Representation of cone signals in the primate retina.

Vision begins with specialized retinal circuits that encode diverse types of information. For Old World primates, these circuits sample three submosaics formed by cone photoreceptors sensitive to short, middle, and long wavelengths. For spatial acuity, the photon catch between any two cones is compared for discrimination of patterns as fine as the cone mosaic. For color vision, the photon catch between different cone types is compared for discrimination of fine spectral differences on the basis of hue. The retinal circuits for these two tasks differ at the synaptic level to form distinct representations of signals from the cone mosaic.