Reports of near death experiences range from people being drawn towards a blinding light or feeling as if they are hovering above their own bodies.
There is also a condition called “Cotard” – or “walking corpse” syndrome, where a person believes they are dead. It has been seen following trauma and during the advanced stages of typhoid and multiple sclerosis.
But a group of scientists is now claiming out-of-body experiences are all in the head.
The scientists, from the universities of Edinburgh and Cambridge, reviewed studies into changes in the brain that cause certain sensations associated with near-death experiences.
They say such experiences are the result of the brain trying to make sense of the death process.
Researcher Caroline Watt said one of the most common reports – that of people seeing a bright light drawing them into an afterlife situation – is more than likely produced by the death cells we use to process the light picked up by our eyes and turn it into pictures.
“The most parsimonious explanation is not that you are travelling to some spiritual realm – it is simply your brain trying to make sense of the unusual experiences you are having,’ Dr Watt said.
“If you put on a virtual reality headset showing an image of yourself three feet in front, you can trick your brain into thinking that is you over there, and get the sense you are outside your body,’ Dr Watt added.
In another example, the hormone noradrenaline, which is released when we suffer from stress and injuries, could be behind the feelings of love and peace many experience when they seem to be approaching death.
Dr Sam Parnia, director of resuscitation research at the State University of New York and author of What Happens When We Die said he did not agree with the findings.
Dr Parnia, who is close to completing a three-year study of hospital patients’ recollections of their near-death experiences, said: “Every experience, whether near-death or otherwise – such as depression, happiness and love – is mediated by the brain.
“In fact, many experiences share the same brain regions, and so it is not unusual to be able to reproduce them.
“Discovering those areas, or reproducing them, doesn’t imply the experience is not real.
“We wouldn’t say love, happiness and depression are not real.
“Furthermore, many people accurately report “seeing” events taking place at a time when the brain doesn’t function, such as during cardiac arrest.
“These cannot be explained by brain changes, since the brain had shut down and “flatlined”.
“While seeming real to those who experience them, near-death experiences provide a glimpse of what it is like to die for the rest of us.”