Effects of Chromaticities and Occlusion of Shaft on Magnitude of the Müller-Lyer Illusion

Abstract

The magnitude of the Müller-Lyer illusion was investigated using the Brentano figure by varying the chromaticities of the shaft and the fins along the cone-excitation axes and by varying the occlusion status of the shaft by the fins. 72 college students participated using the staircase method. The stimuli whose shaft and the fin chromaticities were the same produced larger illusions than stimuli with different chromaticities regardless of the luminance contrast between the figure and the surround. When the shaft appeared in front of the fins, the illusion effect was stronger than when the shaft was occluded by the fins.