Effects of sleep deprivation on eye movement behavior in flight simulation

To examine the effects of 32 h of SD(sleep deprivation) on eye movement behavior in flight task. Four subject who were skilled in flight simulator participated the experiment. They were asked to perform a level flight task in a flight simulator. Eye movement data and flight performance data were measured at the following hours: 11:00, 15:00, 04:00, 11:00, 15:00. The subjects workload and fatigue were assessed with method of NASA-TLX (national aeronautics and space administration-task load index) and RPE(rating of perceived exertion). Eye movement indices of average pupil area, average saccade amplitude and average saccade velocity decreased during the 32 h SD and they all showed significantly change in the final SD while the index of average fixation time increased in the final SD. Flight performance deteriorated during the 32 h SD, but not significantly. The feeling of fatigue and workload reported by subjects both increased during the 32 h SD. Daily rhythm effects on the measured indices were also found, there were a obviously change at the hour of 04:00. 32 h of SD has obvious effects on eye movement behaviors which have close relations to fatigue because of SD. The eye movement measurement can served as a tool to continually monitor fatigue online.