axon vs psyche

axon

noun
  • A nerve fibre which is a long slender projection of a nerve cell, and which conducts nerve impulses away from the body of the cell to a synapse. 

psyche

noun
  • The human mind as the central force in thought, emotion, and behavior of an individual. 

  • The human soul, mind, or spirit. 

  • A small white butterfly, Leptosia nina, family Pieridae, of Asia and Australasia. 

verb
  • To put (someone) into a required psychological frame of mind. 

  • To treat (someone) using psychoanalysis. 

  • To intimidate (someone) emotionally using psychology. 

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