Body ownership - the sense that one's body belongs to one's self - is central to self-awareness, and yet is something that most of us take completely for granted. We experience our bodies as being an integral part of ourselves, without ever questioning how we know that our hands belong to us, or how we can distinguish our body from its surroundings.
These issues have long intrigued philosophers and psychologists, but had not been investigated by neuroscientists until recently. Now researchers from the Karolinska Institute report that they have induced a "body-swap" illusion, whereby subjects perceived the body of another person as belonging to themselves.