time
- Stay hydrated with water
- Ask a sober friend to cut you off after a certain number of drinks
A good rule of thumb is to only consume one drink per hour and to have a glass of water for every drink you consume.
Be aware of blackout warning signs. If you’re having difficulty concentrating, remembering recent events or keeping track of a conversation, you may be close to getting blackout drunk. If you’re in that situation, find someone you trust and find a safe ride home.
If you’re worried about how much a friend has had to drink, ask him about something that occurred 10 to 15 minutes ago. If he can’t remember, he might be blacked out. The best option is get the friend home safely. If you see warning signs for alcohol poisoning or overdose — such as vomiting, difficulty breathing, or cold or blue skin — then get emergency medical help immediately.
If you think you’ve experienced a black out, talk to friends that you were with about what happened. If you made an unsafe sexual decision, talk to your doctor about being tested for a sexually transmitted disease.
You can recover from an alcohol blackout by drinking water and beverages containing electrolytes, such as sports drinks.
Eating fruits, vegetables and other nutritious foods can also help your body recover from a long night of drinking.
You don’t have to drink heavily or quickly to have fun. If you’re unable to control how much you drink, avoid drinking altogether. You can still have fun while being sober. If you have experienced a blackout before, you’re ly at a higher risk for blacking out in the future and should exercise caution.
Getting blackout drunk: how alcohol can leave you with no memory of the night before
Whether it happened to you or someone else, everyone knows what blackout drunk means.
It’s probably ruined countless relationships and friendships, but what exactly causes it? Obviously, alcohol is the culprit, the process itself is quite complex.
According to science, blackouts are the result of alcohol blocking the brain’s ability to form new memories due to an increase in inhibition stemming from changes in neurotransmitter levels.
How memory works
Before we look at what alcohol does to the brain during a blackout, we first need to look at how memory works in the human brain.
Many researchers believe in the general model of memory formation proposed by Atkinson and Shiffrin in 1968.
This model (depicted below) suggests that all sensory input is encoded into a short-term memory that – after the process of rehearsal – is then consolidated into a long-term memory.
Image credit National Institute of Alcohol Abuse and Alcoholism
Where alcohol comes in
Research shows that alcohol primarily inhibits the ability of the brain to encode information in short-term memory storage into long-term memories.
Typically, someone who is very intoxicated can remember information immediately after they are exposed to it because it is kept active in their short-term memory for around one minute or more. However, the encoding process that consolidates this short-term memory into a long-term memory is inhibited by alcohol.
In short, alcohol inhibits our ability to form new memories – each experience of the night simply passes through our conscious experience without ever leaving a lasting impact.
You might be asking yourself why someone who is blackout drunk can still remember their name and where they went to school as a child. Although alcohol affects the consolidation of short-term memories, it doesn’t affect long-term memories that were encoded prior to intoxication, making the recall of these memories possible even in states of extreme inebriation.
Alcohol primarily acts as a gamma-Aminobutyric acid (GABA) agonist, meaning that it increases the levels of the GABA neurotransmitter throughout the brain by binding to GABA receptors. As the main inhibitory neurotransmitter in the human brain, activation of these receptors reduces the rate of neuronal firing in standard cellular processes.
When alcohol concentrations reach very high levels – such as those seen during blackouts – it also acts as an N-methyl-D-aspartate (NMDA) antagonist, in turn decreasing the levels of the glutamate, the neurotransmitter that acts on these receptors. Since glutamate is an excitatory neurotransmitter, blocking its receptors further inhibits neuronal firing.
After alcohol causes a widespread inhibition of brain activity through its action on GABA and NMDA receptors, it inhibits long-term potentiation – the cellular process that consolidates short-term memories into long-term memories through the strengthening of connections between neurons in the brain. This strengthening occurs specifically in areas of the brain associated with memory, such as the hippocampus.
Image credit Pixabay
The hippocampus is a structure in the brain located in the medial temporal cortex that plays a large role in the formation of memories. Long-term potentiation is known to occur primarily in this brain region and NMDA receptors in particular are known to play an important role in this process, which is why receptor blockage by alcohol is connected to its inhibition.
How much is too much?
Although it seems safe to assume that drinking large quantities of alcohol causes blackouts – and indeed blackouts almost always happen during periods of heavy drinking – heavy drinking alone is not enough to cause a one.
Other factors such as the speed of drinking and drinking on an empty stomach are necessary to cause blackouts due to their connection to rapid increases in blood alcohol content (BAC).
Even social drinkers can fall victim to alcohol blackouts by letting their BAC increase too fast.
“They were inexperienced,” said Daniel Goodwin, a researcher who has conducted numerous studies on the effects of alcohol on memory, in reference to first-year medical students that reported experiencing at least one blackout. “They drank too much too quickly, their blood levels rose extremely quickly, and they experienced amnesia.”
Ultimately, pacing the speed at which you drink and ensuring that you keep some food in your stomach will lessen the lihood that you will experience a blackout after consuming large amounts of alcohol. Without paying attention to these factors, you risk waking up with no memory of your night, or worse – with alcohol poisoning.