impulse vs intrusive thought

impulse

noun
  • A wish or urge, particularly a sudden one prompting action. 

  • A thrust; a push; a sudden force that impels. 

  • The integral of force over time. 

verb
  • To impel; to incite. 

intrusive thought

noun
  • an unwelcome involuntary thought, image or idea 

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