at heart vs centrally

at heart

prep
  • In spirit; according to one's beliefs, views or feelings; deep down, fundamentally, really. 

  • Wished earnestly for; held in high esteem. 

centrally

adv
  • In a central manner or situation; at, to, through or from the centre. 

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