title: Motion sickness susceptibility associated with visually induced postural instability and cardiac autonomic responses in healthy subjects.
abstract: CONCLUSIONS
  This study supports the hypothesis that postural sway and autonomic responses to moving visual stimuli may be associated with motion sickness susceptibility. Characteristics of the cardiac sympathovagal balance during exposure to provocative stimulation may be a marker of individual susceptibility to motion sickness.
  
  
  OBJECTIVE
  To assess the relationship between postural and autonomic responses to a simulated visual motion environment and reported susceptibility to motion sickness.
  
  
  METHODS
  Fifteen healthy subjects were exposed to sinusoidally oscillating visual motion in roll at frequencies of 0.1-0.4 Hz. Recordings were made of postural sway and respiratory frequency and electrocardiograms were obtained from which heart rate variability (HRV) was computed in order to probe cardiac sympathetic and parasympathetic activity.
  
  
  RESULTS
  In subjects with a low susceptibility to motion sickness as rated using a standardized questionnaire, there was no significant effect of visual stimulus on postural sway or HRV at any frequency of motion. Subjects with a high susceptibility to motion sickness showed significant postural instability induced by visual stimuli (p < 0.01). Visual stimuli presented at a frequency of 0.1 Hz significantly increased the low-frequency power (LF) of HRV, decreased the high-frequency power (HF) of HRV and increased the LF:HF ratio in these subjects (p < 0.05).
authors.affiliation: Department of Otolaryngology, Gifu University School of Medicine, Yanagido, Gifu, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Yokota
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Aoki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Mizuta
authors.forename: Yatsuji
authors.initials: Y
authors.lastname: Ito
authors.forename: Naoki
authors.initials: N
authors.lastname: Isu
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D003196:Computer Graphics; D004198:Disease Susceptibility / Q000503:physiopathology; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009041:Motion Sickness / Q000209:etiology* / Q000503:physiopathology*; D010775:Photic Stimulation; D011187:Posture / Q000502:physiology*; D011795:Surveys and Questionnaires