"Sometimes, it is hard for them (the patients) to find words to explain it."
The questionnaire asks people about their level of certainty that a remembered experience was a real event and not imagined or dreamed. "They (the patients) are very convinced that it is real," Laureys said.
A simple Internet search reveals hundreds of accounts of near-death experiences -- some real, some perhaps invented. Many people are convinced they are proof positive that an afterlife exists outside of the physical realm -- and that it is wondrous.
There are reports of religious images appearing at times in NDEs, but they are not limited to one single religion, and they don't always appear. Sometimes Buddha, Jesus or Mohammed appear, but usually they don't, Laureys said.
Nevertheless, an NDE can make a convert of a skeptic. Dr. Eben Alexander is a well-known case of an agnostic scientist who became convinced of the existence of the spiritual.
He has often shared his story in television interviews with journalists and expressed his views in lectures and in books and video presentations, which he sells on his website.
Alexander, a neurosurgeon, according to his autobiography, has described his experience in the same terms as the Belgian researchers: "hyper-reality," "too real to be real."
In the beginning, he tried to interpret his experience as a brain function, he wrote on his website, but he became increasingly spiritual. He has come to the conclusion that people are reincarnated.
Alexander says his experience could not have been a hallucination, because the parts of the brain necessary to produce his experiences were basically dead when he had them.
It's your brain, Laureys tells you
Laureys strongly disagrees. "There is no evidence there can be conscious experience without brain activity," he said.
Lying in your hospital bed, you have become a true believer, and you are happier for it.
But your brain never died, the doctor tells you. You were in a coma. Perhaps your heart stopped for a while; maybe it didn't. But that's not even necessary to have an out-of-body experience.
"Many individuals having had NDEs were not physically in danger of death suggesting that the perception, on its own, of the risk of death seems to be important in eliciting NDEs," the study said.
It's enough just to think you're dying to have one.
The American Psychological Association concurs. It defines near-death experiences as "profound psychological events with transcendental and mystical elements, typically occurring to individuals close to death or in situations of intense physical or emotional danger."
In the case of coma patients, the brain producing the NDE may be functioning minimally, but it is still alive, Laureys hypothesized. He said one can stimulate certain parts of the brain to produce single elements of the experience.
It's a vivid hallucination, Laureys' report surmises. "It was a normal brain activity that produced their extraordinary perceptions."
Needs more research