For a long time, these strange phenomena have fascinated doctors, scientists, religious scholars and amateur theorists.
Generally speaking, out-of-body experiences are associated with illness or traumatic events, and researchers in the UK and Switzerland have published a study in the academic journal Science describing how out-of-body experiences may occur in healthy people.
The experiments relied on finding out what makes a person's brain know that he is located inside his body.
It is primarily vision, but there are several senses and other processes that must work in concert.
What would happen if a person could step outside of himself and look around the room, seeing his body as an outsider?
Would he still feel like he was in his own body, or would his sense of self shift to where his point of view - his "eyes" - were?
To answer these questions, British researchers at the Institute of Neurology at University College London conducted two tests.
In the first test, volunteers sat in a chair with a video monitor covering their eyes.
The monitors projected images from two cameras located about 6 feet behind the test subjects.
Each camera acted as an eye, with one projecting on the left side of the display and the other on the right.
This effect resulted in the participant seeing an image from an angle 6 feet behind themselves.
A researcher then stood in front of the camera so that he appeared to be next to the participant's "virtual body.
From this position, he touched the chests of both the real and virtual bodies with two plastic rods.
The result was that participants felt like they were in their virtual bodies, even though they felt the touch of the sticks.
Many described the experience as interesting or strange.
The second test used sweat sensors to measure participants' emotional responses.
In front of a video camera, a researcher waved a hammer at the participant's virtual body.
The sensors showed that the participants were afraid they would actually be hit by the hammer.
Researchers from Switzerland conducted a third test in the cognitive neuroscience lab at the ETH.
The researchers showed the volunteers one of three 3D projections: blocks, dummies, or the volunteers' own bodies.
Then, someone touched the volunteer's back while another person touched the back of the projector with a brush - in some cases simultaneously.
The researchers then blindfolded the volunteers, moved them backward, and removed the blindfold.
When asked to return to the position they were previously standing in, those whose backs were touched at the same time as the body image would move to the projected position - not where they were initially standing.
Those who observed the touched dummy or blocks returned to the correct position.
Lack of oxygen changes brain activity.
The brain responds to trauma by "leaving" the body, helping a person to survive.
Stress can cause a variety of bodily sensations to become confused, including a person's sense of bodily self, known as proprioception.
Some people believe in spiritual endeavors, or that disembodiment can be achieved consciously, such as through hypnosis.
So did the British and Swiss experiments produce true out-of-body experiences?
Both experiments seem to suggest that a person's sense of self depends on cooperation between the senses, and that experiments can radically disrupt this connection.
Past experiments have shown that the body plays an important role in how a person recognizes his or her 'self'.
Dr. Henrik Ehrsson, the lead researcher on the study at University College London, conducted a study in which subjects' brains were tricked into believing that the rubber hand was the subject's real hand.
One of the researchers on the Swedish study, Dr. Olaf Blank, said their efforts produced an almost out-of-body experience, "but not all of it," adding that they were tricking people.
Unlike true out-of-body experiences, in which a person believes that he is actually outside of his body, these participants still believe that the projected image is some kind of "other".
Nonetheless, this study shows how the brain can be tricked, and how perceiving one's own body can have a powerful effect on self-awareness and physical location.
Dr. Elson believes that his experiments produced a true disembodied experience.
Compiled by Tungo Spectroscopy