Virtual reality stimulation modulates saccular activity and vestibular system responses

The saccule detects vertical linear head movements and contributes to postural control by transmitting sensory information to the central nervous system. However, little is known about how visual cues and the resulting vestibular-ocular reflex affect vestibular responses. This study investigated changes in saccule-related vestibulospinal reflex responses using visually simulated vertical acceleration in a virtual reality (VR) environment.

The study involved 32 healthy individuals (16 males and 16 females), aged between 18 and 40 years (mean age: 28.56 ± 9.02 years). All participants underwent bilateral cervical vestibular-evoked myogenic potential (cVEMP) testing under three experimental conditions: a baseline measurement without VR; during visually simulated vertical elevator motion with VR; and immediately after the cessation of motion with VR (retest).

When the responses were compared at the end of the study, cVEMP P1-N1 amplitudes were found to be significantly increased (p < 0.001). This increase in amplitude persisted in the post-VR condition (p < 0.001). No significant changes in P1 or N1 latencies were observed between conditions.

Exposure to visually simulated vertical self-motion in a virtual reality environment appears to modulate cVEMP responses, which reflect saccule-related vestibulospinal reflex activity. These findings emphasise the importance of visual-vestibular interaction in shaping vestibular reflex responses in conditions involving sensory conflict. While this study was conducted on a healthy young cohort, its.