Cybersickness Onset With Reflexive Head Movements During Land and Shipboard Head-Mounted Display Flight Simulation

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA528015&Location=U2&doc=GetTRDoc.pdf

Cybersickness Onset With Reflexive Head Movements During Land
and Shipboard Head-Mounted Display Flight Simulation

Frederick Patterson; Eric Muth

NAMRL Report Number 10-43

Military communities have long recognized the value of using flight simulations for enhancement of mission performance. Although flight simulators depicting virtual images of mission profiles are known to improve situational awareness, pilots using head-mounted display virtual reality (HMD/VR) environments often report increased signs and symptoms associated with simulator sickness. With shipboard deployment of HMD/VR training devices, disparity between VR visual flight conditions and ship induced vestibular accelerations may generate changes in reflexive head movement, and thereby influence risk of simulator sickness. In this study, nine subjects flew a head-mounted display HMD/VR flight simulation during land based and shipboard conditions. Reflexive head positioning and simulator sickness questionnaires (SSQ)
were used to evaluate differences between the two conditions. Results indicate that both land and shipboard HMD/VR flight simulations produced optokinetic cervical reflex (OKCR) responses (p< 0.001) in both coronal and sagittal planes; however between land and sea conditions, these OKCR variations were not statistically significant. In contrast, land and sea OKCR head yaw did show a significant increase during shipboard trials. With respect to simulator sickness, SSQ scores were significantly elevated after exposure to both land and sea HMD/VR conditions; however SSQ differences (between land and sea conditions) did not reach a significant level. In summary, non-motion (land) HMD/VR flight simulations provoke significant coronal and sagittal OKCR responses that do not change when low sea state shipboard motion is introduced; however, low sea-state shipboard motion did appear to trigger significant increases
in OKCR head yaw. With regard to predicting the early onset of cybersickness, correlations between coronal OKCR and SSQ data suggest the possibility of an inverse trend between reported simulator sickness and head movement.