Scientists believe it's the last gasp of a dying brain

Some say they floated above their own body, others claim to have walked along a light-filled tunnel or to have been suffused with a sense of peace.

But rather than being a brush with the afterlife, near-death experiences may simply be caused by an electrical storm in the dying brain.

A study of the brains of critically ill men and women revealed a brief burst of activity moments before death.

Researcher Lakhmir Chawla, an intensive care doctor, said: 'We think that near-death experiences could be caused by a surge of electrical energy as the brain runs out of oxygen.

As blood flow slows down and oxygen levels fall, the brain cells fire one last electrical impulse.

'It starts in one part of the brain and spreads in a cascade and this may give people vivid mental sensations.'

Dr Chawla, of the George Washington University medical centre in Washington DC, monitored the brain activity of seven terminally-ill people to ensure the painkillers they were being given were working.

In each case, the gradual tailing off of brain activity in the hour or so before death was interrupted by a brief spurt of action, lasting from 30 seconds to three minutes.

Levels were similar to those seen in fully-conscious people - even though blood pressure was so low as to be undetectable - and could generate vivid images and feelings, said the researcher.

Writing in the Journal of Palliative Medicine, he said: 'We speculate that in those patients who are successfully revived, they may recall the images and memories triggered by this cascade.

'We offer this as a potential explanation for the clarity in which many patients have "out of body" experiences when successfully revived from a near-death event.'

Research released last month put near-death experiences down to high levels of carbon dioxide in the blood altering the chemical balance of the brain and tricking it into 'seeing' things.

A previous study found that almost one in five heart attack patients whose lives were saved reported having near-death experiences.

These included out-of-body experiences, pleasant feelings, seeing a tunnel, a light, deceased relatives or their life 'flashing before their eyes'.

Southampton University researchers are trying to pin down whether the experiences have a medical explanation by asking 1,500 heart attack patients to recall any memories after their cardiac arrest.

In one test, pictures that can be seen only from above are being placed on high shelves in resuscitation rooms in 25 UK and U.S. hospitals.

If any patients can recall the images, it will suggest a genuine out-of-body experience. Lead researcher Dr Sam Parnia said: 'We see death as a moment but actually it is a process which modern medicine can often reverse.

Death starts when the heart stops beating, but we can intervene and bring people back to life, sometimes even after three to four hours when they are kept very cold.

'It could be that a far higher proportion of people have near-death experiences but don't remember them.'

He added that Dr Chawla had not provided proof that the electrical surges he recorded were linked to near-death experiences, saying: 'Since all the patients died, we cannot tell what they were experiencing.'
www.dailymail.co.uk/sciencetech/article-1282598/Near-death-experiences-explained-Scientists-believe-gasp-dying-brain.html#ixzz0pzi8XyHO

Printer friendly version

Email this article to a friend

Last updated 08/06/2010

Homepage