A novel tactile braille-stroop test (TBSt)

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 (a) a single non-sensical triplet of braille letters embossed on all stimuli, and (b) the first three consonants of the material’s name, embossed in braille, congruently, or (c) incongruently. A total of 45 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, not only in the incongruent condition but also in the non-sense (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 non-sensical letter strings, a Stroop effect.