Investigating the contributions of the right temporoparietal junction in sensory reweighting and cybersickness

Abstract

Accurate perception of body position relative to gravity relies on the integration of visual, vestibular, and proprioceptive inputs. In virtual reality (VR), conflict between these sensory inputs can cause cybersickness – a visually-induced form of motion sickness. Sensory reweighting – a neural mechanism which shifts perceptual reliance on specific sensory cues based on prior experience and cue availability – has been proposed as a mechanism to mitigate cybersickness. However, the higher-order neural mechanisms underlying sensory reweighting in VR remain unclear. This exploratory study examined the role of the right temporoparietal junction (rTPJ) — a region involved in sensory integration, salience, and conflict detection — in sensory reweighting and cybersickness mitigation. Before and after a high-intensity VR experience, participants completed the Oriented CHAracter Recognition Test (OCHART) to assess sensory cue weighting and ranked their cybersickness throughout the VR experience using the Fast Motion Sickness scale (FMS). During VR, transcranial direct current stimulation (tDCS) was applied to the rTPJ to modulate neural activity. We hypothesized that anodal stimulation would enhance rTPJ activity, promote more efficient sensory reweighting, and reduce cybersickness, whereas cathodal stimulation would have the opposite effects. Results showed no significant differences in sensory cue weighting or FMS scores across stimulation conditions. Additionally, there was no association observed between changes in sensory weights and cybersickness. These findings suggest that rTPJ stimulation before VR is insufficient to modulate sensory reweighting or alleviate cybersickness. Future research should investigate the effect of rTPJ tDCS before and after VR and consider vestibular-specific reweighting measures, such as the subjective visual vertical or postural measures, such as sway path length. More specific measures of sickness, such as the Simulator Sickness Questionnaire (SSQ) should also be considered to better quantify the changes in cybersickness subtypes.