Effects of sleep deprivation on pilot's cognitive behavior in flight simulation

This study examined the effects of 32 h of continuous SD(Sleep Deprivation) on cognitive behavior in simulated flight. Four subjects who were skilled in flight simulator took part in the experiment. Eye movement and flight parameters were measured in the following 5 time periods: 1100 on DAY 1, 1500, 0400 on DAY 2, 1100, and 1500. Subject's cognitive 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 changes in the final SD while the index of average fixation time increased in the final SD. Flight performance that evaluated by four flight parameters of the deviation of height, pitch angle, yaw angle and tilt angle 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. Effects of daily rhythm were also found, there were a obviously change at the hour of 0400. 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 be served as a tool to continually monitor fatigue online.