Visual sensitivity in the presence of alternating monochromatic fields of light

Abstract

Human visual sensitivity was investigated at the time of transition from one monochromatic field of light to another, with brightness held constant. Three measurements of threshold of a superimposed test field were made: before, during and after the transition between the two fields. Change in sensitivity was studied as a function of the wavelength difference between the background fields. Results indicate a reduction in sensitivity at the time of transition which is not necessarily maximal to largest wavelength differences. The increase of sensitivity after the change, on the other hand, was usually greatest to the largest difference in wavelength. These findings are shown to be dependent upon the luminance level of the fields and the wavelength of the test field. The results are discussed in relation to recent studies of physiological responses to the substitution of chromatic stimuli.