The Athlete in Your Brain

Posted by Christian Cazares on March 9, 2017 in Neuroscience, Sports | Leave a comment

      Wide eyes and skeptical silence preceded the thunderous cheers heard throughout PB Cantina as Patriots running back James White plowed through the Falcon’s defensive line and into their end zone.  For every knocked down beer glass and drunken hug jovially made during the roaring, spirited celebration, the reluctant sports fan enclosed within every navy blue and white jersey was broken down bit by bit into a true believer. Yet remarkably, Super Bowl LI was not the only instance of a historic comeback within the last year. After losing a sizable lead in the 8th inning, the Chicago Cubs rallied towards an emotional finish in the 10th, ending a mammoth of a championship drought after 107 heartbreaking years. Against all odds and only a few months later, the Cleveland Cavaliers overcame a similar 3-1 series deficit to take the championship win from the stunned Golden State Warriors’ record-breaking team.

Can you believe it?

     At the peak of performance anxiety, when the pressure from hundreds of thousands of watchful eyes was as tangible as the tightly stitched strips of cowhide on a baseball, these athletes somehow persevered and pushed the boundaries of human dexterity, stamina, and resilience for the win. But the journey towards becoming a professional sportsman may be difficult to put into words; while the sweat, tears, victories and adversity can be vividly recalled by those who experience them on their athletic quest to the top, shooting accuracy improvements may go unnoticed until they’ve exceed measurable expectations.

     Recently, neuroscientists studying movement and behavior have begun to accumulate evidence supporting the idea that the brain drives athletic growth, creating and strengthening connections in an imperceptible fashion. For example, you may not be able to explain how you learned to ride a bike, but you know you got better when you noticed yourself becoming more confident and falling less and less. Here, we’ll be taking a closer look at the key brain areas involved in the development of physical skill expertise, and the strides neuroscience has made in figuring out what differentiates the brain of a beer-league hockey player from the brain of a Stanley Cup champion.

Swinging the Bat: The Motor Cortex

     Your brain’s representation of your body’s muscles can adapt as a result of increased use and expertise. The motor cortex receives a myriad of information from other brain areas to assist voluntary movement.  If you’re on the free throw line, your memories of how to position your hands on the ball, your awareness of where the basket is in space, and the visual scene of the net and backboard originating from your eyes are all accessible by the motor cortex to facilitate your throw. Remarkably, a subset this brain region, the primary motor cortex, contains a motor map of the body that is proportionate to dexterity demands: your hands and fingers comprise a greater section of this map than, say, your quadriceps. For example, experienced string players have been shown to have larger representations of their fingers in this brain area [1].

Different proportions for different muscles.

     Given the hours of practice involved in the development of a world class athlete, we might think that these findings would hold if we were to put Stephen Curry in a brain scanner. However, unlike the string player study, the different complexity of movements involved in sports like basketball make it difficult to come to such a conclusion; there is more to basketball than using your hands to become an expert 3-point shooter. Instead, neuroscientists have turned their attention to areas in communication with the motor cortex, one of which is the cerebellum.

Aim for the Ball: The Cerebellum

     Actions made with your limbs need to be smoothed out during their trajectory. As a shortstop reaches out for the ball, the sequence of fine muscle movements needed to make the catch employ an internal clock within the brain that modifies the timing and duration of the player’s arm extension. The cerebellum is the key region involved in this process; its critical role may have become clear to you after more than a couple of drinks. You may notice yourself making clumsy mistakes, exerting a greater effort in order to walk straight, all because excessive alcohol consumption disrupts the function of the cerebellum.

The cerebellum at large.

     During the periods in between drinking (also known as daytime on a Monday), the cerebellum receives information from the outside world via the areas of the brain processing sensory input. In addition, information about the movements you’ve previously executed comes in from the motor cortex, is processed in the cerebellum, and is sent back for future actions. This creates a loop in your brain that is constantly active, refining your movements through the continuous feedback being received from the environment and your body. This loop is what makes you reaching out to your nose without poking your eye possible!

Within the cerebellum.

     This leads us back to our previous question: would an experienced basketball player have a different brain structure than a novice? Using magnetic resonance imaging (MRI), which takes three-dimensional snapshots of your brain anatomy, South Korean researchers found larger volume in a specific sub region (vermian V2) of the cerebellum in basketball players compared to naïve control subjects [2]. This finding suggests that through acquisition and practice of motor skills, brain regions involved in refining actions adapt depending on how often an action is performed. However, whether these differences were simply a result of the different lifestyles between the two comparison groups (athletes exercise more frequently) remains to be seen. Curiously, this is not the only loop set in place in the brain that allows the facilitation and execution of movement.

Learning to Shoot: The Basal Ganglia

     The basal ganglia are a collection of, discrete subcortical structures that mediate action selection and coordinate voluntary movements. Damage to the basal ganglia gives rise to symptoms of motor dysfunction, such as those seen with Parkinson’s disease, where cell death in a specific subpopulation of neurons within this system leads to rigidity and difficulty in initiating movement. The vast interconnection between the different nuclei allows for the fast transmission of cortical information that is then sent to the sensory relay station of the brain, the thalamus, which then transmits information back onto the cortex where the cycle begins anew.

The basal ganglia and its subcomponents.

     The basal ganglia use feedback from previous action outcomes to reinforce learning. They are thought to refine and modulate movement by biasing future action selection via evaluations of  reward and punishment. Since sports training involves using performance feedback to guide how to kick a ball or swing a bat, it is reasonable to assume that the brain of an athlete may have a different structure in this particular region.

     Neuroscientists put this idea to the test by comparing structural magnetic resonance images of professional track-and-field athletes to those of naive control subjects [3]. They found that while total brain volumes were similar across the two groups, there were grey matter differences in sections of the basal ganglia loop, suggesting a larger brain cell population in this region for athletes compared to the control group. Furthermore, these differences remained two years later, notably after a period through which the Summer Olympics took place, alluding to non-transient changes that persisted over the years.  The authors used these results to imply that the brain morphology of reward-related and movement coordination areas correlate with top athlete’s ability to reach world-class expertise. However, it would be remiss not to question whether these differences are mediated by factors outside of an athlete’s profession, or whether these findings would apply throughout different sports.

The Brain of Champions

The loop of action.

     There is no universal consensus among neuroscientists about the underlying contributions to an athlete’s expertise. Maybe anyone can reach the levels of professional athlete performance given an unlimited amount of practice, or it could simply be that LeBron James was genetically gifted with the capacity to become the player he is now. Whether our environment or our genes are the sole determinants of our human potential will be a matter of debate for decades to come. What these studies do point out, however, is that anatomical differences can indeed arise in relation to your expertise as an athlete. Future studies should extend these findings by making similar comparisons among different athletic disciplines, and further delineate and dissect whether any other brain differences can be found even among expert athletes. Perhaps the transition from novice to expert belie a change in brain structure different from that of an expert without a championship to that of a five time SuperBowl champion. Now I have to find out how to get in touch with the Warriors and Cavs to see if they want to settle the score off the court and in a brain scanner.

He mad.

References:

1.Elbert T, Pantev C, Wienbruch C, Rockstroh B, Taub E (1995) Increased cortical representation of the fingers of the left hand in string players. Science. 13;270(5234):305-7. PubMed PMID: 7569982.

2. Park, IS, Lee, KJ, Han, JW et al. (2009) Experience-Dependent Plasticity of Cerebellar Vermis in Basketball Players. Cerebellum. 8: 334.

3. Taubert M, Wenzel U, Draganski B, Kiebel SJ, Ragert P et al. (2015) Investigating Neuroanatomical Features in Top Athletes at the Single Subject Level. PLOS ONE. 10(6): e0129508.