FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-14/12

Title and Subtitle: EEG Correlates of Fluctuation in Cognitive Performance in an Air Traffic Control Task

Report Date: November 2014

Authors: Krishnan VK, Dasari D, Ding L

Abstract: Performance changes that are attributed to mental fatigue in real-world tasks need reliable monitoring to prevent occupational hazards. The present study investigated the association of cognitive functional decrements over time with neurophysiological patterns indicative of mental fatigue when performing a low-fidelity simulated air traffic control task for up to two hours. Electroencephalography (EEG) and performance data, i.e., response time and routing time for navigating aircraft, were simultaneously collected during the task.

Cognitive capacities of participants were assessed using the Minicog rapid assessment battery before and after the task. Acquired EEG signals were epoched into multiple segments of 10 minutes over time, and these segmented EEG data were statistically compared with each other using non-parametric statistical analysis to identify neurophysiological patterns due to the time-on-task effect. Significant changes in EEG power spectra were localized to the midline regions from the frontal and parietal areas of the human brain. Significant changes in performance data were also observed in response time and routing time.

These observed changes in EEG power spectra and performance data suggest a consistent correlation among them in the time domain in individual sessions and participants, as well as at the group level. Both deteriorating cognitive performance and EEG, indicative of the development of mental fatigue, occurred at approximately 70 minutes into the task. Such a correlation suggests EEG signals are promising for use in developing a reliable online mental fatigue monitoring system.

Key Words: Mental Fatigue, EEG, Cognitive Performance, Power Spectral Analysis, Non-Parametric Analysis

No. of Pages: 26