Abstract
Simultaneous brightness contrast, or contrast enhancement, was studied using foveally viewed points of light as stimuli. Threshold and binocular brightness-matching techniques were used. When two stimuli are shown together, the presence of the second has two effects upon the brightness of the first. (a) The brightness is augmented, as if by the addition of a proportion of the light from the second stimulus. The proportion declines with separation of the two simuli. (b) As stimulus intensity increases, brightness rises at a slower rate when the second stimulus is present. Effect (b) eventually overbalances (a). When seven stimuli are shown together, the (a) effects sum linearly. No clear pattern of summation is detected for the (b) effects.
© 1965 Optical Society of America
Full Article | PDF ArticleMore Like This
James P. Thomas
J. Opt. Soc. Am. 53(9) 1033-1037 (1963)
Tom N. Cornsweet and Davida Y. Teller
J. Opt. Soc. Am. 55(10) 1303-1308 (1965)
H. G. Sperling and C. L. Jolliffe
J. Opt. Soc. Am. 55(2) 191-199 (1965)