The feeling one is floating out of their body and looking down on themselves, or their hand has been possesed by an alien being or an evil entity are common examples of whether the soul exists, or that the world is full of paranormal influences. But is this really the case? And have their been credible alternative explanations for these and other phenomena?

In January 2000, stories about a surgeon, Robert Smith, emerged in the meda, who had amputated the legs of two patients at their own request and was planning a third amputation. The news stories described the patients as suffering from a type of "Body Dysmorphic Disorder". 

Studies have pointed to a condition called Body Integrity Identity Disorder, which blurs the distiction of who is the "owner" of parts of their own body.  An apparently rare condition characterized by a burning and incessant desire to amputate an otherwise perfectly healthy limb.

The first documented case of this disorder dates back to 1785, by anatomist Jean-Joseph Sue, who described the case of an Englishman who fell in love with a one-legged woman, and wanted to become an amputee himself so that he could win her heart. He offered a surgeon 100 guineas to amputate his leg and, when the surgeon refused, forced him to perform the operation at gunpoint.

Mo will look at the archives and delve into recent developments in neuroscience of the self to see whether we can shed some light for past stories of paranormal and anomalous psychological experiences.

Mo Costandi is a molecular and developmental neurobiologist and writes The Neurophilosophy blog for the Guardian. He can be found lurking as @mocost on Twitter.