A hypothesis of perceptual filling-in process for spatio-temporal frequency of dynamic textures

Perceptual filling-in is a famous visual illusion. We have proposed a hypothesis of the 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. This hypothesis introduces perceptual power, which is distinguishability of the small area from the surrounding dynamic texture. Beyond a brief transient, perceptual power decreases from initial values according to texture movement from the beginning of 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. According to this hypothesis, we reported estimation of the time course of perceptual power at EBMS-BMES2002. However, that study ignored transient characteristics by which the surrounding texture starts to move. This study estimates the time course of perceptual power while considering the initial transient. 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 frequencies of the surrounding texture. These results were applied to the filling-in process hypothesis. As a result, we inferred that perceptual power decreases with spatio-temporal sensitivity of vision.