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The haptic Muller-Lyer illusion in sighted and blind people
Perception (2002)
  • Morton A. Heller, Eastern Illinois University
  • Deneen D. Brackett, Eastern Illinois University
  • Kathy Wilson, Eastern Illinois University
  • Keiko Yoneyama, Eastern Illinois University
  • Amanda Boyer, Eastern Illinois University
  • Heather Steffen, Eastern Illinois University

We examined the effect of visual experience on the haptic Mu« ller-Lyer illusion. Subjects made size estimates of raised lines by using a sliding haptic ruler. Independent groups of blind- folded-sighted, late-blind, congenitally blind, and low-vision subjects judged the sizes of wings-in and wings-out stimuli, plain lines, and lines with short vertical ends. An illusion was found, since the wings-in stimuli were judged as shorter than the wings-out patterns and all of the other stimuli. Subjects generally underestimated the lengths of lines. In a second experiment we found a nonsignificant difference between length judgments of raised lines as opposed to smooth wooden dowels. The strength of the haptic illusion depends upon the angles of the wings, with a much stronger illusion for more acute angles. The effect of visual status was nonsignificant, suggesting that spatial distortion in the haptic Mu« ller-Lyer illusion does not depend upon visual imagery or visual experience.

  • psychology,
  • haptic Muller-Lyer illusion,
  • blindfolded-sighted,
  • late-blind,
  • congenitally blind,
  • low-vision
Publication Date
Citation Information
Morton A. Heller, Deneen D. Brackett, Kathy Wilson, Keiko Yoneyama, et al.. "The haptic Muller-Lyer illusion in sighted and blind people" Perception Vol. 31 (2002)
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