Contribution and functional connectivity between cerebrum and cerebellum on sub-lexical and lexical-semantic processing of verbs

Abstract

Language comprehension requires sub-lexical (e.g., phonological) and lexical-semantic processing. We designed a task to compare the sub-lexical and lexical-semantic processing of verbs during functional magnetic resonance imaging (fMRI). Likewise, we were interested in the dichotomous representation of concrete-motor versus abstract-non-motor concepts, so two semantic categories of verbs were included: motor and mental. The findings support the involvement of the left dorsal stream of the perisylvian network for sub-lexical processing during the reading of pseudo-verbs and the ventral stream for lexical-semantic representation during the reading of verbs. According to the embodied or grounded cognition approach, modality-specific mechanisms, i.e.,, sensory-motor systems, and the well-established multimodal left perisylvian network contribute to semantic representation for concrete and abstract verbs. The present study detected a preferential modality-specific system for abstract-mental verbs. The visual system was recruited by mental verbs and showed functional connectivity with the right crus I/lobule VI from the cerebellum, suggesting the existence of this network to support the semantic representation of abstract concepts. These results confirm the dissociation between sub-lexical and lexical-semantic processing and provide evidence about the neurobiological basis of semantic representations for abstract verbs.