Citation

Alary F, Goldstein R, Duquette M, Chapman CE, Voss P, Lepore F. Exp. Brain Res. 2008; 187(4): 587-594.

Affiliation

Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Département de Psychologie, Université de Montréal, CP 6128, Succ. Centre-Ville, Montreal, QC H3C 3J7, Canada.

Copyright

(Copyright © 2008, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s00221-008-1327-7

PMID

18305930

Abstract

Growing evidence suggests that blind subjects outperform the sighted on certain tactile discrimination tasks depending on cutaneous inputs. The purpose of this study was to compare the performance of blind (n = 14) and sighted (n = 15) subjects in a haptic angle discrimination task, depending on both cutaneous and proprioceptive feedback. Subjects actively scanned their right index finger over pairs of two-dimensional (2-D) angles (standard 90 degrees ; comparison 91-103 degrees ), identifying the larger one. Two exploratory strategies were tested: arm straight or arm flexed at the elbow so that joint movement was, respectively, mainly proximal (shoulder) or distal (wrist, finger). The mean discrimination thresholds for the sighted subjects (vision occluded) were similar for both exploratory strategies (5.7 and 5.8 degrees , respectively). Exploratory strategy likewise did not modify threshold in the blind subjects (proximal 4.3 degrees ; distal 4.9 degrees ), but thresholds were on average lower than for the sighted subjects. A between-group comparison indicated that blind subjects had significantly lower thresholds than did the sighted subjects, but only for the proximal condition. The superior performance of the blind subjects likely represents heightened sensitivity to haptic inputs in response to visual deprivation, which, in these subjects, occurred prior to 14 years of age.

Language: en