Brigner W L, Crouch J G
Percept Mot Skills. 1985 Aug;61(1):81-2. doi: 10.2466/pms.1985.61.1.81.
Binocular rivalry and the Margaret Thatcher illusion were used to assess the bias, if any, of perceptual set. The data for 8 students suggest that set is negatively biased.