Functional topography of the human cerebellum revealed by functional neuroimaging studies

Abstract

Functional imaging studies in healthy subjects report cerebellar activation during a wide range of tasks, from motor execution (finger tapping, motor learning, smooth pursuit eye movements) to higher-level cognitive tasks (Tower of London, working memory paradigms, verbal fluency) in which motor responses are eliminated or controlled for. The anatomical connections between the cerebellum, spinal cord, and sensorimotor and association areas of the cerebral cortex suggest a functional topography exists within the human cerebellum, such that different cerebellar regions are part of distributed spinocerebellar and cerebro-cerebellar circuits. This concept is supported by data from functional imaging studies, in which regional activation patterns differ for sensorimotor vs. cognitive and affective task paradigms. Here these neuroimaging data are reviewed and both cross-task comparisons and within-task topography are considered. The evidence indicates that cerebellar activation patterns are related to the specific demands of a given task, and the localization of the activation patterns reflects the engagement of different cerebro-cerebellar circuits. Establishing cerebellar functional topography in humans has important implications for the interpretation of functional imaging data, the understanding of clinical outcomes in cerebellar damage or disease, and the broader understanding of the role of the cerebellum in motor and cognitive function.