Modulation of cerebellar activation by predictive and non-predictive sequential finger movements.

We investigated the modulation of cerebellar activation by predictive and non-predictive sequential finger movements. It is hypothesized that the prediction of desired movement sequences and adaptation to new movement parameters is mediated by the cerebellum. Using functional MRI at 1.5 T, seven normal subjects performed sequential finger to thumb opposition movements, either in predictive (repeatedly 2,3,4,5) or non-predictive (randomized) fashion at a constant frequency of 1 Hz. Performance and error rates were monitored by simultaneous recording of the finger movements. Predictive sequential finger opposition movements activated a cerebellar network including the lobuli IV-VI ipsilateral to the movements, the contralateral lobuli IV-VI, the vermis, and lobuli VIIB-VIII ipsilaterally. Non-predictive compared to predictive finger opposition movements activated a broader area within the ipsi- and contralateral anterior cerebellum, lobuli IV-VI, the vermis, and the ipsilateral lobuli VIIB-VIII. Additional activation foci were found in the contralateral lobuli VIIA and VIIB-VIII. Our study demonstrates a modulated information processing within the cerebellar network dependent on the predictability of movement sequences.