中華心理學刊 民100，53卷，4期，399-411
Chinese Journal of Psychology 2011, Vol.53, No.4, 399-411

Lothar Spillmann（Department of Neurology, University Hospital Freiburg）

Abstract

With a stabilized retinal image the percept rapidly disappears from view due to local adaptation, resulting in fading and filling-in (Gerrits, Stassen, & van Erning, 1984; Troxler, 1804). This observation demonstrates that in the absence of involuntary eye movements (drifts, saccades), we are functionally blind. The last twenty years have seen a surge of experiments designed to specify the conditions under which fading and filling-in occur. We know that with prolonged fixation targets assimilate into the background and become invisible, whether static, moving, or flickering (Spillmann, Neumeyer, & Hunzelmann, 1984). Such backgrounds need not be uniform and steady; a textured background or dynamic visual noise are as effective and can be even more so. Two hypotheses may account for fading and filling-in: (i) Generalization of brightness or texture across the enclosed surface region by edge-selective cells using form and color information; and (ii) active spreading of information from the edge by way of lateral propagation. There is evidence for both in cortical areas V1-V3. Two stages for fading and fillingin are distinguished: slow deterioration of the border and fast invasion of the enclosed surface from the surround. Current debate focuses on a comparison between filling-in of artificial scotomata (patches differing from the surround in brightness, color or texture) and real scotomata (blind spot, retinal lesions). We have found that filling-in requires little surround information. For example, a thin red ring hugging the boundary of the physiological blind spot will uniformly and completely fill-in the enclosed blind spot area. Similarly, a thin chromatic double contour will induce watercolor spreading over a wide area. These observations suggest cortical mechanisms involving long-range horizontal interactions to account for brightness and color perception on uniform areas.

Keywords: brightness, color, fading, filling-in, texture