Driver monitoring systems with focus on drowsiness and inattention aim to reduce car crashes. To achieve this goal, previous research has shown that driver eye blink features (blink frequency, duration etc.) are correlated to some extent with drowsiness. Hence, within a level of uncertainty they can contribute to driver drowsiness warning systems. In order to improve such systems, we investigated blink characteristics with respect to their different origins. We observed that in a real road experiment using electrooculography, blinks occur both spontaneously or due to gaze shift. Gaze shifts between fixed positions, which occurred due to secondary visuomotor task, induced and modulated the occurrence of blinks. Moreover, the direction of the gaze shift affected the occurrence of such blinks. Based on the eye movements during another experiment in a driving simulator without a secondary task, we found that the amount of gaze shift (between various positions) is positively correlated with the probability of the blink occurrence. Therefore, the paper recommends handling gaze shift-induced blinks (e.g. during visual distraction) differently from those occurring spontaneously in drowsiness warning systems. (Author/publisher)
Abstract