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Prof. Olaf Blanke and his colleagues from the Laboratory of Cognitive Neuroscience at EPFL in Switzerland have been doing research on the neural-correlates of out-of-body-experiences since at least 2002. This new study is very unusual, as they claim to be able to produce an out-of-body-experience when the user of special goggles is shown a projected image of themselves while being poked with a stick.

   

Out-of-body experiences are most common in people who endure intense meditation practices, experience sleep paralysis, and following certain types of head injuries. Research such as this strives to discover exactly how the brain creates the out-of-body-experience sensation.

It is arguable whether these experiencies re-produce bona-fide NBE's, but it is an interesting effect nonetheless.

NewScientist just posted a video to YouTube featuring Olaf's group inducing out-of-body-experiences:

 

The out-of-body experiments were conducted by two research groups using slightly different methods intended to expand the so-called rubber hand illusion.

 

In that illusion, people hide one hand in their lap and look at a rubber hand set on a table in front of them. As a researcher strokes the real hand and the rubber hand simultaneously with a stick, people have the vivid sense that the rubber hand is their own.

 

When the rubber hand is whacked with a hammer, people wince and sometimes cry out.

 

The illusion shows that body parts can be separated from the whole body by manipulating a mismatch between touch and vision. That is, when a person’s brain sees the fake hand being stroked and feels the same sensation, the sense of being touched is misattributed to the fake.

 

The new experiments were designed to create a whole body illusion with similar manipulations.

 

In Switzerland, Dr. Olaf Blanke, a neuroscientist at the École Polytechnique Fédérale in Lausanne, Switzerland, asked people to don virtual reality goggles while standing in an empty room. A camera projected an image of each person taken from the back and displayed 6 feet away. The subjects thus saw an illusory image of themselves standing in the distance.

 

Then Dr. Blanke stroked each person’s back for one minute with a stick while simultaneously projecting the image of the stick onto the illusory image of the person’s body.

 

When the strokes were synchronous, people reported the sensation of being momentarily within the illusory body. When the strokes were not synchronous, the illusion did not occur.

 

In another variation, Dr. Blanke projected a “rubber body” — a cheap mannequin bought on eBay and dressed in the same clothes as the subject — into the virtual reality goggles. With synchronous strokes of the stick, people’s sense of self drifted into the mannequin.

 

A separate set of experiments were carried out by Dr. Henrik Ehrsson, an assistant professor of neuroscience at the Karolinska Institute in Stockholm, Sweden.

 

Last year, when Dr. Ehrsson was, as he says, “a bored medical student at University College London”, he wondered, he said, “what would happen if you ‘took’ your eyes and moved them to a different part of a room? Would you see yourself where you eyes were placed? Or from where your body was placed?”

 

To find out, Dr. Ehrsson asked people to sit on a chair and wear goggles connected to two video cameras placed 6 feet behind them. The left camera projected to the left eye. The right camera projected to the right eye. As a result, people saw their own backs from the perspective of a virtual person sitting behind them.

 

Using two sticks, Dr. Ehrsson stroked each person’s chest for two minutes with one stick while moving a second stick just under the camera lenses — as if it were touching the virtual body.

 

Again, when the stroking was synchronous people reported the sense of being outside their own bodies — in this case looking at themselves from a distance where their “eyes” were located.

 

Then Dr. Ehrsson grabbed a hammer. While people were experiencing the illusion, he pretended to smash the virtual body by waving the hammer just below the cameras. Immediately, the subjects registered a threat response as measured by sensors on their skin. They sweated and their pulses raced.

 

They also reacted emotionally, as if they were watching themselves get hurt, Dr. Ehrsson said.

 

People who participated in the experiments said that they felt a sense of drifting out of their bodies but not a strong sense of floating or rotating, as is common in full-blown out of body experiences, the researchers said.

 

The next set of experiments will involve decoupling not just touch and vision but other aspects of sensory embodiment, including the felt sense of the body position in space and balance, they said.


Link to the New York Times Article


Here are some of the previous studies involving Prof. Olaf Blanke on out-of-body experiences - the links are to PDF documents.


Blanke O, Thut G (2006). Inducing out of body experiences. In: Tall Tales (ed. G. Della Sala), Oxford: Oxford University Press.

Blanke O et al.Linking OBEs and self processing to mental own body imagery at the temporo-parietal junction. J Neurosci 25:550-55

Blanke O, Arzy S. (2005) Out-of-body experience, self, and the temporoparietal junction. Neuroscientist 11:16-24.

Buenning S, Blanke O. (2005) The out-of body experience precipitating factors and neural correlates. Prog Brain Res 150 333-353.

Blanke O (2004) Out-of-body experience and their neural basis. Brit Med J 329:1414-1415.

Blanke O,et al(2004) Out-of-body experience and autoscopy of neurological origin. Brain 127:243-258.[Editorial Frith C (2004) Brain 127 2.

Blanke O. (2004) The neurology of Out-of-body experiences Proceedings of the 5th Symposium of the Bial Foundation, Vol 5:193-218.

Blanke O (2007) From out-of-body experiences to the neural mechanisms of self consciousness. Companion to Consciousness, Oxford University Press. (in press)

 

Blanke O, Arzy S, Landis T. (2007) Illusory perception of body and self. In: Handbook of Neurology (Ed. G. Goldenberg) (in press).

 

Easton S, Blanke O, Mohr C (2007) A putative implication for fronto-parietal connectivity in out-of-body experiences. Cortex (in press).

 

Blanke O, Castillo V (2007) Clinical neuroimaging in epileptic patients with autoscopic hallucinations and out-of-body experiences.Case report and review of the literature. Epileptologie 24: 90-96.

mmm mmmm - Good Stuff!

More articles about this at ArsTechnica NeuroPhilosophy MindHacks Physorg

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9:32am April 19-5:00 GMT