Study on the correlation between physiological and subjective workload measurements

The measurement of mental workload is an important aspect of human factor research. The purpose of this study was to evaluate the mental workload of subject in simulate flight using both physiological and subjective workload measurements, compare relative sensitivity during the three phases of flight: takeoff, climb & cruise & descent, approach & landing. Four graduate students volunteered to participate in the trials, which took place in a flight simulator which used Boeing777 as the prototype. The physiology monitoring system was used to record the ECG of the subject, and after the flight task, the subject was asked to perform three NASA-TLX tests on the three phases. The physiological measures (mean HR, HF power) and NASA-TLX measures were found to be sensitive to the mental workload for the different phases of simulate flight. And mean HR seemed to be a better measure of mental workload than HRV HF power. Mean HR was greatest during the phase of approach & landing, which is the critical phase during the simulate flight task. The correlation analysis showed that there was a good linear relationship between NASA-TLX scores and mean HR of each flight phase. The results of this study indicated that the physiological variable (HR, HRV) and NASA-TLX can be used to characterize workload for the different phases of flight.