PhD Scientific Days 2023

Neurosciences - Posters G

Frequency-dependent reduction of cyber-sickness in Virtual Reality by transcranial oscillatory stimulation of the vestibular cortex

Text of the abstract

INTRODUCTION: Virtual reality (VR) applications are pervasive of everyday life, as in working, medical and entertainment scenarios. Despite technological advances of VR devices, there is yet no effective solution to nausea, dizziness, and general discomfort that most of users undergo.
This is what is referred to as cyber-sickness (CS), a disabling vestibular syndrome resulting from a mismatch of integration among visual, proprioceptive, and vestibular information.

METHOD: 37 healthy subjects; 6 min VR rollercoaster ride (Epic Rollercoaster) experience displayed through a head-mounted Oculus Quest 2 wearing GSR electrodes. Biophysical modelling: using SimNIBS, target areas are bilateral parietal-insular-vestibular cortex (PIVC) and the posterior insular cortex (PIC). Baseline and 3 tACS stimulation sessions: 2 Hz, 10 Hz and Sham (10 Hz experimental conditions, 2 Hz and Sham control conditions). During the rollercoaster ride they reported CS sensations (seconds) and during recovery phase, subjects answered the Simulator Sickness Questionnaire (SSQ), regarding the symptoms of CS.
Whole sample: 10-Hz tACS significantly reduced CS nausea versus 2-Hz tACS (p=.025). 18 out of all 41 subjects (44%) worsened their nausea during the rollercoaster ride during 2 Hz-tACS versus Sham.

RESULTS: Suitable of improvement (29 subjects): CS nausea during 10-Hz tACS significantly decreased both versus Sham (p= .05) and versus 2-Hz tACS (p= .021); 22 out of the 33 (67%) improved the nausea during 10 Hz-tACS versus Sham.
GSR : reduction during 10 Hz-tACS versus 2 Hz-tACS condition (p= .001) and a significant increase during 2 Hz-tACS versus Sham condition (p= .005), but not significant difference between 10 Hz-tACS and Sham.

CONCLUSIONS: Results open a new way to facilitate the use of VR in different working, medical and entertainment scenarios, with potential exploitation to other
vestibular dysfunctions.