PERCEPTUAL FADING OF VISUAL TEXTURE BORDERS

A light gray square was displayed on a background of dynamic two-dimen sional noise. After 10 sec of steady eccentric fixation, the square di sappeared completely and the region corresponding to it was ''filled i n'' by dynamic noise from the surround. Furthermore, when the whole di splay was switched off, a persisting patch of dynamic two-dimensional noise was seen in the region corresponding to the gray square. This pe rsistent patch could be seen for almost 10 sec on some trials, suggest ing that a dynamic neural representation of the surrounding ''twinkle' ' is being created in this region. The fading of the square was especi ally pronounced in peripheral vision. Also, displacing the square by a small distance was usually sufficient to restore its visibility but t his distance increased with eccentricity. This may be a consequence of the progressive increase of receptive field size with eccentricity th at has been noted in both area 17 and MT. The perceptual fading and '' filling in'' that we report concurs with the recent physiological obse rvations of Pettet and Gilbert [(1991) Society for Neuroscience Abstra cts, 17, 10901 and Gilbert and Wiesel [(1992) Nature, 356, 150-1521 in area 17 of cats and primates.