Top Athletes Can React Quicker

A study conducted by scientists at Brunel University and at the University of Hong Kong has found that expert sportsmen are quicker to observe and react to their opponents' moves than novice players, exhibiting enhanced activation of the cortical regions of the brain.

The results of the study, which appear in the most recent issue of NeuroReport, show that more experienced sports players are better able to detect early anticipatory clues from opposing players' body movements, giving them a split second advantage in preparing an appropriate response.
 
Recent studies have demonstrated how expertise affects a range of perceptual-motor skills, from the imitation of hand actions in guitarists, to the learning of action sequences in pianists and dancers. In these studies, experts showed increased activation in the cortical networks of the brain compared with novices.

Fast ball sports are particularly dependent on time-critical predictions of the actions of other players and of the consequences of those actions, and for several decades, sports scientists have sought to understand how expertise in these sports is developed.

This most recent study, headed by Dr Michael Wright, was carried out by observing the reaction time and brain activity of badminton players of varying degrees of ability, from recreational players to international competitors. Participants were shown video clips of an opposing badminton player striking a shuttlecock and asked to predict where the shot would land.

In all participants, activation was observed in areas of the brain previously associated with the observation, understanding and preparation of human action; expert players showed enhanced brain activity in these regions and responded more quickly to the movements of their opponents.

Expertise in sports is not only dependent on physical prowess, then, but also on enhanced brain activity in these key areas of the brain. The observations made during this study will certainly have implications for how we perceive the nature of expertise in sport and perhaps even change the way athletes train.

See also: The Cognitive Benefits of Being a Sports Fan and How To See A 130 MPH Tennis Serve

Source:  Wolters Kluwer Health / Lippincott Williams & Wilkins and Functional MRI reveals expert-novice differences during sport-related anticipation : Neuroreport

Stroke Patients Benefit From New Brain And Motor Skills Research

Bioengineers have taken a small step toward improving physical recovery in stroke patients by showing that a key feature of how limb motion is encoded in the nervous system plays a crucial role in how new motor skills are learned.

Published in a recent issue of Neuron, a Harvard-based study about the neural learning elements responsible for motor learning may help scientists design rehabilitation protocols in which motor adaptation occurs more readily, potentially allowing for a more rapid recovery.

Neuroscientists have long understood that the brain's primary motor cortex and the body's low-level peripheral stretch sensors encode information about the position and velocity of limb motion in a positively-correlated manner rather than as independent variables.

"While this correlation between the brain's encoding of the position and the velocity of motion is well-known, its potential importance and practical use has been unclear until now," says coauthor Maurice A. Smith, Assistant Professor of Bioengineering at the Harvard School of Engineering and Applied Sciences (SEAS) and the Center for Brain Science in the Faculty of Arts and Sciences.

Smith and colleagues showed that the correlated neural tuning to position and velocity is also present in the neural learning elements responsible for motor learning. Moreover, this correlated drive can explain key features of the motor adaptation process.

To study and record motor adaptation, the researchers had subjects grasp a robotic arm. The device was programmed to simulate novel physical dynamics as subjects made reaching motions. In addition, the team used a newly developed measurement technique called an "error-clamp" to tease apart the resulting data.

The method measures motor output during learning, allowing learning-related changes in motor output over the course of a movement to be dissociated from feedback adjustments that correct motor errors that happen simultaneously.

"Conceptually, this error-clamp is analogous to a voltage-clamp, commonly used in electrophysiology to measure how ions move through a neuron's membrane when it fires," explains lead author Gary C. Sing, a graduate student at SEAS. "The general idea is that devising an experimental method to clamp and control the key variable in an experiment can allow for greater insight into the underlying physiology."

Analysis of the data extracted by the error-clamp technique led to the creation of a computational model that identifies a set of vectors that characterize the principal components of motor adaptation in the state space of physical motion. While such analysis is commonplace in systems engineering -- for example, in evaluating how a bridge might react to high winds or earthquakes -- the method has only been recently applied to how motor output evolves.

"We observed that the initial stages of motor learning are often quick but non-specific, whereas later stages of learning are slower and more precise," says Sing. "Further, we saw that some physical patterns of movement are learned more quickly than others."

By understanding what types of motor adaptations are easier to learn, the researchers hope to design rehabilitation activities that will encourage patients to use an affected limb more.

"In stroke rehabilitation, patients who make a greater effort to use their impaired limbs can achieve better outcomes," says Smith. "However, there is often a vicious cycle, as a patient is far less likely to use an impaired limb if his or her other limb is fine. This pattern slows recovery and leads to greater impairment of the affected limb."

Smith and his colleagues are beginning studies with stroke patients to determine whether training them with such optimized patterns will, in fact, improve their rate of motor learning and speed up recovery.
More broadly, untangling the algorithms the brain uses for motor learning could help improve a wide range of neural and muscular rehabilitation programs. The researchers also anticipate that such findings could be one day be adapted for enhancing the brain/machine interfaces increasingly used for those with amputated limbs.

Sources:  Harvard University and "Primitives for Motor Adaptation Reflect Correlated Neural Tuning to Position and Velocity"

Take Your Brain To The Gym

The moment of truth has arrived, again. The holidays have passed, the bowl games are over and you have renewed your annual New Year's resolution to get back into shape... for real. Don't worry, you are not alone. According to the Centers for Disease Control (CDC), 63 percent of Americans have a Body Mass Index (BMI) in excess of 25 (defined as overweight), while a quarter are greater than 30 (obese).

Its not just kids that benefit from exercise. As we get older, those extra pounds start to affect other areas of our health, contributing to the onset of diabetes, hypertension and high cholesterol.

Several new studies in the last month have now built stronger links between our levels of physical activity and the health of our most important body part, the brain. Conditions such as dementia, Parkinson's, Alzheimer's and even mild age-related memory loss can be delayed by regular physical activity.

Shrinking brain

According to John Ratey, clinical associate professor of psychiatry at Harvard Medical School and author of "Spark: the revolutionary new science of exercise and the brain" (2008, Little, Brown), "Age happens. Getting older is unavoidable, but falling apart is not."

Starting at age 40, we lose about 5 percent of our brain volume per decade, but then at age 70 other conditions may start to accelerate the deterioration. As we age, our cells are less able to cope with stress from waste products such as free radicals.

In the brain, as this stress claims more neuron cells, the web of interconnections between neurons weakens. As we each have more than one hundred billion neurons with each having oodles of connections to other neurons, this gradual net loss is not as dramatic, at first. However, as we age, if this neurodegenerative process accelerates, then our general focus and memory loss as well as more serious conditions like Alzheimer's may appear.

What the aging brain needs is a pumped-up blood flow. Exercise-induced neurotrophins such as brain-derived neurotropic factor (BDNF), vascular endothelial growth factor (VEGF), as well as the neurotransmitter dopamine are needed to grow and fertilize new and existing neurons and their synapse connections. Ratay calls BDNF "Miracle-Gro for the brain."

Make new brain cells

Researchers at the National Cheng Kung University Medical College in Taiwan recently tested the effects of BDNF in the brains of mice of different ages. Half were trained to run a maze for 1 hour a day for exercise, while the control group did not exercise.

As expected, the researchers first found that neurogenesis, the creation of new neuron cells in the brain, dropped of dramatically in the middle-aged mice compared with younger mice. They also were able to conclude that exercise significantly slows down the loss of new nerve cells in the middle-aged mice.

Production of neural stem cells improved by approximately 200 percent compared to the middle-aged mice that did not exercise.

Increase blood flow

OK, that was mice. What about humans?  University of North Carolina brain researchers recently found that older adult humans who regularly exercised had increased blood flow in their brains. They compared long-time exercisers with sedentary adults using 3D MRI brain-scanning techniques.

"The active adults had more small blood vessels and improved cerebral blood flow," said the study's senior author, J. Keith Smith, associate professor of radiology at UNC School of Medicine. "These findings further point out the importance of regular exercise to healthy aging."

The research builds on a host of other studies, summarized in an August review, that show a balanced diet and regular exercise can protect the brain and ward off mental disorders.

Helps manage glucose

Finally, in a report released last month, Scott A. Small, associate professor of neurology at Columbia University Medical Center, found that levels of blood sugar (glucose) have a direct effect on blood flow in the brain.

By testing 240 elderly volunteers, and using functional magnetic resonance imaging (fMRI), Small and his colleagues found a correlation between elevated blood glucose levels and decreased cerebral blood flow, in the dentate gyrus, an area in the brain's hippocampus that has a direct effect on our memories. This corresponds with Smith's findings by showing that exercise may help manage glucose levels, which will improve blood flow to the brain.

Small's previous imaging studies have shown that physical exercise causes an improvement in dentate gyrus function.

"By improving glucose metabolism, physical exercise also reduces blood glucose" Small said. "We have a behavioral recommendation — physical exercise."

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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.



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