Noisy Galvanic Vestibular Stimulation Primarily Affects Otolith-Mediated Motion Perception

• Published in: Neuroscience Vol. 399; pp. 161 - 166
• Main Authors: Keywan, Aram, Jahn, Klaus, Wuehr, Max
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 10.02.2019
• Subjects: noisy galvanic stimulation; otoliths; semicircular canals; stochastic resonance; vestibular motion perception; CoP; nGVS; SCCs; noisy galvanic stimulation; vestibular motion perception; MV; RMS; stochastic resonance; otoliths; SR; semicircular canals
• ISSN: 0306-4522; 1873-7544; 1873-7544
• DOI: 10.1016/j.neuroscience.2018.12.031

•Imperceptible nGVS enhances vestibular motion perception in healthy subjects.•This enhancement is primarily observed in motion perception mediated by otolith organs but not by semicircular canals.•Individuals with higher baseline threshold for vestibular motion perception show greater enhancements during nGVS. Noisy galvanic vestibular stimulation (nGVS) has been shown to improve vestibular perception in healthy subjects. However, it is unclear whether both the semicircular canals (SCCs) and otolith organs contribute to this enhancement or is it confined to one of these structures. To elucidate this matter, nGVS amplitudes with optimal effect on postural control were determined in 12 healthy subjects during upright stance. These amplitudes were then applied during perceptual direction-recognition tasks in inter-aural translation (otolith-mediated perception) as well as yaw rotation with the head pitched forward 71 deg (SCC-mediated perception) and compared to sham stimulation. Nine out of 12 subjects showed significantly improved direction-recognition thresholds in the inter-aural translation task during nGVS compared to sham stimulation (p ≤ 0.03; mean threshold reduction: 38.8%). Only 6 of 12 subjects showed mild improvements in the yaw rotation task during nGVS (p > 0.05). In addition, elevated baseline thresholds during the inter-aural translation task significantly correlated with a larger magnitude of improvement (R = 0.72, p = 0.01). In conclusion, nGVS appears to primarily impact otolith-mediated perception while only mildly affecting the SCCs. Thus, this stimulation approach could be a complementary candidate to vestibular implants that are currently limited to SCC-mediated vestibular function.