cerebellum vs cerebrum

cerebellum

noun
  • Part of the hindbrain in vertebrates. In humans it lies between the brainstem and the back of the cerebrum and is formed of two lateral lobes and a median lobe. It plays an important role in sensory perception, motor output, balance and posture. 

cerebrum

noun
  • The principal and most anterior part of the brain in vertebrates, which is located in the front area of the skull and divided into two hemispheres, left and right, separated by a fissure. In humans it is the largest part of the brain and is responsible for the integration of complex sensory functions and the initiation and coordination of voluntary activity, and the higher mental functions such as consciousness, thought, reason, emotion, and memory. 

How often have the words cerebellum and cerebrum occurred in a corpus of books? (source: Google Ngram Viewer )