The effects of reverse operation in simulated carrier aircraft landing on mental workload

Objective To compare the subjects' scores of National Aeronautics and Space Administration-task load index (NASA-TLX), the indexes of ECG and performance between the reverse target tracking task and the ordinary target tracking task which simply simulate"reverse operation"of carrier aircraft landing, and to preliminarily investigate the effect of"reverse operation"on pilot's mental workload and its influence factors. Methods Twenty-five young male subjects accomplished the reverse and the ordinary target tracking tasks with two degrees of difficulty. ECG signals were recorded during the resting period before the task, periods of each task and the resting period after the task. Each subjects filled in NASA-TLX scale after the completion of each task and had a score feedback for each task. The scores of NASA-TLX and the indexes of performance were analyzed by analysis of variance (ANOVA) in 2×2 factorial design. The indexes of ECG were analyzed by Friedman M test and the multiple comparisons were carried out by LSD-t test. Results The scores of NASA-TLX and the average tracking distance of the reverse target tracking task were higher than those of the ordinary target tracking task (F=21.70, 16.14, P<0.05) and the highest appeared in the reverse dual task (F=6.67, P<0.05). HR also had the corresponding change (χ2=34.87, P<0.05), but the indexes of HRV had no significant differences. Conclusions Mental workload of the reverse operation task is higher than that of the ordinary operation task if the other conditions are the same. The reverse operation impacts mental workload severer when more information processing is required. Mental demand, physical demand and frustration level are the major influence factors of causing high mental workload in reverse operations. Key words: Workload; Cognition; Habituation, psychophysiologic; Work capacity evaluation; Electrocardiography