Artist's depiction of the separation stage of an<unk> , which often precedes free movement An<unk>  <unk>  or sometimes OOBE) is a phenomenon in which a person perceives the world from a location outside their physical<unk> . An<unk>  is a form of autoscopy (literally "seeing self"), although this term is more commonly used to refer to the pathological condition of seeing a second self, or doppelgänger. The term<unk>  was introduced in 1943 by G. N. M. Tyrrell in his book Apparitions, and was adopted by researchers such as Celia Green, and Robert Monroe, as an alternative to belief-centric labels such as "astral projection" or "spirit walking".<unk> s can be induced by traumatic brain injuries, sensory deprivation, near-death<unk> s, dissociative and psychedelic drugs, dehydration, sleep disorders, dreaming, and electrical stimulation of the brain, among other causes. It can also be deliberately induced by some. One in ten people has an<unk>  once, or more commonly, several times in their life. Psychologists and neuroscientists regard<unk> s as dissociative<unk> s occurring along different psychological and neurological factors.
Out-of-body experience
Therapeutic relationship
Situational strength
Personal narrative
Aerospace physiology
Archetypal pedagogy
Haptic communication
Adequate stimulus