Department of Psychology, Humboldt State University, Arcata, CA 95521, USA. email@example.com
PURPOSE: This study investigated the physiological correlates of motion sickness provoked by viewing an optokinetic rotating drum. METHOD: A total of 52 subjects viewed an optokinetic rotating drum for 16 min. Subjective symptoms of motion sickness (SSMS) and ratings of over-all sickness were measured during the drum rotation. Electrogastrogram (EGG), electroencephalogram (EEG), electrocardiogram, and skin conductance were measured as physiological correlates of motion sickness. RESULTS: Analysis by Pearson's correlation showed that the subjects who had higher scores of SSMS during the drum rotation generated the following: a) a higher rating of over-all sickness (r = 0.76); b) a higher ratio of spectral power of EGG at 4-9 cycles per minute (cpm) between drum rotation and baseline periods (r = 0.63); c) a higher net percent increase of spectral power in the EEG frequency band 0.5-4 Hz between drum rotation and baseline periods on C3 (r = 0.29) and C4 (r = 0.31); d) a higher ratio of spectral power of EEG frequency band 0.5-4 Hz between drum rotation and baseline periods on C3 (r = 0.31); and e) a higher level of net increase in skin conductance from baseline to drum rotation (r = 0.30). CONCLUSION: The increase of EGG at 4-9 cpm activity, gastric tachyarrhythmia, is the most sensitive physiological index of the severity of symptoms of motion sickness.