Motion-induced blindness for dynamic targets: Further explorations of the perceptual scotoma hypothesis

Motion-induced blindness (MIB) is a striking phenomenon wherein fully visible and attended objects may repeatedly fluctuate into and out of conscious awareness when superimposed onto certain global moving patterns. Perhaps the most remarkable feature of MIB is that objects can disappear even when they are moving. Here we report several novel demonstrations of MIB for dynamic objects, including the observations that (a) MIB can occur for dynamic targets defined by various types of complex visual distortions (akin to those that may occur with various types of metamorphopsias), and (b) MIB is more robust for downward-drifting compared to upward-drifting objects (perhaps because of the related motions of floaters in the eye's vitreous humor). To interpret these results, we focus on the idea that MIB may arise not from a limitation or failure of visual processing, but instead from a perceptual scotoma: MIB may reflect a functional inference in visual processing, eliminating some novel stimuli from awareness in much the same way that the visual system chronically eliminates percepts that would otherwise arise from visual impairments (such as scotomas) or features that are not in the external world in the first place (such as shadows from retinal blood vessels).