Activity-Induced “Colour Blob” Formation

Principal Component Analysis of patterns taken from a natural colour image shows that only one of the main components is significantly colour selective, and it is unoriented. This result suggests an activity-based explanation of the formation of “colour blobs” in primary visual cortex. We describe a network simulation of processing in the retina, lateral geniculate nucleus and adaptive visual cortex which self-organizes in response to natural colour images and produces “featuremaps” in which islands of a few unoriented colour-sensitive cells are surrounded by a sea of oriented non-colour-selective cells.