Electroencephalography during on-the-road driving in older untreated insomnia patients and normal sleepers

•We assess morning fluctuations in background EEG during driving performance.•We measure driving performance using an on-the-road test after a normal night of sleep.•Alpha and beta power in the EEG of insomniacs was low as compared to controls.•EEG in insomniacs did not vary over time compared to controls.•Changes in EEG power spectra and driving performance are not related. Insomniacs report decreased performance in daily routines, which may have detrimental consequences for car driving. We compared changes over time in driving performance (measured as Standard Deviation of Lateral Position – SDLP) and background EEG between 20 untreated insomnia patients (52–70 years old) and 21 normal sleepers (54–73 years old) during a 1h on-the-road driving test after a normal night of sleep, in the morning. SDLP did not differ between groups and increased slightly over time to similar degrees in both groups. EEG alpha and beta power were lower in insomniacs as compared to normal sleepers. Alpha and beta power slightly reduced during driving in normal sleepers but remained at a constant low level in insomniacs. Changes in EEG power and SDLP were not related. It is concluded that on-the-road driving performance does not differ between older insomniacs and older normal sleepers and that changes in spectral EEG measures of cortical arousal and in driving performance are not related.