Chromatic adaption and the fundamental stimuli

A bipartite adaption stimulus with a horizontal dividing line adapted the upper half of the retina to red or yellow light and the lower half to white light. Monochromatic test stimuli between 460 and 520 nm were presented to the red or yellow adapted portion of the retina. After desaturating the test stimulus with red light, it was possible to match it to a mixture of 458 and 520 nm. From these data one can plot on a mixture diagram the shifts in color produced by the two kinds of adaption. The data support a zone theory of color vision similar to that proposed by Adams.