Representation of similarity as a goal of early visual processing

Abstract

We consider the representational capabilities of systems of receptive fields found in early mammalian vision, under the assumption that the successive stages of processing remap the retinal representation space in a manner that makes objectively similar stimuli (such as different views of the same 3D object) closer to each other, and dissimilar stimuli farther apart. We present theoretical analysis and computational experiments that compare the similarity between stimuli as they are represented at the successive levels of the processing hierarchy, from the retina to the nonlinear cortical units. Our results indicate that the representations at the higher levels of the hierarchy are indeed more useful for the classification of natural objects such as human faces.