Brain activity surges after death, study finds

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

According to a study published yesterday in the Proceedings of the National Academy of Sciences, the brain keeps on working for up to 30 seconds after blood flow stops.

University of Michigan scientists did their research on nine lab rats that were anesthetised and then subjected to induced cardiac arrest as part of the experiment. In the first 30 seconds after their hearts were stopped, they all showed a surge of brain activity, as observed in electroencephalograms.

"We were surprised by the high levels of activity," said senior author George Mashour, professor of anesthesiology and neurosurgery at the University of Michigan.

"In fact, at near-death, many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting that 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.

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

AFP