An Evaluation of Pilot Electroencephalographic Activity during a Helicopter Tracking Task

Two experimental test pilots performed an in-flight target tracking task on NRC's highly modified fly-by-wire Bell 205 helicopter. Target tracking errors, Cooper-Harper handling quality ratings, and pilot control activity confirmed that task difficulty was proportional to target velocity. Electroencephalography (EEG) data was acquired to investigate task-dependent changes in theta (4-8 Hz), alpha (8-13 Hz), and beta (13-22 Hz) oscillations. In addition, EEG-derived workload and task engagement indices were computed from these EEG bands and compared across task difficulty conditions. The EEG workload index was proportional to task difficulty for both pilots, whereas the EEG engagement indices revealed that the pilots' vigilance may have been higher during the low-velocity and high-velocity trials than the medium-velocity trials. These findings suggest that EEG-derived metrics provide complementary information about in-flight changes in pilot cognitive state that are not easily detected using subjective ratings, performance measures, or control activity metrics.