Eye movement inhibits the facilitation of perceptual filling-in

When a small figure is presented in human peripheral vision, it becomes invisible and invaded by surrounding texture, within a few seconds. This visual illusion is called perceptual filling-in. Time to filling-in (filling-in time) is varied by the properties of small figure, surround texture and some experimental conditions. In our preliminary study (Yokota, IEEE/IC-EMBS 2005), we found that incomplete fixation distributes filling-in time. Furthermore, that we can see nothing by restraining eye movement artificially is well known. Therefore, we can consider that filling-in time is influenced by eye movement. Although it has been recently reported that eye movement influences the filling-in occurrence (Martinez-Conde, Neuron 2006), the relation between eye movement and the filling-in time has rarely been reported. For this study, we measured the filling-in time for three subjects, for four surrounding textures, with simultaneous recording of eye movement. The results show that the filling-in time correlates to the standard deviation of the power of the eye distance from the fixation point. Furthermore, we found relatively strong correlation between the filling-in time and the power of high frequency component 50-200 (Hz) in the eye movement, though the correlation of the power of low frequency component 10-50 (Hz) is not so high. Thus we suppose that filling-in is inhibited by small involuntary eye movement.