Relationship between Eye Movement and Facilitation of Perceptual Filling-in

For a few seconds, under certain circumstances, a subject perceives a filling-in target as filled by its surrounding texture when a small area (filling-in target) with different texture from its surroundings is presented to the person's peripheral vision. This illusion is perceptual filling-in. The characteristics of filling-in have been clarified, e.g., the filling-in time depends on textural properties, such as the filling-in target size, and the eccentricity with which the filling-in target is projected. Filling-in characteristics must be elucidated to understand the mode of information processing in human vision because filling-in has been considered to contribute greatly to effective capturing of external visual information. Facilitation of filling-in is generally evaluated using the time to filling-in (filling-in time). Furthermore, that we can see nothing by restraining eye movement artificially is well known. Eye movement is necessary to acquire visual information. In our preliminary experiments, time to filling-in is disturbed by subjects' eye movements (EMBEC 2005). Therefore, we can consider that facilitation of filling-in is influenced by eye movement. Although it has been recently reported that eye movement influences the filling-in time while measuring filling-in time, the relation between eye movement and the time to filling-in has rarely been reported. For this study, we measured the filling-in time for four surrounding textures, with simultaneous recording of eye movement. Results show that the time to filling-in correlates the standard deviation of the eye position. Furthermore, a strong correlation was found between filling-in time and the power of small involuntary eye movements for two of three subjects.