Project Report from the year 2013 in the subject Psychology - Methods, grade: A, University of Cambridge (Department of Experimental Psychology), course: Natural Sciences Tripos, language: English, abstract: The principle of adaptive independence regarding middle- and short-wave cones was tested by Stiles "Two-colour threshold technique". Using yellow background light, the sensitivity of middle-wave cones was lowered and the shift in higher sensitivity of middle-cones to short-wave cones to blue test flashes was found to occur at a background radiance of 0.03 W/m^2sr.