Transfer of sensorimotor adaptation between different movement categories.

It is well known that sensorimotor adaptation will transfer from the practiced to the unpracticed arm, which has been taken as evidence that adaptation is located in the brain before the divergence point for left and right arm control. We now explore whether adaptation will transfer between different movement categories as well. Subjects were exposed to a 60-deg visual rotation first in a tracking and then in a pointing task, or vice versa. We found a substantial transfer of adaptation between tasks, but its magnitude was larger from pointing to tracking than from tracking to pointing. This benefit of pointing persisted when the use of cognitive strategies was minimized by a concurrent, attention-demanding task, but it was lost when pointing amplitudes were very small. We conclude that adaptation is located in the brain before the divergence point for different movement categories, and that movements with a large ballistic component facilitate adaptation transfer.