Stationarity Perception and Virtual Reality Sickness
Authors
Halow, Savannah J.
Issue Date
2024
Type
Dissertation
Language
Keywords
Stationarity Perception , Vestibular , Virtual Reality , Vision
Alternative Title
Abstract
Stationarity perception involves accurately perceiving a stable visual environment, a critical skill for self-motion. This perception relies on evaluating signals from eye and head movements for congruence. Through a series of experiments, we systematically manipulated the consistency between visual and vestibular signals to determine the visual range of gains allowing for the perception of a stable environment. Participants, wearing head-mounted displays, moved their heads (or were moved passively via a rotating chair) and indicated if the visual feedback felt too slow or fast. Analyzing these responses revealed the most compatible visual gain for perceiving stability (accuracy) and how sensitive this perception was to changes in visual gain (precision). Across studies, we varied conditions involving neck motor signals during active and passive movements, the visual stimulus's spatial frequency and location on the retina, and fixation behavior (whether the fixation point was scene- or head-fixed). We also tested this stationarity perception and VR sickness during repetitions of the task over three days and across rotational axes. In our first study, we found that perception was most accurate and precise during scene-fixed fixation and during active motion. In the second study, spatial frequency and stimulus retinal location affected stationarity perception precision, but not accuracy. Additionally, VR sickness was measured using the Simulator Sickness Questionnaire (SSQ) and found associations with perceptual performance. Reduced accuracy was linked to higher nausea scores, while decreased precision aligned with higher oculomotor discomfort, disorientation, and total scores. In our final study, we found improvements to measurements of precision of stationarity perception. We also found some associations between stationarity perception and VR sickness, but only during yaw rotations. These studies have been critical for characterization of the phenomenon of stationarity perception as well as its relationship to VR sickness. These results may guide future research into self-motion and VR sickness mitigation.