Semantic and syntactic specialization during auditory sentence processing in 7-8-year-old children.

Previous studies indicate that adults show specialized syntactic and semantic processes in both the temporal and frontal lobes during language comprehension. Neuro-cognitive models of language development argue that this specialization appears earlier in the temporal than the frontal lobe. However, there is little evidence supporting this proposed progression. Our recently published study (Wang, Rice, & Booth, 2020), using multivoxel pattern analyses, detected that children as young as 5 to 6 years old exhibit specialization and integration in the temporal lobe, but not the frontal lobe. In the current study, we used the same approach to examine semantic and syntactic specialization in children ages 7 to 8 years old. We found support for semantic specialization in the left middle temporal gyrus (MTG) for correct sentences and in the triangular part of the left inferior frontal gyrus (IFG) for incorrect sentences. We also found that the left superior temporal gyrus (STG) played an integration role and was sensitive to both semantic and syntactic processing during both correct and incorrect sentence processing. However, there was no support for syntactic specialization in 7- to 8-year-old children. As compared to our previous study on 5- to 6-year-old children, which only showed semantic specialization in the temporal lobe, the current study suggests a developmental progression to semantic specialization in the frontal lobe. This project represents an important step forward in testing neuro-cognitive models of language processing in children.