Pr. Delucia et al., DIAMOND-WINGED VARIANTS OF THE MULLER-LYER FIGURE - A TEST OF VIRSU (1971) CENTROID THEORY, Perception & psychophysics, 55(3), 1994, pp. 287-295
Diamond-winged variants of the Muller-Lyer figure were used to test pr
edictions of Virsu's (1971) theory of the Muller-Lyer illusion based o
n efferent readiness for eye movements toward the figure's center of g
ravity. A Muller-Lyer figure with diamond-shaped wings resulted in a g
reater center-of-gravity distance than the corresponding, conventional
Muller-Lyer figure, but fin length and the rest of the figure remaine
d constant; in Virsu's study, fin length and center-of-gravity distanc
e covaried. Results were consistent with Virsu's data when we used the
stimulus conditions that he reported. Results from a wider range of s
timuli challenge Virsu's theory, and thus are consistent with the conc
lusions of Brigell, Uhlarik, and Goldhorn (1977).