Abstract
The illusory sense of self-motion that can occur when the visual field moves coherently ('vection') has revealed key insights into how sensory information is integrated. In the natural environment, moving through space generates an immediate perception that we are in motion. In the case of illusory self-motion, there are delays in the region of 5-10 seconds between seeing the visual field move and the feeling of vection. It has been suggested that this delay occurs due to the lack of concurrent vestibular signals accompanying visual motion onset. Any reduction in this delay could improve virtual reality (VR) immersiveness and potentially reduce 'simulator-sickness'. Researchers have attempted to reduce visual-vestibular mismatch using a technique that applies electrical stimulation to the vestibular organs, known as galvanic vestibular stimulation (GVS). Applying GVS can modulate vection and can visibly reduce nausea in VR. However, GVS is an invasive stimulation method that requires significant expertise to use appropriately. Here, we tested two techniques with the potential to provide similar benefits to GVS that are minimally invasive: chair vibration, and bone conducted vibration (BCV) applied to the mastoid processes. We examined vection magnitude and latency for wide field visual rotations, applying transient stimulation either concurrently or asynchronously with the start of visual motion. We found that both GVS and BCV, but not chair vibration, reduced vection latency compared to control when applied at the same time as visual motion onset. This difference vanished when stimulation and visual motion onset were asynchronous. Inspection of vection magnitude responses indicated no consistent differences across conditions. While we had used only roll for visual motion in the first experiment, a second experiment confirmed the same effects for yaw and pitch rotation. We therefore propose BCV as a promising candidate for reducing simulator sickness and increasing immersiveness in virtual environments.
Meeting abstract presented at VSS 2016