Evidence that endpoint feedback facilitates intermanual transfer of visuomotor force learning by a cognitive strategy

Abstract

Humans continuously adapt their movement to a novel environment by recalibrating their sensorimotor system. Recent evidence, however, shows that explicit planning to compensate for external changes, i.e. a cognitive strategy, can also aid performance. If such a strategy is indeed planned in external space, it should improve performance in an effector independent manner. We tested this hypothesis by examining whether promoting a cognitive strategy during a visual-force adaptation task performed in one hand can facilitate learning for the opposite hand. Participants rapidly adjusted the height of visual bar on screen to a target level by isometrically exerting force on a handle using their right hand. Visuomotor gain increased during the task and participants learned the increased gain. Visual feedback was continuously provided for one group, while for another group only the endpoint of the force trajectory was presented. The latter has been reported to promote cognitive strategy use. We found that endpoint feedback produced stronger intermanual transfer of learning and slower response times than continuous feedback. In a separate experiment, we found evidence that the aftereffect is indeed reduced when only endpoint feedback is provided, a finding that has been consistently observed when cognitive strategies are used. The results suggest that intermanual transfer can be facilitated by a cognitive strategy. This indicates that the behavioral observation of intermanual transfer can be achieved either by forming an effector-independent motor representation, or by sharing an effector-independent cognitive strategy between the hands.

Ipsilateral transfer of motor skill from lower to upper limb in healthy adults: A randomized controlled trial

“…Intermanual transfer was facilitated in the endpoint feedback condition, suggesting that effector-independent learning was facilitated by a cognitive strategy [39]. Despite the differences of experimental design and tasks in the above-mentioned studies [17,[37][38][39][40], the cognitive aspect, which is inherent in the task, improved the intermanual transfer. It should be noted that our study design did not aim to elucidate the respective contributions of the cognitive and motor aspects to ipsilateral transfer.…”

“…Explicit (cognitive) processes were found to be primarily responsible for intermanual transfer of a visuomotor adaptation task when participants adapted to a large visuomotor distortion of which they were aware [ 17 ]. Elements of the task environment, such as the type of visual feedback available, can also alter the balance between cognitive strategies and motor adaptation and affect intermanual transfer [ 39 ]. Intermanual transfer was facilitated in an endpoint feedback condition that consisted of cognitive strategy.…”

“…It was suggested that restricted visual feedback to the endpoint relied heavily on a cognitive strategy to solve the task because reaction times increased in that task. Intermanual transfer was facilitated in the endpoint feedback condition, suggesting that effector-independent learning was facilitated by a cognitive strategy [ 39 ]. Despite the differences of experimental design and tasks in the above-mentioned studies [ 17 , 37 – 40 ], the cognitive aspect, which is inherent in the task, improved the intermanual transfer.…”

“…Therefore, it seems that the combined practice of the motor and cognitive aspects was required to trigger ipsilateral transfer from the LL to the UL. Indeed, there is evidence that intermanual transfer can be facilitated by a cognitive strategy [17,[37][38][39][40]. Explicit (cognitive) processes were found to be primarily responsible for intermanual transfer of a visuomotor adaptation task when participants adapted to a large visuomotor PLOS ONE distortion of which they were aware [17].…”

Dynamic motor practice improves movement accuracy, force control and leads to increased corticospinal excitability compared to isometric motor practice

“…We chose to only provide visual endpoint feedback to promote the role other intrinsic feedback mechanisms including proprioception during the trial. Furthermore, Havas et al (2021) have recently suggested that this can promote cognitive strategy use during motor learning compared to when feedback is presented continuously.…”