Near-death survivors have reported seeing bright
white lights and having out-of-body experiences
A surge of electrical activity in the brain could
be responsible for the vivid experiences
described by near-death survivors, scientists
report.
A study carried out on dying rats found high levels of
brainwaves at the point of the animals' demise.
US researchers said that in humans this could give
rise to a heightened state of consciousness.
The research is published in the Proceedings of
the National Academy of Sciences
.
The lead author of the study, Dr Jimo Borjigin, of the
University of Michigan, said: "A lot of people thought
that the brain after clinical death was inactive or
hypoactive, with less activity than the waking state,
and we show that is definitely not the case.
"If anything, it is much more active during the dying
process than even the waking state."
Consciousness
From bright white lights to out-of-body sensations
and feelings of life flashing before their eyes, the
experiences reported by people who have come close
to death but survived are common the world over.
However, studying this in humans is a challenge, and
these visions are little understood.
To find out more, scientists at the University of
Michigan monitored nine rats as they were dying.
In the 30-second period after the animal's hearts
stopped beating, they measured a sharp increase in
high-frequency brainwaves called gamma
oscillations.
These pulses are one of the neuronal features that
are thought to underpin consciousness in humans,
especially when they help to "link" information from
different parts of the brain.
In the rats, these electrical pulses were found at even
higher levels just after the cardiac arrest than when
animals were awake and well.
Dr Borjigin said it was feasible that the same thing
would happen in the human brain, and that an
elevated level of brain activity and consciousness
could give rise to near-death visions.
Neurons in the brain may go into overdrive around
the point of death
"This can give us a framework to begin to explain
these. The fact they see light perhaps indicates the
visual cortex in the brain is highly activated - and we
have evidence to suggest this might be the case,
because we have seen increased gamma in area of
the brain that is right on top of the visual cortex," she
said.
"We have seen increased coupling between the
lower-frequency waves and the gamma that has
been shown to be a feature of visual awareness and
visual sensation."
However, she said that to confirm the findings a
study would have to be carried out on humans who
have experienced clinical death and have been
revived.
Commenting on the research, Dr Jason Braithwaite,
of the University of Birmingham, said the
phenomenon appeared to be the brain's "last
hurrah".
"This is a very neat demonstration of an idea that's
been around for a long time: that under certain
unfamiliar and confusing circumstances - like near-
death - the brain becomes overstimulated and
hyperexcited," he said.
Striking
"Like 'fire raging through the brain', activity can
surge through brain areas involved in conscious
experience, furnishing all resultant perceptions with
realer-than-real feelings and emotions."
But he added: "One limitation is that we do not know
when, in time, the near-death experience really
occurs. Perhaps it was before patients had
anaesthesia, or at some safe point during an
operation long before cardiac arrest.
"However, for those instances where experiences
may occur around the time of cardiac arrest - or
beyond it - these new findings provide further meat
to the bones of the idea that the brain drives these
fascinating and striking experiences"
Dr Chris Chambers, of Cardiff University, said: "This
is an interesting and well-conducted piece of
research. We know precious little about brain activity
during death, let alone conscious brain activity.
These findings open the door to further studies in
humans.
"[But] we should be extremely cautious before
drawing any conclusions about human near-death
experiences: it is one thing to measure brain activity
in rats during cardiac arrest, and quite another to
relate that to human experience."
m.bbc.co.uk/news/science-environment-23672150

At the point of death, I think bright white light indicates heaven, while thick darkness (black out) indicates hell!

Scientist will surely always prove otherwise though!

It it's same 30secs for humans, then they should ask for forgiveness so they can make heaven,within the time-phrase.