Shift in lateralization during illusory self‐motion: EEG responses to visual flicker at 10 Hz and frequency‐specific modulation by tACS

Abstract

Self-motion perception is a key aspect of higher vestibular processing, suggested to rely upon hemispheric lateralization and alpha-band oscillations. The first aim of this study was to test for any lateralization in the EEG alpha band during the illusory sense of self-movement (vection) induced by large optic flow stimuli. Visual stimuli flickered at alpha frequency (approx. 10 Hz) in order to produce steady state visually evoked potentials (SSVEPs), a robust EEG measure which allows probing the frequency-specific response of the cortex. The first main result was that differential lateralization of the alpha SSVEP response was found during vection compared with a matched random motion control condition, supporting the idea of lateralization of visual-vestibular function. Additionally, this effect was frequency-specific, not evident with lower frequency SSVEPs. The second aim of this study was to test for a causal role of the right hemisphere in producing this lateralization effect and to explore the possibility of selectively modulating the SSVEP response. Transcranial alternating current stimulation (tACS) was applied over the right hemisphere simultaneously with SSVEP recording, using a novel artefact removal strategy for combined tACS-EEG. The second main result was that tACS enhanced SSVEP amplitudes, and the effect of tACS was not confined to the right hemisphere. Subsequent control

Effects of transcranial alternating current stimulation on spiking activity in computational models of single neocortical neurons

“…Further work could also explore different frequencies, stimulation waveforms or orientations. Animal studies have shown that the firing rate of neurons increases with a steeper temporal change ( Fröhlich and McCormick, 2010 ) and several human studies have investigated the effects of stimulation waveforms on brain oscillations ( Dowsett et al, 2020 ; Dowsett and Herrmann, 2016 ) showing that different waveforms differentially modulate brain oscillations.…”

Different EEG brain activity in right and left handers during visually induced self-motion perception

“…EEG recordings synchronized with participants' perceptual states were obtained in order to accurately distinguish between periods of object-and self-motion. Given that alpha oscillations have been linked to vection [29][30][31] and associated with bistable perception [32][33][34], the EEG analyses focused primarily on alpha band activity and on potential differences in this band between left and right handers.…”

A Review of Electrostimulation-based Cybersickness Mitigations

“…Inspired by tDCS, future cortical studies can be planned with alternating current (AC) stimulation [41] to see if AC stimulation could achieve better inhibitory effect. This is because the brain neurons have oscillatory nature (e.g., the commonly-known brain wave electroencephalogram), therefore we surmise that the AC stimulation that has an antiphase with neurons oscillation may indeed follow a better pattern of results than tDCS.…”