Authors: Dean Burnett
The more connections a specific memory has, and the “stronger” (more active) the synapse is, the easier it is to access, in the same way that it's easier to travel to somewhere with multiple roads and transport links than to an abandoned barn in the middle of a wilderness. The name and face of your long-term partner, for example, is going to occur in a great deal of memories, so it will always be at the forefront of your mind. Other people aren't going to get this treatment (unless your relationships are rather more atypical),
so remembering their names is going to be harder.
But if the brain has already stored someone's face and name, why do we still end up remembering one and not the other? This is because the brain has something of a two-tier memory system at work when it comes to retrieving memories, and this gives rise to a common yet infuriating sensation: recognizing someone, but not being able to remember how or why, or what their name is. This happens because the brain differentiates between familiarity and recall.
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To clarify, familiarity (or recognition) is when you encounter someone or something and you know you've done so before. But beyond that, you've got nothing; all you can say is this person/thing is already in your memories. Recall is when you can access the original memory of how and why you know this person; recognition is just flagging up the fact that the memory exists.
The brain has several ways and means to trigger a memory, but you don't need to “activate” a memory to know it's there. You know when you try to save a file onto your computer and it says, “This file already exists”? It's a bit like that. All you know is that the information is there; you can't get at it yet.
You can see how such a system would be advantageous; it means you don't have to dedicate too much precious brain power to figuring out if you've encountered something before. And, in the harsh reality of the natural world, anything that's familiar is something that didn't kill you, so you can concentrate on newer things that might. It makes evolutionary sense for the brain to work this way. Given that a face provides more information than a name, faces are more likely to be “familiar.”
But this doesn't mean it's not intensely annoying for us modern humans, who regularly have to make small talk with people we're certain we know but can't actually recall
right now. That's the part most people can relate to, the point where recognition turns to full-on recall. Some scientists describe it as a “recall threshold,”
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where something becomes increasingly familiar, until it reaches a crucial point and the original memory is activated. The desired memory has several other memories linked to it, and these are being triggered and cause a sort of peripheral or low-level stimulation of the target memory, like a darkened house being lit by a neighbor's fireworks display. But the target memory won't actually activate until it is stimulated above a specific level, or threshold.
You've heard the phrase “it all came flooding back,” or you recognize the sensation of a quiz answer being “on the tip of your tongue” before it suddenly occurs to you? That's what's happening here. The memory that caused all this recognition has now received enough stimulation and is finally activated, the neighbor's fireworks have woken those living in the house and they've turned all the lights on, so all the associated information is now available. Your memory is officially jogged, the tip of your tongue can resume its normal duties of tasting things rather than providing an unlikely storage space for trivia.
Overall, faces are more memorable than names because they're more “tangible,” whereas remembering someone's name is more likely to require full recall than simple recognition. I hope this information means that you'll understand that if we ever meet for a second time and I don't remember your name, I'm not being rude.
Actually, in terms of social etiquette, I probably
am
being rude. But now at least you know why.
A
glass of wine to refresh your memory
(How alcohol can actually help you remember things)
People like alcohol. So much so that alcohol-related issues are an ongoing problem for many populations. These issues can be so widespread and constant that dealing with them ends up costing billions.
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So why is something so damaging also so popular?
Probably because alcohol is fun. Aside from causing a dopamine release in the areas of your brain dealing with reward and pleasure (see
Chapter 8
), thus causing that weird euphoric buzz that social drinkers enjoy so much, there's also social convention built up around alcohol; it's almost a mandatory element of celebration, bonding and just general recreation. Because of this, you can see why the more detrimental effects of alcohol are regularly overlooked. Sure, hangovers are bad, but comparing and laughing about the severity of respective hangovers is yet another way of bonding with friends. And the ridiculous ways in which people behave when drunk would be deeply alarming in some contexts (in a school, perhaps, at 10 a.m.) but when everyone does it, it's just fun, right? A necessary relief from the seriousness and conformity demanded of us by modern society. So, yes, the negative aspects of alcohol are considered a price worth paying by those who enjoy it.
One of these negative aspects is memory loss. Alcohol and memory loss go hand in unsteady hand. It's a comedy staple in sitcoms, stand-up and even personal anecdotes, usually involving someone waking up after a drunken night
and finding himself in an unexpected situation, surrounded by traffic cones, unfamiliar garments, snoring strangers, irate swans and other things that wouldn't be in a person's bedroom under normal circumstances.
So how then can alcohol possibly actually
help
your memory, as the title of this bit suggests? Well, it's necessary to go over why alcohol affects our brain's memory system in the first place. After all, we ingest countless different chemicals and substances every time we eat anything, why don't they cause us to slur our words or pick fights with lamp-posts?
It's due to the chemical properties of alcohol. The body and brain have several levels of defence to stop potentially harmful substances entering our systems (stomach acids, complex intestinal linings, dedicated barriers to keep things out of the brain . . .) but alcohol (specifically ethanol, the type we drink) dissolves in water and is small enough to pass through all these defences, so the alcohol we drink ends up spread throughout our bodily systems via the bloodstream. And when it builds up in the brain, several bags of wrenches are thrown into some very important workings.
Alcohol is a depressant.
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Not because it makes you feel dreadful and depressed the next morning (although, good lord, it does), but because it actually depresses activity in the nerves of the brain; it reduces their activity like someone lowering the volume on a stereo. But why would this make people behave in
more
ridiculous ways? If brain activity is reduced, shouldn't drunk people just sit there quietly and drool?
Yes, some drunk people do precisely this, but remember that the countless processes the human brain is carrying out every waking moment require not just making things happen, but
preventing
things from happening. The brain controls
pretty much everything we do, but we can't do everything all at once, so much of the brain is dedicated to inhibition and stopping activation of certain brain areas. Think of the way traffic is controlled in a large city; it is a complex job, relying on stop signs or red traffic lights to some degree. Without them the city would grind to a messy halt in a matter of minutes. Similarly, the brain has countless areas that provide important and essential functions but
only when needed
. For example, the part of your brain that moves your leg is very important, but not when you're trying to sit in a meeting, so you need another part of the brain to say, “Not now, buddy,” to the leg-controlling part.
Under the influence of alcohol, the red traffic lights are dimmed or switched off in the brain regions that normally keep giddiness, euphoria and anger in check or suppressed. Alcohol also shuts down the areas responsible for speech clarity or walking coordination.
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It is worth noting that our simpler, fundamental systems, controlling things such as heart rate, are deeply entrenched and robust, whereas the newer, more sophisticated processes are more easily disrupted or damaged by alcohol. There are similar parallels in modern technology; you could drop a 1980s Walkman down a flight of stairs and it might still work, but tap a smartphone on the corner of a table and you end up with a hefty repair bill. Sophistication results in vulnerability, it seems.
So with the brain and alcohol, “higher” functions are the first to go. Things like social restraint, embarrassment and the little voices in our head that say, “This probably isn't a good idea.” Alcohol silences these pretty quickly. When you're drunk you're more likely to say what's on your mind or take a
crazy risk just to get a laugh, such as agreeing to write an entire book about the brain.
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The last things to be disrupted by alcohol (and it has to be a lot to get to this point) are the basic physiological processes, such as heart rate and breathing. If you're so drunk you get into this state, you'll probably lack sufficient brain function to be capable of being worried, but you really
really
should be.
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Between these two extremes, there's the memory system, which is technically both fundamental and complex. Alcohol seems to have a particular tendency to disrupt the hippocampus, the main region for memory formation and encoding. It can also limit your short-term memory, but it's the long-term memory disruption via the hippocampus that causes the worrying gaps when you wake up the next day. It's not a complete shutdown of course; memories are usually still being formed, but less efficiently and more haphazardly.
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Interesting aside: for most people, drinking enough to block memory formation completely (alcoholic blackouts) would mean they're so intoxicated they can barely speak or stand. Alcoholics, however, are different. They've been drinking a lot for a long time, so much so that their bodies and brains have actually adapted to deal with, and even require, a regular alcohol intake, so they can remain upright and coherent (more or less) despite consuming way more alcohol than your average person could withstand (see
Chapter 8
).
However, the alcohol they've consumed still has an effect on the memory system, and if there's enough sloshing around in their heads it can cause a full “shutdown” of memory formation
while they're still talking and behaving normally
thanks to their tolerance. They don't show any outward signs of problems, but ten minutes later, they've no memory of what they've
been saying or doing. It's as though they stepped away from the controls of a video game and someone else took over; it looked the same to anyone watching the game, but the original player has no idea what's been happening while they were in the bathroom.
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Yes, alcohol disrupts the memory system. But, in very specific circumstances, it can actually
help
recall. This is the phenomenon known as state-specific recall.
We've covered already how the external context can help you recall a memory; you're better able to recall it if you are in the same environment where the memory was acquired. But, and here's the clever bit, this also applies to the
internal
context, or “state,” hence state-dependent recall.
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To put it simply, substances such as alcohol or stimulants or anything that alters brain activity bring about a specific neurological state. When the brain is suddenly having to deal with a disruptive substance washing around everywhere, this does not go unnoticed, any more than you wouldn't notice that your bedroom was suddenly full of smoke.
This can also apply to mood; if you learn something while in a bad mood, you're more likely to recall it later if you're in a bad mood again. It's a massive oversimplification to describe moods and mood disorders as “chemical imbalances” in the brain (despite many who do just that) but the overall levels of chemical and electrochemical activity that result in and from a specific mood is something the brain can recognize, and does. Thus, the context
inside
your head is potentially just as useful as the one
outside
your head when it comes to triggering memories.
Alcohol does disrupt memories, but only after a certain point; it's perfectly possible to have the pleasant buzz of a few
beers or glasses of wine and still remember everything the next day. But if you were to be told some interesting gossip or useful information after a couple of glasses of wine, your brain would encode your slightly intoxicated state as part of the memory, so would be better able to retrieve this memory if you were to have another couple of glasses of wine (on a different night, not right after the first two). In this scenario, a glass of wine can indeed improve your memory.
Please don't take this as a scientific endorsement for drinking heavily when studying for exams or tests. Turning up drunk for a test will be problematic enough to cancel out any minor memory advantages this provides you with, especially if it's a driving test.
But there is still some hope for desperate students: caffeine affects the brain and produces a specific internal state that can help trigger memories, and a lot of students pull caffeine-fueled all-nighters when cramming for exams, so if you attend the exams similarly stimulated by excessive caffeine then it could well help with remembering some of the more important details from your notes.
It's not exactly irrefutable evidence, but I did once (unknowingly) employ this tactic in college, where I stayed up all night revising for an exam I was particularly worried about. A lot of coffee kept me going and I indulged in an extra-large mug right before the exam, to ensure I stayed conscious throughout. I ended up getting 73 percent on the exam, one of the highest grades in my class.