Perceptual Wlling-in from the edge of the blind spot

Looking at the world with one eye, we do not notice a scotoma in the receptor-free area of the visual Weld where the optic nerve leaves the eye. Rather we perceive the brightness, color, and texture of the adjacent area as if they were actually there. The mechanisms underlying this kind of perceptual Wlling-in remain controversial. To better understand these processes, we determined the minimum region around the blind spot that needs to be stimulated for Wlling-in by carefully mapping the blind spot and presenting individually Wtted stimulus frames of diVerent width around it. Uniform Wlling-in was observed with frame widths as narrow as 0.05° visual angle for color and 0.2° for texture. Filling-in was incomplete, when the frame was no longer contiguous with the blind spot border due to an eye movement. These results are consistent with the idea that perceptual Wlling-in of the blind spot depends on local processes generated at the physiological edge of the cortical representation. © 2006 Elsevier Ltd. All rights reserved.