Characteristic EEG differences between voluntary recumbent sleep onset in bed and involuntary sleep onset in a driving simulator

Objective To investigate the differences in electroencephalographic (EEG) characteristics for voluntary sleep onset in bed sleeping and involuntary sleep onset in driving. Methods EEG measurement and analysis on 20 human subjects were conducted during recumbent bed sleeping as well as involuntary sleeping during a simulated driving platform. Each experiment was conducted on separate days. Results Vertex and spindle waves showed differing morphology under each condition. Vertex sharpness during recumbent sleep onset was significantly sharper than involuntary sleep onset during simulated driving. Sharpness of vertices from night-driving was significantly sharper than with day-driving. Triple conjoined vertex waves only occurred with voluntary recumbent sleep onset. A conjoined vertex spindle waveform was statistically associated with sleep onset whilst driving. Conclusions This study has identified distinctive differences in EEG graphoelements during the sleep onset phase of recumbent and simulated driving conditions suggesting that EEG graphoelements are affected by cortical processes and vary according to the prevalent sleep condition. Significance This study could provide a further basis for developing safety alerting devices for the detection of sleep onset in the hope of improving driving safety.