Neural Correlates of Morphosyntactic Processing in Spanish-English Bilingual Children: A Functional Near-Infrared Spectroscopy Study

Purpose: The aim of this study was to examine the effects of early bilingual exposure on Spanish-English bilingual children's neural organization of English morphosyntactic structures. This study examines how children's age and lan-guage experiences are related to morphosyntactic processing at the neural level.Method: Eighty-one children (ages 6-11 years) completed an auditory sentence judgment task during functional near-infrared spectroscopy neuroimaging. The measure tapped into children's processing of early-acquired (present progressiveing) and later-acquired (past tense -ed and third-person singular -s) English morphosyntactic structures, the primary language of academic instruction.Results: We observed effects of syntactic structure and age. Early-acquired morphemic structures elicited activation in the left inferior frontal gyrus, while the later-acquired structures elicited additional activations in the left middle temporal gyrus and superior temporal gyrus (STG). Younger children had a more distributed neural response, whereas older children had a more focal neural response. Finally, there was a trending association between children's English language use and left STG activation for later-acquired structures. Conclusion: The findings inform theories of language and brain development by highlighting the mechanisms by which age and language experiences influ-ence bilingual children's neural architecture for morphosyntactic processing.