title: Solving the mystery of the human cerebellum.
abstract: The mystery of the human cerebellum is this: Why did it enlarge so dramatically in the last million years of human evolution, concomitantly with the greater enlargement of the cerebral cortex? A solution to this mystery was proposed in the 20th century as a result of research by several groups of scientists who investigated the contributions of the cerebellum to the cerebral cortex. In contrast to the 19th century investigations, which were focused on the motor functions of the cerebellum, the focus of the subsequent investigations was expanded to include some mental functions because evidence was produced that the cerebellum contributes to cognition. It was proposed that the combination in the cerebellum of motor and mental capabilities enables the cerebellum to confer on humans some adaptive advantages of great value, and this ability would explain why the human cerebellum has continued to enlarge so dramatically. A valuable adaptive advantage that is included in the proposal is the possibility that the cerebellum couples the motor function of articulating speech to the mental function that selects the language to be spoken, thus helping to produce fluent human speech and language. The validity of this proposal about linguistic processing has not yet been verified. Therefore the mystery of cerebellar enlargement in humans is not yet solved and requires further research.
authors.affiliation: Channing House, 850 Webster Street, Palo Alto, CA 94301, USA. leiner2@mac.com
authors.forename: Henrietta C
authors.initials: HC
authors.lastname: Leiner
mesh_terms: D000818:Animals; D002526:Cerebellar Diseases / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D002531:Cerebellum / Q000033:anatomy & histology / Q000502:physiology*; D002986:Clinical Trials as Topic; D003071:Cognition / Q000502:physiology*; D006801:Humans; D009483:Neuropsychological Tests
references.citation: Brain Behav Evol. 1975;11(2):73-90
references.pmid: 1174934
references.citation: J Comp Neurol. 1992 Dec 22;326(4):549-60
references.pmid: 1484123
references.citation: Neurology. 1995 Sep;45(9):1785-6
references.pmid: 7675253
references.citation: Trends Neurosci. 1993 Nov;16(11):444-7
references.pmid: 7507614
references.citation: Science. 1994 Aug 12;265(5174):949-51
references.pmid: 8052851
references.citation: Neuron. 1996 Jan;16(1):13-5
references.pmid: 8562076
references.citation: Science. 1994 Oct 21;266(5184):458-61
references.pmid: 7939688
references.citation: J Clin Neurophysiol. 1988 Oct;5(4):307-23
references.pmid: 3053783
references.citation: Mt Sinai J Med. 1974 Jan-Feb;41(1):103-19
references.pmid: 4592824
references.citation: J Cogn Neurosci. 1989 Spring;1(2):153-70
references.pmid: 23968463
references.citation: Ital J Neurol Sci. 1987 Oct;8(5):425-36
references.pmid: 3323123
references.citation: Behav Neurosci. 1989 Oct;103(5):998-1008
references.pmid: 2679667
references.citation: Behav Neurosci. 1986 Aug;100(4):443-54
references.pmid: 3741598
references.citation: Int Rev Neurobiol. 1997;41:233-54
references.pmid: 9378590
references.citation: Int Rev Neurobiol. 1997;41:535-53
references.pmid: 9378607