The cerebellum is highly stereotyped in its cellular circuitry. Output neurons in the nuclei with
one exception excite their downstream targets in other parts of the nervous system. Yet the
much more voluminous cerebellar cortex inhibits these output neurons. This has suggested
that the desired output activity pattern is achieved by removing all unwanted activity patterns
('sculpting'). Lesions of the lateral cerebellum impair cognitive functions including speech.
These lateral portions are active during imagined as well as overt movements. Imagined …