Visual perception is a unitary experience that simply has no vestige of the separate processes and mechanisms that underlie the generation of the percept. An individual photoreceptor cannot uniquely convey information about spatial, temporal, and chromatic properties of the stimulus. The information is contained in the pattern of stimulation across the photoreceptors. The initial stages of retinal processing separate and collect signals in the photoreceptoral array in different ways to derive information rudimentary to the perceptions of brightness, color, shape and contour, and motion.