Effect of passengers’ active head tilt and opening/closure of eyes on motion sickness in lateral acceleration environment of cars

Abstract

This study examined the effect of passengers’ active head-tilt and eyes-open/eyes-closed conditions on the severity of motion sickness in the lateral acceleration environment of cars. In the centrifugal head-tilt condition, participants intentionally tilted their heads towards the centrifugal force, whereas in the centripetal head-tilt condition, the participants tilted their heads against the centrifugal acceleration. The eyes-open and eyes-closed cases were investigated for each head-tilt condition. In the experimental runs, the sickness rating in the centripetal head-tilt condition was significantly lower than that in the centrifugal head-tilt condition. Moreover, the sickness rating in the eyes-open condition was significantly lower than that in the eyes-closed condition. The results suggest that an active head-tilt motion against the centrifugal acceleration reduces the severity of motion sickness both in the eyes-open and eyes-closed conditions. They also demonstrate that the eyes-open condition significantly reduces the motion sickness even when the head-tilt strategy is used.

Practitioner Summary: Little is known about the effect of head-tilt strategies on motion sickness. This study investigated the effects of head-tilt direction and eyes-open/eyes-closed conditions on motion sickness during slalom automobile driving. Passengers’ active head tilt towards the centripetal direction and the eyes-open condition greatly reduce the severity of motion sickness.

Keywords:

• Motion sickness
• carsickness
• head tilt
• open/closed eyes
• lateral acceleration

Acknowledgements

The authors are grateful to Yoshimitsu Kawai, Makoto Sumikawa and Ena Dejima of Ritsumeikan University for their assistance in data collection. The authors would also like to thank Tsukinowa Driving School for allowing us to use their driving course.

Disclosure statement

No potential conflict of interest was reported by the authors.