The monologue of the double: allocentric reduplication of the own voice alters bodily self perception

During autoscopic phenomena, people perceive a double of themselves in extrapersonal space. Such clinical allocentric self-experiences often co-occur with auditory hallucinations, yet experimental setups to induce similar illusions in healthy participants have been limited to visual doubles. We investigated whether feeling the presence of an auditory double could be provoked in healthy participants and how it might affect spatial aspects of bodily self-consciousness. We recorded the own versus another person’s voice while walking around in the room using binaural headphones from an egocentric and an allocentric perspective. In comparison to listening to their own moving voice egocentrically, when listening to themselves allocentrically, participants reported a strong feeling of a presence with a similarly high degree of self-identification, suggesting a successful induction of the feeling of an acoustic doppelganger. When pointing to the source of the own voice participants localized it closer to themselves than when listening to another person’s voice, suggesting a change in spatial perception. Interestingly, the opposite pattern was found in participants that had previous hallucinatory experiences. These findings show that listening to one’s own voice allocentrically can manipulate bodily self-consciousness and self-related spatial perception. This paradigm enables the experimental study of the relationship between auditory vocal hallucinations and bodily self-consciousness, bridging important clinical phenomena and experimental knowledge.