Scientists elicit the sensation of an apparition or 'ghost' in a laboratory setting using a robotic device to trick the brains of test subjects. Matthew Stock reports.
Scientists in Switzerland have created the feeling of an unseen presence - or ghost - in the lab. This robotic device reproduces the subject's movement by touching them on the back. But by introducing a slight delay, the distorting of temporal and spatial perception induces a 'ghostly' sensation. Research leader Professor Olaf Blanke said the distorting of the "sensorimotor" brain signals had some surprising results. (SOUNDBITE) (English) PROFESSOR OLAF BLANKE, DIRECTOR OF THE CENTER FOR NEUROPROSTHETICS, BERTARELLI CHAIR IN COGNITIVE NEUROPROSTHETICS AT EPFL, SAYING: "And we built a robot which allows us to distort this signal, which makes it hard - or impossible actually - our robot makes it impossible for our healthy subjects now to predict those signals... actually some subjects reacted very strongly and they reported that not only that somebody else was touching them, but somebody else was also present. So strong, that some of them decided not to finish the experiment." Blanke's team from the Swiss Federal Institute of Technology first scanned the brains of people who reported the phenomena. They found that in patients with neurological disorders there were abnormalities in regions that contribute to multisensory signal processing. The robot recreates this sensation in healthy individuals. Blanke says eventually he wants to develop therapies based on the study that will reverse these feelings in patients. This, he says, could include a wearable device. (SOUNDBITE) (English) PROFESSOR OLAF BLANKE, DIRECTOR OF THE CENTER FOR NEUROPROSTHETICS, BERTARELLI CHAIR IN COGNITIVE NEUROPROSTHETICS AT EPFL, SAYING: "So this is something that the patient will have maybe inserted in his clothes; smart textiles in a way. And should there be strong manifestations in this case, one could provide feedback in a way that is now not optimised to induce such a psychotic state but to dis-regulate or to down-regulate such a state." While the study didn't set out to disprove the existence of ghosts, for the scientists at least, they exist only in our minds.