Bilateral Ventral Pathways Support Phonological Awareness at Reading Onset in Spanish-Speaking Children.

Reading is a fundamental human skill that has been widely studied. While substantial progress has been made in identifying the white matter pathways supporting reading in adults, less is known about the neural substrates underlying reading acquisition in children. Moreover, existing evidence primarily focuses on a small set of languages, thereby raising questions about the generalizability of these findings. In this study, we address this gap by examining the white matter correlates of phonological awareness-a well-established precursor of reading development-in a cohort of monolingual Mexican Spanish-speaking children. Contrary to the classical view that left-lateralized dorsal pathways support phonological awareness, our results reveal that fractional anisotropy in bilateral ventral tracts, but not dorsal tracts, correlates with phonological awareness in this population. These findings challenge the traditional dichotomy between dorsal and ventral stream functions, instead highlighting the flexible and language-dependent nature of the neural mechanisms that support early reading development in children.