Out of your body experiences

The study participant sits in a chair wearing a pair of head-mounted video displays. These have two small screens over each eye, which show a live film recorded by two video cameras placed beside each other two metres behind the participant's head. The image from the left video camera is presented on the left-eye display and the image from the right camera on the right-eye display. The participant sees these as one 'stereoscopic' (3D) image, so they see their own back displayed from the perspective of someone sitting behind them. (Credit: Image courtesy of University College London) (Reference: Here.)

The above link is a fascinating article on inducing out of body experiences. The part that caught my attention is this:

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

Last year, when Dr. Ehrsson was “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 your eyes were placed?” he said. “Or from where your body was placed?”

To find out, he asked people to sit in a chair and wear goggles connected to two video cameras placed six feet behind them. The left camera projected to the left eye, the right camera 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 the 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 situated.

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.

Years ago, my friend Andy mentioned just such a experiment. He put as: What would you see if you could take your eyeballs out of your head and the point them at yourself? I think we have an answer here.

Also, here's a thought: If people feel that these experiments are actually happening to them, that is, the threat of a hammer induces feeling of being hit by hammer, then we have a very effective means for torture. If a captive can be led to think wrongly, then torture would be physically harmless (or somewhat, given that one responds physically the effect is not truly harmless) yet highly effective.

Hat tip: Ilachina