Tactile Elevation Perception in Blind and Sighted Participants and Its Implications for Tactile Map Creation

Although previous research has shown that elevation influences detection and discrimination thresholds for single tactile stimuli and that the physiological response of fingertip receptors varies with texture, little is known about the influence of these parameters on the identification of stimuli in the context of multiple symbols as found on tactile maps. This study seeks to determine the optimal elevation of tactile map symbols. In the study, sighted and visually impaired participants performed tactile symbol identification tasks. The effect of elevation on identification accuracy was measured in the first experiment. In the second experiment, the effect of elevation and symbol texture on identification speed was measured. Results showed that symbol elevation influenced both speed and accuracy of identification; thresholds were higher than those found in studies on detection and discrimination but lower than on existing tactile maps. The symbol elevations necessary for identification (0.040 to 0.080 mm) are considerably lower than would be expected on the basis of existing tactile maps (generally 0.5 mm or higher) and design guidelines (0.4 mm). As predicted from existing knowledge of tactile perception, rough features were identified more quickly than smooth ones. Visually impaired participants performed better than sighted ones. These findings can be applied to aid in the development of maps that are more durable and legible.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 208-223
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01142340
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 21 2009 9:03PM