perseveration

Noun

• Uncontrollable repetition of a particular response, such as a word, phrase, or gesture, despite the absence or cessation of a stimulus, usually caused by brain injury or other organic disorder.
• The tendency to continue or repeat an act or activity after the cessation of the original stimulus.
• The act or an instance of persevering; perseverance.
• Argument by repetition; a mantra.