cerebral cortex vs neocortex

cerebral cortex

noun
  • The grey, folded, outermost layer of the cerebrum that is responsible for higher brain processes such as sensation, voluntary muscle movement, thought, reasoning, and memory. 

neocortex

noun
  • The top layer of the cerebral hemispheres in the brain of mammals; part of the cerebral cortex. 

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