Examining the role of phonological and semantic mechanisms during morphological processing of sentences in seven-year-old children

Morphology refers to the smallest difference in sound that makes a difference in meaning, such as walkversus walked. Morphological skill is a key linguistic feature that impacts language and literacyoutcomes, but its neural underpinnings have mostly been examined at the word-level. We examined ifphonological and semantic mechanisms play a role during morphological processing in sentences inseven-year-old children using functional magnetic resonance imaging (fMRI). Using a novel functionallocalizer approach that correlates brain activation during sound and meaning in-scanner tasks withstandardized scores for phonology and semantics, we show that morphological processing is especiallyreliant on phonological mechanisms given significant activation in the left dorsal inferior frontal gyrus(IFG) and left posterior superior temporal gyrus. Semantic mechanisms were engaged to a lesser degree in the left ventral IFG. Exploratory whole-brain analyses revealed a brain-behavior correlation in the cerebellum showing that greater activation during morphological processing was related to lowerlanguage abilities. Our results suggest that processing morphological structures in sentences reliesmostly on phonemic segmentation, and that those with lower language may compensate for their lowerphonological skill by engaging the cerebellum to amplify and refine those phonemic representations toaid in segmentation when listening to sentences.Keywords: fMRI, language, morphology, phonology, semantics