Visual feedback of the moving arm allows complete adaptation of pointing movements to centrifugal and Coriolis forces in human subjects

A classical visuo-manual adaptation protocol carried out on a rotating plat form was used to test the ability of subjects to adapt to centrifugal and C oriolis forces when visual feedback of the arm is manipulated. Th ree main results emerge: Ia) an early modification of the initial trajectory of the movements takes place even without visual feedback of the arm; (b) despite the change in the initial trajectory, the new external force decreases the accuracy of the pointing movements when vision is precluded; (c) a visual a daptive phase allows complete adaptation of the pointing movements performe d in a modified gravitoinertial field, Therefore vision would be essential for subjects to completely adapt to centrifugal and Coriolis forces. Howeve r, other sensory signals (i.e. vestibular and proprioceptive) may constitut e the basis for early but partial correction of the pointing movements. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.