Some report feeling as if they are hovering above their own bodies, while others find themselves drawn towards a blinding light. But out-of-body experiences are nothing more than a trick of the mind, scientists claim.
drawn towards: 接近；朝…方向移动
They say that common spooky scenarios, such as floating above a hospital bed or walking towards the light at the end of a tunnel, can be explained by the brain trying to make sense of the process of death.
spooky : 幽灵般的；有鬼般的；令人毛骨悚然的
Scientists from the universities of Edinburgh and Cambridge reviewed studies into changes in the brain that cause certain sensations associated with near-death experiences.
Researcher Caroline Watt said one common vision – that of people seeing a bright light which seems to be drawing them into the afterlife – is probably produced by the death of the cells we use to process the light picked up by our eyes and turn it into pictures.
‘It is simply your brain trying to make sense of the unusual experiences you are having,’ Dr Watt said.
Feelings of being out of the body can also be explained by the brain’s behaviour, the journal Trends in Cognitive Sciences reports.
‘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.
‘The scientific evidence suggests that all aspects of the near-death experience have a biological basis.’
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.
However, other scientists say we should not be so quick to dismiss people’s accounts.
Sam Parnia, of the University of Southampton, stressed that being able to trace something back to the brain does not mean it is not real.
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.