Abstract
While the brain network for Braille reading (BR) in the blind is well known, fMRI studies on Braille writing (BW) are lacking. Consequently, no comparative network analysis of BW vs. BR exists. Here, we report the first BW/BR study, together with the effect of text familiarity on both. Methods: FMRI was conducted in a Siemens 3T Trio scanner. Our custom MRI-compatible drawing/writing tablet was further modified to provide for BR and BW. Each of five paragraphs of novel Braille text describing objects, faces and navigation sequences was read, then reproduced twice by writing from memory, then read a second time (20s/task). Results and Conclusions: BR: During the initial reading (unfamiliar text), the tactually-sensed Braille letters strongly activated the classical grapheme area, but its activation was drastically reduced on the second reading (familiar text). Despite the lack of vision, visual areas (V1-3) were strongly activated during both readings. Interestingly, activation in key mirror neuron areas, including the anterior intraparietal sulcus (aIPS) and inferior frontal gyrus (IFG), significantly expanded as a function of the familiarity of the text, in contrast to the marked decrease in the grapheme area. Taken together, these patterns of activation imply a shift from detailed “visual” processing of Braille-letter forms to an embodied cognition interpretation of the same Braille text when familiar. BW: Braille writing engaged a significantly more extensive network than BR, particularly in the initial writing block. Also, in contrast to drawing in the blind (Likova, 2012), BW generated focal activation restricted to the most foveal part of V1, presumably reflecting the focal demands of such a precision task. This first study of the brain network for Braille writing-from-memory, its comparison to the Braille reading network, and the effects of text familiarity on them, further allows for comparison with visual writing/reading mechanisms.
Meeting abstract presented at VSS 2015