Out-of-Body Experience

Out-of-Body Experience  were long a source of fascination for people, as there are stories about the "adventures" outside the body for the past several thousand years. The feeling of floating and ability to observe your body from the outside are typical features of these experiences that have puzzled over the time doctors, philosophers and theologians. If for millennia people have attributed the phenomenon of paranormal forces today, thanks to research conducted in recent years by experts in neuroscience, these strange experiences were explained.

Doctors have identified a number of diseases that can lead to body experience, among them the epilepsy and stroke. 

Out-of-Body Experience may become manifest after traumatic events like traffic accidents or drug overdoses and during extreme sports or meditation. Statistics show that one in 10 people is part of such a lifelong experience.

Recently, many scientists were able to induce body experience healthy volunteers, under laboratory conditions, making some important steps to demystify this phenomenon.

The first body experience success in the laboratory

Henrik Ehrsson, cognitive neuroscience professor at the Karolinska Institute in Stockholm, is one of the researchers have made numerous efforts to study the  Out-of-Body Experience
.

The first experiment yielded a body experience under laboratory conditions took place in 2007, was made by Professor Ehrsson. He started from the following premise: "What would happen if we" make "eyes of a volunteer and I move to another part of the room? Does it continue to see the location of the body, or the new position of the eyes? ".

To find the answer, Ehrsson asked for volunteers to sit on a chair and wear special glasses, connected to two video cameras at two meters behind them. Volunteers receive the left lens of the camera videos taken from the left and the right ones captured by the camera lens on the right, so that they saw their virtual back from the perspective of a person located 2 meters behind their body.

Then the teacher Ehrsson used two plastic sticks with one of them slightly volunteers împungând chest, without them noticing, and the other repeating action under the cameras, nonexistent chest touching the "virtual person". When the two were synchronized gestures, volunteers reported that they were part of body experience, feeling that is where there were "eyes" of their own body where he looked.

So even if the volunteers could see his body, meaning that it is in the same place as the beginning of the experiment, the brain has recalculated the "self" in the room, which has led to the experience.

To confirm that the volunteers really perceive to be the area where the cameras, Professor Ehrsson used a hammer in the next phase of the experiment, pretending hitting force as cameras, where he found virtual body. Sensors on the skin of volunteers are identified immediately accelerated pulse and sweat levels, symptoms of fear, typical reaction of the human body in case of threats.

Medical studies show that people will perceive their bodies as part of the self due sense called "proprioception". Thus, the brain builds a sense of "self" combining the received signals from skin, muscles and joints with the eye data. Normally, these different sensory streams combine perfectly, resulting in a feeling of "self".

The experiment showed that when sensory information from these flows do not match, the sense of "self" disappears. In these cases, the brain forces a decision, which can lead to feeling that "self" is in another body. This was the result that the observed Dr. Ehrsson.

Professor Ehrsson experiment was the first case in which successful induction of body experience where healthy volunteers. The study also was the first case in which they managed to induce perception of self in a place other than the body are volunteers. 'Details of this illusion is a major success because it reveals the mechanism by which the feeling that we are inside ourselves. Its identification is an important step, because accepting her body as the center through which we perceive the world is a fundamental aspect of self-awareness, "said Ehrsson.

Amazing new experiments

To test the limits of human brain in the perception of their body, Professor Ehrsson continued studies. One of them started from the fact that stroke victims, in very rare cases, get to charge a "phantom member" - a third hand, for example.

Performing an experiment, Dr. Ehrsson found that volunteers can fool brain in minutes, convincing him to perceive the presence of a third hand.

This discovery was made after the five separate experiments performed on 154 volunteers. The participants were seated at the table, and their right hand was placed near an artificial hand made of rubber. Once you sit, the researchers covered the shoulder and right arm with a white towel, creating the illusion that the volunteer had three hands. Then, researchers reached two hands simultaneously (right arm of the volunteer and artificial). After about 30 seconds of simultaneous attacks, the volunteers began to feel the touch on both arms achieved by charging and the third hand as part of their body.

Sensors placed on the left hand confirmed that volunteers perceived artificial arm as part of the body, physiological reactions to the "threat" it with a knife are identical to those observed when the right arm was subjected to this treatment.

Arvid Guterstam, one of the team of researchers led by Ehrsson, explained the reasons for this experience: "As a result of optical illusion, the brain is a conflict over which of the two right hands belongs to the volunteer body. Naturally we would find that only one of the two hands to be perceived as belonging to the body, but brain solves this conflict by accepting both right hands as members, so that subjects feel they have three hands. "

Researchers believe the discovery may be used to improve the lives of people forced to use the prosthesis, and in the future to allow paralyzed patients to operate robotic States.

In another experiment, researchers at Karolinska Institute have used similar methods to persuade the 200 participants in the study that is a little Barbie doll body (measuring 30 cm in length) or that of a huge model ( measuring 4 meters in length). Volunteers to induce the sensation of being in the artificial body, researchers have turned again to stimulate simultaneous real body of volunteers and the artificial in that they believed that it is.

When volunteers arrived to collect the body as artificial, it was shown a cube, the researchers asked them to show, using the hands, how big is it. When participants believed that the body is Barbie doll, cube seemed huge, however, when believers in the body of a giant cube seem small. Thus, the experiment showed that the perception of their body is a basic standard used by the brain to perceive the world around.

This illusion is called the "illusion of Alice", inspired by the adventures of the eponymous character "Alice in Wonderland". In his book, Lewis Carroll, Alice fell after drinking a magic potion, becoming huge after taking a cake. Bjorn van der Hoort, one of the authors of the study, says that this illusion could be used to make specialists to identify with some microrobots (for example, to operate at the microscopic level in the body of a patient) or gigantic robots (to perform repairs in a hole oil or nuclear power).

In another study, coordinated by Professor Mel Slater of the Universitat de Barcelona, ​​researchers were able to convince male volunteers that are in the body of a girl. They have managed to create this illusion by using headphones connected to a virtual reality system that volunteers wore when they were touched on the arm. "Our experiment is the first research which shows that the feeling of body ownership can be transferred entirely on a virtual body". Catalan university study indicates that the feelings of self and body ownership can be handled easily. Researchers suggest this could be used to treat diseases that are based on distorted perception of their body, and anorexia.

The existence of the soul in jeopardy?

All these experiments that reveal how the brain builds a person's self image has led some researchers to argue that the results have impact on philosophy, beyond the potential of using these discoveries to develop new technologies.

Thomas Metzinger, Director of the Theoretical Philosophy Group Johannes Gutenberg University in Mainz, Germany, explains why the specialists in neuroscience experiments, and Henrik Ehrsson, are extremely important. "There are certain things, such as self-concept, which people thought could not be understood by science. Now, it is shown that the false self is easily manipulated by scientists. I believe that research conducted by Henrik points out that there is no "soul" or a self that is independent of the brain, "said Metzinger.

Asked if he believes that science can explain everything, Dr. Ehrsson gave a firm answer: "Absolutely! Maybe it will take several hundred years, but are convinced that science will provide a full explanation and more complex as the human mind. Perhaps philosophers not to like this and will continue to support that there are still unanswered questions regarding the human mind, but we understand all the elements ".

In recent years, scientists have been able to decipher many mysteries of the human brain, providing a response to "tunnel of light" between life and death, addressing the theme of free will and describing the two systems of the human mind. Today, neuroscience is a growing, promising in the coming years we provide an explanation of how the brain constructs effect known as "self".