Out-of-body experience, heautoscopy, and autoscopic hallucination of neurological origin

Autoscopic phenomena (AP) are rare visual illusions where a person sees a second own body in external space, including out-of-body experiences, autoscopic hallucinations, and heautoscopy. This article reviews and statistically analyzes 41 neurological patients described over the past century, extracting phenomenological, functional, and anatomical variables that distinguish or are comparable among the three types. The findings provide testable hypotheses for future research. The authors suggest that scientifically demystifying AP can help investigate the cognitive functions and brain regions underlying normal corporeal awareness and self-consciousness.

Study at a glance

Abstract

Autoscopic phenomena (AP) are rare illusory visual experiences during which the subject has the impression of seeing a second own body in extrapersonal space. AP consist of out-of-body experience (OBE), autoscopic hallucination (AH), and heautoscopy (HAS). The present article reviews and statistically analyzes phenomenological, functional, and anatomical variables in AP of neurological origin (n = 41 patients) that have been described over the last 100 years. This was carried out in order to further our understanding of the underlying mechanisms of AP, much as previous research into the neural bases of body part illusions has demystified these latter phenomena. Several variables could be extracted, which distinguish between or are comparable for the three AP providing testable hypotheses for subsequent research. Importantly, we believe that the scientific demystification of AP may be useful for the investigation of the cognitive functions and brain regions that mediate processing of the corporeal awareness and self consciousness under normal conditions.