Automatic behavior: A behavior that is performed without conscious knowledge and that does not appear to be under conscious control.
This curious type of behavior occurs in a number of neurological and psychiatric disorders. The neurologic disorders associated with automatic behavior include narcolepsy (the sudden recurrent uncontrollable compulsion to sleep) and some forms of epilepsy (such as psychomotor epilepsy). The psychiatric conditions associated with automatic behavior include schizophrenia (catatonic type) and fugue (flight) states.
Automatic behavior involves doing something "automatically" and not remembering afterwards how one did it or even that one did it. Automatic behavior is also called automatism.