Effects of Orientation and Redundancy on Tactual Perception of Form

The present study determined the effects of absolute spatial orientation and Redundancy-I on the tactual recognition of metric figures. Four orientations (base horizontal distinctive contour upward, base horizontal distinctive contour downward, base vertical distinctive contour to S's right, base vertical distinctive contour to S's left) were used with random and redundant figures. The stimuli displayed consisted of raised dots; standard Braille values were employed for dot height and spacing. In terms of both speed and accuracy of recognition, performance was better for random than for redundant figures. The effect of spatial orientation was negligible. Results are considered in regard to the comparative influence of similar stimulus parameters in the perception of visual and tactual form.