Parallel and Serial Connections Between Human Color Mechanisms

This chapter explains parallel and serial connections between human color mechanisms. The concept of a discrete number of independent mechanisms functioning in parallel has been first used in human vision as an explanation for the trivariance of color vision. The current picture of the color system consists of a series of stages, each with a number of mechanisms functioning in parallel. Successive stages are composed of mechanisms that combine the outputs of the previous stage. The first few stages of color processing are simple and understood better than any other sensory system. Analogies from color mechanisms have been used in models for spatial frequency discrimination, motion perception and adaptation. However, a number of color phenomena are extremely complex and cannot be satisfactorily explained in terms of known mechanisms. The chapter illustrates that, if mechanistic explanations of complex color phenomena are successful, they can provide general insights into the processing of complex information by other parts of the nervous system.