Quantitative studies in retinex theory a comparison between theoretical predictions and observer responses to the “color mondrian” experiments

Color in the cortex: single- and double-opponent cells.

Although neurons in primary visual cortex are sensitive to the spatial distribution and intensity of light, their responses have not been thought to correlate with the perception of brightness. Indeed, primary visual cortex is often described as an initial processing stage that sends information to higher cortical areas where perception of brightness, color, and form occurs. However, a significant percentage of neurons in primary visual cortex were shown to respond in a manner correlated with perceived brightness, rather than responding strictly to the light level in the receptive fields of the cells. This finding suggests that even at the first stage of visual cortical processing, spatial integration of information yields perceptual qualities that are only indirectly related to the pattern of illumination of the retina.

https://science.sciencemag.org/content/sci/273/5278/1104.full.pdf

The Representation of Brightness in Primary Visual Cortex

Spatial mapping of monkey V1 cells with pure color and luminance stimuli.

https://cseweb.ucsd.edu/~gary/cs200/w04/papers/blakeslee-99.pdf

A multiscale spatial filtering account of the White effect, simultaneous brightness contrast and grating induction

The responses of single units in the monkey lateral geniculate nucleus to different portions of figures which differed from their backgrounds in color and brightness were examined. Border enhancement was found in the response to luminance figures but not in the response to color figures. In addition, cells showed border enhancement only in the case of a figure which produced an increment (as opposed to a decrement) in their firing rates. In situations in which very striking brightness contrast is seen perceptually, the cells do not show the corresponding changes in firing rate across the whole pattern. The lateral inhibitory mechanisms found in the retina and geniculate can thus account for luminance border enhancement, but not entirely for simultaneous brightness or color contrast, for which other cortical processes of some sort must be responsible.

Paul L. Pease

Papers

Contours and Contrast: Responses of Monkey Lateral Geniculate Nucleus Cells to Luminance and Color Figures

Eye movements in systemically paralyzed macaque monkeys