MINNEAPOLIS / ST. PAUL– Researchers at the University of Minnesota have demonstrated the role of the brain's cerebellum during motor skill learning. By separating the effects of motor learning from changes in performance, they discovered that the cerebellum, long associated with motor skill learning, does not contribute to learning itself, but is engaged primarily in the modification of performance. The findings will be published in the June 14, 2002 issue of Science.
Motor skills are learned through practice, such as when toddlers learn to walk or adults acquire the skills to play tennis.
"Learning these skills invariably leads to changes in motor performance," said James Ashe, M.D., associate professor of neuroscience with the University of Minnesota and the Veterans Affairs Medical Center in Minneapolis. "Because performance change in itself can activate the cerebellum, it's been difficult in the past to determine whether the cerebellum contributes to motor skill learning or whether it's responding to the expression of learning, that is, the change in performance."
To separate the two effects, researchers assigned participants a sequence learning task that healthy subjects typically learn within about 10 minutes, but they blocked the expression of learning (or performance change) by having the subjects perform a second (distractor) task concurrently. When the participants were then asked to perform the sequence without the distractor, they showed evidence of having learned it. By using functional MRI, the researchers were able to look at brain activity during these tasks, one involving learning and the other leading to changes in performance.
"We found that learning goes on elsewhere in the brain, but apparently not in the cerebellum. The cerebellum influences the change in performance," said Ashe. "Hopefully, this will lead to a better understanding of some of the problems that face patients with damage to the cerebellum and better strategies for rehabilitation."