The cerebellar components of the human language network

Despite ample evidence of cerebellar contributions to cognition, including language, its precise role remains debated. We systematically characterize cerebellar language-responsive regions using precision fMRI. We identify four cerebellar regions that respond to language across modalities (experiments 1a and 1b, n = 754). One region-spanning Crus I/II/lobule VIIb-is selective for language relative to diverse non-linguistic tasks (experiments 2a-2f, n = 732), and the rest exhibit mixed selectivity. Similar to the neocortical language system, the language-selective region is engaged during comprehension and production (experiments 3a and 3b, n = 100), shows sensitivity to linguistic difficulty (experiment 3c, n = 5), and responds to both social and nonsocial sentences (experiment 3d, n = 10). Finally, all four regions, but especially Crus I/II/VIIb, are functionally connected to the neocortical language system (experiment 4, n = 85). We propose that these cerebellar regions constitute components of the extended language network, with one region closely mirroring the neocortical network and the rest plausibly integrating information from diverse neocortical regions.