P300 as a measure of workload during a simulated aircraft landing task.

The P300 component of the event-related brain potential was assessed as a measure of mental workload using 12 subjects who flew simulated visual flight rules final approaches and landings under workloads varied by manipulating turbulence and hypoxia. P300 was elicited with auditory and visual "oddball" subsidiary tasks requiring the detection of infrequent tones or flashes of an artificial horizon. The results showed that root mean square error flying performance was systematically degraded by both workload manipulations. P300 amplitude exhibited a complex pattern that was not strongly related to performance. By contrast P300 latency covaried closely with performance, increasing as a function of workload in both modalities. These results suggest that P300 latency indexes the slowing of perceptual/cognitive processing caused by workload and that this measure is sensitive to an important aspect of flying.