Breaking Curveballs And Rising Fastballs Are Optical Illusions

(Credit: iStockphoto/Barry Howell)
Curveballs curve and fastballs go really fast, but new research suggests that no pitcher can make a curveball "break" or a fastball "rise."  Led by Arthur Shapiro of American University and Zhong-Lin Lu of the University of Southern California, the researchers explain the illusion of the curveball's break in a publicly available study in the journal PLoS ONE.

The study comes a year after the same group won the prize for best illusion at the Vision Sciences annual meeting with a demonstration of how an object falling in a straight line can seem to change direction.  That demonstration led to debates among baseball fans over the existence of the break in curveballs, breaking balls and sliders.

There is no debate in the researchers' minds.

"The curveball does curve, but the curve has been measured and shown to be gradual," Shapiro said. "It's always going to follow a parabolic path. But from a hitter's point of view, an approaching ball can appear to break, drop or do a whole range of unusual behaviors."

A little terminology: to many batters and pitchers, a break is a deviation from the relatively straight path of a fastball. In that sense, all curveballs break.  The authors of the study use the term to describe an apparent sudden drop or other change in trajectory as the ball nears home plate. That, they say, is an illusion.

The PLoS ONE study explains the illusion and relates the perceived size of the break to the shifting of the batter's eye between central and peripheral vision.

"If the batter takes his eye off the ball by 10 degrees, the size of the break is about one foot," Lu said.
He explained that batters tend to switch from central to peripheral vision when the ball is about 20 feet away, or two-thirds of the way to home plate. The eye's peripheral vision lacks the ability to separate the motions of the spinning ball, Lu said. In particular, it gets confused by the combination of the ball's velocity and spin.

The result is a gap between the ball's trajectory and the path as perceived by the batter. The gap is small when the batter switches to peripheral vision, but gets larger as the ball travels the last 20 feet to home plate.

As the ball arrives at the plate, the batter switches back to central vision and sees it in a different spot than expected. That perception of an abrupt change is the "break" in the curveball that frustrates batters.

"Depending on how much and when the batter's eyes shift while tracking the ball, you can actually get a sizable break," Lu said. "The difference between central and peripheral vision is key to understanding the break of the curveball."

A similar illusion explains the "rising fastball," Lu added.  The obvious remedy for a batter, repeated by parents and coaches everywhere, is to "keep your eye on the ball."  That is easier said than done, according to the authors. As the ball nears home plate, its size in the batter's field of view spills out of the eye's central vision.

"Our central vision is very small," Shapiro said. "It's the size of the tip of your thumb at arm's length. When an object falls outside of that region, strange perceptions can occur."

Lu noted that the spin of the ball tends to draw the eye to the side, making it even harder for the batter to keep the ball in central vision.  "People's eyes have a natural tendency to follow motion," Lu explained.  His advice to hitters: "Don't trust your eyes. Know the limitations of your visual system. This is something that can be trained, probably."

Lu, Shapiro and their co-authors plan to build a physical device to test the curveball illusion. Their study was carried out with volunteers tracking the movement of a disk on a computer monitor.
To the authors' knowledge, the PLoS ONE study represents the first attempt to explain the break in the curveball purely as a visual illusion. Others have tried to explain the break as a result of the hitter overestimating the speed of a pitch.

Responding to comments from baseball fans, Lu agreed that on television, pitches filmed from behind home plate appear to break. He called it a "geometric illusion" based on the fact that for the first part of a pitch, the viewer sees little or no vertical drop.

The ball is falling at the same rate throughout the pitch, Lu said, but because the pitcher tosses the ball at a slight upward angle, the first part of the pitch appears more or less flat.  As a result, the drop of the ball near home plate surprises the eye.  For Shapiro and Lu, who have studied visual perception for many years, the PLoS ONE results go beyond baseball.

"Humans constantly shift objects between central and peripheral vision and may encounter effects like the curveball's break regularly," the authors wrote. "Peripheral vision's inability to separate different visual signals may have f ar-reaching implications in understanding human visual perception and functional vision in daily life."

Source: University of Southern California and Arthur Shapiro, Zhong-Lin Lu, Chang-Bing Huang, Emily Knight, Robert Ennis. Transitions between Central and Peripheral Vision Create Spatial/Temporal Distortions: A Hypothesis Concerning the Perceived Break of the Curveball. PLoS ONE, 2010; DOI: 10.1371/journal.pone.0013296

See also: Morning Type Pitchers Do Better In Day Games and Virtual Reality Lab Proves How Fly Balls Are Caught

Running Addicts Need Their Fix

Just as there is the endorphin rush of a "runner's high," there can also be the valley of despair when something prevents avid runners from getting their daily fix of miles.

Now, researchers at Tufts University may have confirmed this addiction by showing that an intense running regimen in rats can release brain chemicals that mimic the same sense of euphoria as opiate use. They propose that moderate exercise could be a "substitute drug" for human heroin and morphine addicts.

Given all of the benefits of exercise, many people commit to an active running routine. Somewhere during a longer, more intense run when stored glycogen is depleted, the pituitary gland and the hypothalamus release endorphins that can provide that "second wind" that keeps a runner going.

This sense of being able to run all day is similar to the pain-relieving state that opiates provide, scientists have known. So a team led by Robin Kanarek, professor of psychology at Tufts University, wondered whether they could also produce similar withdrawal symptoms, which would indicate that intense running and opiate abuse have a similar biochemical effect.

Running rodents
The team divided 44 male rats and 40 female rats into four groups. One group was housed inside an exercise wheel, and another group had none. Each group was divided again, either allowing access to food for only one hour per day or for 24 hours per day. Though tests on humans would be needed to confirm this research, rodents are typically good analogues to illuminate how the human body works.
The rodents existed in these environments for several weeks. Finally, all groups were given Naloxone, a drug used to counteract an opiate overdose and produce immediate withdrawal symptoms.

The active rats displayed a significantly higher level of withdrawal symptoms than the inactive rats. Also, the active rats that were only allowed food for one hour per day exercised the most and showed the most intense reaction to Naloxone. This scenario mimics the actions of humans suffering from anorexia athletica, also known as hypergymnasia, that causes an obsession not only with weight but also with continuous exercise to lose weight.

"Exercise, like drugs of abuse, leads to the release of neurotransmitters such as endorphins and dopamine, which are involved with a sense of reward," Kanarek said. "As with food intake and other parts of life, moderation seems to be the key. Exercise, as long as it doesn't interfere with other aspects of one's life, is a good thing with respect to both physical and mental health."

The study appears in the August issue of Behavioral Neuroscience, published by the American Psychological Association.

Treatment ideas
Kanarek hopes to use these results to design treatment programs for heroin and morphine addicts that substitute the all-natural high of exercise in place of the drugs.  "These findings, in conjunction with results of studies demonstrating that intake of drugs of abuse and running activates the endogenous opioid and dopamine reward systems, suggest that it might be possible to substitute drug-taking behavior with naturally rewarding behavior," she writes.

She also wants to do further research on understanding the neurophysiology of extreme eating and exercise disorders. "The high comorbidity of drug abuse and eating disorders provides further evidence of a common neurobiological basis for these disorders," Kanarek concludes.

Cyclists' Sore Seats Signal Serious Symptoms

For any guy who has endured more than thirty minutes on a road bicycle seat, there is usually some concern over the strange numbness that occurs in places that should not go numb. Well, a new study has some good and bad news.

Spanish researchers have found that active male cyclists have lower quality sperm to the point of infertility risk. Among other things, they blame the painful "function over form" design of the wedge bicycle seat.

The good news is that unless you're training to be in the next Tour de France with Lance Armstrong, your time on the saddle shouldn't do any long-term damage.

A team led by professor Diana Vaamonde, from the University of Cordoba Medical School, tracked the workout regimen of 15 Spanish triathletes, with an average age of 33 who had been training for at least eight years, while also monitoring their sperm morphology.



For those in the test group that covered more than 180 miles per week on their bikes, the percentage of normal looking sperm dropped from a group average of 10 percent to 4 percent, a rate where infertility problems begin. Increased swimming or running did not affect sperm quality.

"We found a statistically adverse correlation between sperm morphology and the volume of cycling training undertaken per week," Vaamonde said. "We believe that all the factors inherent in this sports activity, especially with regards to the cycling part, may affect sperm quality," she added. "Moreover, we think that normal physiological homeostasis – the body’s ability to regulate its own environment – may become irreversibly altered, therefore resulting in complex anomalies."

Vaamonde cited three possible reasons for the results: the increased heat during exercise, the friction and pressure against the seat causing microtrauma on the testes, and the overall rigor of intense exercise.

The study was released last week in Amsterdam at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE).

The Spanish researchers were following up on research from 2002 that showed similar results for mountain bikers. In that study, Austrian researcher Ferdinand Frauscher tested 40 active (two hours per day) mountain bikers with 30 non-bikers. He found that the bikers had about half the sperm count of the non-bikers. Frauscher explained (as only a medical doctor can) the possible reasons: "The exact causes for the decreased sperm motility are unclear. We believe that repeated mechanical trauma to the testicles results in some degree of vascular damage, and may thereby cause a reduction in sperm motility." Ouch.

For casual bike riders, the risk is still quite low. Allan Pacey, senior lecturer in andrology at the University of Sheffield, told BBC News, "It is important to stress that even if the association between cycling and poor sperm morphology is correct, men training for triathlons are spending much more time in the saddle than the average social cycler or someone who might cycle to and from work."

For those that are still not okay with the "saddle sores," there are always the anatomically correct seats and the padded biker shorts, not to mention recumbent bikes. Beyond that, maybe a nice jog would be better.

How Should Cheating Be Defined In Sports?


When Milwaukee Brewers pitcher Chris Capuano reports for spring training in April, he will be anxious to demonstrate the effects of a performance-enhancing off-season. His brain will benefit from a sharper focus while his throwing arm will boast an extra boost that has been missing since 2006. Stimulants? Steroids? Scandal? No need to panic, he just had LASIK surgery for his eyes and "Tommy John" surgery for his injured elbow. Of course, had he chosen amphetamines to improve his focus or steroids to increase his strength, he would have been banned and berated. 

Society Decides
There is confusion over the means and methods athletes have available to enhance their performance. Certainly, corrective eye surgery to raise your vision level to 20/20 seems fair, but many athletes go into the procedure hoping to come out with enhanced 20/15 or 20/10 eyesight. Replacing a damaged elbow ligament with a tendon doesn't seem like cheating, but what if its done on a healthy elbow hoping for a few more miles per hour on a fastball that has faded over the years?

Earlier this month, a commentary in the journal Nature recommended a fresh look at cognitive-enhancing drugs and where to draw the line in the sand between natural performance and enhanced performance. The authors, an esteemed group of neuroscientists and ethicists, argued that "enhanced" is only defined by the rules set by society.
Certainly, abuse of prescription drugs, such as Ritalin and Adderall, is illegal because of the potential, harmful side effects. Still, reports of the rising use of these drugs by college students and professionals show the demand for options beyond nutrition, exercise and sleep.
These drugs are just the first generation of possible brain boosting supplements, which is why the Nature commentators are calling for an organized, stigma-free approach to evaluating the risks, benefits and ethics of future products.

Even in Major League Baseball, there is mounting evidence that cognitive-enhancing drugs may be on the rise. Since MLB banned amphetamines in 2006, there has been a dramatic rise in the number of therapeutic use exemptions issued to players for attention-deficit disorder diagnoses, for which drugs like Ritalin and Adderall can be legitimately prescribed. In 2006, 28 players applied for the exemption, while a year later there were 103. There is suspicion that many of these ADD diagnoses are just excuses to get the pills.


Legal Jolt

So, what if there was a cognitive-enhancing, sports supplement that increased alertness, concentration, reaction time and focus while also decreasing the perception of muscle fatigue? Even more encouraging, this supplement is sold in millions of outlets and is socially accepted worldwide. It comes in three sizes, tall, grande or venti – coffee. More specifically, caffeine has been the subject of many recent studies of its effectiveness, both cognitively and physiologically.

Earlier this year, Dr. Carrie Ruxton completed a literature survey to summarize 41 double-blind, placebo-controlled trials published over the past 15 years to establish what range of caffeine consumption would maximize benefits and minimize risk for cognitive function, mood, physical performance and hydration. The studies were divided into two categories, those that looked at the cognitive effects and those that looked at physical performance effects.
The results concluded that there was a significant improvement in cognitive functions like attention, reaction time and mental processing as well as physical benefits described as increased "time to exhaustion" and decreased "perception of fatigue" in cycling and running tests.

Given these results, how exactly does caffeine perform these wonderful tricks? Dr. Ruxton explains from the study, "Caffeine is believed to impact on mood and performance by inhibiting the binding of both adenosine and benzodiazepine receptor ligands to brain membranes. As these neurotransmitters are known to slow down brain activity, a blockade of their receptors lessens this effect."
Bottom line, the chemicals in your brain that would cause you to feel tired are blocked, giving you a feeling of ongoing alertness. This pharmacological process is very similar to that of the ADD drugs.

If caffeine is such a clear cut performance enhancing supplement, why did the World Anti-Doping Agency (WADA) first add caffeine to its banned substance list, only to remove it in 2004? At the time that it was placed on the banned list, the threshold for a positive caffeine test was set to a post-exercise urinary caffeine concentration of about 3-4 cups of strong coffee.
However, more recent research has shown that caffeine has ergogenic effects at levels as low as the equivalent of 1-2 cups of coffee. So, it was hard for WADA to know where to draw the line between athletes just having a few morning cups of coffee/tea and those that were intentionally consuming caffeine to increase their performance level.

So, if Chris Capuano has a double espresso before pitching, his brain, eyes and arm should enhance his performance in the game.  Is that an unfair advantage? Science will continue to offer new and improved methods for raising an athlete's game above the competition. Players, league officials and fans will have to decide where to draw the line.

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Better Golf Ball Design Helps You Play Better Golf


When it comes to improving your golf game, you can spend thousands of dollars buying the latest titanium-induced, Tiger-promoted golf clubs; taking private lessons from the local "I used to be on the Tour" pro; or trying every slice-correcting, swing-speed-estimating, GPS-distance-guessing gadget. But, in the end, it’s about getting that little white sphere to go where you intended it to go. Don't worry, there are many very smart people trying to help you by designing the ultimate golf ball. Of course, they are also after a slice of this billion dollar industry, as any technological advancement that can grab a few more market share points is worth the investment.

In fact, the golf ball wars can get nasty. Earlier this month, Callaway Golf won a court order permanently halting sales of the industry's leading ball, Titleist's Pro V1, arguing patent infringements involving its solid core technology which Callaway acquired when it bought Spaulding/Top Flite in 2003. Titleist disagrees with the decision and will appeal, but in the meantime has altered its manufacturing process so that the patents in question are not used.

The challenge for golf ball manufacturers is to design a better performing ball within the constraints set by United States Golf Association. The USGA enforces limits on the size, weight and initial performance characteristics in an attempt to keep the playing field somewhat level. Every "sanctioned" golf ball must weigh less than 1.62 ounces with a diameter smaller than 1.68 inches. It also must have a similar initial velocity when hit with a metal striker, and rebound at the same angle and speed when hit against a metal block. So, what is left to tinker with? Manufacturers have focused on the internal materials in the ball and its cover design.

Today's balls have 2, 3 or 4 layers of different internal polymer materials to be able to respond differently when hit with a driver versus, say, a wedge. When hit with a driver at much higher swing speed, the energy transfer goes all the way to the core by compressing ball, reducing backspin. During a slower swing with a club that has more angle loft, the energy stays closer to the surface of the ball and allows the grooves of the club to grab onto the ball's cover producing more spin. When driving the ball off of the tee, the preference is more distance and less loft, so a lower backspin is required. For closer shots, more backspin and control are needed.

The Science of Dimples
Which brings us to the cover of the ball and all of the design possibilities. Two forces affect the flight and distance of flying spheres, gravity and aerodynamics. Eventually, gravity wins once the momentum of the ball is slowed by the aerodynamic drag. Since all golf clubs have some angular loft to their clubface, the struck ball will have backspin. As explained by the Magnus Force effect, the air pressure will be lower on the top of the ball since that side is moving slower relative to the air around it. This creates lift as the ball will go in the direction of the lower air pressure. Counteracting this lift is the friction or drag the ball experiences while flying through the air.

Think about a boat moving through water. At the front of the boat, the water moves smoothly around the sides of the boat, but eventually separates from the boat on the back side. This leaves behind a turbulent wake where the water is agitated and creates a lower pressure area. The larger the wake, the more drag is created. A ball in flight has the same properties.

The secret then is how to reduce this wake behind the ball. Enter the infamous golf ball dimples. Dimples on a golf ball create a thin turbulent boundary layer of air molecules that sticks to the ball's contour longer than on a smooth ball. This allows the flowing air to follow the ball's surface farther around the back of the ball, which decreases the size of the wake. In fact, research has shown that a dimpled ball travels about twice as far as a smooth ball.


So, the design competition comes down to perfecting the dimple, since not all dimples are created equal! The number, size and shape can have a dramatic impact on performance. Typically, today's balls have 300-500 spherically shaped dimples, each with a depth of about .010 inch. However, varying just the depth by .001 inch can have dramatic effects on the ball's flight.

Regarding shape, these traditional round dimple patterns cover up to 86 percent of the surface of the golf ball. To create better coverage, Callaway Golf's HX ball uses hexagon shaped dimples that can create a denser lattice of dimples leaving fewer flat spots. Creating just the right design has traditionally been a trial-and-error process of creating a prototype then testing in a wind tunnel. This time-consuming process does not allow for the extreme fine-tuning of the variables.

Simulation Solution
At the 61st Meeting of the American Physical Society's Division of Fluid Dynamics this week in San Antonio, a team of researchers from Arizona State University and the University of Maryland is reporting new findings that may soon give golf ball manufacturers a more efficient method of testing their designs. Their research takes a different approach, using mathematical equations that model the physics of a golf ball in flight. ASU's Clinton Smith, a Ph.D. student and his advisor Kyle Squires collaborated with Nikolaos Beratlis and Elias Balaras at the University of Maryland and Masaya Tsunoda of Sumitomo Rubber Industries, Ltd. The team has been developing highly efficient algorithms and software to solve these equations on parallel supercomputers, which can reduce the simulation time from years to hours.

Now that the model and process is in place, the next step is to begin the quest for the ultimate dimple. In the meantime, when someone asks you, "What's your handicap?" you can confidently tell them, "Well, my golf ball's design does not optimize its drag coefficient which results in a lower loft and spin rate from its poor aerodynamics."

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Related Articles on Sports Are 80 Percent Mental:
Putt With Your Brain - Part 2 

Getting The Call Right With Technology



The loneliest men in sports have not been making any friends lately. 
Both umpires and referees have been making news, despite their often repeated goal, stated by World Series rookie umpire Tom Hallion said last month after Game 3: “As an umpire, you never want to be involved in the outcome of the game.” He added: “We like to get every play right. We’re human beings, and sometimes we get them wrong.” 
Hallion and his five partners at October's Fall Classic did not quite reach their goal. In Game 3, Hallion called Carl Crawford safe at first on a close play, but replays showed he was out. In Game 4, it was the Phillies who benefited after veteran umpire, Tim Welke, called Jimmy Rollins safe at third during a rundown, despite an obvious tag on his backside.


The men in stripes are not doing any better. Veteran NFL referee, Ed Hoculi (aka "Guns"), blew a call in Week 2's Broncos/Chargers game.  Broncos' quarterback Jay Cutler let the ball slip out of his hand and the Chargers recovered.  However, Hoculi ruled the play an incomplete pass. The video replay booth called it a fumble, but since Hoculi had blown his whistle, the call could not be reversed. 
Not to be outdone by their American counterparts, two English soccer officials have set a new standard for head-scratching calls.
In a Sept. 22 game between Watford and Reading, referee Stuart Atwell and one of his linesmen, Nigel Bannister, combined to become the ultimate sales pitch for any type of goal-line replay technology. After a scramble in front of goal, the ball bounced across the end line, two yards wide of the nearest goalpost. As both teams headed up the field and Watford prepared for a goal kick, Bannister signaled to Atwell that he saw the ball cross the line between the goalposts and that Reading should be awarded a goal. To the astonishment of all 22 players on the field and the 14,761 fans, Atwell overruled his own eyes and gave the goal to Reading. The replay made it painfully obvious how wrong the call was: 


So, assuming officials want some kind of automated technical assistance, what is available?
First, pure video instant replay gives officials a second, slower chance to see the play again and possibly adjust their live call. All four major sports leagues in the United States use replay at some level. 
In addition to judging if a shot was taken before the buzzer, the NBA added replay this season to differentiate 2-point versus 3-point baskets. MLB commissioner Bud Selig has put a stop to the spread of replay beyond the home run/foul ball call for now, but public pressure may change that. The NHL’s use of replay focuses mainly on different goal scoring scenarios. The NFL is the most advanced user of replay to judge multiple situations.
Second, an emerging selection of decision-support tools can make the actual call for the officials using location-based technology. In tennis, the Hawk-Eye system is being used at such high-profile events as Wimbledon and the U.S. Open. 
A system of six high-speed cameras records a ball's movement, which is useful when it bounces near one of the court lines. It feeds the cameras' input to a central computer that analyzes the data from all angles and then creates a motion graphic that simulates the ball's location when it bounces on the court, either on the line or next to the line, with a judgment of "in" or "out."
A player can challenge a line umpire's original call, but Hawk-Eye's ruling is then final. The interesting illusion that tennis fans have accepted is watching this 3D simulation as if it is based on a single camera’s footage of the ball. Actually, the sequence shown to viewers is Hawk-Eye's best estimate as to what actually happened based on the data it received from the cameras. There have been more than 550 challenges at the U.S. Open since 2006 when Hawk-Eye was installed. Thirty percent of those challenges resulted in a call being reversed.
In soccer, Adidas and Cairos Technologies have partnered to create an "intelligent" ball that includes a microchip that transmits its location on the field to a computer. 
The system also places a thin, underground electrical wire that surrounds each goal. If the ball's location is sensed to be completely inside the boundary of the goal, a signal is sent to a watch worn by the referee indicating that a goal has been scored. 
This technology would have saved Atwell and Bannister from their embarrassment. However, after extensive testing at several FIFA tournaments, Sepp Blatter, president of FIFA, announced in March that instead of technology, two additional human referee assistants would be used to judge whether a goal was scored. "Let it be as it is and let's leave it (soccer) with errors," Blatter said. "The television companies will have the right to say he (the referee) was right or wrong, but still the referee makes the decision — a man, not a machine." Interestingly, the English Premier League was also testing the use of Hawk-Eye as an alternative to Adidas' smart ball.
Even if the umps and refs don't want to use the technology, sports television producers still want to empower the fans.
In baseball, ESPN's "K-zone" and Fox Sports' "Fox Trax" show a virtual representation of pitches and the strike zone to let us judge the accuracy of the home-plate umpire's calls. Think that last called strike was a bit outside?  Watch the computer generated replay that is accurate to within one-half inch. 
Then, go ahead and yell at the ump. If only they could come up with a way to transmit our voices directly into the stadium.

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Hockey Hits Are Hurting More


One painful lesson every National Hockey League rookie learns is to keep your head up when skating through the neutral zone. If you don't, you will not see the 4700 joules of kinetic energy skating at you with bad intentions.
During an October 25th game, Brandon Sutter, rookie center for the Carolina Hurricanes, never saw Doug Weight, veteran center of the New York Islanders, sizing him up for a hit that resulted in a concussion and an overnight stay in the hospital.  Hockey purists will say that it was a "clean hit" and Weight was not penalized.

Six days before that incident, the Phoenix Coyotes' Kurt Sauer smashed Andrei Kostitsyn of the Montreal Canadiens into the sideboards. Kostitsyn had to be stretchered off of the ice and missed two weeks of games with his concussion. Sauer skated away unhurt and unpenalized. See video here.

Big hits have always been part of hockey, but the price paid in injuries is on the rise. According to data released last month at the National Academy of Neuropsychology's Sports Concussion Symposium in New York, 759 NHL players have been diagnosed with a concussion since 1997. For the ten seasons studied, that works out to about 76 players per season and 31 concussions per 1,000 hockey games. During the 2006-07 season, that resulted in 760 games missed by those injured players, an increase of 41% from 2005-06. Researchers have found two reasons for the jump in severity, the physics of motion and the ever-expanding hockey player.
In his book, The Physics of Hockey, Alain Haché, professor of physics at Canada's University of Moncton, aligns the concepts of energy, momentum and the force of impact to explain the power of mid-ice and board collisions.
As a player skates from a stop to full speed, his mass accelerates at an increasing velocity. The work his muscles contribute is transferred into kinetic energy which can and will be transferred or dissipated when the player stops, either through heat from the friction of his skates on the ice, or through a transfer of energy to whatever he collides with, either the boards or another player.
The formula for kinetic energy, K = (1/2)mass x velocity2, represents the greater impact that a skater's speed (velocity) has on the energy produced. It is this speed that makes hockey a more dangerous sport than other contact sports, like football, where average player sizes are larger but they are moving at slower speeds (an average of 23 mph for hockey players in full stride compared to about 16 mph for an average running back in the open field).
So, when two players collide, where does all of that kinetic energy go? First, let's look at two billiard balls, with the exact same mass, shape and rigid structure. When two balls collide on the table, we can ignore the mass variable and just look at velocity. If the ball in motion hits another ball that is stationary, then the ball at rest will receive more kinetic energy from the moving ball so that the total energy is conserved. This will send the stationary ball rolling across the table while the first ball almost comes to a stop as it has transferred almost all of its stored energy.
Unfortunately, when human bodies collide, they don't just bounce off of each other. This "inelastic" collision results in the transfer of kinetic energy being absorbed by bones, tissues and organs. The player with the least stored energy will suffer the most damage from the hit, especially if that player has less "body cushion" to absorb the impact.
To calculate your own real world energy loss scenario, visit the Exploratorium's "Science of Hockey" calculator. For both Sutter and Kostitsyn, they received checks from players who outweighed them by 20 pounds and were skating faster.
The average mass and acceleration variables are also growing as today's NHL players are getting bigger and faster. In a study released in September, Art Quinney and colleagues at the University of Alberta tracked the physiological changes of a single NHL team over 26 years, representing 703 players. Not surprisingly, they found that defensemen are now taller and heavier with higher aerobic capacity while forwards were younger and faster. Goaltenders were actually smaller with less body mass but had better flexibility. However, the increase in physical size and fitness did not correspond with team success on the ice. But the checks sure hurt a lot more now. 
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Rotate It Like Ronaldo?





"Rotate it like Ronaldo" just doesn't have the same ring to it as "Bend it like Beckham", but the curving free kick is still one of the most exciting plays in soccer/football. Starting with Rivelino in the 1970 World Cup and on to the specialists of today, more players know how to do it and understand the basic physics behind it, but very few can perfect it. But, when it does happen, by chance or skill, it is the highlight of the game.



But let's take a look at this from the other side, through the eyes of the goalkeeper. Obviously, its their job to anticipate where the free kick is going and get to the spot before the ball crosses the line. He sets up his wall to, hopefully, narrow the width of the target, but he knows some players are capable of bending the ball around or over the wall towards the near post. If you watch highlights of free kick goals, you often see keepers flat-footed, just watching the ball go into the top corner. Did they guess wrong and then were not able to react? Did they guess right but misjudged the flight trajectory of the ball. How much did the sidespin or "bend" affect their perception of the exact spot where the ball will cross the line? To get an idea of the effect of spin, here's a compilation of Beckham's best free kick goals (there's a 15 second intro, then the highlights) :







Researchers at Queen's University Belfast and the University of the Mediterranean in France tried to figure this out in this paper. They wanted to compare the abilities of expert field players and expert goalkeepers to accurately predict if a free kick would result in an on-target goal or off-target non-goal. First, a bit about why the ball "bends". We can thank what's called the "Magnus Force" named after the 19th-century German physicist Gustav Magnus. As seen in the diagram below, as the ball spins counter clockwise (for a right-footed player using his instep and kicking the ball on the right side), the air pressure on the left side of the ball is lower as the spin is in the same direction as the oncoming air flow. On the right side of the ball, the spin is in the opposite direction of the air flow, building higher pressure. The ball will follow the path of least resistance, or pressure, and "bend" or curve from right to left. The speed of the spin and the velocity of the shot will determine the amount of bend. For a clockwise spin, the ball bends from left to right.







The researchers showed the players three different types of simulated kicks, a kick bent to the right, a kick bent to the left and a kick with no spin at all. They showed the players these simulations with virtual reality headsets and computer controlled "kicks" and "balls" which they could vary in flight with different programming. The balls would disappear from view at distances of 10 and 12.5 meters from the goal. The reasoning is that this cutoff would correspond with the deadline for reaction time to make a save on the ball. In other words, if the keeper does not correctly guess the final trajectory and position of the ball by this point, he most likely will not be able to physically get to the ball and make the save.







The results showed that both the players and the keepers, (all 20 were expert players from elite clubs like AC Milan, Marseille, Bayer Leverkusen, Schalke 04), were able to correctly predict the result of the kicks with no spin added. However, as 600 RPM spin, either clockwise or counter-clockwise, was added to the ball, the players success declined significantly. Interestingly, the keepers did no better, statistically, then the field players. The researchers conclusion was that the players used the "current heading direction" of the ball to predict the final result, rather than factoring the future affect of the acceleration and change in trajectory caused by the spin.



Just as we saw in the Baseball Hitting post, our human perception skill in tracking flying objects, especially those that are spinning and changing direction, are not perfect. If we understand the physics of the spinning ball, we can better guess at its path, but the pitcher or the free kick taker doesn't usually offer this information beforehand!



Craig, C.M., Berton, E., Rao, G., Fernandez, L., Bootsma, R.J. (2006). Judging where a ball will go: the case of curved free kicks in football. Naturwissenschaften, 93(2), 97-101. DOI: 10.1007/s00114-005-0071-0

Baseball Brains - Fielding Into The World Series

With the crack of the bat, the ball sails deep into the outfield. The center-fielder starts his run back and to the right, trying to keep his eyes on the ball through its flight path. His pace quickens initially, then slows down as the ball approaches. He arrives just in time to make the catch. What just happened? How did he know where to run and at what speed so that he and the ball intersected at the same exact spot on the field. Why didn't he sprint to the landing spot and then wait for the ball to drop, instead of his controlled speed to arrive just when the ball did? What visual cues did he use to track the ball's flight?  Did Willie Mays make the most famous catch in baseball history because he is one of the greatest players of all-time with years of practice? Maybe, but now take a look at this "Web Gems" highlight video of 12 and 13 year-olds from last year's Little League World Series:

Just like we learned in pitching and hitting, fielding requires extensive mental abilities involving eyes, brain, and body movements to accomplish the task. Some physical skills, such as speed, do play a part in catching, but its the calculations and estimating that our brain has to compute that we often take for granted. The fact that fielders are not perfect in this skill, (there are dropped fly balls, or bad judgments of ball flight), begs the question of how to improve? As we saw with pitching and hitting (and most sports skills), practice does improve performance. But, if we understand what our brains are trying to accomplish, we can hopefully design more productive training routines to use in practice.

Once more, we turn to Mike Stadler, associate professor of psychology at University of Missouri, who provides a great overview of current fielding research in his book, "The Psychology of Baseball".

One organization that does not take this skill for granted is NASA. The interception of a ballistic object in mid-flight can describe a left fielder's job or an anti-missile defense system or how a pilot maneuvers a spacecraft through a three dimensional space. In fact, Michael McBeath , a former post doctoral fellow at the NASA Ames Research Center, (now an associate professor at Arizona State University), has been studying fly ball catching since 1995, beginning with his research study, "How baseball outfielders determine where to run to catch fly ball". 

His team developed a rocket-science like theory named Linear Optical Trajectory to describe the process that a fielder uses to follow the path of a batted ball. LOT says the fielder will adjust his movement towards the ball so that its trajectory follows a straight line through his field of vision. Rather than compute the landing point of the ball, racing to that spot and waiting, the fielder uses the information provided by the path of the ball to constantly adjust his path so that they intersect at the right time and place.

The LOT theory is an evolution from an earlier theory called Optical Acceleration Cancellation (OAC) that had the same idea but only explained the fielder's tracking behavior in the vertical dimension. In other words, as the ball leaves the bat the fielder watches the ball rise in his field of vision. If he were to stand still and the ball was hit hard enough to land behind him, his eyes would track the ball up and over his head, or at a 90 degree angle. If the ball landed in front of him, he would see the ball rise and fall but his viewing angle may not rise above 45 degrees. LOT and OAC argue that the fielder repositions himself throughout the flight of the ball to keep this viewing angle between 0 and 90 degrees. If its rising too fast, he needs to turn and run backwards. If the viewing angle is low, then the fielder needs to move forward so that the ball doesn't land in front of him. He can't always make to the landing spot in time, but keeping the ball at about a 45 degree angle by moving will help ensure that he gets there in time. While OAC explained balls hit directly at a fielder, LOT helps add the side-to-side dimension, as in our example of above of a ball hit to the right of the fielder.  More recently, McBeath has successfully defended his LOT theory here and here.

The OAC and LOT theories do agree on a fundamental cognitive science debate. There are two theories of how we perceive the world and then react to it. First, the Information Processing (IP) theory likens our brain to a computer in that we have inputs, our senses that gather information about the world, a memory system that stores all of our past experiences and lessons learned, and a "CPU" or main processor that combines our input with our memory and computes the best answer for the given problem. So, IP would say that the fielder sees the fly ball and offers it to the brain as input, the brain then pulls from memory all of the hundreds or thousands of fly ball flight paths that have been experienced, and then computes the best path to the ball's landing point based on what it has "learned" through practice. McBeath's research and observations of fielders has shown that the processing time to accomplish this task would be too great for the player to react.

OAC and LOT subscribe to the alternate theory of human perception, Ecological Psychology (EP). EP eliminates the call to memory from the processing and argues that the fielder observes the flight path of the ball and can react using the angle monitoring system. This is still up for debate as the IPers would argue "learned facts" like what pitch was thrown, how a certain batter hits those pitches, how the prevailing wind will affect the ball, etc. And, with EP, how can the skill differences between a young ballplayer and an experienced major leaguer be accounted for? What is the point of practice, if the trials and errors are not stored/accessed in memory?

Of course, we haven't mentioned ground balls and their behavior, due to the lack of research out there. The reaction time for a third baseman to snare a hot one-hopper down the line is much shorter. This would also argue in favor of EP, but what other systems are involved?

Arguing about which theory explains a fielder's actions is only productive if we can apply the research to create better drills and practices for our players. The LOT theory seems to be  getting there as an explanation, but there is still debate over EP vs. IP . So many sport skills rely on some of these foundations, that this type of research will continue to be relevant.  As with pitching and hitting, fielding seems to improve with practice.

And then there's the ultimate catch of all-time, that baseball fans have long been buzzing about.  Your reward for getting to the end of this article is this little piece of history...




You were looking for Willie Mays and "The Catch", weren't you?  This ball girl would own the best all-time fielding achievement... if it were real.  But no, just another digital editing marvel.  This was going to be a commercial for Gatorade, then it was put on the shelf.  After it was leaked onto YouTube, the video hoax became a viral hit.  So much so, that Gatorade left it on YouTube and did make a commercial out of it for the 2008 All-Star game.  But, you don't need to tell your Little Leaguers.  Let them dream...

Baseball Brains - Hitting Into The World Series

Ted Williams, arguably the greatest baseball hitter of all-time, once said, "I think without question the hardest single thing to do in sport is to hit a baseball". Williams was the last major league player to hit .400 for an entire season and that was back in 1941, 67 years ago! In the 2008 Major League Baseball season that just ended, the league batting average for all players was .264, while the strikeout percentage was just under 20%. So, in ten average at-bats, a professional ballplayer, paid millions of dollars per year, gets a hit less than 3 times but fails to even put the ball in play 2 times. So, why is hitting a baseball so difficult? What visual, cognitive and motor skills do we need to make contact with an object moving at 70-100 mph?

In the second of three posts in the Baseball Brains series, we'll take a quick look at some of the theory behind this complicated skill. Once again, we turn to Professor Mike Stadler and his book "The Psychology of Baseball" for the answers.  First, here's the "Splendid Splinter" in action:

A key concept of pitching and hitting in baseball was summed up long ago by Hall of Fame pitcher Warren Spahn, when he said, “Hitting is timing. Pitching is upsetting timing.” To sync up the swing of the bat with the exact time and location of the ball's arrival is the challenge that each hitter faces. If the intersection is off by even tenths of a second, the ball will be missed. Just as pitchers need to manage their targeting, the hitter must master the same two dimensions, horizontal and vertical. The aim of the pitch will affect the horizontal dimension while the speed of the pitch will affect the vertical dimension. The hitter's job is to time the arrival of the pitch based on the estimated speed of the ball while determining where, horizontally, it will cross the plate. The shape of the bat helps the batter in the horizontal space as its length compensates for more error, right to left. However, the narrow 3-4" barrel does not cover alot of vertical ground, forcing the hitter to be more accurate judging the vertical height of a pitch than the horizontal location. So, if a pitcher can vary the speed of his pitches, the hitter will have a harder time judging the vertical distance that the ball will drop as it arrives, and swing either over the top or under the ball.

A common coach's tip to hitters is to "keep your eye on the ball" or "watch the ball hit the bat". As Stadler points out, doing both of these things is nearly impossible due to the concept known as "angular velocity". Imagine you are standing on the side of freeway with cars coming towards you. Off in the distance, you are able to watch the cars approaching your position with re
lative ease, as they seem to be moving at a slower speed. As the cars come closer and pass about a 45 degree angle and then zoom past your position, they seem to "speed up" and you have to turn your eyes/head quickly to watch them. While the car is going at a constant speed, its angular velocity increases making it difficult to track.

This same concept applies to the hitter. As the graphic above shows (click to enlarge), the first few feet that a baseball travels when it leaves a pitcher's hand is the most important to the hitter, as the ball can be tracked by the hitter's eyes. As the ball approaches past a 45 degree angle, it is more difficult to "keep your eye on the ball" as your eyes need to shift through many more degrees of movement. Research reported by Stadler shows that hitters cannot watch the entire flight of the ball, so they employ two tactics.

First, they might follow the path of the ball for 70-80% of its flight, but then their eyes can't keep up and they estimate or extrapolate the remaining path and make a guess as to where they need to swing to have the bat meet the ball. In this case, they don't actually "see" the bat hit the ball. Second, they might follow the initial flight of the ball, estimate its path, then shift their eyes to the anticipated point where the ball crosses the plate to, hopefully, see their bat hit the ball. This inability to see the entire flight of the ball to contact point is what gives the pitcher the opportunity to fool the batter with the speed of the pitch. If a hitter is thinking "fast ball", their brain will be biased towards completing the estimated path across the plate at a higher elevation and they will aim their swing there. If the pitcher actually throws a curve or change-up, the speed will be slower and the path of the ball will result in a lower elevation when it crosses the plate, thus fooling the hitter.

To demonstrate the effect of reaction time for the batter, FSN Sport Science compared hitting a 95 mph baseball at 60' 6" versus a 70 mph softball pitched from 43' away.  The reaction time for the hitter went from .395 seconds to .350 seconds, making it actually harder to hit.  That's not all that makes it difficult.  Take a look:


As in pitching, the eyes and brain determine much of the success for hitters. The same concepts apply to hitting any moving object in sports; tennis, hockey, soccer, etc. Over time, repeated practice may be the only way to achieve the type of reaction speed that is necessary, but even for athletes who have spent their whole lives swinging a bat, there seems to be human limitation to success. Tracking a moving object through space also applies to catching a ball, which we'll look at next time.

Baseball Brains - Pitching Into The World Series




With the MLB League Championship Series' beginning this week, Twenty-six teams are wondering what it takes to reach the "final four" of baseball which leads to the World Series. The Red Sox, Rays, Phillies and Dodgers understand its not just money and luck. Over 162 games, it usually comes down to the fundamentals of baseball: pitching, hitting and catching. That sounds simple enough. So, why can't everyone execute those skills consistently? Why do pitchers struggle with their control? Why do batters strike out? Why do fielders commit errors? It turns out Yogi Berra was right when he said, "Baseball is 90% mental, and the other half is physical." In this three part series, each skill will be broken down into its cognitive sub-tasks and you may be surprised at the complexity that such a simple game requires of our brains.

First up, pitching or even throwing a baseball seems effortless until the pressure is on and the aim goes awry. Pitching a 3" diameter baseball 60 feet, 6 inches over a target that is 8 inches wide requires an accuracy of 1/2 to 1 degree. Throwing it fast, with the pressure of a game situation makes this task one of the hardest in sports. In addition, a fielder throwing to another fielder from 40, 60 or 150 feet away, sometimes off balance or on the run, tests the brain-body connection for accuracy. So, how do we do it? And how can we learn to do it more consistently? In his book, The Psychology of Baseball , Mike Stadler, professor of psychology at the University of Missouri, addresses each of these questions.

There are two dimensions to think about when throwing an object at a target: vertical and horizontal. The vertical dimension is a function of the distance of the throw and the effect of gravity on the object. So the thrower's estimate of distance between himself and the target will determine the accuracy of the throw vertically. Basically, if the distance is underestimated, the required strength of the throw will be underestimated and will lose the battle with gravity, resulting in a throw that will be either too low or will bounce before reaching the target. An example of this is a fast ball which is thrown with more velocity, so will reach its target before gravity has a path-changing effect on it. On the other hand, a curve ball or change-up may seem to curve downward, partly because of the spin put on the ball affecting its aerodynamics, but also because these pitches are thrown with less force, allowing gravity to pull the ball down. In the horizontal dimension, the "right-left" accuracy is related to more to the "aim" of the throw and the ability of the thrower to adjust hand-eye coordination along with finger, arm, shoulder angles and the release of the ball to send the ball in the intended direction.

So, how do we improve accuracy in both dimensions? Prof. Stadler points out that research shows that skill in the vertical/distance estimating dimension is more genetically determined, while skill horizontally can be better improved with practice. Remember those spatial organization tests that we took that show a set of connected blocks in a certain shape and then show you four more sets of conected blocks? The question is which of the four sets could result from rotating the first set of blocks. Research has shown that athletes that are good at these spatial relations tests are also accurate throwers in the vertical dimension. Why? The thought is that those athletes are better able to judge the movement of objects through space and can better estimate distance in 3D space. Pitchers are able to improve this to an extent as the distance to the target is fixed. A fielder, however, starts his throw from many different positions on the field and has more targets (bases and cut-off men) to choose from, making his learning curve a bit longer.

If a throw or pitch is off-target, then what went wrong? Research has shown that
despite all of the combinations of fingers, hand, arm, shoulder and body movements, it seems to all boil down to the timing of the finger release of the ball. In other words, when the pitcher's hand comes forward and the fingers start opening to allow the ball to leave. The timing of this release can vary by hundredths of a second but has significant impact on the accuracy of the throw. But, its also been shown that the throwing action happens so fast, that the brain could not consciously adjust or control that release in real-time. This points to the throwing action being controlled by what psychologists call an automated "motor program" that is created through many repeated practice throws. But, if a "release point" is incorrect, how does a pitcher correct that if they can't do so in real-time? It seems they need to change the embedded program by more practice.

Another component of "off-target" pitching or throwing is the psychological side of a player's mental state/attitude. Stadler identifies research that these motor programs can be called up by the brain by current thoughts. There seems to be "good" programs and "bad" programs, meaning the brain has learned how to throw a strike and learned many programs that will not throw a strike. By "seeding" the recall with positive or negative thoughts, the "strike" program may be run, but so to can the "ball" program. So, if a pitcher thinks to himself, "don't walk this guy", he may be subconsciously calling up the "ball" program and it will result in a pitch called as a ball. So, this is why sports pscyhologists stress the need to "think positively", not just for warm and fuzzy feelings, but the brain may be listening and will instruct your body what to do.



So, assuming Josh Beckett of the Red Sox is getting the ball across the plate, will the Rays hit it? That is the topic for next time when we look at hitting an object that is moving at 97 MPH and reaches you in less than half a second.

Putt With Your Brain - Part 2

If there is a poster child sport for our favorite phrase, "Sports Are 80 Percent Mental", it must be golf. Maybe its the slow pace of play that gives us plenty of time to think between shots. Maybe its the "on stage" performance feeling we get when we step up to that first tee in front of our friends (or strangers!) Maybe its the "high" of an amazing approach shot that lands 3 feet from the cup followed by the "low" of missing the birdie putt. 

From any angle, a golf course is the sport psychologist's laboratory to study the mix of emotions, confidence, skill execution and internal cognitive processes that are needed to avoid buying rounds at the 19th hole. Last time, we looked at some of the recent research on putting mechanics, but, as promised, we now turn to the mental side of putting. Sian Beilock and her team at the University of Chicago's Human Performance Lab recently released the latest of a string of research studies on sports performance, or more specifically, how not to choke under pressure. Lucky for us, they chose putting as their sport skill of choice. This ties in with Dr. Beilock's theory of embodied cognition that we featured in Watching Sports Is Good For Your Brain.

An underlying theme to this work is the concept of automaticity, or the ability to carry out sport skills without consciously thinking about them. Performing below expectations (i.e. choking) starts when we allow our minds to step out of this automatic mode and start thinking about the steps to our putting stroke and all of those "swing thoughts" that come with it ("keep your elbows in", "head down", "straight back").


Our brain over analyzes and second-guesses the motor skills we have learned from hundreds of practice putts. Previously, we looked at automaticity in other sports. Of course, a key distinction to the definition of choking is that you are playing "well below expectations". If you normally shoot par, but now start missing easy putts, then there may be distractions that are taking you out of your normal flow. Choking implies a temporary and abnormal event. Automaticity theory would claim that it is these distractions from some perceived pressure to perform that are affecting your game.

Most research into sport skill performance divides the world into two groups, novices and experts. Most sports have their own measures of where the dividing line is between these groups. Expertise would imply performance results not just experience. So, a golfer who has been hacking away for 20 years but still can't break 100 would still be put in the "novice" category.


Sport scientists design experiments that compare performance between the groups given some variables, and then hypothesize on the reason for the observed differences. Beilock, et al have looked at golf putting from several different angles over the years. Their research builds on itself, so let's review in reverse chronological order.

Back in 2001, they began by comparing the two competing theories of choking, distraction theory vs. explicit monitoring theory, and designed a putting experiment to find the better explanation. Distraction theory explains choking by assuming that the task of putting requires your direct attention and that high pressure situations will cause you to perform dual tasks - focus on your putting but also think about the pressure. This theory assumes there is no automaticity in skill learning and that we have to focus our attention on the skill every time.


Explicit monitoring theory claims that over time, as we practice a skill to the point of becoming an "expert", we proceduralize the task so that it becomes "automatic". Then, during a high pressure situation, our brain becomes so concerned about performance that it takes us out of automatic mode and tries to focus on each step of the task. The research supported the explicit monitoring theory as it was shown that the golf putting task was affected by distractions and pressure for the experts but not the novice putters.

So, how do we block out the pressure, so that our automaticity can kick in? Another 2001 study by Beilock looked at mental imagery during putting. Using the same explicit monitoring theory, should we try to think positive thoughts, like "this ball is going in the hole" or "I have made this putt many times"? Also, what happens if a stray negative thought, "don't miss this one!" enters our brain? Should we try to suppress it and replace it with happy self-talk? She set up four groups, one receiving positive comments, one receiving negative comments, one receiving negative comments followed by positive comments and one receiving none as a control group.


As expected, the happy people did improve their putting over the course of the trials, while the negative imagery hurt performance. But, the negative replaced with positive thought group did not show any more improvement over the control group. So, when faced with a high pressure, stressful situation ripe with the possibilities of choking, try to repeat positive thoughts, but don't worry too much if the occasional doubt creeps in.

Our strategy towards putting should also vary depending on our current skill level. While learning the intricacies of putting, novices should use different methods than experts, according to a 2004 study by Beilock, et al. Novice golfers need to pay attention to the step by step components of their swing, and they perform better when they do focus on the declarative knowledge required. 


Expert golfers, however, have practiced their swing or putt so often that it has become "second nature" to the point that if they are told to focus on the individual components of their swing, they perform poorly. The experiment asked both novices and expert golfers to first focus on their actual putting stroke by saying the word "straight" when hitting the ball and to notice the alignment of the putter face with the ball. Next, they were asked to putt while also listening for a certain tone played in the background. When they heard the tone they were to call it out while putting. 

The first scenario, known as "skill-focused", caused the novices to putt more accurately but the experts to struggle. The second scenario, called "dual-task", distracted the novices enough to affect their putts, while the experts were not bothered and their putting accuracy was better. Beilock showed that novices need the task focus to succeed while they are learning to putt, while experts have internalized the putting stroke so that even when asked to do two things, the putting stroke can be put on "auto-pilot".

Finally, in 2008, Beilock's team added one more twist to this debate. Does a stress factor even affect a golfer's performance in their mind before they putt? This time, golfers, divided into the usual novice and expert groups, were asked to first imagine or "image execute" themselves making a putt followed by an actual putt. The stress factor was to perform one trial under a normal, "take all the time you need" time scenario and then another under a speeded or time-limited scenario. 


The novices performed better under the non-hurried scenario in imagining the putt first followed by the actual putt. The experts, however, actually did better in the hurried scenario and worse in the relaxed setting. Again, the automaticity factor explains the differences between the groups.

The bottom line throughout all of these studies is that if you're learning to play golf, which includes putting, you should focus on your swing/stroke but beware of the distractions which will take away your concentration. That seems pretty logical, but for those that normally putt very well, if you feel stress to sink that birdie putt, don't try to focus in on the mechanics of your stroke. Trust the years of experience that has taught your brain the combination of sensorimotor skills of putting.

Just remember the Chevy Chase/Ty Webb philosophy; "I'm going to give you a little advice. There's a force in the universe that makes things happen. And all you have to do is get in touch with it, stop thinking, let things happen, and be the ball.... Nah-na-na-na, Ma-na-na-na...."


ResearchBlogging.orgSian L. Beilock, Thomas H. Carr (2001). On the fragility of skilled performance: What governs choking under pressure? Journal of Experimental Psychology: General, 130 (4), 701-725 DOI: 10.1037//0096-3445.130.4.701

Sian L. Beilock; James A. Afremow; Amy L. Rabe; Thomas H. Carr (2001). "Don't Miss!" The Debilitating Effects of Suppressive Imagery on Golf Putting Performance Journal of Sport and Exercise Psychology, 23 (3)

Beilock S.L.; Bertenthal B.I.; McCoy A.M.; Carr T.H. (2004). Haste does not always make waste: Expertise, direction of attention, and speed versus accuracy in performing sensorimotor skills Psychonomic Bulletin & Review, 11 (2), 373-379

Sian Beilock, Sara Gonso (2008). Putting in the mind versus putting on the green: Expertise, performance time, and the linking of imagery and action The Quarterly Journal of Experimental Psychology, 61 (6), 920-932 DOI: 10.1080/17470210701625626

Putt With Your Brain - Part 1

If Mark Twain thinks golf is "a good walk spoiled", then putting must be a brief pause to make you reconsider ever walking again. With about 50% of our score being determined on the green, we are constantly in search of the "secret" to getting the little white ball to disappear into the cup. Lucky for us, there is no shortage of really smart people also looking for the answer. The first 8 months of 2008 have been no exception, with a golf cart full of research papers on just the topic of putting. 

Is the secret in the mechanics of the putt stroke or maybe the cognitive set-up to the putt or even the golfer's psyche when stepping up to the ball? This first post will focus on the mechanical side and then we'll follow-up next time with a look inside the golfer's mind.

Let's start with a tip that most golf instructors would give, "Keep your head still when you putt". Jack Nicklaus said it in 1974, "the premier technical cause of missed putts is head movement" (from "Golf My Way") and Tiger Woods said it in 2001, "Every good putter keeps the head absolutely still from start to finish" (from "How I Play Golf"). Who would argue with the two greatest golfers of all time? His name is Professor Timothy Lee, from McMaster University, and he wanted to test that observation. So, he gathered two groups of golfers, amateurs with handicaps of 12-40, and professionals with scratch handicaps. Using an infrared tracking system, his team tracked the motion of the putter head and the golfer's head during sixty putts.

As predicted, the amateurs' head moved back in unison with their putter head, something Lee calls an "allocentric" movement, which agrees with the advice that novice golfers move their head. However, the expert golfers did not keep their head still, but rather moved their heads slightly in the opposite direction of the putter head. On the backswing, the golfer's head moved slightly forward; on the forward stroke, the head moved slightly backward. This "egocentric" movement may be the more natural response to maintain a centered, balanced stance throughout the stroke.


"The exact reasons for the opposite coordination patterns are not entirely clear," explains Lee. "However, we suspect that the duffers tend to just sway their body with the motions of the putter. In contrast, the good golfers probably are trying to maintain a stable, central body position by counteracting the destabilization caused by the putter backswing with a forward motion of the head. The direction of head motion is then reversed when the putter moves forward to strike the ball." Does that mean that pro golfers like Tiger are not keeping their heads still? No, just that you may not have to keep your head perfectly still to putt effectively.

So, what if you do have the bad habit of moving your head? Just teach yourself to change your putting motion and you will be cutting strokes off of your score, right? Well, not so fast. Simon Jenkins of Leeds Metropolitan University tested 15 members of the PGA European Tour to see if they could break old physical habits during putting. His team found that players who usually use shoulder movement in their putting action were not able to change their ways even when instructed to use a different motion. Old habits die hard.

Let's say you do keep your head still (nice job!), but you still 3-putt most greens? What's the next step on the road to birdie putts? Of the three main components of a putt, (angle of the face of the putter head on contact, putting stroke path and the impact point on the putter), which has the greatest effect on success? Back in February, Jon Karlsen of the Norwegian School of Sport Sciences in Oslo, asked 71 elite golfers (mean handicap of 1.8) to make a total of 1301 putts (why not just 1300?) from about 12 feet to find out. His results showed that face angle was the most important (80%), followed by putter path (17%) and impact point (3%).

OK, forget the moving head thing and work on your putter blade angle at contact and you will be taking honors at every tee. Wait, Jon Karlsen came back in July with an update. This time he compared green reading, putting technique and green surface inconsistencies to see which of those variables we should discuss with our golf pro. Forty-three expert golfers putted 50 times from varying distances. Results showed that green reading (60%) was the most dominant factor for success with technique (34%) and green inconsistency (6%) trailing significantly.

So, after reading all of this, all you really need is something like the BreakMaster, which will help you read the breaks and the slope to the hole! Then, keep the putter blade square to the ball and don't move your head, at least not in an allocentric way, that is if you can break your bad habit of doing it. No problem, right? Well, next time we'll talk about your brain's attitude towards putting and all the ways your putt could go wrong before you even hit it!

ResearchBlogging.org

Timothy D. Lee, Tadao Ishikura, Stefan Kegel, Dave Gonzalez, Steven Passmore (2008). Head–Putter Coordination Patterns in Expert and Less Skilled Golfers Journal of Motor Behavior, 40 (4), 267-272 DOI: 10.3200/JMBR.40.4.267-272


Jenkins, Simon (2008). Can Elite Tournament Professional Golfers Prevent Habitual Actions in Their Putting Actions? International Journal of Sports Science & Coaching, 3 (1), 117-127


Jon Karlsen, Gerald Smith, Johnny Nilsson (2007). The stroke has only a minor influence on direction consistency in golf putting among elite players Journal of Sports Sciences, 26 (3), 243-250 DOI: 10.1080/02640410701530902

Watching Sports Is Good For Your Brain

When was the last time you listened to a sporting event on the radio? If given a choice between watching the game on a big screen plasma in HD or turning on the AM radio, most of us would probably choose the visual sensation of television. But, for a moment, think about the active attention you need in order to listen to a radio broadcast and interpret the play-by-play announcer's descriptions. As you hear the words, your "mind's eye" paints the picture of the action so you can imagine the scene and situations. Your knowledge of the game, either from playing it or watching it for years helps you understand the narrative, the terms and the game's "lingo".


Now, imagine that you are listening to a broadcast about a sport you know nothing about. Hearing Bob Uecker or Vin Scully say, "With two out in the ninth, the bases are loaded and the Brewers' RBI leader has two strikes. The infield is in as the pitcher delivers. Its a hard grounder to third that he takes on the short hop and fires a bullet to first for the final out." If you have no baseball-specific knowledge, those sentences are meaningless. 

However, for those of us that have grown up with baseball, that description makes perfect sense and our mind's eye helped us picture the scene. That last sentence about the "hard grounder" and the thrown "bullet" may have even triggered some unconscious physical movements by you as your brain interpreted those action phrases. That sensorimotor reaction is at the base of what is called "embodied cognition". 
 
Sian Beilock, associate professor of psychology and leader of the Human Performance Lab at the University of Chicago, defined the term this way: "In contrast to traditional views of the mind as an abstract information processor, recent work suggests that our representations of objects and events are grounded in action. That is, our knowledge is embodied, in the sense that it consists of sensorimotor information about potential interactions that objects or events may allow." She cites a more complete definition of the concept in Six Views of Embodied Cognition by Margaret Wilson. Another terrific overview of the concept is provided by science writer Drake Bennet of the Boston Globe in his article earlier this year, "Don't Just Stand There, Think".


In a study released yesterday, "Sports Experience Changes the Neural Processing of Action Language", Dr. Beilock's team continued their research into the link between our learned motor skills and our language comprehension about those motor skills. Since embodied cognition connects the body with our cognition, the sports domain provides a logical domain to study it.


Their initial look at this concept was in a 2006 study titled, "Expertise and its embodiment: Examining the impact of sensorimotor skill expertise on the representation of action-related text", where the team designed an experiment to compare the knowledge representation skill of experienced hockey players and novices. Each group first read sentences describing both hockey-related action and common, "every-day" action, (i.e. "the referee saw the hockey helmet on the bench" vs. "the child saw the balloon in the air"). They were then shown pictures of the object mentioned in the sentences and were asked if the picture matched the action in the sentence they read.

Both groups, the athletes and the novices, responded equally in terms of accuracy and response time to the everyday sentences and pictures, but the athletes responded significantly faster to the hockey-specific sentences and pictures. The conclusion is that those with the sensorimotor experience of sport give them an advantage of processing time over those that have not had that same experience.


Now, you may be saying, "Ya' think!?" to this somewhat obvious statement that people who have played hockey will respond faster to sentence/picture relationships about hockey than non-hockey players. Stay with us here for a minute, as the 2006 study set the groundwork for Beilock's team to take the next step with the question, "is there any evidence that the athletes are using different parts of their brain when processing these match or no match decisions?" The link between our physical skill memory and our language comprehension would be at the base of the embodied cognition theory. 

So, in the latest research, the HPL team kept the same basic experimental design, but now wanted to watch the participants' brain activity using fMRI scanning. This time, there were three groups, hockey players, avid fans of hockey and novices who had no playing or viewing experience with hockey at all. First, all groups passively listened to sentences about hockey actions and also sentences about everyday actions while being monitored by fMRI.  Second, outside of the fMRI scanner, they again listened to hockey-related and everyday-related action sentences and then were shown pictures of hockey or every day action and asked if there was a match or mis-match between the sentence and the picture.


This comprehension test showed similar results as in 2006, but now the team could try to match the relative skill in comprehension to the neural activity shown in the fMRI scans when listening. Both the players and the fans showed increased activity in the left dorsal premotor cortex, a region thought to support the selection of well-learned action plans and procedures. 

You might be surprised that the fans' brains showed activity in the same regions as the athletes. We saw this effect in a previous post, "Does Practice Make Perfect", where those that practiced a new dance routine and those that only watched it showed similar brain area activity. On the other side, the total novices showed activity in the bilateral primary sensory-motor cortex, an area typically known for carrying out step by step instructions for new or novel tasks. 

So, the interesting finding here is that those with experience, either playing or watching, are actually calling on additional neural networks in their brains to help their normal language comprehension abilities. In other words, the memories of learned actions are linked and assist other cognitive tasks. That sounds pretty much like the definition of embodied cognition and Dr. Beilock's research has helped that theory take another step forward. In her words, "Experience playing and watching sports has enduring effects on language understanding by changing the neural networks that support comprehension to incorporate areas active in performing sports skills."


Take pride in your own brain the next time you hear, "Kobe dribbles the ball to the top of the key, crosses over, drives the lane, and finger rolls over Duncan for two." If you can picture that play in your mind, your left dorsal premotor cortex just kicked into gear!


ResearchBlogging.org






S. L. Beilock, I. M. Lyons, A. Mattarella-Micke, H. C. Nusbaum, S. L. Small (2008). Sports experience changes the neural processing of action language Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0803424105



Lauren E. Holt, Sian L. Beilock (2006). Expertise and its embodiment: Examining the impact of sensorimotor skill expertise on the representation of action-related text Psychonomic Bulletin & Review, 13 (4), 694-701 PMID: 17201372

Video Games Move From The Family Room To The Locker Room

It sounds like a sales job from a 12 year old; "Actually, Dad, this is not just another video game. Its a virtual, scenario-based microcosm of real world experiences that will enhance my decision-making abilities and my cognitive perceptions of the challenges of the sport's environment."  You respond with, "So, how much is Madden 09?"  

With over 5 million copies of Madden 08 sold, the release of the latest version two weeks ago is rocketing up the charts.  Days and late nights are being spent all over the world creating rosters, customizing plays and playing entire seasons, all for pure entertainment purposes.  Can all of those hours spent with controller in hands actually be beneficial to young athletes?  Shouldn't they be outside in the fresh air and sunshine playing real sports?  Well, yes, to both questions.


Playing video games, (aka "gaming"), as a form of learning has been receiving increased recent attention from educational psychology researchers.  At this month's American Psychological Association annual convention, several groups of researchers presented studies of the added benefits of playing video games, from problem-solving and critical thinking to better scientific reasoning.  

In one of the studies by Fordham University psychologist Fran C. Blumberg, PhD, and Sabrina S. Ismailer, MSED, 122 fifth-, sixth- and seventh-graders' problem-solving behavior was observed while playing a video game that they had never seen before.  As the children played the game, they were asked to think aloud for 20 minutes. Researchers assessed their problem-solving ability by listening to the statements they were making while playing.   

The results showed that playing video games can improve cognitive and perceptual skills.  "Younger children seem more interested in setting short-term goals for their learning in the game compared to older children who are more interested in simply playing and the actions of playing," said Blumberg. "Thus, younger children may show a greater need for focusing on small aspects of a given problem than older children, even in a leisure-based situation such as playing video games."

Also, in a recent article on video game learning, David Williamson Shaffer, professor of educational psychology at the University of Wisconsin-Madision and author of the book "How Computer Games Help Children Learn", argues that if a game is realistically based on real-world scenarios and rules, it can help the child learn.  “The question though is," Shaffer said, "is what they are doing a good simulation of what is happening in the real world?"  Shaffer explains the research happening on this topic at his UW lab, named Epistemic Games:





Support for this new era of learning tools is coming from other interesting people, as well.  George Lucas of Star Wars fame has an educational foundation, Edutopia, which has shown recent interest in simulation learning.  Here is their introductory overview and accompanying video:






There are some words of caution out there.  In a recent article, educational psychologist Jane M. Healy, author of "Failure to Connect: How Computers Affect our Children's Minds and What We Can Do About It," urges educators to proceed carefully.  "The main question is whether the activity, whatever it is, is educationally valid and contributes significantly to whatever is being studied," she says.  "The point is not whether kids are 'playing' with learning, or what medium they are playing in — a ball field or a Wii setup or a physics lab or art studio — but rather why they are doing it.  Just because it is electronic does not make it any better, and it may turn out not to be as valuable."

If we accept that there is some validity to teaching/learning with video game simulations, how can we move this to the sports arena?  Obviously, there is no substitute for playing the real game with real players, opponents, pressure, etc., but more teams and coaches are turning to simulation games for greater efficiency in the learning process.  If the objective is to expose players to plays, tactics, field vision and critical thinking, then a gaming session can begin to introduce these concepts that will be validated later on the field during "real" practice.  

This homework can also be done at home, not requiring teammates, fields, equipment, etc.  As mentioned in the videos above, another driving factor in the use of games is to reach this young, Web 2.0 audience through a medium that they already know, understand and enjoy.  The motivation to learn is inherent with the use of games.  The "don't tell them its good for them" secret is key to seeing progress with this type of training.


One of the best examples of video game adaptation for sports learning is from XOS Technologies and their modified version of the Madden NFL game.  In 2007, they licensed the core development engine from EA Sports and created a football simulation, called SportMotion, that can be used for individual training.  

With the familiar Madden user interface, coaches can first load their playbook into the game, as well as their opponent's expected plays.  Then, the athlete can "play" the game but will now see their own team's plays being run by the virtual players.  Imagine the difference in learning style for a new quarterback.  Instead of studying static X's and O's on a two-dimensional piece of paper, they can now watch and then play a virtual simulation of the same play in motion against a variety of different defenses.  With a "first-person" view of the play unfolding, they will see the options available in a "real-time" mode which will force faster reaction and decision-making skills.  

To take the simulation one step further, XOS has added a virtual reality option that takes the game controller out of the player's hands and replaces it with a VR suit and goggles allowing him to physically play the game, throw the ball, etc. through his virtual eyes.  Take a look at this promotional video from XOS:





XOS is winning some high praise for its system, including none other than Phillip Fulmer, Head Coach of the University of Tennesee football team.  “We’re leading the nation by taking advantage of this cutting-edge technology and we couldn’t be more pumped about it,” Fulmer said. “UT football has a long and storied tradition of success and because we look to pioneer groundbreaking concepts before anyone else, we’ll proudly continue that history. The XOS PlayAction Simulator begins a new chapter for UT and we’re pleased to add it to our football training regiment.” 

Albert Tsai, vice president of advanced research at XOS Technologies, says, “We’ve basically added functionality to popular EA video games such as customizable playbooks, diagrams and testing sequences to better prepare athletes for specific opponents.  Additionally, the software includes built-in teaching and reporting tools so that coaches Fulmer, Cutcliffe and Cooter can analyze and track the tactical-skill development of the team. At the same time, the Volunteers can experience immediate benefits because the familiarity with the EA SPORTS brand requires little to no learning curve for their players.”

So, the next time your son (or daughter!) is begging for 10 more minutes on the Xbox to make sure the Packers destroy the Vikings once again (sorry, a little Wisconsin bias), you may want to reconsider pulling the plug.  Then, send them outside for that fresh air.

Starbucks' Secret Sports Supplement

For an athlete, it seems to good to be true. A "sports supplement" that increases alertness, concentration, reaction time and focus while decreasing muscle fatigue or at least the perception of fatigue. It can even shorten recovery time after a game. HGH? EPO? Steroids? Nope, just a grande cup of Juan Valdez's Best, Liquid Lightning, Morning Mud, Wakey Juice, Mojo, Java, aka coffee. Actually, the key ingredient is caffeine which has been studied repeatedly for its ergogenic (performance-enhancing) benefits in sports, both mentally and physically. Time after time, caffeine proves itself as a relatively safe, legal and inexpensive boost to an athlete.

Or does it? If caffeine is such a clear cut performance enhancing supplement, why did the World Anti-Doping Agency (WADA), who also monitors this month's Beijing Olympics for the International Olympic Committee (IOC), first add caffeine to its banned substance list, only to remove it in 2004? At the time that it was placed on the banned list, the threshold for a positive caffeine test was set to a post-exercise urinary caffeine concentration of 12 µg/ml (about 3-4 cups of strong coffee). However, more recent research has shown that caffeine has ergogenic effects at levels as low as the equivalent of 1-2 cups of coffee. So, it was hard for WADA to know where to draw the line between athletes just having a few morning cups of coffee/tea or maybe some chocolate bars and athletes that were intentionally consuming caffeine to increase their performance level. However, caffeine is still on the WADA monitoring list as a substance to screen for and watch for patterns of use.


Meanwhile, athletes are still convinced that caffeine helps them.
In a recent survey from Liverpool John Moores University, 480 athletes were interviewed about their caffeine use. One third of track and field athletes and 60% of cyclists reported using caffeine specifically to give them a boost in competition. In addition, elite-level athletes interviewed were more likely to rely on caffeine than amateurs. Dr. Neil Chester, co-leader of the study, commented about the confusion created by the WADA status change for caffeine, "There's been a lack of communication from WADA and there is a question about whether or not sporting authorities are condoning its use. Ultimately there is a need to clarify the use of caffeine within the present anti-doping legislation."

So, have athletes found a loophole to exploit that gives them an edge? Dr. Carrie Ruxton recently completed a literature survey to summarize 41 double-blind, placebo-controlled trials published over the past 15 years to establish what range of caffeine consumption would maximize benefits and minimize risk for cognitive function, mood, physical performance and hydration. The studies were divided into two categories, those that looked at the cognitive effects and those that looked at physical performance effects. The results concluded that there was a significant improvement in cognitive functions like attention, reaction time and mental processing as well as physical benefits described as increased "time to exhaustion" and decreased "perception of fatigue" in cycling and running tests. Longer, endurance type exercise showed greater results than short-term needs for energy.

Given these results, how exactly does caffeine perform these wonderful tricks? Dr. Ruxton explains from the study, "Caffeine is believed to impact on mood and performance by inhibiting the binding of both adenosine and benzodiazepine receptor ligands to brain membranes. As these neurotransmitters are known to slow down brain activity, a blockade of their receptors lessens this effect. " Bottom line, the chemicals in your brain that would cause you to feel tired are blocked, giving you a feeling of ongoing alertness. Your body still needs the sleep, caffeine just delays the feeling of being tired.

As to the physiological benefits, caffeine has also been shown to stimulate the release of fat into the bloodstream. The early conclusion was that the increased free fatty acids in the blood would allow our muscles to use fat as fuel and spare glycogen (carbohydrates) allowing us to exercise longer. Another theory is that caffeine stimulates the central nervous system reducing our perception of effort so that we feel that we can continue at an increased pace for longer periods.


The discussion on glycogen has recently taken another interesting twist; caffeine's apparent ability to replenish glycogen (the body's primary fuel source) more rapidly
after an intense workout. A team at the Garvan Institute for Medical Research has found that athletes who consumed a combination of carbohydrates and caffeine following an exhaustive exercise had 66% more glycogen in their muscles four hours later, compared to when they consumed carbohydrates alone. 

They asked cyclists to pedal to exhaustion in the lab, then gave them a drink that contained either carbohydrates with caffeine or just carbohydrates (the cyclists did not know which drink they were getting). They repeated the process 7-10 days later and reversed the groups. Muscle biopsies and blood samples were tested for levels of glycogen after each trial period. The researchers did not have an explanation for the increased levels of glycogen resulting from the caffeine-spiked juice. One theory is the higher circulating blood glucose and plasma insulin levels caused by the caffeine were key factors. In addition, caffeine may increase the activity of several signaling enzymes, including the calcium-dependent protein kinase and protein kinase B (also called Akt), which have roles in muscle glucose uptake during and after exercise.

So, before you start drinking the Starbucks by the gallon, here are some guidelines.
You can consume 2-2.5 mg of caffeine per pound of body weight daily to achieve its ergogenic effects. This equates to 250-312 mg for a 125-pound woman and 360-450 mg for a 180-pound man. More is not better, as other research has shown a decline in benefit and an increase in caffeine's side effects beyond this level. One "grande" cup (16 oz.) of Starbucks coffee contains about 320-500 mg of caffeine, while a 12 oz. can of soda will provide 35-70 mg of caffeine. Maybe we'll see the ultimate sports drink soon, kind of like Monster meets Gatorade... wait, its already here: Lucozade Sport with Caffeine Boost!

ResearchBlogging.org





C. H. S. Ruxton (2008). The impact of caffeine on mood, cognitive function, performance and hydration: a review of benefits and risks Nutrition Bulletin, 33 (1), 15-25 DOI: 10.1111/j.1467-3010.2007.00665.x


N. Chester, N. Wojek (2008). Caffeine Consumption Amongst British Athletes Following Changes to the 2004 WADA Prohibited List International Journal of Sports Medicine, 29 (6), 524-528 DOI: 10.1055/s-2007-989231

D. J. Pedersen, S. J. Lessard, V. G. Coffey, E. G. Churchley, A. M. Wootton, T. Ng, M. J. Watt, J. A. Hawley (2008). High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine Journal of Applied Physiology, 105 (1), 7-13 DOI: 10.1152/japplphysiol.01121.2007

Inside An Olympian's Brain


Michael Phelps, Nastia Liukin, Misty May-Treanor and Lin Dan are four Olympic athletes who have each spent most of their life learning the skills needed to reach the top of their respective sports, swimming, gymnastics, beach volleyball and badminton (you were wondering about Lin, weren't you...) Their physical skills are obvious and amazing to watch. For just a few minutes, instead of being a spectator, try to step inside the heads of each of them and try to imagine what their brains must accomplish when they are competing and how different the mental tasks are for each of their sports.


On a continuum from repetitive motion to reactive motion, these four sports each require a different level of brain signal to muscle movement. Think of Phelps finishing off one more gold medal race in the last 50 meters. His brain has one goal; repeat the same stroke cycle as quickly and as efficiently as possible until he touches the wall. There isn't alot of strategy or novel movement based on his opponent's movements. Its simply to be the first one to finish. 

What is he consciously thinking about during a race? In his post-race interviews, he says he notices the relative positions of other swimmers, his energy level and the overall effort required to win (and in at least one race, the level of water in his goggles.) At his level, the concept of automaticity (as discussed in a previous post) has certainly been reached, where he doesn't have to consciously "think" about the components of his stroke. In fact, research has shown that those who do start analyzing their body movements during competition are prone to errors as they take themselves out of their mental flow.


Moving up the continuum, think about gymnastics. Certainly, the skills to perform a balance beam routine are practiced to the point of fluency, but the skills themselves are not as strictly repetitive as swimming. There are finer points of each movement being judged so gymnasts keep several mental "notes" about the current performance so that they can "remember" to keep their head up or their toes pointed or to gather speed on the dismount. There also is an order of skills or routine that needs to be remembered and activated.

While swimming and gymnastics are battles against yourself and previously rehearsed movements, sports like beach volleyball and badminton require reactionary moves directly based on your opponents' movements. Rather than being "locked-in" to a stroke or practised routine, athletes in direct competition with their opponents must either anticipate or react to be successful.



So, what is the brain's role in learning each of these varied sets of skills and what commands do our individual neurons control? Whether we are doing a strictly repetitive movement like a swim stroke or a unique, "on the fly" move like a return of a serve, what instructions are sent from our brain to our muscles? Do the neurons of the primary motor cortex (where movement is controlled in the brain) send out signals of both what to do and how to do it?

Researchers at the McGovern Institute for Brain Research at MIT led by Robert Ajemian designed an experiment to solve this "muscles or movement" question. They trained adult monkeys to move a video game joystick so that a cursor on a screen would move towards a target. While the monkeys learned the task, they measured brain activity with functional magnetic resonance imaging (fMRI) to compare the actual movements of the joystick with the firing patterns of neurons. 

The researchers then developed a model that allowed them to test hypotheses about the relationship between neuronal activity that they measured in the monkey's motor cortex and the resulting actions. They concluded that neurons do send both the specific signals to the muscles to make the movement and a goal-oriented instruction set to monitor the success of the movement towards the goal. Here is a video synopsis of a very similar experiment by Miguel Nicolelis, Professor of Neurobiology at Duke University:


To back this up, Andrew Schwartz, professor of neurobiology at the McGowan Institute for Regenerative Medicine at the University of Pittsburgh School of Medicine, and his team of researchers wanted to isolate the brain signals from the actual muscles and see if the neuron impulses on their own could produce both intent to move and the movement itself. They taught adult monkeys to feed themselves using a robotic arm while the monkey's own arms were restrained. Instead, tiny probes the width of a human hair were placed in the monkey's motor cortex to pick up the electrical impulses created by the monkey's neurons. These signals were then evaluated by software controlling the robotic arm and the resulting movement instructions were carried out. The monkeys were able to control the arm with their "thoughts" and feed themselves food. Here is a video sample of the experiment:

"In our research, we've demonstrated a higher level of precision, skill and learning," explained Dr. Schwartz. "The monkey learns by first observing the movement, which activates his brain cells as if he were doing it. It's a lot like sports training, where trainers have athletes first imagine that they are performing the movements they desire."



It seems these "mental maps" of neurons in the motor cortex are the end goal for athletes to achieve the automaticity required to either repeat the same rehearsed motions (like Phelps and Liukin) or to react instantly to a new situation (like May-Treanor and Dan). Luckily, we can just practice our own automaticity of sitting on the couch and watching in a mesemerized state.

ResearchBlogging.org

R AJEMIAN, A GREEN, D BULLOCK, L SERGIO, J KALASKA, S GROSSBERG (2008). Assessing the Function of Motor Cortex: Single-Neuron Models of How Neural Response Is Modulated by Limb Biomechanics Neuron, 58 (3), 414-428 DOI: 10.1016/j.neuron.2008.02.033

Meel Velliste, Sagi Perel, M. Chance Spalding, Andrew S. Whitford, Andrew B. Schwartz (2008). Cortical control of a prosthetic arm for self-feeding Nature, 453 (7198), 1098-1101 DOI: 10.1038/nature06996

Lifting The Fog Of Sports Concussions


A concussion, clinically known as a Mild Traumatic Brain Injury (MTBI), is one of the most common yet least understood sports injuries.  According to the Centers for Disease Control, there are as many as 300,000 sports and recreation-related concussions each year in the U.S., yet the diagnosis, immediate treatment and long-term effects are still a mystery to most coaches, parents and even some clinicians.  

The injury can be deceiving as there is rarely any obvious signs of trauma.  If the head is not bleeding and the player either does not lose consciouness or regains it after a brief lapse, the potential damage is hidden and the usual "tough guy" mentality is to "shake it off" and get back in the game.


Leigh Steinberg, agent and representative to some of the top professional athletes in the world (including NFL QBs Ben Roethlisberger and Matt Leinart), is tired of this ignorance and attitude.  "My clients, from the day they played Pop Warner football, are taught to believe ignoring pain, playing with pain and being part of the playing unit was the most important value," Steinberg said, "I was terrified at the understanding of how tender and narrow that bond was between cognition and consciousness and dementia and confusion".  Which is why he was the keynote speaker at last week's "New Developments in Sports-Related Concussions" conference hosted by the University of Pittsburgh Medical College Sport Medicine Department in Pittsburgh. 

Leading researchers gathered to discuss the latest research on sports-related concussions, their diagnosis and treatment.  "There's been huge advancement in this area," said Dr. Micky Collins, the assistant director for the UPMC Sports Medicine Program. "We've learned more in the past five years than the previous 50 combined."


So, what is a concussion?  The CDC defines a concussion as "a complex pathophysiologic process affecting the brain, induced by traumatic biomechanical forces secondary to direct or indirect forces to the head."  Being a "mild" form of traumatic brain injury, it is generally believed that there is no actual structural damage to the brain from a concussion, but more a disruption in the biochemistry and electrical processes between neurons.  

The brain is surrounded by cerebrospinal fluid, which is supposed to provide some protection from minor blows to the head.  However, a harder hit can cause rotational forces that affect a wide area of the brain, but most importantly the mid-brain and the reticular activating system which may explain the loss of consciousness in some cases.  

For some athletes, the concussion symptoms take longer to disappear in what is known as post-concussion syndrome.  It is not known whether this is from some hidden structural damage or more permanent disruption to neuronal activity.  Repeated concussions over time can lead to a condition known as dementia pugilistica, with long-term impairments to speech, memory and mental processing.

After the initial concussion, returning to the field before symptoms clear raises the risk of second impact syndrome, which can cause more serious, long-term effects.  As part of their "Heads Up" concussion awareness campaign, the CDC offers this video story of Brandon Schultz, a high school football player, who was not properly diagnosed after an initial concussion and suffered a second hit the following week, which permanently changed his life.  Without some clinical help, the player, parents and coach can only rely on the lack of obvious symptoms before declaring a concussion "healed".  

However, making this "return to play" decision is now getting some help from some new post-concussion tests.  The first is a neurological skills test called ImPACT (Immediate Post-Concussion and Cognitive Testing) created by the same researchers at UPMC.  It is an online test given to athletes after a concussion to measure their performance in attention span, working memory, sustained and selective attention time, response variability, problem solving and reaction time.  Comparing a "concussed" athlete's performance on the test with a baseline measurement will help the physician decide if the brain has healed sufficiently.

However, Dr. Collins and his team wanted to add physiological data to the psychological testing to see if there was a match between brain activity, skill testing and reported symptoms after a concussion.  In a study released last year in the journal Neurosugery, they performed functional MRI (fMRI) brain imaging studies on 28 concussed high-school athletes while they performed certain working memory tasks to see if there was a significant link between performance on the tests and changes in brain activation.  They were tested about one week after injury and again after the normal clinical recovery period.

“In our study, using fMRI, we demonstrate that the functioning of a network of brain regions is significantly associated with both the severity of concussion symptoms and time to recover,” said Jamie Pardini, Ph.D., a neuropsychologist on the clinical and research staff of the UPMC concussion program and co-author of the study.  
 "We identified networks of brain regions where changes in functional activation were associated with performance on computerized neurocognitive testing and certain post-concussion symptoms,” Dr. Pardini added. "Also, our study confirms previous research suggesting that there are neurophysiological abnormalities that can be measured even after a seemingly mild concussion.” 

Putting better assessment tools in the hands of athletic trainers and coaches will provide evidence-based coaching decisions that are best for the athlete's health.  Better decisions will also ease the minds of parents knowing their child has fully recovered from their "invisible" injury.


ResearchBlogging.org

Lovell, M.R., Pardini, J.E., Welling, J., Collins, M.W., Bakal, J., Lazar, N., Roush, R., Eddy, W.F., Becker, J.T. (2007). FUNCTIONAL BRAIN ABNORMALITIES ARE RELATED TO CLINICAL RECOVERY AND TIME TO RETURN-TO-PLAY IN ATHLETES. Neurosurgery, 61(2), 352-360. DOI: 10.1227/01.NEU.0000279985.94168.7F

HGH - Human Growth Hoax?

Athletes, both professional and amateur, as well as the general public are convinced that human growth hormone (HGH), Erythropoietin (EPO) and anabolic-androgenic steroids (AAS) are all artificial and controversial paths to improved performance in sports.  The recent headlines that have included Barry Bonds, Marion Jones, Floyd Landis, Dwayne Chambers, Jose Canseco, Jason Giambi, Roger Clemens and many lesser known names (see the amazingly long list of doping cases in sport) have referred to these three substances interchangeably leaving the public confused about who took what from whom.  With so many athletes willing to gamble with their futures, they must be confident that they will see significant short-term results.  

So, is it worth the risk?  Two very interesting recent studies provide some answers on at least one of the substances, HGH.


A team at the Stanford University School of Medicine, led by Hau Liu MD, recently reviewed 27 historical studies on the effects of HGH on athletic performance, dating back to 1966 (see reference below).  They wanted to see if there were any definitive links between HGH use and improved results.  In some of the studies, test volunteers who received HGH did develop more lean body mass, but also developed more lactate during aerobic testing which inhibited rather than helped performance.  While their muscle mass increased, other markers of athletic fitness, such as VO2max remained unchanged.  “The key takeaway is that we don’t have any good scientific evidence that growth hormone improves athletic performance,” said senior author Andrew Hoffman, MD, professor of endocrinology, gerontology and metabolism.



Both Liu and Hoffman cautioned that the amounts of HGH given to these test subjects may be much lower than the the purported levels claimed to be taken by professional athletes.  They also pointed out that at a professional level, a very slight improvement might be all that is necessary to get an edge of your opponent.  Hoffman also added an insightful comment, “So much of athletic performance at the professional level is psychological.”  If an athlete takes HGH, sees some muscle mass growth and isn't 100% sure of its performance capabilities, might he assume he now has other "Superman" powers?



That is exactly the premise that a research team from Garvan Institute of Medical Research in Sydney, Australia used to find out if HGH users simply relied on a placebo effect.  Sixty-four participants, young adult recreational athletes, were divided into two groups of 32 and tested for a baseline of athletic ability in endurance, strength, power and sprinting.  One group received growth hormone and the other group received a simple placebo.  It was a "double-blind" study in that neither the participants nor the researchers knew during the testing which substance each group received.



At the end of the 8 week treatment, the athletes were asked if they thought they were in the HGH group or the placebo group.  Half of the group that had received the placebo incorrectly guessed that they were on HGH.  Not too surprisingly, the majority of the "incorrect guessers" were men.  Here's where it gets interesting.  The incorrect guessers also thought that their athletic abilities had improved over the 8 week period.  The team retested all of the placebo group and actually did find improvement across all of the tests, but only significantly in the high-jump test.


Jennifer Hansen, a nurse researcher and Dr. Ken Ho, head of the pituitary research unit at Garvan have not released the data on the group that did receive the HGH, but they will in their final report coming soon.



So, let's recap.  On the one hand, we have a research review that claims there is not yet any scientific evidence that HGH actually improves sports performance.  Yet, we have hundreds, if not thousands, of athletes illegally using HGH for performance gain.  Showing the effect of the "if its good enough for them, its good enough for me" beliefs of the public regarding professional athlete use of HGH, we now have research that shows even those who received a placebo, but believed they were taking HGH not only thought they were improving but actually did improve a little.  Once again, we see the power of our own natural, non-supplemented brain to convince (or fool) ourselves to perform at higher levels than we thought possible.





ResearchBlogging.org


Liu, H., Bravata, D.M., Olkin, I., Friedlander, A., Liu, V., Roberts, B., Bendavid, E., Saynina, O., Salpeter, S.R., Garber, A.M. (2008). Systematic review: the effects of growth hormone on athletic performance.. Annals of Internal Medicine, 148(10), 747-758.

Does Practice Make Perfect?


For years, sport science and motor control research has added support to the fundamental assertions that "practice makes perfect" and "repetition is the mother of habit".  Shooting 100 free throws, kicking 100 balls on goal or fielding 100 ground balls must certainly build the type of motor programs in the brain that will only help make the 101st play during the game.  K. Anders Ericsson, the "expert on experts", has defined the minimum amount of "deliberate practice" necessary to raise any novice to the level of expert as 10 years or 10,000 hours.

However, many questions still exist as to exactly how we learn these skills.  What changes happen in our brains when we teach ourselves a new task?  What is the most effective and efficient way to master a skill?  Do we have to be actually performing the skill to learn it, or could we just watch and learn? 


Then, once we have learned a new skill and can repeat it with good consistency, why can't we perform it perfectly every time?  Why can't we make every free throw, score with every shot on goal, and field each ground ball with no errors?  We would expect our brain to just be able to repeat this learned motor program with the same level of accuracy.

To answer these questions, we look at two recent studies.  The first, by a team at Dartmouth's Department of Psychological and Brain Sciences, led by Emily Cross, who is now a post-doc at Max Planck Institute for Cognitive and Brain Sciences in Leipzig, Germany, wanted to know if we need to physically perform a new task to learn it, or if merely observing others doing it would be enough. 

The "task" they chose was to learn new dance steps from a video game eerily similar to "Dance, Dance Revolution".  If you (or your kids) have never seen this game, its a video game that you actually get up off the couch and participate in, kind of like the Nintendo Wii.  In this game, a computer screen (or TV) shows you the dance moves and you have to imitate them on a plastic mat on the floor connected to the game.  If you make the right steps, timed to the music, you score higher.

Cross and the team "taught" their subjects in three groups.  The first group was able to view and practice the new routine.  The second group only was allowed to watch the new routine, but not physically practice it.  The third group was a control group that did not get any training at all.  The subjects were later scanned using functional magnetic resonance imaging (fMRI) while they watched the same routine they had either learned (actively or passively) or not seen (the control group).


As predicted, they found that the two trained groups showed common activity in the Action Observance Network (AON) in the brain (see image on left), a group of neural regions found mostly in the inferior parietal and premotor cortices of the brain (near the top of the head) responsible for motor skills and some memory functions.  In other words, whether they physically practised the new steps or just watched the new steps, the same areas of the brain were activated and their performance of the new steps were significantly similar.  The team put together a great video summarizing the experiment.  

One of the themes from this study is that, indeed, learning a motor skill takes place in the brain.  This may seem like an obvious statement, but its important to accept that the movements that our limbs make when performing a skill are controlled by the instructions provided from the brain.  So, what happens when the skill breaks down?  Why did the quarterback throw behind the receiver when we have seen him make that same pass accurately many times?  


To stay true to our theme, we have to blame the brain.  It may be more logical to point to a mechanical breakdown in the player's form or body movements, but the "set-up" for those movements starts with the mental preparation performed by the brain.


In the second study, electrical engineers at Stanford University took a look at these questions to try to identify where the inconsistencies of movement start.  They chose to focus on the "mental preparation" stage which occurs just before the actual movement.  During this stage, the brain plans the coordination and goal for the movement prior to initiating it.  The team designed a test where monkeys would reach for a green dot or a red dot.  If green, they were trained to reach slowly for the dot; if red, to reach quickly.  By monitoring the areas of the monkeys' brains through fMRI, they observed activity in the AON prior to the move and during the move.  


Over repeated trials, changes in reach speed were associated with changes in pre-movement activity.  So, instead of perfectly consistent reach times by the monkeys, they saw variation, like we might see when trying to throw strikes with a baseball many times in a row.  Their conclusion was that this planning activity in the brain does have an effect on the outcome of the activity.  Previously, research had focused only on breakdowns during the actual move and in the mechanics of muscles.  This study shows that the origin of the error may start earlier.


As electrical engineering Assistant Professor Krishna Shenoy stated, "the main reason you can't move the same way each and every time, such as swinging a golf club, is that your brain can't plan the swing the same way each time."  

Postdoctoral researcher and co-author Mark Churchland added, "The nervous system was not designed to do the same thing over and over again.  The nervous system was designed to be flexible. You typically find yourself doing things you've never done before." 
The Stanford team also has made a nice short video synopsis of their study.

Does practice make perfect?  First, we must define "practice".  We saw that it could be either active or passive.  Second, we know sports skills are never "perfect" all the time, and need to understand where the error starts before we can begin to fix it.