perseverate vs persevere

perseverate

verb
  • To persist in doing something; to continue to repeat an action after the original stimulus has ended. 

  • To cause the perseveration of (a given reflex or response). 

persevere

verb
  • To persist steadfastly in pursuit of an undertaking, task, journey, or goal, even if hindered by distraction, difficulty, obstacles, or discouragement. 

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