Vertical display oscillation effects on forward vection and simulator sickness.
BACKGROUND
The current study investigated the effects that vertical display oscillation had on the development of both vection and simulator sickness.


METHODS
There were 16 subjects who were exposed to optic flow displays which simulated either: 1) constant velocity forward self-motion (pure radial flow); or 2) combined constant velocity forward and vertically oscillating self-motion (radial flow with vertical oscillation at one of three frequencies: 1.8, 3.7, or 7.4 Hz). During each 10-min display exposure, subjects rated the strength of their vection and eight symptoms listed on the Subjective Symptoms of Motion Sickness (SSMS) scale at 2-min intervals. Subjects also completed the Simulator Sickness Questionnaire (SSQ) designed by Kennedy and colleagues before and after each trial, which generated a total SSQ score and three SSQ subscores (nausea, oculomotor symptoms, and disorientation).


RESULTS
Vertically oscillating displays (mean = 5.51; SD = 2.5) were found to produce significantly stronger vection ratings than non-oscillating displays (mean = 3.56; SD = 2.1). Vertically oscillating displays (mean = 58.18; SD = 32.2) were also found to produce significantly more severe sickness (as rated by total SSQ scores) than non-oscillating displays (mean = 29.67; SD = 24.7). Both vection and sickness symptoms increased in magnitude with prolonged exposure to optic flow.


CONCLUSIONS
Our findings appear to represent a special case in visual self-motion perception where high-frequency vertical oscillation both enhances vection and increases simulator sickness when it is incorporated into an optic flow display simulating constant velocity self-motion in depth.
Palmisano
Stephen
S
School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia. Stephenp@uow.edu.au
Bonato
Frederick
F
Bubka
Andrea
A
Folder
John
J
D000328:Adult; D000704:Analysis of Variance; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009041:Motion Sickness / Q000503:physiopathology*; D010775:Photic Stimulation; D012044:Regression Analysis; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires