perception vs understanding

perception

noun
  • Conscious understanding of something. 

  • That which is detected by the five senses; not necessarily understood (imagine looking through fog, trying to understand if you see a small dog or a cat); also that which is detected within consciousness as a thought, intuition, deduction, etc. 

  • Vision (ability) 

  • The organisation, identification and interpretation of sensory information. 

  • Acuity 

understanding

noun
  • The act of one that understands or comprehends; comprehension; knowledge; discernment. 

  • Opinion, judgement or outlook. 

  • An informal contract; mutual agreement. 

  • A reconciliation of differences. 

  • Sympathy. 

  • Reason or intelligence, ability to grasp the full meaning of knowledge, ability to infer. 

adj
  • Showing compassion, tolerance, and forbearance. 

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