Haptic Mental Rotation: More Consistent in Blind Subjects?

Abstract

Four adventitiously blind subjects and four sighted subjects with vision occluded examined a tangible letter J, presented at various orientations, and stated whether the stimulus was in normal or mirror-reversed form. Although the pattern of response-latency measurements suggested a higher rate of rotation of mental images in the sighted subjects, it indicated a greater degree of intersession variability in the orientation of the frame of reference they used. When the effect of this variability was eliminated from the data, the mental rotation functions for the two groups of subjects were virtually identical. These results support the hypothesis of earlier research that shifts in the orientation (defined with respect to external coordinates) of the frame of reference are responsible, at least in part, for apparent differences in mental rotation of blind and sighted subjects.