Reach Adaptation and Proprioceptive Recalibration Following Terminal Visual Feedback of the Hand

Reaches are adapted and proprioceptive sense of hand position is partially recalibrated after training with continuous, misaligned visual feedback. When visual feedback is provided only at the end of the movement, it is unclear if similar changes arise. To test this, participants reached to targets, first with aligned-cursor, then three times with rotated-cursor. After each block, we measured no-cursor reaches and perceived felt hand positions relative to a reference marker. We found that reach aftereffects were slightly smaller than that following training with continuous visual feedback. Additionally, terminal feedback participants incrementally recalibrated their sense of felt hand position over the rotated training blocks. Final proprioceptive recalibration levels were comparable to those in our continuous feedback study. Thus, compared to continuous feedback findings, terminal feedback produced significant, yet smaller, reach aftereffects but similar changes in hand proprioception. Taken together, terminal feedback is sufficient to drive motor adaptation and proprioceptive recalibration.