Quantitative analysis of truck driver EEG during highway operations

Scalp electroencephalograms (EEGs) were collected from each of 80 male, commercial truck drivers during one week of open-highway driving (4 or 5 round trips per week; about 50 hours of driving per driver) as part of the Driver Fatigue and Alertness Study funded by the Federal Highway Administration. Features of the central EEG were selected for extraction based upon known characteristics of the EEG spectrum during sleep onset. Data reduction focused on the contributions to total EEG power from the theta, alpha, sigma and beta spectral bands. The means and regression slopes for the EEG measures were calculated on the time axis and used to estimate EEG values at the beginning and end of each leg of each trip for each driver. The weekly patterns of EEG power appeared to be interpretable by reference to expected circasemidian rhythms. The EEG sigma/beta ratio may provide an index of midafternoon sleepiness while driving.