Global versus local processing in haptic perception of form

Abstract

Preliminary experiments on a “tactile analog” of Navon’s (1977) global/local pattern-identification task are reported. Sighted, early-blind, and late-blind subjects were exposed to large shapes comprised of different, smaller geometric forms, and were asked to “name the shape.” In addition, groups of early- and late-blind subjects attempted identification of conflict braille stimuli, with large braille patterns made up of smaller, standard braille. The pattern of responses was neither totally local nor global for geometric-form information. Braille, however, was size specific, with most early-blind subjects responding locally. Visual and haptic experience altered the pattern of responses for both braille and geometric forms.