Light at the end of the tunnel for scientists studying near-death experiences - Science - News - The Independent

Light at the end of the tunnel for scientists studying near-death experiences

High levels of activity in the brains of rats may give rational answer to 'spiritual' phenomena

Health reporter

Stories of out of body experiences and seeing lights at the end of a tunnel have been told by people brought back from the brink since the days of Plato.

Now, for the first time, scientists say they have observed brain activity in dying rats that may shed light on the mystery of human near death experiences.

Researchers at the University of Michigan analysed the electrical signals in the brains of nine anaesthetised rats undergoing an induced cardiac arrest and saw activity patterns they said were associated with "a hyper-alerted state" shortly after clinical death.

Near death experiences (NDEs), which the study's authors said were reported by 20 per cent of cardiac arrest survivors, are commonly cited as evidence of an afterlife or the separation of the body and the soul - but scientists have increasingly been able to attribute people's experiences to physiological processes and now believe they result from unusual brain activity caused by reduced blood flow to the brain.

Patients commonly report seeing a tunnel and a light, or a sensation of being outside one's own body, often with a sense of calm and inner peace.

"This study, performed in animals, is the first dealing with what happens to the neurophysiological state of the dying brain," said the study's lead author Dr Jimo Borjigin. "We reasoned that if near-death experience stems from brain activity, neural correlates of consciousness should be identifiable in humans or animals even after the cessation of cerebral blood flow."

However, the scientists were surprised by the high level of gamma frequency brain activity they observed, noting that "at near death, many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting the brain is capable of well-organised electrical activity during the early stage of clinical death."

Experts in the UK said that, while the results were intriguing, there was no way of knowing whether the activity observed in the rats was the same that produced the near death experience phenomenon in humans.

"The paper has merely shown - and the authors are extremely clear on this point - that they have demonstrated the change in gamma oscillations occurring over a similar time period to when NDEs are experienced in humans," said Dr David McGonigle, of Cardiff University's school of psychology. "We have no idea what the rats experience - if anything - while the increase in synchronous gamma occurs."

Near death experiences were explored in the film Flatliners NDEs were explored in the film Flatliners (Columbia Pictures)
Doubts have also been raised over the researchers' claims that the signals observed in the dying brains of the rats were similar to a conscious state. Dr McGonigle said that scientist were still "at loggerheads" over what consciousness means, both in humans and in animals.

Dr Anders Sandberg, a neuroscientist and research fellow at Oxford University's Future of Humanity Institute said that neither the findings, nor common stories of near death experiences in humans, should be interpreted as evidence of "life after death".

"A lot of the neural networks in the brain can stimulate themselves without any external signals under the right conditions… oxygen deprivation can certainly mess up many systems at the same time…" he said. "So it could be that during a NDE, the conditions make neurons start to fire and form patterns of activity. These patterns of activity are shaped by how the brain is connected, and we know that some patterns in the visual cortex seem to closely correspond to commonly reported hallucinations (like tunnels).  Higher order parts of the brain might create emotions or ideas in a similar random fashion, populating the experience."

News
Paper trail: the wedding photograph found in the rubble after 9/11 – it took Elizabeth Keefe 13 years to find the people in it
newsWho are the people in this photo? It took Elizabeth Stringer Keefe 13 years to find out
Arts and Entertainment
Evil eye: Douglas Adams in 'mad genius' pose
booksNew biography sheds light on comic genius of Douglas Adams
Sport
FootballFull debuts don't come much more stylish than those on show here
News
i100
PROMOTED VIDEO
Life and Style
Kim Kardashian drawn backlash over her sexy swimsuit selfie, called 'disgusting' and 'nasty'
fashionCritics say magazine only pays attention to fashion trends among rich, white women
Arts and Entertainment
TVShows like Agents of S.H.I.E.L.D are little more than marketing tools
Arts and Entertainment
Hit the roof: hot-tub cinema east London
architectureFrom pools to football pitches, rooftop living is looking up
Travel
travel
News
The ecological reconstruction of Ikrandraco avatar is shown in this illustration courtesy of Chuang Zhao. Scientists on September 11, 2014 announced the discovery of fossils in China of a type of flying reptile called a pterosaur that lived 120 millions years ago and so closely resembled those creatures from the 2009 film, Avatar that they named it after them.
SCIENCE
Life and Style
tech
News
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Matisse: The Cut-Outs exhibition attracted 562,000 visitors to the Tate Modern from April to September
art
Life and Style
Models walk the runway at the Tom Ford show during London Fashion Week Spring Summer 2015
fashionLondon Fashion Week 2014
News
Kenny G
news
News
peopleThe black actress has claimed police mistook her for a prostitute when she kissed her white husband
Life and Style
techIndian model comes with cricket scores baked in
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Energy Markets Analyst

£400000 Per Annum: The Green Recruitment Company: Job Title: Energy Markets An...

Junior Web Analyst – West Sussex – Up to £35k DOE

£30000 - £35000 Per Annum Plus excellent benefits: Clearwater People Solutions...

Nursery Manager

£22000 - £23000 per annum: Randstad Education Bristol: We are currently recrui...

Web Analyst – Permanent – Up to £40k - London

£35000 - £40000 Per Annum: Clearwater People Solutions Ltd: We are currently r...

Day In a Page

Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam
'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

Exclusive extract from Janis Winehouse's poignant new memoir
Is this the role to win Cumberbatch an Oscar?

Is this the role to win Cumberbatch an Oscar?

The Imitation Game, film review
England and Roy Hodgson take a joint step towards redemption in Basel

England and Hodgson take a joint step towards redemption

Welbeck double puts England on the road to Euro 2016
Relatives fight over Vivian Maier’s rare photos

Relatives fight over Vivian Maier’s rare photos

Pictures removed from public view as courts decide ownership
‘Fashion has to be fun. It’s a big business, not a cure for cancer’

‘Fashion has to be fun. It’s a big business, not a cure for cancer’

Donatella Versace at New York Fashion Week