Alcohol – The Biology behind the Buzz

Our relationship with alcohol is complicated – to say the least. Not everyone can hold their drink, some hold one way too often, and some don’t even get a buzz. Truth be told, we’re only just starting to get the gist of how alcohol “works”.

Alcohol: The stimulating depressant

image1As you may already know, alcohol is classified as a ‘depressant’. This is based on the fact that when someone develops a tolerance to valium – the ultimate archetype of depressants – they simultaneously build up a tolerance to alcohol. Valium, like most depressants, targets receptors for GABA – the main inhibitory signalling molecule in the brain.

This is where things get shaky.  The concentration you’d need to activate these GABA receptors with alcohol (0.33mL/L) is just above the amount that makes you embarrassingly pass out in your own vomit (0.3mL/L). Why then, do we get tipsy from just one glass of wine (I know I’m not just speaking for myself here)? And is tipsiness even the same thing as being drunk?

Researchers took a closer look at GABA receptors. These are made of 5 building blocks, the combination of which differs from receptor to receptor. One particularly rare building block – the so-called delta receptor – happens to respond to very low levels of alcohol. The scientists who discovered it even call it the “one glass of wine” receptor (click the link if you don’t believe me).

Using a method called PET, researchers tracked which areas of the brain are more or less active when we are drunk. They injected volunteers with radioactive sugar (it’s not nearly as dangerous as it sounds) and tracked which parts of the brain use it. It was no surprise that the three areas responsible for coordinated movement, rational thought and memory (the cerebellum, prefrontal cortex and hippocampus, respectively) were ever so slightly tuned down after drinking. Also, it just so happens that the “one glass of wine” receptors are found in exactly these three brain areas. So, that would explain why we lumber from one bad decision to another (and forget the worst ones) when we’ve had a bottle or more.

The buzz part seems to be related to higher levels of noradrenaline when we drink. This only tends to happen when our blood alcohol content (BAC) is on the rise, leading to greater impulsivity. Once it tapers off, the effects are reversed: we feel confused, tired, restless and down – and alcohol starts acting like a depressant again.

Drinking Culture – of Monkeys and Men
image2Scientists were lucky to stumble across the perfect model for human drinking culture – on St. Kitts in the Caribbean of all places (talk about serendipity).
The model specimens in question are vervet monkeys, who were brought to the Caribbean over 300 years ago and have developed a curious relationship with alcohol.
Back in the day, vervet monkeys would sample fermented sugar cane from the rum plantations; the modern day vervet prefers cocktails, sneakily stolen from sleeping tourists on the beach front.

image3Most vervet monkeys drink in moderation; so-called “social drinkers”. Roughly 5% -given the open bar that is the lab – will readily drink themselves into a coma. 12% are steady drinkers (unlike the alcoholics, they know their limits), while one in ten is a teetotaller – indulging in soft drinks only.
This distribution is strikingly similar to what we observe in humans. And the similarities run far deeper than that. Like humans, the social drinkers will avoid alcohol before noon and prefer their alcohol mixed in sweet drinks, while the heavy drinkers like to start their day with a drink – and prefer it straight.

image4Vervets have helped researchers understand the genetics behind alcohol preference – it appears we inherit it directly from our parents. In fact, you can predict an animal’s future relationship with alcohol based on levels of neurotransmitter metabolites in its cerebrospinal fluid (CSF) before it’s had its very first cocktail.

Researchers have also noticed a two way relationship between personality and alcohol preference – anxious monkeys don’t drink and those who drink become more anxious.

Towards the end, the researchers pointed out one difference between vervet and human drinking culture: the social status attached to it. In vervets, steady and heavy bingers almost always outdrank the more responsible drinkers. Glancing at tabloid socialites, University sports clubs and most English public school students I’ve met – we may be more like monkeys than they think.

Post by: Isabel Hutchison


The Brain on Tetris

You’re probably all too familiar with Tetris as a procrastination tool – but did you know about its far more reputable role in psychological research?

If you’ve ever played Tetris for a while, you may have noticed its lingering effects– such as daydreaming of objects in the room slotting together. If this sounds vaguely familiar, the diagnosis is (I kid you not): Tetris Syndrome.

That this is indeed a real phenomenon is backed by the fact that it makes a respectably lengthy appearance on Wikipedia. According to said source, it “occurs when people devote sufficient time and attention to an activity that it begins to overshadow their thoughts, mental images and dreams”.

Thus Tetris not only occupies your mind during the task itself, but seems to form a lasting impression on the brain. This has led to its use in psychology, helping to understand various aspects of how our brains work.


Tetris and skill

For one, Tetris has helped shine some light on what happens in the brain when our skills develop. A study in 2009 showed that over the course of a month of playing Tetris, brain areas linked to playing the game gradually reduce their use of glucose (the brain’s natural fuel) while skill levels continuously improve. This means, despite our brains appearing less engaged, they’re doing a better job. The conclusion: greater skills come from a more energy efficient brain.

Tetris to prevent PTSD

That Tetris can help us understand skill acquisition isn’t too surprising….but what about its use as a treatment for post-traumatic stress disorder (PTSD)? Researchers at Oxford University showed that volunteers who played Tetris after watching a truly traumatic video reported half as many flashbacks over the next few days than those who did a trivia quiz. The team’s explanation is that the high cognitive demands of Tetris prevent the traumatic memory from ‘settling in’. As it takes around 6 hours for memories to enter a more long-term state, this treatment has a very limited time-window to work. It essential means we’d need Tetris arcades set up in warzones – seems somewhat questionable if you ask me.

The Tetris diet?

Ok so, maybe Tetris isn’t the thing to play during exam-time then. But maybe it’s worth a go when you’re feeling a bit peckish. It turns out Tetris has the potential to reduce cravings. A group of individuals who were asked about their cravings where split into two: one who played Tetris and one who got to stare at the loading screen (heartless, I know). The players got over their cravings whereas the control group didn’t. Tetris: the new diet? The media definitely took it that way.


Dreams of Tetris

Tetris has also been moonlighting in sleep research. A curious study from Harvard University investigated what happens to the dozing brain after playing Tetris for a ridiculously long period of time. In addition to the usual healthy average Joes and Janes, the study included a few amnesics, as well as a selection of “Tetris experts” (there’s actually a global ranking system for Tetris professionals).



Across three days the ‘experimentees’ played a total 7 hours of Tetris and were asked to describe what they saw when drifting off to sleep each night. “Tetris experts” could hear music (the famous Russian Tetris theme Korobeniki) and see colours from versions they’d played years before; while the amnesics were pretty confused as they didn’t have a clue what Tetris was, nor why some strange person in a lab coat was sitting in their bedroom. Yet even they described geometric shapes falling from the sky and slotting into spaces.

Besides showing that amnesics actually can form visual memories, this study seems to suggest that our daydreams and dozing thoughts are serving a purpose, a kind of subconscious training and integration of old and newly learnt abilities perhaps.

So, far from being just some trivial game that you cannot actually ever win (think about it…), its power to occupy and sway the mind has actually made Tetris an extremely fascinating research tool.


Post by: Isabel Hutchison

The Power of Yawning

No one looks pretty doing it yet somehow, when we see someone compulsively distort their face into a yawn, we feel inclined to do the same. We share this odd behaviour with a whole bunch of animals, who each do it for different reasons. Dogs do it when they’re confused, snakes do it to realign their jaws, lions do it to feign indifference in the face of combat, male penguins yawn to woo a mate and guinea pigs do it to scare enemies with their fierce incisors.

You wouldn’t want to encounter this fellow in a dark alley way.

Ancient Greeks and Mayas believed that yawning was the soul trying to escape the confines of the body and that it could only be stopped by covering your mouth. In Hinduism, yawning is considered a religious offense that must be repented by snapping your fingers and thumb and pronouncing the name of Raina. A more ‘sciency’ (yet equally unproven) notion is that yawning helps replenish blood oxygen.

In truth, yawning has only quite recently been husked of some of its mystery:

Us humans, as it turns out, are literally just cooling our brains (try yawning with a cool pack on your forehead). The reason for this is that our brains work best within a narrow temperature range. Staying awake longer than we should can heat up your brain as processes can get a bit out of control. When we go to sleep our brain temperature drops, allowing our brains to deal with some of the damage done during our waking hours. So perhaps yawning is just a quick fix until we can take a nap or sleep

The balance of chemicals in your brain also affects how much you yawn. Endorphins (increased by exercise, orgasms and horror movies) and adrenaline, generally prevent you from yawning while serotonin (increased by most antidepressants and MDMA) makes you yawn more. Why these chemicals affect yawning the way they do is still a bit of a mystery.

6703771645_f21858a47b_zYawning is contagious. In fact, just hearing someone yawn or reading about it (sorry…) will do the trick. Amazingly, yawning even breaks the species barrier, with studies showing that dogs and chimps will both mimic a human yawn! The degree of contagiousness amongst humans depends on how emotionally close you are to the yawner. Also, individuals with autism/asbergers syndrome don’t yawn in response to others; leading to the suggestion that this mimicry is based on empathy and may be an accurate index of your empathetic capacity. It certainly makes an interesting way of testing friendships…

So why is it contagious?

It all comes down to mirror neurons in your brain. Generally when you see someone move, certain cells in your brain tend to mimic the action. This helps us to imitate the actions of others, but also to understand them. Actually acting out whatever other people do is usually suppressed (see here for a fascinating talk on mirror neurons and their importance). In the case of yawning, it’s not. The reason it’s not suppressed might not be a coincidence – it smells of evolution. One idea is that it gets social animals to increase their vigilance as a group – so all of them keep a cool brain when on the look out for predators. It could also help signal tiredness to fellow group member, a non-verbal way of saying “it’s bed-time kids”.

So don’t feel bad about yawning. You’re boosting your brain power and showing you care. But you should still cover your mouth. 🙂

Post by: Isabel Hutchison