A comparative study of psychophysiological reactions during simulator and real flight

During selection tests in a flight simulator and a real aircraft, physiological workload measures were evaluated. The selection context guaranteed high motivation in the participant to exert additional effort during difficult flight tasks. The aim of the study was to obtain information about the sensitivity to mental effort of several physiological measures and to explore the applicability of these measures in real flight. The following measures were used: heart rate, heart rate variability, respiration (frequency and amplitude), blood pressure, eye blinks (frequency, duration, and amplitude), and saliva cortisol. Blood pressure was the only measure that was difficult to obtain during real flights. All physiological measures showed large differences between baseline and flight tasks. Heart rate, heart rate variability, and respiratory frequency showed similar results in the simulator and real flight. Blink frequency showed an expected decrease during simulator flight, whereas a large increase was found during real flight. This can be partly explained by eye movements, which were made more frequently during real flight. Blink duration was shorter and amplitude was larger during both flights. This indicates that a combination of blink parameters provides better information about workload than blink frequency alone. Cortisol was not affected by the simulator flight, whereas greatly increased levels were found after the real flight. This indicates that cortisol is not affected by mental effort. G-forces during the real flight most likely caused the increased cortisol levels.