Language and the cerebellum: structural connectivity to the eloquent brain

Much remains to be learned about the role(s) of the cerebellum in the neurobiology of language. Contemporary models have focused extensively on the left-hemisphere perisylvian cortex with the assumption that the cerebellum supports more peri-linguistic cognitive processes (e.g., verbal working memory). The goal of this study was to map the structural connectivity profile of domain-specific language regions of interest (ROIs) implicated in semantics, phonology, and syntax relative to connectivity for working memory. Functional imaging data and diffusion-weighted imaging data from the Human Connectome Project (HCP) were analyzed. We found that (a) working memory, motor activity, and language comprehension activated partially overlapping but mostly unique regions of the cerebellum; (b) the linguistic portion of the cerebello-thalamo-cortical circuit was more extensive than the linguistic portion of the cortico-ponto-cerebellar tract; (c) there was a frontal-lobe bias in the connectivity from the cerebellum to the cerebrum; (d) there was some degree of specificity; and (e) for some of the cerebellar tracts, individual differences in picture identification ability correlated with variation in fractional anisotropy. These findings yield insights into the structural connectivity of the cerebellum as it relates to language comprehension – an ability that is unique to humans. ### Competing Interest Statement The authors have declared no competing interest.