Quantification and evaluation of mental workload in a flight simulator based on heart rate variability measurements with miniaturized sensors.

Abstract

Mental Work Load (MWL) is closely connected to human cognitive performance and therefore a vital aspect in evaluating human errors in aviation. Physiological measurements such as the heart rate or Heart Rate Variability (HRV) can be taken to assess MWL independently from the subjective experience of a pilot. For this study, a series of tests in a flight simulator was conducted to evaluate the correlation between different HRV metrics and MWL as well as cognitive performance. From the data, gathered in this study, 5 of the 11 investigated metrics were deter-mined to reliably distinguish time periods with elevated MWL: Heart rate, VLF, Sympathetic Nervous System - Index (SNSI), Parasympathetic Nervous System -Index (PNSI) and Baevsky Stress Index (BSI). Other metrics also exhibited correlations with task difficulty but did not reach statistical significance. None of the measured parameters, recorded during the flight tasks, displayed sig-nificant correlations with cognitive task performance. Two interactions with performance are nonetheless highlighted because they exhibited a stronger impact on performance than the subjective assessment of the test subjects: SNSI and HF. Furthermore, a significant impact of pretrial low-frequency and high-frequency HRV on cognitive performance was observed throughout all phases of the experiment. his thesis provides an overview of HRV measurements employed in current research and offers recommendations for their applicability in studies relating to mental workload.