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Brain activity before death: Study pinpoints a 'hot zone' surge

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A small study out of the United States offers evidence that an area of the brain associated with consciousness can experience a wave of activity for some people right before they die.

The study from the University of Michigan, published May 1 in the peer-reviewed Proceedings of the National Academy of Sciences, recorded the brain activity of four comatose patients who died from cardiac arrest while in hospital and under EEG, or electroencephalogram, monitoring.

With their families' permission, the patients were removed from life support once it was determined that they were beyond medical help.

Of the four patients, two showed an increased heart rate and a surge of gamma wave activity, which the researchers say is considered the fastest brain activity and associated with consciousness.

Those two patients had previous reports of seizures but experienced none in the hour before their deaths.

The other two, meanwhile, showed no similar increase in heart rate or gamma activity in the brain.

"That peak of activity is suggestive that there's something going on that would be an experience that a person has as they pass away," CTV science and technology specialist Dan Riskin told CTV's Your Morning on Monday.

The study is similar to the results of another, published in February 2022, involving an 87-year-old man who died of a heart attack in hospital and showed unexpected activity in the memory retrieval area of his brain.

The team behind that study said the rhythmic brain activity they detected could support the "life flashing before your eyes" theory.

In the latest study, the researchers say they detected activity in the area between the temporal, parietal and occipital lobes in the back of the brain, a so-called "hot zone" associated with dreaming, visual hallucinations in epilepsy, and altered states of consciousness.

The researchers stress that the sample size for the study was small and that it is impossible to know what the patients experienced since none of them survived.

The scientists say larger studies, involving EEG-monitored intensive care unit patients who survive cardiac arrest, could help determine whether bursts in gamma activity are evidence of hidden consciousness near death.

"There's no question that the brain is a complex organ. It does different things under different circumstances," Riskin said.

"But these are people who really cross over that threshold and don't come back by definition and so we really don't know what that experience correlates with."

Watch the full interview with Dan Riskin at the top of the article

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