COLOR‐NAMING FUNCTIONS FOR THE PIGEON¹

Abstract

Six pigeons were trained to match wavelengths in a three-key matching-to-sample paradigm. Test trials were occasionally presented, where probe wavelengths appeared on the center key and choices were made to the training stimuli presented on the side keys. Color naming functions were obtained by plotting the percentage of test trials that each training stimulus wavelength was chosen for each center key probe wavelength. The wavelength where the functions intersected was interpreted as a transition point between pigeon hues. Three experiments employed different wavelengths as training stimuli. The first two experiments demonstrated that the intersection of the color-naming functions occurred in all cases at 540 nm and 595 nm. The third experiment employed 540 nm and 595 nm as two of the three training stimuli, and the relatively slow acquisition, together with the resulting color-naming functions, supported the proposition that 540 nm and 595 nm may be transition point wavelengths between pigeon hues.

Two-itemsame-different concept learning in pigeons

“…We specifically selected stimuli for our training and test sets by attempting to maximize as best we could the perceptual separation between these items. Of course, this was guided by our human perception of these colors and shapes and may or may not reflect how the pigeons view the same color and shape relations (Blough & Blough, 1990;Wright & Cumming, 1971). …”

Wavelength Discrimination Function Derived From Post-Discrimination Gradients in the Pigeon

“…Such differences in the amount of training among the groups should make the maximum discriminability for each group uniform. Wright and Cumming (1971) trained pigeons to match-to-sample and found points of hue transition (color boundaries) for the pigeon at wavelengths 540 and 600 nm. Pigeons were trained to select the side-key stimulus which is identical to the center-key stimulus.…”

“…The retina of the pigeon contains red , orange and yellowish oil droplets, which are located on the outer segments of the cones and which seem necessarily to modify the effects of photopigments (KingSmith, 1969). (3) Sets of wavelengths which are grouped into the same hue for pigeons do not correspond to those for humans (Wright & Cumming, 1971) . (4) There is some physiological knowledge of the pigeon's color vision system (Blough, Riggs, & Schafer, 1972;Bridges, 1962;Donner, 1953; Govardovskii & Zueva, 1977;Graf & Norren, 1974;Granda & Yazulla, 1971; Granit, 1942;Ikeda, 1965;Yazulla & Granda, 1973).…”

“…(4) There is some physiological knowledge of the pigeon's color vision system (Blough, Riggs, & Schafer, 1972;Bridges, 1962;Donner, 1953;Govardovskii & Zueva, 1977;Graf & Norren, 1974;Granda & Yazulla, 1971;Granit, 1942;Ikeda, 1965;Yazulla & Granda, 1973). (5) There are many different psychophysical studies concerned with color vision of the pigeon such as D. Blough (1957), Graf (1969), Romeskie and Yager (1976a), and Yager and Romeskie (1975) on spectral sensitivity, D. Blough (1961) and P. Blough (1972) on wavelength generalization, Schneider (1972) on two-dimensional color space, Wright and Cumming (1971) on color-naming functions, Jitsumori (1976) on color mixture, Wright (1976) on Bezold-Brucke hue shift functions , Wright (1972a) on the influence of ultraviolet radiation, and P. Blough (1975) and Romeskie and Yager (1976b) on saturation discrimination function.…”

A Psychometric Hue Discrimination Function and Unitary Set of Wavelengths Which Have Equal Psychological Spacing for the Pigeon

“…In a matching-to-sample paradigm, Wright and Cumming (1971) showed that pigeons matched stimuli that are member of the same set independent of any wavelength differences among them. The results obtained by Wright and Cumming supported the proposition that each set of wavelengths represents a region which might be identified with the" hue " or" unitary color " of human perception, with the boundaries between the sets occurring at about 540 and 600 nm in the pigeon.…”