Transient processing in chromatic induction.
The non-additivity of steady backgrounds and superimposed test flashes was investigated with 25 observers using a hue cancellation procedure. The subject's task was to vary the ratio of two lights comprising an incremental test flash (delta R/delta G) so as to maintain a unique yellow hue (i.e. red-green equilibrium) in the presence of a long-wavelength adapting background. Measurements were obtained for four different luminances of the test flash (for each background), covering a range of 1.5-2.0 log units. The adaptive hue shifts generally support Walraven's finding that the background affects the hue of the test flash only by way of altering the spectral sensitivities of the receptors, but it does not add to the hue signals from the test flash.