Out-of-body experiences are defined by The Free Dictionary as “a vivid feeling of being detached from one’s body, usually involving observing it and its environment from nearby.”
What happens in the brain during an out-of-body experience? Scientists now know, thanks to a little experimentation.
Creating an out-of-body experience
In a study by researchers from the Karolinska Institute in Sweden, a brain scanner was used along with special camera work to create the illusion for the participants of an out-of-body experience.
Participants were given the illusion of being in a separate part of the room from their bodies, and a scan was done on their brain. They found the areas of the brain that were involved were linked with sensations of body ownership and spatial orientation. These same areas in animals have been dubbed “GPS cells” in previous research and are known to be important for memory and navigation.
According to neuroscientist and lead researcher Dr. Arvid Guterstam, feeling ownership of a body “is a very basic experience that most of us take for granted in everyday life.”
The magic of camera-induced illusion
The subjects of the study were asked to lie down in an MRI scanner. At the same time, they had a head-mounted display to show them a video feed from cameras set up in other parts of the room. The cameras were directed toward a stranger’s body with the image of the subject’s body showing in the background.
Researchers then used a rod to touch the stranger’s body and touch the subject’s body at the same time. This gave the participants the sensation of their body being located elsewhere in the room.
“It’s a very fascinating experience,” Guterstam explained. “It takes a couple of touches, and suddenly you actually feel like you’re located in another part of the room. Your body feels completely normal — you don’t feel as if it’s floating around.”
Findings from the brain scan information showed that the hippocampus, which contains the GPS cells, was involved in determining body location. Another area of the brain that was involved was the posterior cingulate cortex, which perceives sensations of body ownership.
Other studies with illusion
This is not the first experiment conducted by Guterstam and his team. In the past they have conducted what they called the “rubber hand illusion” where a participant watches a rubber hand being stroked, while at the same time someone strokes their hand. This gives the subject the sensation of the rubber hand being their own.
Similar methods have been used to give participants the sensation of being invisible or of having a mannequin’s body.
In animal studies, the GPS cells of the brain have been shown to be directly linked with navigating their body through space, as well as involvement in memory. For these tests, animals had to navigate a virtual maze while electrodes sent signals from their brain.
“But we don’t know what the animals perceive,” said Guterstam.
These, and other studies only affirm the amazing power of the brain. Something we often take for granted.
—The Alternative Daily
Sources:
http://news.discovery.com/human/psychology/out-of-body-experience-is-traced-in-the-brain-150504.htm
http://www.livescience.com/50683-out-of-body-illusion.html
http://www.livescience.com/48157-nobel-prize-medicine-for-brain-gps.html
http://www.livescience.com/9526-body-experiences-simulated.html