Brightness processing in the visual cortex

Single cell recordings have shown that some cells in the primary visual cortex (VI) signal surface brightness. However, fMRI experiments have found brightness related activation only in the higher cortical areas. In a psychophysical setup, we were able to dissociate the reduction of brightness caused by Gabor flankers, similar to the receptive fields in V 1, from the edge induced brightness change. The former resemble the single cell recording results and the latter the fMRI results. (c) 2007 Elsevier Ireland Ltd. All rights reserved.