This interesting article from Science Daily:
A new study, led by Dr Manos Tsakiris from Royal Holloway, University of London, suggests that the way we experience the internal state of our body may also influence how we perceive our body from the outside, as for example in the mirror. The research appears today (5 January) in the Proceedings of the Royal Society B.
Psychologists measured how good people are at feeling their body from within by asking them to count their heartbeats over a few minutes. They then measured how good people are at perceiving their own body-image from the outside by using a procedure that tricks them into feeling that a fake, rubber hand is their own hand. Click the link above for more.