Body sway responses to pseudorandom support surface translations of vestibular loss subjects resemble those of vestibular able subjects

TL;DR

This study shows that body sway responses to pseudorandom support surface translations are similar in vestibular-loss and vestibular-able subjects, suggesting limited functional role of vestibular signals in this context.

Contribution

It demonstrates that pseudorandom stimuli reveal comparable sway responses in both groups, challenging previous assumptions about vestibular contributions.

Findings

VA and VL responses closely resemble each other

Vestibular signals have limited impact on sway responses in this scenario

Unpredictable stimuli reveal similarities not seen with predictable stimuli

Abstract

Body sway responses evoked by a horizontal acceleration of a level and firm support surface are particular in that the vestibular information on body-space angle BS resembles the proprioceptive information on body-foot angle BF. We compared corresponding eyes-closed responses of vestibular-able (VA) and vestibular-loss (VL) subjects, postulating a close correspondence. In contradistinction to previous studies, we used an unpredictable (pseudorandom) stimulus and found that the eyes-closed and eyes-open responses of the VA closely resembled those of the VL subjects, as expected. We further conclude that the vestibular signals coding head linear translation in VA subjects has in this case too little functional relevance to cause a notable difference between the subject groups.