During an out-of-body experience, people feel a sensation of leaving their own physical body and often see themself floating above it. However, sometimes the experiencer sees their own body – or “doppelganger” – standing right in front of them, as in a mirror, and does not feel a separation from their physical body. Can this be considered an out-of-body experience, and how are these phenomena related? This issue is addressed in the latest article in NeuroImage: Clinical journal by researchers Eva Blondiaux, Lukas Heydrich, and Olaf Blanke.
Autoscopy is the experience of seeing the image of your body from the outside. During these illusory visual experiences, the person sees a second body that they perceive as their own. Autoscopic phenomena include out-of-body experience (OBE), autoscopic hallucination (AH), and heautoscopy (HAS). All three effects are based on visual body duplication.
During an autoscopic hallucination, the subject sees their double but, at the same time, feels themself in their physical body. During heautoscopy, the subject’s consciousness switches between bodies, so they cannot say with any certainty which body they are in at the moment. And, finally, during an out-of-body experience, consciousness is completely switched into the body of the double, through whose eyes we see our own body from the outside. Moreover, if in the case of AH, the subject realizes their experience is a hallucination, in the latter two cases, the situation is perceived as reality.
In order to understand how these phenomena are related and how they differ, scientists compared networks of brain lesions in 26 neurological patients who reported experiencing these phenomena and identified the similarities and variances in their patterns. As in previous studies, in all three phenomena, the temporoparietal junction, which is responsible for our self-determination in space, was found to play a central role — 90% of the lesions causing autoscopy affected this region. However, each form of autoscopy was associated with additional specific brain networks.
AH is caused by the activity of the bilateral precuneus, associated with the perception of one’s own face. This is why patients often report seeing their own faces during hallucinations, as clearly as if they were looking in a mirror. Heautoscopy, on the other hand, has pronounced motor and linguistic aspects. This is due to the fact that the parts of the brain involved in this case are responsible for inner speech, which is consistent with the fact that a person “switches” consciousness between bodies. OBE has vestibular and spatial components associated with dissociation under the influence of the brain network, arising from the bilateral angular gyrus.
In fact, out-of-body experiences are the most powerful form of autoscopy phenomenon, involving complete separation from the physical body. Moreover, all three phenomena are related, which suggests that a person who has experienced one of these phenomena also has a higher chance of experiencing others. Have you ever seen your “doppelganger”?
The article was published in March 2021 in the journal NeuroImage: Clinical.
