The human brain is actually two brains, each capable of advanced mental functions. When the cerebrum is divided surgically, it is as if the cranium contained two separate spheres of consciousness.
D000818:Animals; D001921:Brain / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology*; D000882:Haplorhini; D006801:Humans; D008297:Male; D008606:Mental Processes