1 Hit in 0.049 sec

Perceptual grouping-dependent lightness processing in human early visual cortex

H. Boyaci, F. Fang, S. O. Murray, D. Kersten
2010 Journal of Vision  
Lightness, the perceived relative achromatic reflectance of a surface, depends strongly on the context within which the surface is viewed. Modest changes in the two-dimensional configuration or three-dimensional scene geometry may lead to profound variations in lightness even though the surface luminance remains constant. Despite recent progress, we are far from a complete understanding of how various aspects of spatial context affect lightness processing in the cortex. Here we use a novel
more » ... we use a novel stimulus to show that perceptual grouping through occluders can affect lightness. We first report behavioral results showing how lightness across occlusion depends on spatially distant image features, including luminance and contrast. Next using functional magnetic resonance imaging (fMRI) we show that human early visual cortex responds strongly to occlusion-dependent lightness variations with little or no attention. These results suggest that elements of threedimensional scene interpretation play a role in early cortical processing of lightness.
doi:10.1167/10.9.4 pmid:20884602 fatcat:gva6ekuukbdsrav52r7yiiugyi