Brains in their feat

Footballers skills seem light years from our own. But, Tom Stafford argues, the jaw-dropping talents on the World Cup pitch have more in common with everyday life than you might think.

The first week of the 2014 World Cup has already given us a clutch of classic moments: Robin Van Persie’s perfect header to open the Dutch onslaught against the Spanish; Australian Tim Cahill’s breathtaking volley to equalise against Holland; and Mexican keeper Guillermo Ochoa defying an increasingly desperate Brazilian attack.

We can’t help but be dazzled by the skills on display. Whether it is a header lobbed over an open-mouthed goalie, or a keeper’s last-second leap to save the goal, it can seem as if the footballers have access to talents that are not just beyond description, but beyond conscious comprehension. But the players sprinting, diving and straining on Brazil’s football pitches have a lot more in common with everyday intelligence than you might think.

We often talk about astonishing athletic feats as if they are something completely different from everyday thought. When we say a footballer acts on instinct, out of habit or due to his training, we distance what they do from that we hear echoing within our own heads.

The idea of “muscle memory” encourages this – allowing us to cordon off feats of motor skill as a special kind of psychological phenomenon, something stored, like magic potion, in our muscles. But the truth, of course, is that so called muscle memories are stored in our brains, just like every other kind of memory. What is more, these examples of great skill are not so different from ordinary thought.

If you speak to world-class athletes, such as World Cup footballers, about what they do, they reveal that a lot of conscious reasoning goes into those moments of sublime skill. Here’s England’s Wayne Rooney, in 2012, describing what it feels like as a cross comes into the penalty box: “You’re asking yourself six questions in a split second. Maybe you’ve got time to bring it down on the chest and shoot, or you have to head it first-time. If the defender is there, you’ve obviously got to try and hit it first-time. If he’s farther back, you’ve got space to take a touch. You get the decision made. Then it’s obviously about the execution.”

All this in half a second! Rooney is obviously thinking more, not less, during these most crucial moments.

This is not an isolated example. Dennis Bergkamp delighted Dutch fans by scoring a beautiful winning goal from a long pass in the 1998 World Cup quarter final against Argentina (and if you watch a clip on YouTube, make sure it the one with the ecstatic commentary by Jack van Gelder). In a subsequent interview Bergkamp describes in minute detail all the factors leading up to the goal, from the moment he made eye contact with the defender who was about to pass the ball, to his calculations about how to control the ball. He even lets slip that part of his brain is keeping track of the wind conditions. Just as with Rooney, this isn’t just a moment of unconscious instinct, but of instinct combined with a whirlwind of conscious reasoning. And it all comes together.

Studies of the way the brain embeds new skills, until the movements become automatic, may help make sense of this picture. We know that athletes like those performing in the World Cup train with many years of deliberate, mindful, practice . As they go through their drills, dedicated brain networks develop, allowing the movements to be deployed with less effort and more control. As well as the brain networks involved becoming more refined, the areas of the brain most active in controlling a movement change with increased skill  – as we practice, areas deeper within the brain reorganise to take on more of the work, leaving the cortex, including areas associated with planning and reasoning, free to take on new tasks.

But this doesn’t mean we think less when we’re highly skilled. On the contrary, this process called automatisation means that we think differently. Bergkamp doesn’t have to think about his foot when he wants to control a ball, so he’s free to think about the wind, or the defender, or when  exactly he wants to control the ball. For highly practiced movements we have to think less about controlling every action but what we do is still ultimately in the service of our overall targets (like scoring a goal in the case of football). In line with this, and contrary to the idea of skills as robotic-reflexes, experiments show that more flexibility develops alongside increased automaticity.

Maybe we like to think footballers are stupid because we want to feel good about ourselves, and many footballers aren’t as articulate as some of the eggheads we traditionally associate with intelligence (and aren’t trained in being articulate), but all the evidence suggests that the feats we see in the World Cup take an immense amount of thought.

Intelligence involves using conscious deliberation at the right level to optimally control your actions. Driving a car is easier because you don’t have to think about the physics of the combustion engine, and it’s also easier because you no longer have to think about the movements required to change gear or turn on the indicators. But just because driving a car relies on automatic skills like these, doesn’t mean that you’re mindless when driving a car. The better drivers, just like the better footballers, are making more choices each time they show off their talents, not fewer.

So footballer’s immense skills aren’t that different from many everyday things we do like walking, talking or driving a car. We’ve practiced these things so much we don’t have to think about how we’re doing them. We may even not pay much attention to what we’re doing, or have much of a memory for them (ever reached the end of a journey and realised you don’t recall a single thing about the trip?), but that doesn’t mean that we aren’t or couldn’t. In fact, because we have practiced these skills we can deploy them at the same time as other things (walking and chewing gum, talking while tying our shoe laces, etc). This doesn’t diminish their mystery, but it does align it with the central mystery of psychology – how we learn to do anything.

So while you may be unlikely to find yourself in the boots of Bergkamp and Rooney, preparing to drill one past a sprawling keeper, you can at least console yourself with the thought that you’re showing the skills of a World Cup legend every time you get behind the wheel of your car.

A bonus BBC Future column from last week. Here’s the original.

How muggers size up your walk

The way people move can influence the likelihood of an attack by a stranger. The good news, though, is that altering this can reduce the chances of being targeted.

How you move gives a lot away. Maybe too much, if the wrong person is watching. We think, for instance, that the way people walk can influence the likelihood of an attack by a stranger. But we also think that their walking style can be altered to reduce the chances of being targeted.

A small number of criminals commit most of the crimes, and the crimes they commit are spread unevenly over the population: some unfortunate individuals seem to be picked out repeatedly by those intent on violent assault. Back in the 1980s, two psychologists from New York, Betty Grayson and Morris Stein, set out to find out what criminals look for in potential victims. They filmed short clips of members of the public walking along New York’s streets, and then took those clips to a large East Coast prison. They showed the tapes to 53 violent inmates with convictions for crimes on strangers, ranging from assault to murder, and asked them how easy each person would be to attack.

The prisoners made very different judgements about these notional victims. Some were consistently rated as easier to attack, as an “easy rip-off”. There were some expected differences, in that women were rated as easier to attack than men, on average, and older people as easier targets than the young. But even among those you’d expect to be least easy to assault, the subgroup of young men, there were some individuals who over half the prisoners rated at the top end of the “ease of assault” scale (a 1, 2 or 3, on the 10 point scale).

The researchers then asked professional dancers to analyse the clips using a system called Laban movement analysis – a system used by dancers, actors and others to describe and record human movement in detail. They rated the movements of people identified as victims as subtly less coordinated than those of non-victims.

Although Professors Grayson and Stein identified movement as the critical variable in criminals’ predatory decisions, their study had the obvious flaw that their films contained lots of other potentially relevant information: the clothes the people wore, for example, or the way they held their heads. Two decades later, a research group led by Lucy Johnston of the University of Canterbury, in New Zealand, performed a more robust test of the idea.

The group used a technique called the point light walker. This is a video recording of a person made by attaching lights or reflective markers to their joints while they wear a black body suit. When played back you can see pure movement shown in the way their joints move, without being able to see any of their features or even the limbs that connect their joints.

Research with point light walkers has shown that we can read characteristics from joint motion, such as gender or mood. This makes sense, if you think for a moment of times you’ve recognised a person from a distance, long before you were able to make out their face. Using this technique, the researchers showed that even when all other information was removed, some individuals still get picked out as more likely to be victims of assault than others, meaning these judgements must be based on how they move.

Walk this way

But the most impressive part of Johnston’s investigations came next, when she asked whether it was possible to change the way we walk so as to appear less vulnerable. A first group of volunteers were filmed walking before and after doing a short self defence course. Using the point-light technique, their walking styles were rated by volunteers (not prisoners) for vulnerability. Perhaps surprisingly, the self-defence training didn’t affect the walkers’ ratings.

In a second experiment, recruits were given training in how to walk, specifically focusing on the aspects which the researchers knew affected how vulnerable they appeared: factors affecting the synchrony and energy of their movement. This led to a significant drop in all the recruits’ vulnerability ratings, which was still in place when they were re-tested a month later.

There is school of thought that the brain only exists to control movement. So perhaps we shouldn’t be surprised that how we move can give a lot away. It’s also not surprising that other people are able to read our movements, whether it is in judging whether we will win a music competition, or whether we are bluffing at poker. You see how someone moves before you can see their expression, hear what they are saying or smell them. Movements are the first signs of others’ thoughts, so we’ve evolved to be good (and quick) at reading them.

The point light walker research a great example of a research journey that goes from a statistical observation, through street-level investigations and the use of complex lab techniques, and then applies the hard won knowledge for good: showing how the vulnerable can take steps to reduce their appearance of vulnerability.

My BBC Future column from Tuesday. The original is here. Thanks to Lucy Johnston for answering some of my queries. Sadly, and suprisingly to me, she’s no longer pursuing this line of research.

Workout music and your supplementary motor cortex

Why do we like to listen to tunes when we exercise? Psychologist Tom Stafford searches for answers within our brains, not the muscles we are exercising.

Perhaps you have a favourite playlist for going to the gym or the park. Even if you haven’t, you’re certain to have seen joggers running along with headphones in their ears. Lots of us love to exercise to music, feeling like it helps to reduce effort and increase endurance. As a psychologist, the interesting thing for me is not just whether music helps when exercising, but how it helps.

One thing is certain, the answer lies within our brains, not the muscles we are exercising. A clue comes from an ingenious study, which managed to separate the benefits of practicing a movement from the benefits of training the muscle that does the movement. If you think that sounds peculiar, several studies have shown that the act of imagining making a movement produces significant strength gains. The benefit isn’t a big as if you practiced making the movement for real, but still the benefit of thinking about the movement can account for over half of the benefit of practice. So asking people to carry out an imaginary practice task allows us to see the benefit of just thinking about a movement, and separates this from the benefit of making it.

Imaginary practice helps because it increases the strength of the signal sent from the movement areas of the brain to the muscles. Using electrodes you can record the size of this signal, and demonstrate that after imaginary practice people are able to send a stronger, more coherent signal to the muscles.

The signals to move the muscles start in an area of the brain called, unsurprisingly, the motor cortex. It’s in the middle near the top. Part of this motor area is known as the supplementary motor cortex. Originally thought to be involved in more complex movements, this area has since been shown to be particularly active at the point we’re planning to make a movement, and especially crucial for the timing of these actions. So, this specific part of the brain does a very important job during exercise, it is responsible for deciding exactly when to act. Once you’ve realised that a vital part of most sporting performance is not just how fast or how strong you can move, but the effort of deciding when to move, then you can begin to appreciate why music might be so helpful.

The benefits of music are largest for self-paced exercise – in other words those sports where some of the work involved is in deciding when to act, as well as how to act. This means all paced exercises, like rowing or running, rather than un-paced exercises like judo or football. My speculation is that music helps us perform by taking over a vital piece of the task of moving, the rhythm travels in through our ears and down our auditory pathways to the supplementary motor area. There it joins forces with brain activity that is signalling when to move, helping us to keep pace by providing an external timing signal. Or to use a sporting metaphor, it not only helps us out of the starting blocks but it helps to keep us going until we reach the line.

Of course there are lots of other reasons we might exercise to music. For example, a friend of mine who jogs told me: “I started running to music so I didn’t have to listen to my own laboured breathing.” He might well have started for that reason, but now I’ll bet the rhythm of the music he listens to helps him keep pace through his run. As one song might have put it, music lets us get physical.

This is my BBC Future column from last week. The original had the much more accessible title of “The Psychology of Workout music“, but is our site (dammit) and I can re-title how I want.

BBC Future column: Hypnic Jerks

Here’s my column at BBC Future from last week. You can see the original here. The full listof my columns is here and  there is now a RSS feed, should you need it

As we give up our bodies to sleep, sudden twitches escape our brains, causing our arms and legs to jerk. Some people are startled by them, others are embarrassed. Me, I am fascinated by these twitches, known as hypnic jerks. Nobody knows for sure what causes them, but to me they represent the side effects of a hidden battle for control in the brain that happens each night on the cusp between wakefulness and dreams.

Normally we are paralysed while we sleep. Even during the most vivid dreams our muscles stay relaxed and still, showing little sign of our internal excitement. Events in the outside world usually get ignored: not that I’d recommend doing this but experiments have shown that even if you sleep with your eyes taped open and someone flashes a light at you it is unlikely that it will affect your dreams.

But the door between the dreamer and the outside world is not completely closed. Two kinds of movements escape the dreaming brain, and they each have a different story to tell.

Brain battle

The most common movements we make while asleep are rapid eye-movements. When we dream, our eyes move according to what we are dreaming about. If, for example, we dream we are watching a game of tennis our eyes will move from left to right with each volley. These movements generated in the dream world escape from normal sleep paralysis and leak into the real world. Seeing a sleeping persons’ eyes move is the strongest sign that they are dreaming.

Hypnic jerks aren’t like this. They are most common in children, when our dreams are most simple and they do not reflect what is happening in the dream world – if you dream of riding a bike you do not move your legs in circles. Instead, hypnic jerks seem to be a sign that the motor system can still exert some control over the body as sleep paralysis begins to take over. Rather than having a single “sleep-wake” switch in the brain for controlling our sleep (i.e. ON at night, OFF during the day), we have two opposing systems balanced against each other that go through a daily dance, where each has to wrest control from the other.

Deep in the brain, below the cortex (the most evolved part of the human brain) lies one of them: a network of nerve cells called the reticular activating system. This is nestled among the parts of the brain that govern basic physiological processes, such as breathing. When the reticular activating system is in full force we feel alert and restless – that is, we are awak

Opposing this system is the ventrolateral preoptic nucleus: ‘ventrolateral’ means it is on the underside and towards the edge in the brain, ‘preoptic’ means it is just before the point where the nerves from the eyes cross. We call it the VLPO. The VLPO drives sleepiness, and its location near the optic nerve is presumably so that it can collect information about the beginning and end of daylight hours, and so influence our sleep cycles. As the mind gives in to its normal task of interpreting the external world, and starts to generate its own entertainment, the struggle between the reticular activating system and VLPO tilts in favour of the latter. Sleep paralysis sets in.

What happens next is not fully clear, but it seems that part of the story is that the struggle for control of the motor system is not quite over yet. Few battles are won completely in a single moment. As sleep paralysis sets in remaining daytime energy kindles and bursts out in seemingly random movements. In other words, hypnic jerks are the last gasps of normal daytime motor control.

Dream triggers

Some people report that hypnic jerks happen as they dream they are falling or tripping up. This is an example of the rare phenomenon known as dream incorporation, where something external, such as an alarm clock, is built into your dreams. When this does happen, it illustrates our mind’s amazing capacity to generate plausible stories. In dreams, the planning and foresight areas of the brain are suppressed, allowing the mind to react creatively to wherever it wanders – much like a jazz improviser responds to fellow musicians to inspire what they play.

As hypnic jerks escape during the struggle between wake and sleep, the mind is undergoing its own transition. In the waking world we must make sense of external events. In dreams the mind tries to make sense of its own activity, resulting in dreams. Whilst a veil is drawn over most of the external world as we fall asleep, hypnic jerks are obviously close enough to home – being movements of our own bodies – to attract the attention of sleeping consciousness. Along with the hallucinated night-time world they get incorporated into our dreams.

So there is a pleasing symmetry between the two kinds of movements we make when asleep. Rapid eye movements are the traces of dreams that can be seen in the waking world. Hypnic jerks seem to be the traces of waking life that intrude on the dream world.

Flatline movement

I’ve just found another video of the Lazarus sign, the spinal reflex that triggers an arm raising and crossing movement in recently brain dead patients.

We’ve covered the mechanism behind the somewhat disconcerting movement before, and have noted an earlier video, but this one seems to have been uploaded quite recently.

The movement is triggered by a reflex arc – a basic neural circuit that doesn’t go any further than the spinal cord which means that it can initiate movement even when the brain is non-functional.

When the doctor taps your knee and causes a knee jerk, he or she is triggering exactly this effect. In fact, these movements can be triggered all over the body.

If you’ve ever had a complete neurological examination the neurologist will tap on various points to trigger numerous reflex arcs to check that the nerves going to and from certain muscle groups are in good working order.

One of these arcs causes the movement in the Lazarus sign, which, needless to say, can be quite disconcerting for doctors and quite confusing for relatives if the patient has just passed way.

In fact, you can see from the video how ‘lifelike’ the movement seems.

Probably not recommended if you’re uncomfortable with the sight of recently dead people moving.

Link to video of Lazarus sign.

A note on human behaviour

Enjoying the Natural History Museum yesterday, I came across this exhibit somewhere in the geology section:

The exhibit is a serious of columns, which you pass from right to left. The penultimate column is to illustrate the idea of ice, and you’re invited by a palm shape to put your palm to the column (which is indeed cold). The interesting thing is the final column, which is meant to illustrate gravity somehow (it was broken yesterday, so I don’t know how it is supposed to do this). Notice how the metal around the IVY of gravity is worn away. None of the other columns had this. Obviously hundreds of visitors a day are drawn to this exhibit, press their palms to the ICE column and then go on to touch, in exactly the same way, the GRAVITY column even though this isn’t part of the way they are supposed to interact with the exhibit.

Psychologists know that what people have done before is the best predictor of what they will do in the future. Whole industries are devoted to helping us establish, or break, habits. This exhibit on geological forces illustrates how easily some behavioural precedents can be set. We love touching things, and although we aren’t meant to, permission to do it once is all that is required to set off an immediate repetition of the behaviour.

Pointing the finger

Photo by Flickr user Adam Crowe. Click for sourceA brief yet intriguing description of a talk on pointing, by the ever versatile neuroscientist and philosopher Ray Tallis at the recent Hay Literary Festival.

A spellbinding hour with philosopher and self-confessed “many-layered anorak” Raymond Tallis on the subject of pointing. Yes, sticking your finger in the air and directing it at an object. It is, he argued, one of the attributes that mark us out as human beings with a sense of ourselves and others in a shared space: no other animal, including pointers and chimps, can use pointing fully. He reflected on its use for babies as a staging post towards acquiring language; and noted that in autistic children there is often an absence of pointing. He talked about pointing and power: the pointing that marks some unfortunate from a crowd and summons them to who-knows-what; the Malcolm Tucker-esque jabbing of the air that is tantamount to “a one-fingered punching at the self”. Then there is the disembodied, absent, generalised pointing of the fingerpost, which has “the ghost of intention about it”.

Link to description in The Guardian (via @Matthew_Broome)