Tactile perception in blind Braille readers: A psychophysical study of acuity and hyperacuity using gratings and dot patterns

• Published in: Perception & psychophysics Vol. 62; no. 2; pp. 301 - 312
• Main Authors: Grant, Arthur C., Thiagarajah, Mahesh C., Sathian, K.
• Format: Journal Article
• Language: English
• Published: Austin, TX Psychonomic Society 01.02.2000
• Subjects: Adult; Aged; Attention; Biological and medical sciences; Blindness - psychology; Discrimination Learning; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Middle Aged; Orientation; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychophysics; Reading; Sensory Aids; Sensory Thresholds; Tactile perception; Touch; Human; Hyperacuity; Tactile sensitivity; Eye disease; Vision disorder; Braille writing; Blindness; Sensory handicap; Experimental study; Psychophysics; Acuity
• ISSN: 0031-5117; 1532-5962
• DOI: 10.3758/BF03205550

It is not clear whether the blind are generally superior to the sighted on measures of tactile sensitivity or whether they excel only on certain tests owing to the specifics of their tactile experience. We compared the discrimination performance of blind Braille readers and age-matched sighted subjects on three tactile tasks using precisely specified stimuli. Initially, the blind significantly outperformed the sighted at a hyperacuity task using Braille-like dot patterns, although, with practice, both groups performed equally well. On two other tasks, hyperacute discrimination of gratings that differed in ridge width and spatial-acuity-dependent discrimination of grating orientation, the performance of the blind did not differ significantly from that of sighted subjects. These results probably reflect the specificity of perceptual learning due to Braille-reading experience.