ideate vs use one’s head

ideate

noun
  • The actual existence supposed to correspond with an idea; the correlate in real existence to the idea as a thought or existence. 

adj
  • Produced by an idea. 

verb
  • To apprehend in thought so as to fix and hold in the mind; to memorize. 

  • To generate an idea. 

use one’s head

How often have the words ideate and use one’s head occurred in a corpus of books? (source: Google Ngram Viewer )