How Do we Detect One's Eye Movements

When we see someone in the front of us, how we get information from his (her) eyes? To understand how we pay attention to one's eye movements and when we notice the eye movements, we investigated the detection of eye movements. In the experiment, the observers were asked to judge the direction of one eye or both eyes by the 2AFC procedure in three tasks. In one of tasks, one face was presented and both eyes moved either rightward or leftward. In the remaining two tasks, only the right half side (or only the left side) of one face was presented and the right (or the left) eye moved either rightward or leftward. The relationship between the detection thresholds based on correct judgments and the rotating degrees of eye movements was analyzed. The result showed that no difference of thresholds among tasks was found, although most observers preferentially looked at the right side of the face. However, observers detected the eye movements in the right direction more easily than the eye movements in the left direction, in the right half side of one face. These results suggest that the asymmetrical distributions of gaze fixations and the attention are not related.