Functional mapping of the human cerebellum with positron emission tomography.

Alterations of local neuronal activity induced within the human cerebellum by tactile stimulation and voluntary movement were mapped with positron emission tomographic measurements of brain blood flow. Finger movements produced bilateral, parasagittal blood-flow increases in anterior, superior hemispheric cortex of the cerebellum. Responses to tactile finger stimulation were coextensive with responses to voluntary finger movements but were less intense. Saccadic eye movements produced midline blood-flow increases in the posterior vermis of the cerebellum. Positron emission tomography now permits investigation of functional-anatomical relations within the human cerebellum.