SEPARATE CEREBELLAR AREAS FOR MOTOR CONTROL

CEREBELLAR activation was measured using functional magnetic resonance imaging, while seven normal subjects tapped their lingers paced by to ne sequences with or without tone omission. The cerebellar anterior lo be (Larsell's H IV-V) ipsilateral to the movement was activated to a s imilar degree irrespective of the presence or absence of the tone omis sion. In contrast, the lateral part of the bilateral posterior lobe (H VIIa) was significantly highly activated for the tone sequence with r andom omission, compared with either that without omission or that wit h regular omission. The result suggests that the H IV-V is involved in motor execution, while the lateral part of H VIIa is involved in onli ne motor adjustment to unpredictable sensory stimuli. NeuroReport 9: 2 359-2362 (C) 1998 Rapid Science Ltd.