Transfer of learning between the arms during bimanual reaching.

This study examined how movement of one arm affects the rate of motor adaptation of the other arm during bimanual reaching in a viscous force-field. Forty healthy adult subjects performed four reaching tasks: (1) by dominant arm, (2) by nondominant arm, (3) by both arms with only dominant arm experiencing force-field and (4) by both arms with only nondominant arm experiencing the force-field. For dominant arm rate of motor adaptation was greater during the bimanual task than the unimanual task. For nondominant arm reaching errors were higher during the bimanual than unimanual task. These results suggest that during bimanual reaching, transfer of learning between arms occur in both directions and movement information transferred depends on arm dominance.