Understanding implicit sensorimotor adaptation as a process of proprioceptive re-alignment

Abstract

Multiple learning processes contribute to successful goal-directed actions in the face of changing physiological states, biomechanical constraints, and environmental contexts. Amongst these processes, implicit sensorimotor adaptation is of primary importance, ensuring that movements remain well-calibrated and accurate. A large body of work on reaching movements has emphasized how adaptation centers on an iterative process designed to minimize visual errors. The role of proprioception has been largely neglected, thought to play a passive role in which proprioception is affected by the visual error but does not directly contribute to adaptation. Here, we present an alternative to this visuo-centric framework, outlining a model in which implicit adaptation acts to minimize a proprioceptive error, the distance between the perceived hand position and its intended goal. This proprioceptive re-alignment model (PReMo) is consistent with many phenomena that have previously been interpreted in terms of learning from visual errors, and offers a parsimonious account of numerous unexplained phenomena. Cognizant that the evidence for PReMo rests on correlational studies, we highlight core predictions to be tested in future experiments, as well as note potential challenges for a proprioceptive-based perspective on implicit adaptation.

Minimal impact of proprioceptive loss on implicit sensorimotor adaptation and perceived movement outcome

“…Traditionally, models of visuomotor adaptation have focused on how the target position, specified by vision, serves as a proxy of the prediction, and is compared with visual feedback in defining the sensory prediction error. However, motivated by limitations with a visuo-centric view, we have proposed an alternative kinesthetic re-alignment model, which reframes implicit adaptation as a process driven by a kinesthetic error, the mismatch between the perceived and desired position of the hand (Tsay et al, 2022). By this view, the perceived hand position is not just influenced by vision but also reflects information from proprioceptive afferents and prior beliefs about the desired sensory outcome (i.e., the target).…”

“…Implicit adaptation is assumed to be driven by a sensory prediction error, the difference between the predicted and actual sensory consequences of a movement. Whereas most models of implicit adaptation have focused on how visual information defines the sensory prediction error, we have recently proposed that this error signal is kinesthetic, the difference between the desired and perceived hand position, with adaptation serving to align these two signals and restore optimal motor performance (Tsay et al, 2022). Here, we examined implicit adaptation and kinesthetic perception in rare individuals who lack proprioceptive signals from the upper limbs.…”

Different time scales of common-cause evidence shape multisensory integration, recalibration and motor adaptation

“…Reduced binding again could result in the reduced error sensitivity that has been shown for variable visuo‐motor rotations (Avraham et al, 2020; Albert et al, 2021) – after all there should be little benefit from adjusting movement directions as a consequence of visually indicated errors that depend on random spatial offsets between hand and cursor positions. Similarly detailed analyses of sensory recalibration are missing, but there is evidence that variations of motor adaptation often imply concomitant variations of recalibration (Tsay et al, 2022).…”

How prism adaptation reveals the distinct use of size and positions in grasping

“…The present results add to the interpretation of prism adaptation. Generally, prism adaptation is considered as consisting of two components: a slow automatic realignment between vision and proprioception (Salomonczyk et al 2011 ; Tsay et al 2022 ), combined with a deliberate strategic component (Kornheiser 1976 ; Prablanc et al 2020 ). Any aftereffects are thus due to the realignment component.…”