Limitations of PET and lesion studies in defining the role of the human cerebellum in motor learning

PET studies using classical conditioning paradigms are reported. It is emphasized that PET studies show “cerebellar involvement” and not “specific function” in learning paradigms. The importance of dissociating motor performance and learning deficits in human lesions studies is demonstrated in two exemplary studies. The different role of the cerebellum in adaptation of postural reflexes and learning of complex voluntary arm movements is discussed, [THACH]