The wavelength composition of the light reflected from an object changes considerably in different conditions of illumination. Nevertheless, the color of the object remains the same. This property, so-called "color constancy," is the most important property of the color visual system. It has been unclear based on previous work whether the attribute of color constancy is innate or acquired after birth.
In work reported this week, researcher Yoichi Sugita of the Neuroscience Research Institute, Tsukuba, Japan, shows that visual experience in early infancy is indispensable for normal development of the color constancy. He raised baby monkeys for nearly a year in a separate room where the illumination came from only monochromatic lights. After extensive training afterwards, the monkeys were able to perform color matching tasks, but their judgment of color similarity was quite different from that of normal animals. Furthermore, they had severe deficits in color constancy; their color vision was very much wavelength-dominated, such that they were unable to compensate for the changes in wavelength composition. These results indicate that early visual experience is indispensable for normal color perception.