Brightness induction: unequal spatial integration with increments and decrements.
Modern theories of brightness induction include an influence from regions that do not share a border with the target. This study tested whether the spatial range of neural integration is the same with incremental versus decremental contrast edges in relatively remote parts of the background. Using an asymmetric matching task, observers set the brightness of a comparison ring, within its own uniform surround, to match the brightness of a test ring within a contiguous surround and a noncontiguous background. The measurements showed that the area of integration depended on the incremental versus decremental contrast polarity at the edge between the surround and background. This implies that brightness induction from an inhomogeneous background must consider the polarity of contrast edges within the whole scene.
Hong
Sang Wook
SW
Department of Psychology, University of Chicago, Chicago, IL, USA.
Shevell
Steven K
SK
D000221:Adaptation, Ocular; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity; D006801:Humans; D008027:Light; D008029:Lighting; D010364:Pattern Recognition, Visual; D014794:Visual Fields