The dominance of touch by vision: sometimes incomplete

It is generally agreed that, when the two senses are in conflict, vision dominates touch. In the series of experiments reported here the discrepancy between the visual and the haptic images was progressively increased. In each experiment half of the observes were adults and half children, and half of each group wore a glove which concealed the distortion produced by the lens. In experiment 1 the visual image of a haptic square was transformed by a week or strong cylindrical lens so that the sides were in the ratio 1:1.5 or 1:1.8. Gloved observers selected a comparison image close to the visual image. Bare-handed observers gave compromise judgements with the strong lens, but judgements similar to those of the gloved observers with the weak lens. In experiment 2 the square had a visual image which was either a diamond or a parallelogram, the parallelogram having angles of 70 degrees and 110 degrees. Observers described and drew their percepts, which were generally in accord with the visual image. There were no significant differences due to age, a finding contrary to that of Page and Locke, nor were there differences in experiment 2 due to the gloved-hand-bare-hand dimension. It is concluded (i) that repeated observations do not destroy the effect, (ii) tht considerable discrepancies between the visual and haptic images do not destroy the effect, but (iii) that feedback from a bare hand can reduce the effect when it is of considerable magnitude.