Automatic behavior, from the Greek automatos or self-acting, is the spontaneous production of often purposeless verbal or motor behavior without conscious self-control or self-censorship. This condition can be observed in a variety of contexts, including schizophrenia, psychogenic fugue, epilepsy (in complex partial seizures and Jacksonian seizures), narcolepsy or in response to a traumatic event. The individual does not recall the behavior. According to the book 'The Mind Machine' by Colin Blakemore, hypoglycemia usually leads quickly to unconsciousness, but as blood glucose level falls, there is 'a window of experience between sanity and coma in which self-control is lost', and the body 'behaves on its own'.
Automatic behavior can also be exhibited whilst in the REM state—subjects can hold conversations, sit up and even open their eyes. Those acts are considered sub-conscious as most of the time the events cannot be recalled by the subject. It is most common when the subject has had under 10 hours sleep within a 36 hour period.
See also