Estimation of driver's attentive state to visual objects outside the vehicle when driver is in low arousal level by using lambda response of eye-fixation-related potentials

In order to design driving support systems that adapt to the driver's states, this paper investigates the relationship between driver's arousal level and eye-fixation-related potential (EFRP) while driving and the possibility as a metric to estimate the driver's state. The experiment which required participants to perform monotonous driving task was conducted using motion-based driving simulator. During the experiment, electroencephalogram (EEG) and electrooculogram (EOG) were measured. Their arousal levels were evaluated based on subjective questionnaires, alpha wave power of EEG and lateral deviation of their car position. The results indicate that the peak amplitude of lambda response of EFRP decreases when driver's arousal level decreases and that the decrease of the peak amplitude of lambda response also tends to appear earlier than the increase of alpha wave power. These results imply that EFRP would be a usable metric to estimate unsafe driver's states.