Scientists find clues to visions from other side

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Scientists find clues to visions from other side

There may be a scientific explanation for the vivid near-death experiences, such as seeing a light, some people report after surviving a heart attack, scientists say.

Apparently, the brain keeps working for up to 30 seconds after blood flow stops, according to a study in the Proceedings of the National Academy of Sciences.

'Seeing the light' is an experience commonly linked to near-death experiences.

'Seeing the light' is an experience commonly linked to near-death experiences.Credit: Julian Kingma

University of Michigan scientists did research on nine lab rats that were anaesthetised and subjected to induced cardiac arrest.

In the first 30 seconds after their hearts were stopped, they all showed a surge of brain activity, observed in electroencephalograms (EEGs) that indicated highly aroused mental states.

''We were surprised by the high levels of activity,'' said senior author George Mashour, professor of anaesthesiology and neurosurgery at the university. ''In fact, 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.''

Similar results in terms of brain activity were seen in rats that were asphyxiated.

''This study tells us that reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that is characteristic of conscious processing,'' author Jimo Borjigin said. ''It also provides the first scientific framework for the near-death experiences reported by many cardiac arrest survivors.''

About 20 per cent of people who survive cardiac arrest report having had visions during a period known to doctors as clinical death.

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Ms Borjigin said she hopes her team's study ''will form the foundation for future human studies investigating mental experiences occurring in the dying brain''.

Mainstream science has long considered the brain to be inactive during this time. Some experts questioned how much a study on rats can reveal about humans.

Anders Sandberg, of Oxford University described the research as ''simple'' and ''well done'', but urged caution interpreting it.

We were surprised by the high levels of activity. In fact, at near-death, many known electrical signatures of consciousness exceeded levels found in the waking state...

''EEG tells us things about brain activity a bit like listening at traffic noise tells you what is going on in a city. It is certainly informative, but also an average of a lot of individual interactions,'' he said.

''No doubt some people will presumptuously claim this is further evidence for life after death, which is doubly silly.

''Near-death experiences are in themselves just experiences.''

AFP

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