Advanced Feedback Enhances Sensorimotor Adaptation

Abstract

It is widely recognized that sensorimotor learning is enhanced when the feedback is provided throughout the movement compared to when it is provided at the end of the movement. However, the source of this advantage is unclear: Continuous feedback is more ecological, dynamic, and available earlier than endpoint feedback. Here we assess the relative merits of these factors using a method that allows us to manipulate feedback timing independent of actual hand position. By manipulating the onset time of endpoint feedback, we found that adaptation was modulated in a non-monotonic manner, with the peak of the function occurring in advance of the hand reaching the target. Moreover, at this optimal time, learning was of similar magnitude as that observed with continuous feedback. By varying movement duration, we demonstrate that this optimal time occurs at a relatively fixed time after movement onset, an interval we hypothesize corresponds to when the comparison of the sensory prediction and feedback generates the strongest error signal.