Increasing cerebellar beta rhythms shifts cerebral oscillatory signatures of context-driven language processing
Year: 2026
Type: preprint
Abstract: While there is growing consensus that the cerebellum is part of the cerebrally centred network underlying language processing, the direct nature of its contribution to comprehension and production remains unknown. In particular, while both processes require lexical access, production additionally involves motor processes linked to articulatory planning, which has fuelled the view that the cerebellum is primarily involved in motor control in language production. Cortically, both lexical access and articulatory planning are known to be driven by alpha-beta power decreases. To disentangle cerebellar involvement in language, this study investigated the modulatory effect of transcranial alternating current stimulation (tACS) over the right cerebellum on context-driven language comprehension and production. In a cross-over, double-blind, sham-controlled within-participants design, 32 healthy volunteers received 20 minutes of 20-Hz tACS (2 mA peak-to-peak) targeting the right posterior cerebellum. Immediately afterwards, they performed a context-driven language task while EEG was recorded from 32 channels. In the task, visually presented lead-in sentences creating a constraining or unconstraining context were followed by a picture depicting the final word of the sentence. Participants were instructed to name the picture (production) or judge its animacy (comprehension). Responses became slower overall following active compared to sham tACS, and this increase was more pronounced in the comprehension task. In line with previous work, reliable context-related oscillatory power decreases were observed in response to the context manipulation, but exhibited a different pattern across tasks and stimulation conditions. For production, beta-centred power decreases following sham shifted to temporally and spatially extended alpha power decreases following active tACS. By contrast, alpha-centred power decreases following sham tACS in the comprehension task increased following active tACS. Increasing beta activity in the right posterior cerebellum thus affected early stages of context-driven language processing linked to lexical access in both language domains. The stimulation-induced spectral, spatial and temporal shifts suggest recruitment of alternative cortical resources as a consequence of cerebellar network modulation. This interpretation is consistent with the cerebellum functioning as a network node coordinating temporal dynamics across distributed language regions.
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7221179001