"Participants in a recent psychological study will probably never a look at mannequins – or their own bodies – in quite the same way again. Before the study, they knew their ar ms belonged to them and synthetic ones didn ’t, simply because seeing is believing. Now they ’re not so sure. Researchers at Car negie Mellon University in Pittsburgh asked subjects to keep their eyes on a rubber ar m that was sitting on a table in front of them, With the subject ’s left arm hidden from view by a screen, the researchers simultaneously stroked both the rubber hand and the subject ’s hand with a paintbrush. Even though they knew their own hand was being stroked behind the screen, nearly all the subjects experienced the same bizarre sensation: they felt the fake hand was actually their own.