WordNet (r) 3.0 (2006):

perseveration
    n 1: the tendency for a memory or idea to persist or recur
         without any apparent stimulus for it
    2: the act of persisting or persevering; continuing or repeating
       behavior; "his perseveration continued to the point where it
       was no longer appropriate" [syn: perseverance,
       persistence, perseveration]