Increased motor control of a phantom leg in humans results from the visual feedback of a virtual leg

Although previous research reported that the visual feedback of a 'virtual arm' increased the control of a phantom arm, it did not consider that the repeated attempt to move the phantom may have contributed to the effect. Twenty-one lower limb amputees reported the response of their phantom leg during repeated attempts to move both legs in one of two conditions, a control condition in which the amputee only viewed the movements of their intact leg and an experimental condition in which the amputee additionally viewed the movements of a 'virtual' leg. It was found that viewing a virtual leg resulted in amputees reporting a significantly greater number of movements of their phantom leg than with attempted movement alone. The implications were discussed in terms of visuo-motor adaptation and theories of motor control. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.