Tolerable Displacement for Perceiving a Natural Scene as Stable across Saccadic Eye Movements

Abstract

We conducted an experiment in which subjects observed a picture of a natural scene while the picture was displaced according to a subject’s saccades. The threshold displacement ratio (the length of picture displacement/the length of saccade) that allowed subjects to perceive the stable picture was measured. In experiment 1 the threshold ratio was measured for each of five pictures when the picture was displaced in the same direction as each saccade. In experiment 2 the direction of the picture displacement was set in the same, opposite or orthogonal to the movement of the eye to examine effects of the relative displacement direction. The results showed that the subjects perceived a picture as stable despite fairly large displacement during saccades; the threshold ratio was influenced by the pictures and ranged from 18% to 26%. It was also found that the displacement in the same direction as the eye was more detectable than that in the opposite direction.