Source : Webster's Revised Unabridged Dictionary (1913)

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

Source : WordNet®

cerebration
     n : the process of thinking (especially thinking carefully);
         "thinking always made him frown"; "she paused for
         thought" [syn: {thinking}, {thought}, {intellection}, {mentation}]