The effects of arm length, size of angle, and spatial separation on Morinaga's illusion.

Abstract

The effects of arm length, spatial separation between angles, size of angle, and practice on the degree of misalignment in a modified version of Morinaga’s illusion were assessed. Size of angle was manipulated between subjects (n=15/group), whereas arm length, spatial separation, and practice were varied within subjects. Results showed: (1) that as the length of the arm increased, the degree of illusion decreased; (2) that as spatial separation increased, the degree of illusion increased; and (3) an interaction between size of angle and practice. The results were related to Day et al.’s (1982) assimilation theory of Morinaga’s illusion.