Wednesday, 4 December 2013

Following In The Footsteps of Cricketing Giants

I once met a cricket master at a local public school who, some years previously, had taken a team of boys to India. He told me that one of his opening batsmen had asked his opposite number, by way of conversation, what their highest opening partnership had been. “664” was the reply. This partnership, between Sachin Tendulkar and Vinod Kambli, was made in Mumbai’s inter-school Harris Shield, and Tendulkar made 326, not out.
In the past three seasons, three cricketers have broken Tendulkar’s record in the same competition. Remarkably, they all played for the same school team – Rizvi Springfield in Mumbai. Sarfaraz Khan made 439 at the age of just 12. Earlier this year, and still only 15, he smashed a century for India Under-19 against South Africa in just 66 balls. Armaan Jaffer scored 473 at the age of 14, having previously scored 498 in another tournament two years previously. Now, Prithvi Shaw has eclipsed them by making 546 shortly after his 15th birthday. Pritvi’s story is quite remarkable. When he was just 4 years old his mother died, by which time he had already enrolled in the local cricket academy. At the age of 8 he started commuting to Rizvi Springfield School in West Mumbai with his father. Speaking on the BBC’s “Outlook” programme, this is how he described his day: “It was quite hard to travel. So we wake up at 4 o’clock, get the train at 6 o’clock….my school starts at 8.00 so it was a quite busy schedule. After my school from 8.30 to 2.30 I was having MIG practice (his cricket club in Mumbai). The practice was from 3 o’clock to 6.30. And then go to tuition at 8 o’clock, and then coming back at 11/11.30, and then eating then sleeping”. And it’s not just in Mumbai. Krishna Narayan from Kerala has become a YouTube sensation after his father posted videos of him batting form the age of 4. He’s now 9 years old. These kids generally have fathers who are somewhere on the spectrum from very supportive to extremely pushy to living their dreams through their kids. And therein lays the danger. In fact there are two dangers. Firstly, the father’s anxiety for the son to succeed transmits itself to the child who therefore loses the enjoyment of just playing. And the second danger is that the child believes that he is naturally supremely talented and doesn’t develop the mental strength to deal with setbacks. For an excellent article on this, see: At least they are unlikely to suffer the date of probably the greatest batting prodigy of all. In 1899, 13-year old AEJ Collins scored 628 not out playing for Clarke’s House, Clifton College, Bristol. This remains the highest score ever made in a competitive cricket match. Although he batted over four afternoons, he actually spent less than seven hours at the crease. Born in India, he was already an orphan by the time he began at Clifton, where he held a scholarship. A sporting all-rounder, he played half-back for the rugby XI, and won a bronze medal for boxing at a public school competition in 1901. He never played first class cricket, but joined the Army. In 1914, at the age of 29, he was killed in the First Battle of Ypres. David Donner

Tuesday, 19 November 2013

The A - Z of Sports Vision - Sleep

The importance of a good night’s sleep is often underestimated in sport. Mah et al (2011) studied the effect of giving college basketball players an extended sleep (between about 80 and 110 extra minutes). They found that the players were able to sprint faster, and were 9% more accurate in their free throws. By contrast, Winter (2013) found that the higher the level sleepiness of a Major League Basketball player, the less likely he would still be in the league three seasons later. And all this has more to do with the eyes than you might think. Many with be familiar with the two light receptor cells in the eye – the rods and cones. But here’s another group of cells known as photoreceptive retinal ganglion (prg) cells. The existence of these cells had first been proposed in 1923 by a Harvard graduate called Clyde Keeler, who noticed that the pupils of mice reacted to light even when they had no rods and cones. The idea lay dormant until the 1990s, when Oxford Professor Russell Foster was studying circadian rhythms, the daily cycles of our bodies, which appeared to be related to light levels. It was known, for instance, that if people live in the dark for days on end, their circadian rhythms drift, so they might end up sleeping in the day rather than at night. In 1999 Foster found that mice who had eyes, but no rods and cones, kept the same circadian rhythms as sighted mice. Then, in 2002, Berson et al found that these prg cells contained a photosensitive pigment called melanopsin, showing that this was the mechanism that’s used to set our daily cycles, including our sleep cycles. This explains why there are some completely blind people who are able to tell whether or not a light is on in the room, even though they don’t know how they do it. When melanopsin is stimulated, we become more alert and wakeful. And it’s most stimulated by blue light. So if you want a really good night’s sleep, you need a dark room, but you can have some red light as this doesn’t stimulate melanopsin. Leaving your curtains slightly open may give enough blue light to get you going in the morning, so you can start preparing for your sporting endeavours of the day. David Donner

Wednesday, 16 October 2013

The A - Z of Sports Vision - Reaction Times

Research into reaction times goes back more than a hundred years. In 1911 Ladd & Woodworth produced average reaction times for visual, auditory and kinaesthetic (touch) stimuli as 189.5ms, 146ms and 150ms respectively. Since then, other researchers have found similar figures, although improved technology has shown reaction times for kinaesthetic stimuli to be the quickest, at between 120 and 140ms (Vickers 2007). You can actually break reaction times down into different phases. Firstly, the stimulus has to be recognised and an appropriate response prepared. Then there’s a phase where the muscles begin to contract (as measured by electromyography – EMG) but there’s no movement. Finally there’s a phase where the movement response can be observed. Although the average auditory response time is 140-160ms, the threshold for Olympic sprints is lower because reaction time can be decreased with training (Carlton 1981). When Linford Christie was disqualified (see J is for jumping the gun) the threshold was 100ms, but it’s since been raised to 120ms. A group led by Joan Vickers looked at the reaction times of baseball player Mark McGwire. In his career McGwire averaged a home run every 10.61 at bats, the best at bats home run ratio in baseball history (Babe Ruth is second). They looked at videos of his record-breaking 1997-98 season, measuring his reaction time (the time between the release of the ball from the pitcher and the movement of the bat towards the ball) and his movement time (the time between the first forward bat movement and contact with the ball). They found that McGwire waited longer before moving his bat than other great players, and swung his bat faster than any other player in history. This fits in with research by Bahill & LaRitz (1984) who found that college players tracked the ball until it was around 2.75 metres from the plate while Major League players kept up with the ball until it was almost 1.5 metres form the plate. McGwire’s performances don’t appear to have been because of exceptional vision – he actually had poor acuity in one eye and wore contact lenses when playing. This suggests that his ability was more due to anticipation as a result of practice than an innate ability. For instance, batters do anticipate at least partly on the basis of previous balls and strikes against them. Laboratory-based research has found that batters’ decision-making processes were 60ms faster when they had this “count information” compared with when it wasn’t available (Farrow & Kemp, 2003). McGwire may have had one advantage, however: in 2010 he publicly admitted to using performance-enhancing drugs throughout his career. David Donner

Tuesday, 10 September 2013

The A - Z of Sports Vision - Quantum Biology

“Q” should really be for the Quiet Eye, but as I've already talked about that, it’s an opportunity to talk about a sport that’s rarely mentioned in terms of sports vision – pigeon racing. The term quantum biology was first coined by Edwin Schrödinger (of Schrödinger’s cat fame) in 1944. It’s always seemed miraculous that birds are able to navigate so accurately over such long distances. It’s been assumed that they do this by using the earth’s magnetic field, but it’s only recently that our understanding of quantum physics has enabled us to speculate on how they actually do it. As soon as one enters the world of quantum physics, things start to get seriously weird pretty quickly. For instance, in quantum superposition, particles can have different states such as a particle or a wave, until you observe them. To take the idea to an absurd level, Schrödinger suggested that a cat in a sealed box could be both alive and dead until the box was opened. There is also the phenomenon of “entanglement” in which unconnected particles influence each other, so that measuring one affects the measurements of the other. It’s this process of entanglement that is thought to take place within the bird’s retina that enables it to navigate. The idea is that a photon entering the bird’s eye releases a pair of molecules, each with an unpaired electron. Each of these electrons has an angular velocity, or spin, that can be altered by a magnetic field. Under quantum entanglement, the spin of one electron will affect the spin of the other, no matter how far apart they are. The birds might even have an image of the magnetic field that overlaps the visual image. So far, the only suggested use of quantum biology in humans is that it may explain how we are able to distinguish different smells. But it’s early days; who knows what we may find out in the future? David Donner

Monday, 2 September 2013

The A - Z of Sports Vision - Paralysis by Analysis

Take something you do every day without thinking about it – brushing your teeth, for instance, Next time you brush your teeth try and think about the precise movements that you are making with your hand. If you manage to keep this up for a while, you’ll find that brushing your teeth is no longer the simple process that it was on the previous occasion. If you start thinking about the mechanics of a routine process that we normally do sub-consciously, the result is that our performance deteriorates: “paralysis by analysis”. This is particularly common in sport: when something goes wrong, it’s very tempting to start analysing the mechanics of what happened, with the result that a blip becomes a catastrophe. Jackson & Beilock (2008) asked skilled soccer players to dribble the ball through a series of pylons while paying attention to the side of their foot that most recently contacted the ball. Their performance was worse in terms of being slower and having more errors compared with when they were given no instructions. Similar results have been found in baseball where skilled university-level players were asked to perform a hitting task. They heard a randomly presented noise and were told to indicate whether their bat was moving up or down at the instant they heard the noise. Biomechanical swing analysis revealed that the resultant deterioration in performance was at least in part due to a disruption in the sequencing and timing of the components of their swing. The more complex the skill, the greater is likely to be the loss of performance when the player concentrates on the step-by-step components of that skill (Masters et al 1993). It’s also more likely to occur in a high pressure situation, such as hitting a golf putt to win a golf championship (Masters et al, 1993). And it’s golf, and in particular Tiger Woods, that has given us an example of how paralysis by analysis can be overcome. Tiger’s father Earl taught him to putt when he was just a toddler. He told him to rotate his head and really look at the hole, then come back to the ball. He repeated this two or three times until he built up a picture in his head. All he had to do now was to “putt to the picture”. In other words you want to tell your subconscious brain, in as much detail as possible, exactly what you want it to do. But don’t tell it how to do it. David Donner

Friday, 9 August 2013

The A - Z of Sports Vision - Occlusion

Andy Murray is generally reckoned to be the best service returner in the world. He achieves this because he is the best at anticipating the opponent’s serve. How does he do that? One of the best ways of finding out is by occluding the vision of experts so that they can only see part of the opponent’s service action. These experiments have shown that experts can predict the direction of a serve before the racket makes contact with the ball. They are able to use cues such as the motion of the arm holding the racket that occur early in the opponent’s service action (Abernethy & Russell, 1987). The next step has been to see if lesser players can be trained to anticipate better by having their vision occluded at crucial points. Farrow & Abernethy (2002) put this to the test with 32 intermediate-level schoolboy tennis players. They were tested before and after training, with a retention test 32 days later. The tests consisted of facing actual tennis serves on a court whilst wearing occlusion goggles that cut off their sight at various points from 900ms before the server’s racket hit the ball, to a time after contact when the ball was approaching the net. They anticipation was judged according to the direction of the first movement they made as they attempted to return the serve (even though they couldn't actually see it at that point). During training, they watched video clips of serves that were occluded at various points. They had to say immediately where they thought the serve was directed. They would then watch it again when there was no occlusion, so they could assess how accurate they had been. One group was given specific information about the anticipatory cues used by experts, such as the location of the ball toss and the racket head angle just before contact (explicit knowledge), whilst a second group was not given this information but had to estimate the speed of each occluded serve (implicit knowledge). A placebo group did not have video training, but watched videos of tennis matches for an equivalent time. There was also a control group that didn't watch any videos. All four groups also had physical tennis training as well during the 4 weeks. The only group that showed a significant improvement in their anticipation was the implicit training group. They showed an improvement when their vision was occluded after the ball had been tossed, but before contact was made. This period has been shown to be crucial for service prediction (Farrow, Abernethy & Jackson, 2005). The placebo and control groups showed no improvement. Although the explicit group had high scores on average, they did not show an improvement in anticipation. This could be because they had too much information, whereas the implicit group concentrated on the racket movement in order to estimate the speed of the serve, and this was also the best indicator of the serve’s direction. Similar improvements from occlusion training have been found for baseball hitters (Fadde, 2006). Other sports will no doubt catch up in time: for example, there is no reason why it shouldn't be used to help goalkeepers trying to save penalties. David Donner

Monday, 1 July 2013

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

Monday, 3 June 2013

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

Monday, 13 May 2013

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

Thursday, 18 April 2013

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

Tuesday, 9 April 2013

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

The A-Z of Sports Vision - Inattentional Blindness

Some years ago I was driving along and in front of me was a van waiting to turn right into a side road. The driver appeared to be waiting for a motorcyclist coming in the opposite direction before turning. However, to my horror, he started to turn at exactly the moment the motorcyclist drew level with him. It was almost as if the van driver had been waiting for the motorcyclist before turning into him. I’m sure that wasn’t the case, but this was actually an example of “inattentional blindness”, and is a common cause of accidents between cars and motorcycles. Fortunately, in this case the motorcyclist wasn’t too badly injured. The term inattentional blindness refers to the failure to detect an unexpected object or event if attention is diverted to another task or object, even if it is right in front of the observer (Furley, Memmert & Heller, 2010). One of the most dramatic examples of inattentional blindness was demonstrated by Simons & Chabris, (1999). In a series of experiments, observers watched a video of two teams playing basketball. One team wore white shirts, the other black, and the observers had to count the number of passes made by either the white team or the black team. Partway through this task, either a woman with an umbrella or a person in a gorilla costume unexpectedly walked through the centre of the action for about five seconds before exiting the display. The observers were then asked if they had seen an unexpected object. 35% of observers failed to notice the woman with the umbrella, and 56% failed to notice the gorilla. In sport, there’s a balance between being focused on what you’re doing, and being so intensely focused on one area that you miss important information elsewhere. Because players can’t absorb all the information that might be presented to them on a sports field, coaches often guide them towards which cues to take notice of and which to ignore. The danger, however, is that this can make them blinkered and adversely affect their decision-making. Interestingly, it’s been found that expert athletes seem to prefer to pay proportionally less attention to highly likely events and more attention to less likely events (see Memmert, 2009 for an overview). In theory, this should mean that experienced athletes should be less susceptible to inattentional blindness. When Furley, Memmert & Heller (2010) studied expert basketball players, they found the phenomenon was still strong, although they were indeed not as susceptible as novice players. This indicates that predetermined plays, such as are often seen in American football, may not be the most advantageous. A less rigid approach, with fewer instructions, might actually be beneficial. Inattentional blindness can be an especially big problem for officials. In football, for instance, the referee might be distracted by some shirt-tugging, and not notice a handball, or even the ball crossing the goal line. I look forward to the day when the chant goes round the ground “You must be inattentionally blind, ref!” David Donner

Thursday, 14 March 2013

King John

Another weekend of brutal attrition, otherwise known as the Six Nations is over. Obviously poor weather was a major factor, but it’s hard to remember any actual rugby that was played in any of the matches. Surely there will come a point when people will start thinking twice about forking out £90 or so when they receive such a paltry return in terms of entertainment? It’s fortuitous that the BBC chose this week to broadcast a documentary on Barry John. Watching those old clips of him play is to be reminded that rugby can be about more than just the use of human battering rams. Here was a player who ran with his head up, always looking for space to exploit. For the sake of the game, let’s hope that there’s still room in the game for such a player. I actually found the programme hard to watch, because I couldn’t believe that such a great player was now living such a small life. If you haven’t seen it, it’s available on BBC iPlayer until Friday 15th. David Donner

The A-Z of Sports Vision - Chunking

If you showed a game of chess to someone who had no knowledge of the game, they would look at the pieces and the board itself and try to make some sense of what they saw. If, however, they were a chess player they might look at the positions of some key pieces, like the queens, and start to see some threats and opportunities. If they were a Grandmaster, they would instantly recognise patterns, focus in on a key area, and possibly see checkmate in three moves. This ability to put a large amount of information into a more manageable form is called “chunking”. The same kind of thing can be seen on a rugby field. The elite fly half doesn't have to look from player to player working out in detail where everyone is in relation to everyone else. Instead, the pattern of play is recognised in their long-term memory. Not only does this give them more time than a lesser player, it means they can then access information about previous actions that have worked in similar situations. They can then access the relevant motor program, which is a set of pre-structured motor commands from the brain to the muscles which produces a coordinated movement. The system is not too rigid, because it allows for late changes in the visual field. For instance, if the fly half has decided to float a long pass out to the wing, he can abort at the last moment if he spots an opposition player about to intercept. Building up these representations in the brain doesn't happen overnight, but takes many hours of experience. This is what practice is for. If you want your rugby backs to recognise overlaps, you need to put them in a series of small-sided competitive drills, some with overlaps and some not, so they recognise them, learn how to exploit them, and also learn how to defend them. To me, this is little more than a statement of the bleedin’ obvious. Yet this week Mike Catt, the England attack coach, said that England are having to coach execution of overlaps because some players are not doing it at their clubs. The decision making and swift-handed execution shown by the All Blacks in recent matches is the standard to which England and the other Home Unions should be aiming. At the moment, they’re a long way behind, and will drift ever further away unless some of the coaching at clubs improves. David Donner

Monday, 11 February 2013

The A - Z of Sports Vision - Heuristics

A batsman slogs the ball into the outfield. A fielder has to run round and judge where and when the ball is going to land so that he can position himself to take the catch. How does he do it? How does he work out all the different permutations of ball speed, height and distance in just a second or two? The answer is he doesn't: he uses a heuristic (although he probably doesn't know he’s using it). A heuristic is a kind of rule-of-thumb that enables people to solve problems and make judgements when there is little time to do so. In the case of the fielder, the trick is to adjust his speed so that the angle of gaze (the angle between the eye and the ball, relative to the ground) remains constant. This is the same method by which a dog might catch a Frisbee (McLeod & Dienes, 1996). A footballer at the edge of the penalty area may have the choice of passing or taking a shot. Does she choose the first thing that comes to mind (“take-the-first” heuristic)? Investigating teenage handball players, Johnson & Raab (2003) found support for this idea. Players were shown a situation on video, and had to describe the first option that they thought of. They were then given another 45 seconds to view the picture before being asked to select the best option. In 60% of cases, they chose the first option they thought of as being the best. Interestingly, having longer to think about it didn't improve the quality of the players’ final choices. Those that changed their minds would have been better off sticking to their original thought. This is because the first choice isn't just a random thought. For elite athletes, it’s embedded in their long-term memory through countless hours of practice. It’s like a simple “If…then” programme (If you see this, then do that). This is why the best players make the game look easy. Because for them, it does become a simple game. David Donner

Monday, 21 January 2013

The A - Z of Sports Vision - Gaze

The difference between gaze control and eye movements is that gaze control takes into account movements of the head as well as just the eyes. Often, if you’re following an object such as a moving ball, you need to move your head so that you can accurately fixate the point at which you make contact with the ball (by bat, foot, racket etc.) In many sports, the ball moves too fast for the athlete to be able to follow it accurately without moving your head. In fact, the common exhortation to “keep your eyes on the ball” simply isn't possible. In cricket, Land & McLeod (2000) found that elite batsmen actually moved their gaze ahead of the ball, so that they were “lying in wait” for the bounce of the ball on the pitch. This enabled them to make the most appropriate stroke response. Similar strategies were found in table tennis by Ripoll and Fleurance (1988). Players need to be able to track the path of the ball early in its flight so they can predict the bounce point. In tennis, Ripoll & Fleurance found that players visually tracked the ball for on average 150 milliseconds for flat forehands, and 185ms if there was topspin as well. Similarly in cricket, Land & McLeod found that elite batsmen tracked the ball for the first 150 – 200ms of its flight. Just because you’re looking at one place, doesn't necessarily mean that your attention is focused on the same spot. For instance, a boxer who wants to make a body shot can do so without taking his eyes off his opponent’s face. If he had to look down every time, it would give his intention away to his opponent. The fact that he doesn't have to suggests that the two systems – gaze control and attention – are completely separate. However, more recent research has suggested otherwise. Shepard et al (1986) found that it wasn't possible for participants in their studies to change their gaze from one point to another whilst maintaining their visual attention on the initial point. Studies using brain imaging have since discovered that the same nerve pathways within the brain are involved in both moving the gaze and shifting visual attention. So athletes can be looking at one place whilst thinking about somewhere else, but moving the eyes means shifting the attention. It’s also been found by Shepard and others that the shift of attention comes before the shift in gaze. Elite athletes seem to be able to control their attention and gaze on crucial positions at crucial moments in many sports. This is the “Quiet Eye”. But you’ll have to wait until “Q” to find out more about that. David Donner

Friday, 11 January 2013

The A - Z of Sports Vision - Feedback

When you are learning a new skill, you want feedback as to how you are doing. In fact there are two kinds of feedback: one gives you knowledge of the result (did I score a goal?) and the other gives you knowledge about your performance (did I kick the ball correctly?) Salmoni (1984) suggested that although feedback guides the performer to the correct movement, it can have negative effects when provided too frequently. The brain has its own feedback system from the senses, including feedback from our muscles as we carry out physical tasks. The problem is that the learner can become so dependent on the feedback provided by the coach, that this natural learning system is undermined, and there’s nothing to rely on when the coach’s feedback is no longer available. Feedback that is provided at the same time as the movement is particularly detrimental to learning. This type of feedback typically has very strong performance-enhancing effects during practice; but clear performance decrements, relative to when feedback is provided after the movement, are seen in transfer and retention tests (Park, Shea and Wright, 2000 for example). A problem with a lot of the feedback given to learners is that it tends to direct their attention to their own movements, which is generally less effective for learning than concentrating on the effects of one’s movements. Reducing the relative feedback frequency, on the other hand, might give the learner a chance, at least once in a while, to perform the movement without being too concerned about their performance. Janelle et al (1997) gave participants a throwing task using their non-dominant hand. There were three groups: two received additional feedback in the form of a video replay and comments from an expert, and one group didn't receive this. Of those that received the extra feedback, one group received after each group of five throws, and the other received the feedback only when they requested it. In the practice phase, those who received the extra feedback threw better than those who didn't receive it. However, on a retention test some days later, participants who had received additional feedback only when they had asked for it during practice demonstrated better throwing form and accuracy than participants in the other groups. This suggests that skill retention may be enhanced if instructors provide feedback only when learners request it during practice sessions. Great coaches are able to design practice so that feedback is embedded into the drill, leading to automatic readjustment, which in turn improves the quality of the feedback, generating further improvements and so on. Positioning oneself in this kind of feedback loop produces astonishing improvements (Syed 2011). David Donner

The A - Z of Sports Vision - Eye Dominance

If you point to a distant object, close one eye and then the other, you’ll notice that when one eye is closed you’re no longer lined up. This is the effect of parallax, when there are two lines of sight, one for each eye. The brain has to choose one eye for alignment, and this is known as the dominant eye, though “aligning eye” might be a better description. You might think that eye dominance would match handedness, but there are many instances of “cross dominance”, For instance, Griffiths (2002) found that 40% of left-handed batsmen playing for Scotland were right-eye dominant. Even in archery, where aiming is obviously the essence of the sport, 18.75% of internationals studied were found to have cross dominance. In his study, Griffiths found that deliberately making the dominant eye blurred strongly affected the performance of clay pigeon shooters, not surprisingly. But for tennis players, the greater effect came from blurring the non-dominant eye. And these weren't just any tennis players: they included previous winners and finalists at Wimbledon, The US, Australian and French Open Championships. And it was those who were right-handed and right-eye dominant who were most affected when their non-dominant (left eye) was blurred. This suggests that it would be their depth perception that was affected. In cricket, eye dominance can affect the stance, with a right-eye dominant right-handed batsman requiring a slightly more open stance to ensure that the right eye is aligned with the ball. Unfortunately, this stance is often coached to youngsters without checking their eye dominance first. Eye dominance may also be part of the explanation for the number of elite cricketers whose batting stance is the opposite of their bowling action. Misalignment of the dominant eye is a well documented cause of errors when putting in golf. I've seen several cases where a consistent missing of putts to one side has been caused by using different eyes when aligning the ball with the hole and the putter to the ball. I use a different eye for alignment depending on which hand I use for putting, which is why both hands should be used when testing for eye dominance. Bizarrely, I naturally align with my left eye when I point with my right hand, and vice versa. I've no idea why I do this, but it does explain why, when I used to shoot, my first shot was always off target, and I had to aim to the side to compensate. If I’d known, I could have just closed my left eye. David Donner