Haptic Perception of the Mueller-Lyer Illusion by the Blind

Abstract

4 groups of Ss, congenital blind, blinded in adulthood, sighted blindfolded, and sighted visual, were each shown to experience the Mueller-Lyer illusion to a statistically reliable extent. The extent of illusion in the sighted blindfolded group was significantly less than that in each of the other three groups. None of the other pairs of means were significantly different. The results were discussed in terms of their implications for perspective theories of visual illusions and in terms of the blind Ss' presumably better utilization of short-term memory for retaining haptic relationships.