'Motion-induced blindness' (MIB) and 'perceptual filling-in' (PFI) are two phenomena of temporary blindness in which, after prolonged viewing, perceptually salient target repeatedly disappear out of view for several seconds. Previous studies of PFI emphasize the importance of retinal adaptation to the target boundary and suggest that eye fixation is necessary for target disappearance and eye movement leads to target reappearance. We have shown that MIB and PFI share common mechanisms, and that although boundary adaptation is involved in MIB and PFI, it is neither a necessary nor a sufficient condition (Hsu, Yeh, & Kramer, 2006, Vision Research, 1973-1981). This raises the doubt on whether eye fixation/movement is necessary for target fading/reappearance. We hypothesize that target fading is caused by competition between target and background elements for visual awareness, through the attention mechanism. To test this, we monitored eye movement and manipulated attention in both MIB and PFI. Although participants reported more fading when their eyes fixated than moved, they still experienced target reappearance with strict eye fixation. In contrast, attention manipulation without eye movement affected target fading and reappearance, supporting the view that attention is critical for the temporary blindness in MIB and PFI.?
