The A - Z of Sports Vision - Neurons

The normal adult brain contains around 85 billion nerve cells or neurons, each with between 1,000 and 10,000 connections to other cells, via between 100 trillion and 1,000 trillion synaptic connections. If that wasn't mind-boggling enough, consider what’s going on in the unborn foetus. In the last month of pregnancy, new neurons appear and migrate to where they are needed at the rate of 250,000 per second, resulting in almost a trillion cells at birth. These neurons are then rapidly pruned down to the 85 billion or so that we have for the rest of our life. Studies have compared the brain structures of animals raised in various environmentally normal, deprived or enriched settings. The enriched settings provided the opportunity to interact with toys, treadmills and obstacle courses. Animals placed in enriched environments had brains that were larger and contained more synaptic connections. By contrast, studies Romanian orphans (Chugani et al, 2001 for example) show significant reduced brain function as well as a smaller brain size compared with children who were adopted. As the baby explores and interacts with its environment, the neurons in its brain transmit signals to each other. To achieve the precision of the mature brain, stimulation in the form of movement and sensory experiences during the early developing years is necessary. Experience appears to exert its effects by strengthening and bonding synapses – the connections between neurons. The neural networks that are used get stronger, those that are not wither away, just as unused brain cells start dying in the first weeks after birth. Due to differences in experience, not even identical twins are wired the same. This interplay is life-long. Even the adult brain can continue to re-wire itself and make connections after exposure to new situations. The more that a particular brain network is activated the stronger the signal becomes (external stimuli send electrical impulses racing from one part of the brain to another). The brain consolidates learning by pruning away synapses and wrapping myelin around other connections to stabilise and strengthen them. At some point the signal becomes so strong and stable that these connections cannot be pruned away. Myelin is thought to be crucial in developing expert-level skills. The thicker the myelin gets, the better it insulates and the faster and more accurately the signals travel. It’s this that seems to be the key to developing a reliable golf swing or tennis serve. There’s increasing evidence that physical activity is one of the main ways the brain develops, with greater neuron and synapse production (for instance Gould et al, 1999, 2000, 2004). It seems there can be even greater rewards when decision making is involved with extensive practice (Brown et al 2003). Draganski et al (2004) used fMRI scans to examine the effect of juggling on brain development. After three months of juggling, a significant increase in grey matter (un-myelinated nerve cells) was detected in the occipital cortex and visual areas of jugglers compared with non-jugglers. If you really want to give your kids a head start in terms of hand-eye coordination, teach them to juggle. David Donner

The A - Z of Sports Vision - Music

In 2008, the US Track and Field (USATF) banned headphones and other music-playing devices at all USATF-sanctioned running events. This was for safety reasons, because athletes wearing headphones might not hear instructions from officials, other athletes trying to overtake them, or even road traffic in some cases. Many other organisers have since followed suit, but some athletes say they would rather not race than be without their MP3 players. That’s because music can aid sporting performance in a number of ways. Firstly, music can divert the mind from feelings of fatigue. For instance, Karageorghis & Terry (1999) found a 10% reduction in perceived exertion during running on a treadmill. This only works if the exercise isn’t too vigorous. But even then, although there’s no reduction in the perceived effort, the runner is still likely to find it a more pleasurable experience compared with no music. In 2009, a study of female basketball players in Australia found players who had a tendency to choke were significantly more accurate in free-throw shooting during high pressure situations if they first listened to “Always Look on the Bright Side of Life” from “Life of Brian”. It seems that the music distracted them from thinking about the mechanics of their throw. Music can also be used to get the athlete into their preferred mental state before a completion. Although for some this might be something upbeat to get the adrenaline flowing, others use it to stay relaxed. For instance Dame Kelly Holmes used the soulful ballads of Alicia Keys in her pre-event routine at the Athens Olympics in 2004. Karageorghis & Lee (2001) found that a combination of music and imagery enabled participants to hold on to weights for longer when compared with music or imagery alone or neither. Performing at the same tempo as the music has been found to be advantageous in a number of sports. Bacon, Myers & Karageorghis (2008) found that cyclists required 7% less oxygen to do the same work when they cycled in time to music compared with when they just listened to background music that was asynchronous (not at the same tempo). In February 1998, Haile Gebrselassie of Ethiopia smashed the indoor world record for 2,000 metres while listening to the rhythmical pop song “Scatman”, which was played over loud speakers. Music can also be used to enhance young athletes’ motor skills. For example, “Push It” by Salt-n-Pepa helps athletes hone shot-putt technique. The lyric reinforces the need for athletes to putt (i.e. push) the shot rather than trying to throw it, the most common technical error. Finally, music can help athletes get “in the zone” (also known as “flow”). Pates, Karageorghis, Fryer & Maynard (2003) looked at the effect of pre-task music on the performance of three college netball players. Two reported an increase in their perception of flow, and all three showed considerable improvement in shooting performance. David Donner

The A - Z of Sports Vision - Long Loop Reflexes

There are several different kinds of reflexes in the human body. Short loop reflexes involve just one nerve junction or synapse. An example is the well-known knee-jerk reaction. This occurs if a leg, swinging free, is tapped at the patellar ligament, just below the knee. A nerve signal is sent to the spine that the ligament has gone slack, as happens when you start to fall over. This signal reaches the spinal cord where, on the other side of the synapse, a responding nerve signal is sent out to make the quadriceps muscle contract. If you were falling, this would propel you into the air and give you a chance to regain your balance. When the doctor does it, you just kick your leg out. But there are also reflexes which involve several synapses. An example is the withdrawal reflex that ensures that you move your hand away rapidly if you touch a hot object. Pain receptors in the affected area send a nerve impulse to the spinal cord, which relays the message to the nerves that control flexor muscles in that area. A third nerve impulse results in that part of the body withdrawing from the painful stimulus. All this takes about half a second, before you are consciously aware that it’s happened. In sport, the connection between the stimulus and the reflex is usually less direct, for example a goalkeeper having to adjust to save a deflected shot. These kinds of actions are known as long loop reflexes because they have some involvement of the brain, rather than just in and out of the spinal column. Wayne Gretzky is generally acknowledged to have been the greatest ice hockey player ever. He played in the National Hockey League for 20 seasons, and holds the career record for total points scored (goals and assists) and assists. And yet Gretzky was always the runt of the team. Small, skinny, slow and with a weak shot. He didn’t even have the most accurate shot, although he was accurate. But he was the fastest at initiating a shot when he saw the opportunity to score, such as from a rebound. He also had the fastest long loop reflex times of anyone examined at the University of Columbia laboratories in Canada. It’s possible that these exceptional reflexes were just a genetic fluke. However it’s also possible that stimulation, particularly at a young age, is crucial. And there are few better examples of stimulation at a young age than Wayne Gretzky. Almost as soon as he could walk he was sliding around the floor in his socks, pretending to skate. He was skating on ice at the age of two on a frozen river that ran through his grandparents’ farm. He practised shots with a rubber ball and a cut-down hockey stick. His father built a rink in the family’s back yard and invited the neighbouring kids to play where he spent thousands of hours. He was ready to play junior league hockey at the age of 5, but had to wait until he was 6 before a team would take him, even though the minimum age was supposed to be 10. When he was 10, he scored 378 goals in a season. Asking how much of a player’s success is down to nature and how much to nurture is like asking how much of the flavour of a cake is down to its ingredients and how much is due to the cooking. But it seems highly unlikely that Gretzky would have been as good a player if he had not had essentially unlimited practice time in those early years. And the same is probably true of those exceptionally fast long loop reflexes. David Donner

The return of ...It Must Be Love!

“The blogs are great” says Dan the Man, “but you need something to brighten them up occasionally: any more tennis stories?” Who does he think I am? Jeremy Clarkson? I don’t race across Africa or interview celebrities. I play tennis with some other blokes, and if we were supermarket products we’d be labelled “Best before 1990”; or in some cases “before 1970”; or in others “Not applicable”. We seem to have picked up a few injuries recently. It started when I was playing with Jonathan the slice against Barry the Beard and the Reverend Ian. They had played quite a few drop shots in front of JtS which he had got nowhere near, so when they played another one cross-court I decided to go for it. Unfortunately, JtS decided to go for it as well. I actually thought it was quite an achievement to deliver a body check on my partner that a NHL ice hockey player would have been proud of, and which put him out of action for three weeks, whilst at the same time completing a backhand down the line for an outright winner. BtB, being Barry, claimed he was “too busy watching you to kiss and cuddle to attempt to go for the ball”. Fortunately, I remembered an earlier moment when BtB’s momentum when going for a shot on the baseline had sent him careering off towards the next court where he met Roger the Backpacker running in the opposite direction. “You can talk” I said. “At least I didn't run off the court to do it. You were like a schoolgirl who’s just seen Justin Bieber”. Unfortunately I’d forgotten that Barry’s knowledge of 21st Century cultural references couldn't exactly be described as encyclopedic. “Who’s Justin Bieber?” I've also heard that Barry the Beard has had a nasty injury when he ran off the side of the court into a brick wall the other side of the netting. Apparently the netting was too close anyway and he’s considering legal action. Our group is known as “The Doctors” because there were originally two doctors in it, although we now only have a retired anesthetist. We do have two retired solicitors, so when someone’s lying on the ground injured there’s invariably a call of “Let me through, I’m an injury compensation lawyer”. And then last week I looked across to the next court after hearing some kind of commotion. Roger the Backpacker was holding his nose in some discomfort. For some reason, the thought occurred to me that his partner, The Reverend Ian, had completely lost it and punched RtB in the face. I immediately dismissed the thought and assumed that the two had collided accidentally. It turned out, however, that Roger had contrived to hit himself with his own racket. It was one of those unifying moments when, as the blood started to seep from RtB’s nose, the rest of us were clearly thinking the same thing: “If only we’d had a video camera to record that”. Because it is a truth, universally acknowledged, that there are few things more enjoyable than watching someone else carry out a completely self-inflicted injury. It was as if Richard the Poke had carried out his trademark “stroke” (for want of a better word) in reverse. But that wouldn't have carried sufficient force even to reach the nose, let alone break the skin. No, this was made with the full swing of the racket, which makes the achievement of following through right in the middle of your own face all the more remarkable. So I’m going to start wearing one of those cameras that are used to determine what elite sportsmen are looking at. Of course I shall say it’s in the name of research, but I will actually be hoping that history repeats itself and I can sell the video. All those channels that just endlessly repeat old shows could replace them with an endless loop of RtB attempting to rearrange his own conk. Not only would viewing figures soar, but the World Database of Happiness (believe me – there really is such a thing) would show Britain soaring up the happiness league table. Someone should tell David Cameron. David Donner

The A-Z of Sports Vision - Knowledge

Coaches are expected to give their athletes some feedback about their performance, and this can mean the athletes can gain different types of knowledge. Knowledge of results tells athletes how they have performed in relation to the goal they were trying to achieve, whereas knowledge of performance tells them about the quality of their performance, regardless of the outcome. Knowledge of results includes how far a long jumper has jumped, or the score of an archery shooter. Of course, there are many times when the result is obvious to the athlete, such as whether or not a shot has resulted in a goal or been saved. There are risks involved, however. For instance, a tennis player can see if their serve has landed in or out, and may be tempted to play safe and go for accuracy which may limit the development of their serve. Novice tennis players will know that they are hitting some shots harder than others, but are unlikely to have precise information about how fast the ball is travelling. Davies (1989) used an artificial method of giving this feedback so that the speed of the serve could be increased. The player served at a wall the same distance away that the net would be. Two lines were marked on the wall – one at the height of the net and another some feet higher, above which it had been assessed that the service would be “long”. The knowledge of results came in the form of the distance of the rebound from the wall. The player’s service speed rose rapidly, and the player was able to select for himself the most appropriate service technique. This is essential; otherwise when knowledge of result is withdrawn the performance will decline to its previous level since nothing will have been learned. Knowledge of performance might include the coach telling the player they should have passed the ball when they took a shot, or a technical comment about a bowler’s action. Video can be an effective way of giving athletes knowledge of their performance. I recently videoed some scrum halves passing the ball, and it was immediately apparent that they tended to kick their back leg out as they released the ball. This is clearly an attempt by the subconscious brain to retain balance, but it suggests that they are not as balanced as they should be in the first place. The trick now will be to get them to be more balanced without having to think consciously about their feet placement, as such an internal focus is likely to affect their performance adversely. I’d like to give them an image that would encapsulate the whole movement. By the time we get to “V for video”, I should know how successful I've been. David Donner

The A-Z of Sports Vision - Jumping the Gun

In international sprint events, such as the 100 metres, a false start is called if an athlete’s foot increases the force on their starting block within 100 milliseconds of the gun. The IAAF decided on this threshold in the belief that humans cannot react to a sound in less than 100ms. Is this right? Komi, Ishikawa & Salmi (2009) found that there was quite a bit of variation in reaction times, and that the values in some cases were even below 80ms. They therefore recommended to the IAAF that the value should be reduced to 80 or 85ms. They also suggested that high speed cameras should be used to detect any first movement before the set minimum reaction time, rather than pressure on the blocks. Brown, Kenwell, Maraj & Collins (2008) reviewed reaction times for the 2004 Olympics in Athens. They found that runners in Lane 1 had an average reaction time of 160ms, whereas those in Lane 2 took 171ms. The slowest lane, for some reason, was Lane 7 (rather than the expected Lane 8) with 185ms. When experiments were carried out on athletes and non-athletes, they found that non-athletes had faster reaction times when the sound was louder. Assessment of their blinks suggested that being startled produced faster reaction times. Athletes, it seemed, were able to produce their fastest reactions without being startled. During their experiments, the researchers noted that 21% of participants recorded reaction times faster than 100ms, although subjects only had to move an arm in response, rather than their whole body. Nevertheless, it’s interesting that Linford Christie was disqualified in the 1996 Olympic final with a reaction time of 86ms, and was convinced that he had not jumped the gun. One other thing: Lipps, Galecki & Ashton-Miller analysed reaction times of male and female sprinters at the 2008 Beijing Olympics. They found that men and women could react in as little as 109ms and 121ms respectively. However, they believe that this difference is an artefact caused by the fact that the rule of how much extra force is needed to put on the blocks to register a start time is the same for both men and women. Taking into account the less muscle strength of the women compared to the men, the force requirement should be reduced by about 22%. Effectively, they claim, this allows women to false start by up to 21ms without penalty. If they had a visual system of starting, such as a light flashing on, and a visual system to detect early movement, perhaps it would all be fairer. David Donner

Eye Colour and Trustworthiness

Does the colour of your eyes indicate how trustworthy you are? Research by Kleisner et al (2013) appears to suggest that it does. Some aspects of behaviour and eye colour have been researched previously. For instance, Rosenberg & Kagan (1989) found that blue-eyed infants were more inhibited, shy and timid than brown-eyed infants. Coplan et al (1998) found that boys with blue eyes were socially warier than boys with brown eyes, although no such differences were found between blue- and brown-eyed girls. In the latest experiment, 238 participants were shown photographs of 40 males and 40 females, and rated them for trustworthiness on a scale of one to ten. In order to check if eye colour was really the relevant factor, the irises were then re-coloured using Photoshop. These re-coloured photos were then assessed for trustworthiness by a second group of 106 participants. They found that brown-eyed faces were perceived as more trustworthy than the blue-eyed ones. For male faces, the eye colour of those rating the photos had no effect. But for female faces, those with blue eyes received lower ratings from those with brown eyes than with blue eyes. However, all those doing the rating, irrespective of their own eye colour, perceived brown-eyed faces as more trustworthy than blue-eyed ones. But when the eye colours were digitally changed, there was no change in perceived trustworthiness, showing that it wasn’t actually eye colour that was significant. So what was going on? It turns out that men with a larger mouth, a broader chin, a bigger nose and more prominent eyebrows positioned closer to each other were rated more trustworthy. And brown-eyed men are more likely to have these characteristics. There was a similar but insignificant effect for women, possibly because of less variation in female face shape. As the Eagles put it, “You can’t hide your lyin’ eyes”. David Donner