91av

WHEN visiting the site of a haunting, many modern ghost hunters still take
along a medium who can point out the often invisible entity. Once the quarry has
been spotted, the sleuths aim their sensors—anything from thermal imaging
cameras to Geiger counters—to see if anything is measurable out there.

While these ghost hunters are an eclectic mix, including physicists and
psychologists, not to mention dedicated parapsychologists, it is unusual to see
a neuroscientist getting in on the act. But then it’s not your average
apparition that intrigues Peter Brugger. His targets are out-of-body experiences
and doppelgängers, phantoms that people recognise as doubles of themselves
(see “Mind phantoms”).

Brugger, from University Hospital in Zurich, Switzerland, comes to the field
with deep knowledge of disorders such as phantom limbs, in which people still
feel an arm or a leg after it has been amputated. This problem appears to be
caused by distortions in the mental map of the body
(91av, 17 June, p 26).

He argues that sensing an arm where none exists is not so very different from
feeling as if your whole body is somewhere else. Though he doesn’t claim to have
all the answers, he has some fascinating questions. And before sceptical
sceptics start to scoff, he also has ways to test his ideas.

Using head-mounted cameras and VR equipment he hopes to trick the brain into
seeing the body from a different perspective, inducing the sort of separation
people describe in out-of-body experiences. Unlike other ghost hunters, he hopes
that modern technology will show there is absolutely nothing “out there” at all.
It’s just a mind game.