Psychophysical studies of monkey vision—I. Macaque luminosity and color vision tests

Abstract Macaque monkeys and normal human observers were tested on the same apparatus for the presence of a Purkinje shift, and for spectral sensitivity under scotopic and photopic conditions. The flicker fusion point for different lights was used as a measure of visual sensitivity in these tests and the testing procedure was a four-alternative forced choice. The results show that macaque monkeys and normal human observers show a rod-cone break at the same flicker frequency, and are very similar in both relative and absolute scotopic and photopic sensitivity. Macaque monkeys, normal human observers and color-defective human observers were also tested under identical conditions in several measures of color vision.