Abstract
The authors have been analysing physiological responses to low-frequency oscillations, such as electroencephalogram (EEG), electrocardiogram (ECG), respiration, perspiration, electrogastrogram (EGG), facial expression. There were some difficulties in estimating physiological changes through stages of motion sickness incidence. And therefore, establishment of some physiological indices of motion sickness and/or human errors has been desired for a long time so as to obtain objective evaluation and clarify the mechanism of motion sickness and human errors. In this paper, some time-frequency-analysis methods are examined in detail which can quantify the electroencephalogram change in the time domain as well as in the frequency domain. The Gabor transform was applied to subjects' encephalogram during exposure to low-frequency oscillations in a ship-motion simulator. Measurement of some students of a university of mercantile marine was also conducted at the navigation bridge on board a training ship. The authors concluded that the proposed method could demonstrate EEG changes quantitatively and it helps well in evaluating one's motion sickness incidence and/or human error occurrence.
