Spectral Sensitivity of the Fovea I Neutral Adaptation

Photosensitization in relation to mean and standard deviation values.

“…curve. However, in units of microwatts they have been compared with those recently published by ILsia andGraham (1952), andHurvich andJameson (1953), and so closely agree with them that any discrepancies are felt to be accounted for in terms of individual differences. All show inflections varying in amount between 440 and 450 m/A, and again at 490 mfi.…”

An opponent-process theory of color vision.

“…It can fairly be assumed that the achromatic, white response is closely connected with the distribution of the brightness quality throughout the visible spectrum, and Fig. 3 therefore shows two functions (which we have measured by a threshold technique) that give the whiteness distribution of an equal energy spectrum for two observers (20). The induced rather than directly stimulated black component of the achro- matic white-black response pair has this same distribution, but of opposite sign, since the strength of the black contrast response is directly related to the magnitude of either the surrounding or the preceding whiteness or brightness.…”

Subadditivity and superadditivity of heterochromatic lights.

“…In an earlier paper, a formal model of luminance additivity was presented (Wasserman, 1969a). This model was informed by Hering's treatment of the brightness of chromatic stimuli (Hering, 1889(Hering, , 1895Hillebrand, 1889;Hurvich & Jameson, 1953;Wasserman, 1966). The earlier report showed that a single model could explain two disparate phenomena: First, it could simulate Guth's (1965) data, which indicated that certain mixtures of heterochromatic lights were subadditive at threshold in the sense that the threshold-defined luminance of the mixture was less than the sum of the thresholddefined luminances of the components.…”