The influence of spatio-temporal sensitivity on perceptual filling-in induction process

Perceptual filling-in is a famous visual illusion. We have proposed a hypothesis of filling-in process to address the phenomenon when a small homogeneous area (filling-in target), which is surrounded by spatio-temporal frequency limited random-dot dynamic textures, is presented to an observer´s peripheral vision. In the hypothesis, filling-in target visibility is represented by perceptual power. As the target surrounding texture starts to move, beyond a brief transient, perceptual power decreases from initial value according to the motion of the surrounding texture. As perceptual power falls to a certain level, the small area is filled with the surrounding dynamic texture and is perceived to disappear. In this study, the time course of perceptual power is estimated. First, we estimated visual sensitivity for spatio-temporal frequency in peripheral vision by an experiment. Second, the time to filling-in was measured for various spatio-temporal frequency of the surrounding texture. These results were applied to the hypothesis of filling-in process. As the results, we inferred that perceptual power decreases with spatio-temporal sensitivity of vision.