英科学家称“灵魂出窍”实为生理反应
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。
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。
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。
不少有过濒死体验的人曾表示当时感觉意识脱离躯体浮在上空，或被眩目的光芒吸引而去。但科学家表示，这种“灵魂出窍”的感觉只是大脑耍的小花招。
科学家证实，常见的濒临死亡时的怪异情景，比如感到漂浮在医院病床上，或走向隧道尽头的亮光，都是大脑试图厘清死亡过程时的反应。
来自爱丁堡大学和剑桥大学的科学家对死前大脑的变化进行了研究。这些变化导致了人们在临死前会产生特定的感觉。
研究员卡罗琳•瓦特表示，人们在濒死时看到“指引其前往来生的”亮光的现象，可能是因为体内用来处理光线的细胞死亡而产生的影像，我们的双眼平时利用这些细胞接受光线，并转化为图像。
瓦特说：“这只是你的大脑正试图弄懂你从未有过的经历。”
据《认知科学趋势》期刊报道，灵魂出窍的感觉可以用大脑行为来解释。
瓦特博士补充说：“如果你戴上虚拟现实的耳机，让其在你面前3英尺处呈现出你的影像，你就可以骗你的大脑认为那就是你自己，从而产生‘灵魂出窍’的错觉。”
“科学研究证实，所有濒死感觉都有生理学根据。”
另一项研究表明，濒死时平和安详的感觉是受去甲肾上腺素的影响。这一激素通常在人们经历重压或受伤时释放。
但也有科学家认为，不应该这么快就否定人们的描述。
南安普敦大学的萨姆•帕尼亚强调指出，将其追溯为大脑活动并不代表人们的感觉就不真实。
帕尼亚博士说：“不管是不是濒死，人们的沮丧、快乐、爱意等所有体验都是受大脑调节的。”他即将完成一项有关病人濒死感觉回忆的研究，该研究耗时三年。