1966 年 35 巻 3 号 p. 164-176
Increment threshold techniques are widely used in investigating the mechanism of human color-vision. Its various uses are reviewed here. Stiles developed two-color threshold method and obtained spectral sensitivity curves of underlying mechanisms, π1, π2, ……, π5, which were presumed to be: responsible for the color vision. The findings were strongly supported by Rushton's results in which the technique of retinal densitometry was employed. However, the spectral sensitivity curves, derived from the overall sensitivity curves obtained under various adapting conditions by Boynton and Wald did not quite agree with Stiles' results. Further investigations are needed. Summationn index was introduced to analyze the interaction among mechanismsand it appeared that certain mechanisms inhibit with each other along a line of Hering's opponent-color theory. A further development of this method should provide some important data for the study of mechanism of human color vision.