Lesions in the cerebellum impact cross-modal temporal predictions.

The cerebellum (CE) supports the encoding of the precise sensory event timing and the generation of temporal predictions. Here we investigated whether focal CE lesions impact temporal predictions in a cross-modal context. Individuals with CE lesion (n = 9) and healthy-matched controls (HC) were presented with visuo-auditory stimulus pairs, presented in a temporally regular (predictable) or irregular (unpredictable) manner while EEG was recorded. We hypothesized cross-modal temporal predictions to be mediated by pre-stimulus cerebello-cortical beta-band (12-25 Hz) activity. In turn, we expected HC, but not CE patients, to show a modulation of pre-stimulus beta power as a function of temporal prediction. HC showed greater pre-stimulus beta-band suppression presumably related to anticipation of sound onsets, and stronger post-stimulus delta-band (1-4 Hz) power in the predictable than unpredictable condition. Furthermore, they displayed a significant modulation of pre-stimulus delta-beta cross-frequency coupling as a function of temporal predictability. These effects were not observed in the CE group, suggesting a deficit in temporal predictions. These results extend the role of cerebellar predictive timing from sensorimotor to motor-independent cross-modal temporal predictions.