Study explains why people recount memorable experiences before death
Several people who have had near-death experiences have said they see their life flash before their eyes or that memorable moments replay, and other such experiences. New research from the University of Michigan might help us better understand why this happens. The team has found evidence in two dying patients that there are surges in brain activity and these surges are associated with consciousness.
What makes the study different from the previous ones?
While the study is not the first of its kind, what makes the new research different is that it is detailed in a way "that's never been done before," said senior author Jimo Borjigin, to AFP. The study involved four patients who were comatose and on life support. The individuals were monitored using an electroencephalogram (EEG), which measures electrical activity on the brain's surface.
Surges of brain activity were recorded in two patients
Once the ventilators were removed, in about 30 seconds to two minutes, two of the four patients' brains showed surges in gamma waves, the highest-frequency electrical oscillations in the brain. Such gamma wave patterns have been associated with conscious experience, whereas some studies have found the same pattern when a healthy person is actively recalling a memory, learning, or dreaming.
There are similar studies about the surges of brain activity
In 2013, researchers from the University of Michigan discovered the brains of rats showed signs of consciousness up to 30 seconds after their hearts had stopped beating. A separate study in 2022 found that the brain of an 87-year-old man showed surges in gamma wave activity 30 seconds before and after his heart stopped, similar to the 2013 study.
The heightened activity occured in the brain's temporoparietal junction
The team saw increased electrical activity in a region of the brain known as the temporoparietal junction, which is thought to be associated with consciousness and is activated during dreaming, seizures, and out-of-body hallucinations. Borjigin, who was also a part of the 2013 study, thinks the burst of brain activity is because the brain enters a survival mode, once it is deprived of oxygen.
The two patients also had a record of seizures
Borjigin mentions that the two patients whose brains showed spiked gamma activity also had a record of seizures, which according to her might have caused their brains to experience abnormal rhythms.
Borjigin intends to replicate the study's findings via future investigations
In future investigations, Borjigin intends to replicate the study's findings by joining with other medical centers to understand the brain activity in patients who are dying. "If you talk about the dying process, there is very little we know," Borjigin told Live Science. "This is maybe the first study to really show second-by-second how the brain dies."
