Cerebro-cerebellar functional connectivity revealed by the laterality index in tool-use learning

THE function of the lateral part of the human cerebellum was investigated t hrough cerebro-cerebellar functional connectivity. We propose a laterality index method to reveal a functional and possibly anatomical pathway between the cerebral cortex and the cerebellum. The brain activity involved in lea rning a visually-guided tracking skill using a novel computer mouse was mea sured by functional magnetic resonance imaging. The imaging data analyzed u sing the method suggest that the simple lobule and semilunar lobule of the lateral cerebellum have connections with the pars opercularis and pars tria ngularis in the inferior frontal gyrus. A possible function of this cerebro -cerebellar communication loop is tool usage, which is in-between the cogni tive and motor functions of the human cerebellum. (C) 1999 Lippincott Willi ams & Wilkins.