As kids, once we have mastered the complex motor skill of riding a
bicycle, we’re told that its a lifelong skill that we’ll never forget.
Getting all of the moving parts of human and machine in sync with each
other becomes a collective memory that can be called on from age 6 to
60.
Which is surprising, knowing that names, numbers and recent
locations of car keys can be so easily forgotten. What makes motor
skills stick in our brains, ready to be called on at anytime? According
to two teams of cognitive science researchers, we can thank a property
called neuroplasticity which actually changes the structure of our brain
as we learn.
Much like bike riding, mastering ice skating requires some advanced
balance and coordination to stay upright. Knowing when and how much to
lean to one side or the other while arms and legs are swinging is the
type of parallel processing computation that human brains can handle
well.Tucked underneath the larger cerebral hemispheres in the brain, the
cerebellum is known to play an active role in controlling movement by
taking in messages from the spinal cord, combined with signals from
other parts of the brain, and coordinating the precision and timing of
complex motor skills. Damage to the cerebellum causes a lack of
coordination, much like being under the influence causes someone to
stagger and lose their balance.
Neuro researcher Im Joo Rhyu, from the Korea University College of
Medicine, knew from prior studies that intensive motor skill training,
such as juggling or basketball, resulted in physical changes in the
brain as measured by functional magnetic resolution imaging (fMRI).
Now, he wanted to find out if the ability of the brain to adapt itself
over time, known as neuroplasticiy, was sport-specific. Given that the
cerebellum has a right and a left hemisphere, would the physical growth
in neural connections be symmetric on both sides?
His research team chose the perfect sport to investigate, speed
skating. Being able to chase opponents around a tight oval at high
speeds on ice is a showcase for the cerebellum’s functions. The key
difference is that skaters always turn counterclockwise or left around
the track. Years and years of practice to perfect movement in one
direction may show a growth pattern in the brain different from other
sports, Rhyu hyphothesized.
So, he compared the fMRI brain scans of 16 male, professional,
short-track speed skaters with the scans of 18 male, non-skaters who
didn’t even exercise. As predicted, in the experienced skaters, the
right hemisphere of their cerebellums were larger than the left side.
Since the skaters only turn to the left, they spend much more time
balanced on their right foot with short steps on their left. Standing
on your right foot activates the right side of the cerebellum. In
addition, learning a motor skill that requires constant visual
monitoring and adjustments is also thought to occur mainly in the
cerebellum’s right half.
The study appears, appropriately, in the December 2012 issue of
The Cerebellum.
Size is not all that changes in the cerebellum after repeated
training. The increased network of neuron connections between brain
cells also increases to the point of being noticeable on a different
type of brain scan, known as diffusion tensor imaging (DTI). Using this
technology, a research team examined experts in a different sport,
karate.
“Most research on how the brain controls movement has been based on
examining how diseases can impair motor skills,” said Dr Ed Roberts,
from the Department of Medicine at Imperial College London, who led the
study. “We took a different approach, by looking at what enables experts
to perform better than novices in tests of physical skill.
They compared the punch strength of twelve karate fighters who had
achieved black belt status and had an average of almost 14 years of
experience with 12 control subjects who exercised regularly but had no
karate training. Karate punching is not simply a feat of raw muscular
strength. It is combination of speed and the coordination of wrist,
shoulder and torso movement.
As expected, they found that the punch strength of the black belts
was substantially greater than the novices. But the DTI scan also
showed something else very interesting. The white matter of their
cerebellums, which is made up of the tangled network of neuron
connections carrying signals from one cell to another, was structurally
different than in the beginner’s brains.
The results of the study are published in the journal
Cerebral Cortex.
“The karate black belts were able to repeatedly coordinate their
punching action with a level of coordination that novices can’t
produce,” said Roberts. “We think that ability might be related to fine
tuning of neural connections in the cerebellum, allowing them to
synchronise their arm and trunk movements very accurately.”
It is reassuring for athletes to know that all of those hours devoted
to training their skills are actually reshaping and rebuilding their
brain architecture. And for us bike riders, we can understand how the
skinned knees and bruised elbows we endured when the training wheels
came off were worth the effort to program a skill that will last a
lifetime.
Join
Axon Sports on
Twitter and
Facebook.
