on the brain vs rage

on the brain

prep
  • Obsessively in mind. 

rage

noun
  • Violent uncontrolled anger. 

  • A current fashion or fad. 

verb
  • To act or speak in heightened anger. 

  • To move with great violence, as a storm etc. 

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