Near-death experiences often feature out-of-body episodes
Near-death experiences are rare, but if you have one, it is likely to be overwhelmingly peaceful, however painful it might have been to get to that stage. This is the conclusion from the first study into how the cause of trauma affects the content of a near-death experience.
Such episodes are often described as emotionally rich, involving out-of-body sensations, tunnels of light and flashbacks. They most often occur when a person has been resuscitated after a traumatic event.
Steven Laureys, a neuroscientist at the University of Liège in Belgium who works with people in comas and vegetative states, started to investigate after his patients told him of their own near-death experiences. "I kept hearing these incredible stories in my consultations," he says. "Knowing how abnormal brain activity is during a cardiac arrest or trauma, it was impressive how rich these memories were. It was very intriguing."
There are several hypothesises as to how these events arise, such as lack of oxygen to the brain or damage to areas that control emotion. "So you'd expect to see differences between near-death experiences after drowning and those of other traumas," he says.
His team looked at 190 documented events that resulted from traumas including cardiac arrest, drowning, head injury and high anxiety. Using statistical analysis and a measurement called the Greyson scale to assess the number and intensity of different features of the near-death experiences, the team discovered that surprisingly, the reports shared many similarities.
Not like the movies
The most common feature was an overwhelming feeling of peacefulness. The next most common was an out-of-body experience. And many people felt a change in their perception of how time was passing. There were only a few examples of negative experiences. "It turns out to be not so bad to have a dying experience," says Laureys.
Having a life flashback or a vision of the future – the kinds of things often depicted in Hollywood movies – were only reported by a small minority of people.
Laureys's team will now try to find an objective measure of such experiences by scanning the entire brains of people who say they have just had a near-death experience after a cardiac arrest. The team will look for small scars that might reflect the after-effects of the event.
Laureys is aware of the difficulties in investigating something so subjective, but is trying to tackle the subject with an open mind. "We need to accept there are many things we don't understand, but it's important to apply the best scientific method we can" he says. "It's a first step in understand something that is really interesting and could ultimately provide a better understanding of consciousness."
The oldest near-death experience
Near-death experiences have been passed down through folklore, myth and storytelling since ancient civilisations. The oldest medical description of such an event dates back to the 18th century. Philippe Charlier at the University of Versailles in Montigny-le-Bretonneux, France, who researches the history of diseases, describes in the journal Resuscitation how he discovered the reference in an old medical textbook from 1766 called Anecdotes de médecine.
The description was written by Pierre-Jean du Monchaux, a French military physician. He tells the story of a patient with a fever who'd had several blood-letting treatments. The patient was unconscious for a long time but when he awoke he reported that after he lost all external sensations, he saw "such a pure and extreme light that he thought he was in the Kingdom of the Blessed". He told du Monchaux that he remembered the sensation well, and said that "never of all his life had he had a nicer moment".