A Novel Tactile Stroop Test

Abstract Stroop interference effects occur when word reading and the target words' print color naming are incongruent. This interference reflects reading proficiency while naming print color instead of reading color's names. We devised a tactile version of the Stroop test in which the congruity between three target materials (paper, Braillon and plastic) and the embossed materials' names, in braille, was manipulated. The participants' task was to palpate and name the target materials. The baseline condition was a board with 63 cells each containing one of the target materials. Three similarly constructed boards had: i. a single nonsensical triplet of braille letters embossed on all stimuli, and ii. the first three consonants of the material's name, embossed in braille, congruently, or iii. incongruently. Forty-five blind participants were tested; young adults, high-school and elementary school students (16, 10 and 3 mean years of braille reading, respectively).Older, more experienced braille readers showed the largest Stroop interference costs, in speed and accuracy, in the incongruent condition but also in the nonsense (non-word) condition compared to the congruent condition. Also, the adults committed more errors compared to high-school students in the incongruent condition. However, the more experienced braille readers were faster in the congruent condition compared to the non-word condition. Elementary school children showed no relative gains in the congruent versus non-word condition, and only small incongruence (interference) costs in speed or accuracy. These findings indicate that Braille reading competes with tactile material naming, as a function of reading proficiency, even for nonsensical letter strings, a Stroop effect.