Universal brain signature of emerging reading in two contrasting languages
Despite dissimilarities among scripts, a universal hallmark of literacy in adults is the convergent brain activity for print and speech. Little is known, however, how early it emerges. Here we compare speech and orthographic processing systems in two contrasting languages, Polish and English, in 100 7-year-old children performing identical fMRI tasks. Results show limited language variation, with speech-print convergence evident mostly in left fronto-temporal perisylvian regions. Correlational and intersect analyses revealed subtle differences in the strength of this coupling in several regions of interest. Specifically, speech-print convergence was higher for transparent Polish than opaque English in right temporal area, associated with phonological processing. Conversely, speech-print convergence was higher for English than Polish in left fusiform, associated with visual reading. We conclude that speech-print convergence is a universal marker of reading even at the beginning of reading acquisition while minor variations can be explained by the differences in the orthographic transparency.