The Collaborative International Dictionary of English v.0.48:

Cerebration \Cer`e*bra"tion\, n.
   Action of the brain, whether conscious or unconscious.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cerebration
    n 1: the process of using your mind to consider something
         carefully; "thinking always made him frown"; "she paused
         for thought" [syn: thinking, thought, thought
         process, cerebration, intellection, mentation]