EEG and ECG changes during selected flight sequences

Mental workload has become a critical factor in the design and use of modern aircraft. Because of the complexity of the human-machine system, it is necessary to determine workload, fatigue, and level of performance using noninvasive electrophysiological measures.

Our objective was to identify the electrophysiological indicators of mental workload during piloting tasks.

Electroencephalographic (EEG) and electrocardiographic (ECG) activity was recorded during actual flight, with a profile planned to produce different levels of mental workload.

In-flight EEG and ECG recordings enabled us to document mental workload levels. During active segments, delta and theta band activity increased (p < 0.05 or greater); results showed an increase of 22.5% for theta band activity during active flight segments compared with in-flight rest periods. Inversely, alpha band activity diminished: the decrease between ground baseline and all flight sequences was 30% (p < 0.05 or greater). These variations were reversed during the in-flight rest sequences. Instrumental flight caused an increase in the theta and alpha frequency band activity in the parietal-occipital area (p < 0.05 or greater); the alpha/beta ratio also increased. Heart rate increased during the active segments and fell during the in-flight rest periods. The mean difference between active segments and in-flight rest periods was of 8.89 bpm (i.e., an increase of 11.5%; p < 0.01). Heart rate was correlated to the EEG activity of the delta and beta bands in the central area (C3, Cz, C4, p < 0.05).

The electrophysiological measures recorded provide useful indicators of the mental workload required by different flight sequences.