Motor skills have diverse neural bases: Spared and impaired skill acquisition in Huntington's disease

The striatum contributes to the learning of some, but not all, motor skills. The researchers suggest that the striatum plays a role when participants learn a repeating sequence of movements, but it does not contribute when they learn a new mapping between perceptual cues and the appropriate motor response. The researchers tested patients with striatal damage due to Huntington's disease (HD) on 2 versions of a tracking task. In 1 task, the target moved randomly, allowing participants to learn the relationship between the joystick and cursor. Patients showed normal learning. In the other task, the target moved in a repeating pattern, and participants could improve performance by learning the repeating sequence of movements necessary to track the pattern. Patients were impaired on this task. Learning sequences is impaired in HD, whereas learning new mappings between perceptual cues and responses is not.