In a sample of 108 male subjects, age 13 through 89, foveal CFF was measured using 10 light/dark ratios, 2/98 to 98/2, under two levels of surround luminance: 0.04 and 23.6 ml. One at a time, individual differences, surround, age, and the light/dark ratios were held constant in several analyses of variance. Stepwise, inductive regression equations were calculated. Reliability of the data varied as a function of the experimental conditions. All first-order variables, the second-order interactions with the exception of Age ×Surround, and the third-order interaction, were shown to significantly influence CFF. The best predictors of CFF were the lowest light/dark ratios, the primary variables, combined with age, the secondary variable.
RICHARD G. DOMEY, "Statistical Properties of Foveal CFF as Function of Age, Light/Dark Ratio, and Surround," J. Opt. Soc. Am. 54, 394-396 (1964)