title: Validating an efficient method to quantify motion sickness.
abstract: OBJECTIVE
  Motion sickness (MS) can be a debilitating side effect associated with motion in real or virtual environments. We analyzed the effect of expectancy on MS and propose and validate a fast and simple MS measure.
  
  
  BACKGROUND
  Several questionnaires measure MS before or after stimulus presentation, but no satisfactory tool has been established to quickly capture MS data during exposure. To fill this gap, we introduce the Fast MS Scale (FMS), a verbal rating scale ranging from zero (no sickness at all) to 20 (frank sickness). Also, little is known about the role of expectancy effects in MS studies. We conducted an experiment that addressed this issue.
  
  
  METHODS
  For this study, 126 volunteers participated in two experiments. During stimulus presentation, participants had to verbally rate the severity of MS every minute before filling in the Simulator Sickness Questionnaire (SSQ). To measure expectancy effects, participants were separated into three groups with either positive, negative, or neutral expectations.
  
  
  RESULTS
  We compared the verbal ratings with the SSQ scores. Pearson correlations were high for both the SSQ total score (r = .785) and the nausea subscore (r = .828). No expectancy effects were found.
  
  
  CONCLUSIONS
  The FMS is a fast and valid method to obtain MS data. It offers the possibility to record MS during stimulus presentation and to capture its time course. We found expectancy not to play a crucial role in MS. However, the FMS has some limitations.
  
  
  CONCLUSIONS
  The FMS offers improved MS measurement. It is fast and efficient and can be performed online in environments such as virtual reality.
authors: Department of Experimental Psychology, Johannes Gutenberg-Universität Mainz, Germany. behrang.keshavarz@uni-mainz.de
authors: Behrang
authors: B
authors: Keshavarz
authors: Heiko
authors: H
authors: Hecht
mesh_terms: D003198:Computer Simulation; D003220:Conflict, Psychological; D059026:Diagnostic Self Evaluation; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D009041:Motion Sickness / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D009325:Nausea / Q000209:etiology*; D011187:Posture / Q000502:physiology; D012720:Severity of Illness Index