Pi. Laurinen et al., EARLY CORTICAL INFLUENCES IN OBJECT SEGREGATION AND THE PERCEPTION OFSURFACE LIGHTNESS, Psychological science, 8(5), 1997, pp. 386-390
The apparent brightness of a surface is profoundly influenced by the b
rightness of an adjacent surface, but these contrast effects are reduc
ed when the surfaces are perceived as separate three-dimensional entit
ies. Previous work has suggested that high-level perceptual and cognit
ive processes involved in scene segmentation may be responsible for mo
difying a surface's appearance. We demonstrate large reductions in con
trast effects when the cues available for segmentation are restricted
to those that isolate separate groups of early cortical neurons in the
visual system. Out data contradict standard contrast-signaling models
of brightness perception and imply that mechanisms of figure-ground s
egmentation are already available at low levels of visual processing.