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.

Subtle Visual Latency Can Profoundly Impair Implicit Sensorimotor Learning

“…2a and 3a), Wang et al observed asymptotic learning that either merely matched our minimum-delay condition (20°, from their online experiments) or fell short (15°, from laboratory-controlled experiments). These observations suggest that it is the reduction of latency from positive baseline levels to near-zero values, rather than the creation of “negative” latency with advanced feedback, which is likely responsible for the enhanced learning observed by Wang et al 17 . We do note however, that complicating comparisons with our work and other studies of latency, where latencies were precisely controlled, the effective latency reduction for the advanced feedback condition varied widely with the movement time for each trial.…”

“…While the effect of visual feedback latency on sensorimotor learning has been the subject of multiple studies [13][14][15]17,[19][20][21][22][23][24][25][26][27][28][29][30][31] , only a fraction [13][14][15]17,19 reliably measured the baseline latency upon which additional experimentally-imposed delays were administered. Therefore, remarkably, both the actual latency of the experimental conditions and of the reference conditions to which they were compared were unknown in most studies.…”

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18].5° for explicit generalization. Moreover, we found that, like implicit adaptation during the training and retraining periods, the local component of implicit generalization grew as latency decreased (5.6±0.9° vs 7.7±0.7° for 85ms vs. 25ms, t(66)=1.8, p= 0.042; and 5.5±1.0° vs 7.7±0.7° for 300ms vs. 25ms, t(66)=1.7, p= 0.043).…”

Bridging event-related potentials with behavioral studies in motor learning

“…As a result, the error was distributed throughout the participant’s reaching movement. For motor adaptation, there are significant differences between online and endpoint feedback ( Shadmehr et al, 2010 ; Taylor et al, 2014 ; Brudner et al, 2016 ; Wang et al, 2022 ). Consequently, it is worth taking both veridical and online feedback into consideration for future experiment design.…”

Signatures of contextual interference in implicit sensorimotor adaptation

“…To fill this gap, we used a novel visuomotor rotation task in which learning is limited to implicit adaptation (figure 1a) [23][24][25][26][27]. On each trial, the participant reached to one of three visual targets with feedback provided by a visual cursor.…”