Source : Webster's Revised Unabridged Dictionary (1913)

Automatism \Au*tom"a*tism\, n.
   The state or quality of being automatic; the power of
   self-moving; automatic, mechanical, or involuntary action.
   (Metaph.) A theory as to the activity of matter.

Source : WordNet®

automatism
     n : any reaction that occurs automatically without conscious
         thought or reflection (especially the undirected behavior
         seen in psychomotor epilepsy)