Virtual reality stimulation modulates saccular activity and vestibular system responses

Area of Science:

• Neuroscience
• Vestibular System Research
• Human Physiology

Background:

• The saccule, a part of the vestibular system, detects vertical head movements and aids postural control.
• The influence of visual cues and the vestibular-ocular reflex on saccular responses remains unclear.
• Understanding visual-vestibular interactions is key to explaining sensory processing during motion.

Purpose of the Study:

• To investigate how simulated vertical acceleration in virtual reality (VR) affects saccule-related vestibulospinal reflex responses.
• To examine the impact of visual stimuli on vestibular reflex activity.

Main Methods:

• 32 healthy adults (18-40 years) participated.
• Bilateral cervical vestibular-evoked myogenic potential (cVEMP) testing was performed under three conditions: baseline, during VR simulated vertical motion, and post-VR.
• cVEMP amplitudes and latencies were measured.

Main Results:

• cVEMP P1-N1 amplitudes significantly increased during and after VR simulated vertical motion (p < 0.001).
• No significant changes in P1 or N1 latencies were observed across conditions.
• The observed amplitude increase indicates a modulation of saccule-related vestibulospinal reflex activity.

Conclusions:

• Visually simulated vertical self-motion in VR modulates cVEMP responses, reflecting altered saccule-related vestibulospinal reflex activity.
• These findings underscore the significant role of visual-vestibular interaction in response to sensory conflict.
• Further research may explore these effects in different populations.