Skip to main content
Kent Academic Repository

Quantifying Virtual Self-Motion Sensations Induced by Galvanic Vestibular Stimulation

Gallagher, M., Romano, F., Bockisch, C.J., Ferrè, E.R., Bertolini, G. (2023) Quantifying Virtual Self-Motion Sensations Induced by Galvanic Vestibular Stimulation. Journal of Vestibular Research, 33 (1). pp. 21-30. ISSN 0957-4271. (doi:10.3233/ves-220031) (KAR id:99173)

Abstract

Background: The vestibular system provides a comprehensive estimate of self-motion in 3D space. Widely used to artificially stimulate the vestibular system, binaural-bipolar square-wave Galvanic Vestibular Stimulation (GVS) elicits a virtual sensation of roll rotation. Postural responses to GVS have been clearly delineated, however quantifying the perceived virtual rotation vector has not been fully realised.

Objective: We aimed to quantify the perceived virtual roll rotation vector elicited by GVS using a psychophysical approach on a 3D turntable.

Methods: Participants were placed supine on the 3D turntable and rotated around the naso-occipital axis while supine and received square-wave bipolar-binaural GVS or sham stimulation. GVS amplitudes and intensities were systematically manipulated. The turntable motion profile consisted of a velocity step of 20°/s2 until the trial velocity between 0-20°/s was reached, followed by a 1°/s ramp until the end of the trial. In a psychophysical adaptive staircase procedure, we systematically varied the roll velocity to identify the exact velocity that cancelled the perceived roll sensation induced by GVS.

Results: Participants perceived a virtual roll rotation towards the cathode of approximately 2o/s velocity for 1 mA GVS and 6o/s velocity for 2.5 mA GVS. The observed values were stable across repetitions.

Conclusions: Our results quantify for the first time the perceived virtual roll rotations induced by binaural-bipolar square-wave GVS. Importantly, estimates were based on perceptual judgements, in the absence of motor or postural responses and in a head orientation where the GVS-induced roll sensation did not interact with the perceived direction of gravity. This is an important step towards applications of GVS in different settings, including sensory substitution or Virtual Reality.

Item Type: Article
DOI/Identification number: 10.3233/ves-220031
Additional information: For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.
Uncontrolled keywords: Vestibular system; Galvanic Vestibular Stimulation; Natural Vestibular stimulation, vestibular perception
Subjects: H Social Sciences
Divisions: Divisions > Division of Human and Social Sciences > School of Psychology
Funders: Economic and Social Research Council (https://ror.org/03n0ht308)
Depositing User: Maria Gallagher
Date Deposited: 14 Dec 2022 16:43 UTC
Last Modified: 04 Mar 2024 16:44 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/99173 (The current URI for this page, for reference purposes)

University of Kent Author Information

  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.