Color mixing in the pigeon. A psychophysical determination in the longwave spectral range.
Pigeons were trained to discriminate between spectral lights and additive mixtures in the 580-640 nm range. Two behavioral procedures were used: (I) a simultaneous instrumental discrimination and (II) successive "autoshaping" discrimination. Pigeons were able to make color mixture matches within this spectral range with satisfactory precision. Matchings determined by the animal correspond well to those predicted on the basis of the spectral sensitivities of two (or even three) pigment-droplet combinations present in the pigeon retina.