Updating of an internal model without proprioception: a deafferentation study

This study sought to determine whether intact proprioception is required to adapt to a novel kinematic environment. We compared adaptation with a rotated visual feedback between a deafferented patient and healthy participants. They performed reaching movements towards visible targets while vision of the cursor was rotated by 30° with respect to hand position. The patient adapted at the same rate and to the same extent as the controls when exposed to the rotated visual feedback. She also presented large aftereffects following removal of the perturbation. This suggests that proprioception is not an absolute requirement to update a kinematic internal model. Adaptation was likely mediated by a comparison between the sensory consequences of a movement as predicted by a forward model and the visual feedback from that movement.