notice vs pick up on

notice

verb
  • To become aware of; to observe. 

  • To be noticeable; to show. 

noun
  • A published critical review of a play or the like. 

  • A written or printed announcement. 

  • Advance notification of termination of employment, given by an employer to an employee or vice versa. 

  • The act of observing; perception. 

  • A formal notification or warning. 

  • Prior notification. 

pick up on

verb
  • To notice, observe, learn, or understand, especially something otherwise overlooked. 

  • To adopt a practice in which others already engage. 

  • To continue or build upon (for example, a task, analysis, or narrative), beginning from a point at which someone has previously stopped. 

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