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 language 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 progressive – ing ) 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 influence bilingual children's neural architecture for morphosyntactic processing.