Cerebellar Control of Movement

Principal Investigator: Amy Bastian

Cerebellar damage disrupts movement coordination. Actions ranging from walking to reaching become inaccurate and difficult to control, which has deleterious effects on most functional movements. Therapeutic approaches for cerebellar motor disorders (i.e. 'ataxia') rely heavily on rehabilitation since there are no medications that systematically improve movement coordination. Rehabilitation is limited by the fact that cerebellar damage also disrupts motor learning, or the ability to learn movements through practice. Cerebellar damage dramatically impairs error-driven motor adaptation, or the ability to elicit trial-by-trial changes in a movement in response to errors. Normally, this type of motor learning results in storage of a new motor pattern that has to be actively unlearned. Storage of a new motor pattern is impaired or absent in people with cerebellar damage.

Here, we investigate novel strategies for helping people with cerebellar damage learn to improve movement coordination. Preliminary results suggest that (1) people with cerebellar damage can show motor learning, but only when errors are due to predictable changes in the environment (i.e. perturbations) that are small and gradual, (2) this form of learning is based on cerebral mechanisms and is therefore distinct from cerebellum-dependent motor adaptation and, (3) this cerebral motor learning can be modulated with non-invasive brain stimulation. Our long-term goal is to determine if there are motor learning mechanisms that remain available to people with cerebellar damage, and if they can be leveraged to improve therapeutic approaches.