Additional visual feedback improves aiming movement performance with practice but may foster dependency in individuals with cerebellar dysfunction: a proof-of-principle study

Abstract

BACKGROUND: Cerebellar dysfunction impairs voluntary movement by disrupting sensorimotor integration, particularly the processing of somatosensory and visual information. External visual feedback has been proposed as a compensatory strategy, but its effectiveness in facilitating performance improvement with practice remains uncertain.

AIM: To determine whether additional visual feedback enhances performance in individuals with cerebellar dysfunction during upper limb aiming movements.

METHODS: This longitudinal crossover design study included 28 adults (14 with cerebellar dysfunction, 14 healthy controls) who practiced discrete aiming movements with and without additional visual feedback across two days of sessions, with practice blocks preceded and followed by brief pre- and post-tests. A 24–48 h washout period separated the sessions. Immediate performance outcomes, including planning and execution variables, were analyzed.

RESULTS: Participants with cerebellar dysfunction demonstrated shorter movement times, higher peak velocities, and smaller final position errors when provided with additional visual feedback. These improvements disappeared once feedback was withdrawn, indicating no retention of gains. Control participants showed improved performance through practice, regardless of the feedback condition.

INTERPRETATION: Additional visual feedback enhanced immediate performance in individuals with cerebellar dysfunction; however, no retention was observed. These findings highlight reliance on visual cues and underscore the need for caution when incorporating such strategies into rehabilitation protocols.