A ridiculous number of science-fiction TV series and films have moments where characters exchange minds, from the brilliance of Quantum Leap to the latest season of Heroes. Body-swapping is such a staple of imaginative fiction that it’s tempting to think that it has no place being scientifically investigated. But Valeria Petkova and Henrik Ehrsson beg to differ – while actually exchanging minds is clearly impossible, these two scientists have created an illusion that can make people feel that another body – be it a mannequin or an actual person – is really theirs.

The idea that our bodies are part of ourselves is so obvious and permanent that it seems ridiculous to consider any other alternative. But