The German term Doppelgänger was introduced in 1796 in a collection of short stories colloquially known as Siebenkäs, published by the German writer Johann Paul Friedrich Richter, who was also known as Jean Paul (1763-1825). In the Anglo-Saxon literature the term Doppelgänger is either used untranslated (in the form of doppelganger), or translated as * double. In biomedicine both terms are used to denote a *visual hallucination depicting a mirror image of oneself, such as may occur in cases of * autoscopy, *heautoscopy, and other instances of * reduplicative hallucination. The term doppelgänger is also used in the context of the * syndrome of subjective doubles. The term * somaesthetic doppelgänger is used as a synonym for the term * sensed presence. In parapsychology a doppelgänger is an astral or etheric counterpart of the physical body, which is believed to be capable of temporarily moving about in extracorporeal space. The historical literature is replete with references to doppelgängers allegedly observed by the affected individual as well as by third parties. A well-known example is the story of St. Anthony of Padua (1195-1231), who reportedly preached simultaneously in two different places during the year 1226. Parapsychologists use the term bilo-cation to refer to this phenomenon. To facilitate the study of the physiological correlates of doppelgängers, the Austrian psychiatrist Erich Menninger-Lerchenthal (d. 1966) proposed the term eigenen Doppelgänger (one's own doppelgänger) to denote doubles that are perceived by the affected individual, but not by others. Neu-roscientific studies of such eigenen Doppelgänger often hint at a biological correlate located in an area at the occipito-temporo-parietal junction.
References
Blanke, O., Mohr, C. (2005). Out-of-body experience, heautoscopy, and autoscopic hallucination of neurological origin. Implications for neurocognitive mechanisms of corporeal awareness and self-consciousness. Brain Research Reviews, 50, 184-199.
Christodoulou, G.N. (1978). Syndrome of subjective doubles. American Journal of Psychiatry, 135,249-251.
Melton, J.G., ed. (1996). Encyclopedia of occultism and parapsychology. Volume 2. Fourth edition. Detroit, MI: Gale.
Menninger-Lerchenthal, E. (1946). Der eigene Doppelgänger. Bern: Verlag Hans Huber.
Jean Paul (1796-1797). Blumen-, Frucht- und Dornenstücke oder Ehestand, Tod und Hochzeit des Armenadvokaten F. St. Siebenkäs im Reichsmarktflecken Kuhschnappel. Berlin:CarlMatz-dorffs Buchhandlung.
Dictionary of Hallucinations. J.D. Blom. 2010.