THE CEREBELLUM:
The Brain's Engine of Agility
Ingrid Wickelgren
Although the cerebellum's role in simple movements has long been appreciated, only recently have scientists begun pinning down how it coordinates complex, multijoint movements. Studies of humans with cerebellar lesions and lab animals show, for example, that the cerebellum predicts and adjusts for the multiple forces on a limb during a complex movement, including those propagating from one joint to another. The cerebellum also controls the relative timing of various muscle contractions to ensure the speed and accuracy of a maneuver. Less clear at the moment are the neural mechanisms underlying cerebellar control of complex movements. But even so, researchers expect that the work may yield insights into how to improve coordination in the hundreds of thousands of people with cerebellar damage due to genetic disease, viral infections, strokes, alcoholism, or normal age-related loss of cerebellar neurons.
