Evaluation of the Arousal Level in Motorcar Driving Using Skin Potential Level II: Its Effectiveness Compared with Other Electrophysiological Quantities

The present paper deals with the relationship between changes in the level of arousal and those in the level of several electrophysiological quantities in motorcar driving. In experiments, five subjects experience motorcar driving on a test circuit with other cars excluded. Each experimental driving session lasts for approximately 30 minutes. Electroencephalogram (EEG), electrocardiogram (ECG), electrooculogram (EOG), and skin potential level (SPL) are recorded; and their correlation to the level of arousal is studied. Results of the experiments show that (1) close correlation is observed between SPL and the level of arousal, (2) EEG alpha power is almost at a constant level during motorcar driving, (3) blinking frequency is weakly correlated to the level of arousal, and (4) no correlation is found between heart rate and arousal change. From these results, we conclude that SPL is the most effective index of the arousal level in motorcar driving. Furthermore, the results suggest a possibility of doze detection in motorcar driving by using SPL as an index of the arousal level.