Special section: Editorial Out of the body, but not out of mind Peter Brugger a, * and Christine Mohr b a Department of Neurology, University Hospital Zurich, Switzerland b Department of Experimental Psychology, University of Bristol, UK ‘‘. some of the delusions of the insane have their origin in what may justly be called motor hallucinations; a disorder of the nervous centres of the motor intuitions generates in consciousness a false conception or delusion as to the condition of the muscles, so that an individual lying in his bed believes himself flying through the air, or imagines his legs, arms, or head, to be separated from his body, just as he has hallucinations of sense when the sensorial centres are disordered.’’ (Maudsley, 1876; pp. 1482–483) What Henry Maudsley wrote more than 130 years ago is remarkable in several respects. First, it shows that out-of- body experiences (OBEs), defined as the sensation of a sepa- ration between body and observing self, have been discussed in the medical literature long before they were labeled as such. Second, the brief passage makes clear that an OBE is more than a mere hallucination and more than a purely visual– perceptual phenomenon. Rather, it reflects a disorder of central ‘‘motor intuitions’’, or in a broader sense, a distur- bance in the representation of information about the current state of one’s body - its posture, kinaesthetics and gravita- tional orientation. Importantly, it is already recognized that there are ‘‘partial OBEs’’, i.e., an illusory reduplication not of one’s entire body, but of just an arm or a leg. Finally, and perhaps most importantly in the context of the present Special Section, Maudsley recognized that only knowledge of the cognitive mechanisms underlying OBEs in the mentally sane will eventually allow an understanding of the complex and sometimes bizarre distortions of corporeal awareness repor- ted by psychotic patients. Even if it is true that 19th century psychiatry and neurology were not entirely blind to the phenomena associated with OBEs, the scattered contributions did not form a proper literature. The key descriptive work on OBEs had its origin out of the body of the mainstream sciences. Stimulated by folk- psychological beliefs, surprisingly invariant across cultures and times (Mead, 1919; Sheils, 1978; Metzinger, 2005) spiritu- alism and occultism embraced the idea of a separate existence of body and mind. While some of the early work contains observational details, potentially revealing even from a current-day perspective (Durville, 1909; De Rochas, 1895, 1896), literally hundreds of monographies on the ‘‘projection of the astral body’’ (Fox, 1962; Muldoon and Carrington, 1929), ‘‘ecsomatic experiences’’ (Green, 1968), or ‘‘soul travelling’’ (Fischer, 1975) propagated interpretations that are far from being compatible with a scientific view of body, mind and corporeal awareness. Around the middle of the 20th century, Austrian psychiatrist Menninger-Lerchenthal (deceased in 1966), set out to bridge some of the gaps between parapsychological and neuro- psychological accounts of the OBE. In a series of publications on heautoscopy (i.e., the doppelga ¨nger experience as a precursor form of an OBE) he noticed that esoteric notions of a second, subtle body and neuropsychiatric models of an illusory sepa- ration between self and body can be reconciled with reference to the concept of ‘‘body schema’’ (Menninger-Lerchenthal, 1946). In particular, Menninger-Lerchenthal emphasized the similar- ities between the phantom limb as it manifests itself after peripheral or central lesions and phantom body, i.e., the expe- rience of oneself as detached from the physical body (e.g., Menninger-Lerchenthal, 1954, 1961) and as ‘‘flying through the air’’, in Maudsley’s description (see also the cover illustration of this issue of Cortex). He was convinced that ‘‘the value of a scientific explanation [of heautoscopy and OBE] for the science of the mind (die Seelenkunde) cannot be overestimated’’ (Menninger-Lerchenthal, 1961, p. 745). We have to assume that language barriers are to be blamed for the fact that Menninger-Lerchenthal’s ideas have * Corresponding author. Department of Neurology, University Hospital Zurich, CH-8091 Zurich, Switzerland. E-mail address: peter.brugger@usz.ch (P. Brugger). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/cortex 0010-9452/$ – see front matter ª 2008 Elsevier Srl. All rights reserved. doi:10.1016/j.cortex.2008.11.004 cortex 45 (2009) 137–140