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

Abstract

Pigeons were trained to discriminate between two wavelengths with a yes/no procedure.Post-discrimination gradients ranging between the training wavelengths (420-470, 470-520, 520-570 and 570-650nm) were obtained for four groups. The sum of the differences between the choice probabilities at adjacent wavelengths was assumed as a measure of the rate of change in apparent color, and a wavelength discrimination function ranging from 430 to 640 nm was obtained. The function was compared with the functions obtained recently with different methods and showed that the wavelength discrimination was best at 450, 500-510, 530-540 and 600 nm spectral regions. The findings were related to generalization gradients, color-naming data and physiological data.Animal psychophysical research has been conducted for approaches to determine the underlying process of pigeon color vision. The pigeon is a good subject for comparative color vision because: (1) It has a well developed color sense and its color mechanism is considered to he at least trichromatic (Hamilton & Coleman, 1933). (2) Its color discrimination mechanism is based on receptor process that are quite different from those found in humans. 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). Blough (1975) and Romeskie and Yager (1976b) on saturation discrimination function.Good wavelength discriminability in the pigeon was demonstrated very early by Hamilton and Coleman (1933) . With the better controls and techniques that are now available, new pigeon wavelength discrimination functions were obtained . Two were based on behavioral studies and 1 The author is indebted to Profes sor Takashi Ogawa of Keio University for his advice throughout the research and Professor Tadasu Oyama of Chiba University for his encouragement . Requests for reprint should be sent to

Recognition of moving video images of conspecifics by pigeons: Effects of individuals, static and dynamic motion cues, and movement

“…Many birds, including pigeons, can perceive ultraviolet light (A. T. D. Bennett & Cuthill, 1994;Emmerton & De1ius, 1980;Wright, 1972a). The pigeon's retina contains more than three morphologically distinguishable cones bearing oil droplets of different color (Govardovski & Zueva, 1977) and the minima ofpigeon 's spectral wavelength discrimination function differ from those ofhumans (Blough, 1972;Jitsumori, 1978;Wright, 1972b). It has been considered that the pigeon's color vision is more than trichromatic (Jacobs, 1981), and at least pentachromatic (De1ius & Emmerton, 1979).…”

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

“…Wright (1979) suggested that the difference in stimulating conditions might encourage the pigeons to use the different retinal fields. This is not the case in the function obtained by Jitsumori (1978) described above. The function showed 510 nm to be a point of good hue discriminability in spite of the use of a uniform stimulus rather than a split-field stimulus.…”

“…The psychometric hue discrimination function obtained in the present study showed a region of good hue discriminability in the wavelengths ranging from 440 to 470 nm outside of the spectrum explored in the experiments of Blough (1972) and Wright (1972). Jitsumori (1978) derived a hue discrimination function from the post-discrimination gradients shown in Fig. 2 on the assumption that the sum of the differences in choice probability at adjacent wavelengths was a measure of the rate of change in apparent color.…”

Pioneering studies in the 1930s on perception: An historical background of experimental psychology in Japan1

“…Recent Japanese psychologists have conducted some experiments on sensation and perception in animals, for example: color vision in the carp, pigeon, monkey, and chimpanzee; optical illusions and size constancy in the monkey; and auditory function in the chimpanzee (Fuji, 1986; Fujita, 1996; Jitsumori, 1976, 1978; Kojima, 1990; Matsuzawa, 1985; Oyama & Jitsumori, 1973; Oyama, Furusaka & Kito, 1986). The old Japanese tradition of animal perception study should be regarded as the historical background of these recent studies.…”