Patients with focal cerebellar lesions show reduced auditory cortex activation during silent reading

- We examined language-related cerebral BOLD-activations in cerebellar patients.
- Maximal lesion overlap in patients was in the medial cerebellum.
- This cerebellar region is activated during silent reading in healthy participants.
- The patients showed reduced auditory cortex activation in this condition.
- Our results suggest a cerebellar role in visual-to-auditory mapping or inner speech.

Functional neuroimaging studies consistently report language-related cerebellar activations, but evidence from the clinical literature is less conclusive. Here, we attempt to bridge this gap by testing the effect of focal cerebellar lesions on cerebral activations in a reading task previously shown to involve distinct cerebellar regions. Patients (N = 10) had lesions primarily affecting medial cerebellum, overlapping cerebellar regions activated during the presentation of random word sequences, but distinct from activations related to semantic prediction generation and prediction error processing. In line with this pattern of activation-lesion overlap, patients did not differ from matched healthy controls (N = 10) in predictability-related activations. However, whereas controls showed increased activation in bilateral auditory cortex and parietal operculum when silently reading familiar words relative to viewing letter strings, this effect was absent in the patients. Our results highlight the need for careful lesion mapping and suggest possible roles for the cerebellum in visual-to-auditory mapping and/or inner speech.