Doppelgänger (German loanword) is the ghostly double of a living person. The word is also used to describe the sensation of having glimpsed oneself in peripheral vision, in a position where there is no chance that it could have been a reflection.
They are generally regarded as harbingers of bad luck. In some traditions, a doppelgänger seen by a person’s friends or relatives portends illness or danger, while seeing one’s own doppelgänger is an omen of death.
Shahar Arzy and colleagues of the University Hospital, Geneva, Switzerland concluded – after a live experiment on a patient – that the left temporoparietal junction of the brain evokes the sensation of self image—body location, position, posture etc. When the left temporoparietal junction is disturbed, the sensation of self-attribution is broken and may be replaced by the sensation of a foreign presence or copy of oneself displaced nearby. This copy mirrors the real person’s body posture, location and position. Arzy and his colleagues suggest that the phenomenon they created is seen in certain mental illnesses, such as schizophrenia, particularly when accompanied by paranoia, delusions of persecution and of alien control. Nevertheless, the effects reported are highly reminiscent of the doppelgänger phenomenon. Accordingly, some reports of doppelgängers may well be due to failure of the left temporoparietal junction.
So have you ever seen your doppelgänger?