Both sides of human cerebellum involved in preparation and execution of sequential movements.

Using an event-related fMRI procedure, we investigated the role of the human cerebellum in sequential finger movements. Subjects performed a delayed sequential finger movement task in which an instructive cue preceded the imperative signal by 16.5 s. Bilateral activation was observed in the cerebellum following both the cue and imperative signals. The activated regions overlapped within the cerebellum, extending across intermediate and lateral regions corresponding to lobules HV-HVII. In contrast, activation in primary motor cortex was primarily restricted to the execution phase and most prominent in the contralateral hemisphere. These results indicate that the cerebellum is bilaterally recruited for the preparation and execution of sequential movements.