Evolution of the Cerebellar Sense of Self

The cerebellum is an intriguing component of the brain. In humans it occupies only 10% of the brain volume, yet has approximately 69 billion neurons; that is 80% of the nerve cells in the brain. The cerebellum first arose in jawed vertebrates such as sharks, and early vertebrates also have an additional cerebellum-like structure in the hindbrain. Shark cerebellum-like structures function as adaptive filters to discriminate 'self' from 'other' in sensory inputs. It is likely that the true ce...