Some people who have faced death report feeling like they are going down a tunnel toward a bright light.
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A surge in brain waves in two dying people after life support is turned off may help explain the phenomenon of near-death experiences.
Feelings of walking down a tunnel toward a bright light, of reliving memories of the past, of hearing or seeing the voices of deceased relatives have all been reported by people in many cultures facing death. However, skeptics say these experiences could be triggered by seeing hallucinations while recovering in the hospital.
We may now have identified the brain activity behind these experiences.
A decade ago, Jimo Borjigin and her colleagues at the University of Michigan School of Medicine showed that electrical activity spikes in the brains of rats when they die.
Some critically ill patients in intensive care units have electrodes placed on their heads to monitor brain waves in a technique called electroencephalography (EEG) if doctors determine they are at risk of an epileptic seizure. increase.
Borjigin’s team combed through the anonymized medical records of people whose EEGs were recorded and whose life support was taken off because they had no chance of recovery, and found four such people.
Brain waves can be seen on the EEG when numerous brain cells fire together in synchronized cycles. These waves can occur at different frequencies.
Previous research suggests that faster frequencies, known as gamma brain waves, are characteristic of consciousness, advanced thought processes, and memory retrieval. This is especially true when it occurs in her two areas on either side of the head, known as the temporoparieto-occipital (TPO) junction.
Two of the four participants in this study showed gamma EEG surges at the TPO junction when life support was withdrawn. This surge of brain waves lasted for several minutes and was sometimes very intense, Borjigin says. “It was insanely expensive”
It is impossible to know if these people had visions when they were dying. says.
Unlike the other two who did not show gamma brain waves, the two who showed gamma brain waves still had enough brain function to increase their heart rate despite the drop in blood oxygen levels. suggested that a functioning autonomic nervous system is required for the development of gamma-EEG surges.
The two were also suspected of having epileptic seizures, which may have permanently affected their brains. However, the increased likelihood of having a near-death experience in people with a history of epilepsy has not been noted until now.
Sam Parnia of NYU Langone Health says gamma wave surges can occur when a person dies because the drop in oxygen levels disables the natural “brake system” of brain activity. “This allows activation of normally dormant pathways, seen as transient electrical spikes,” he says. “You lose the energy-hungry braking system.”
The findings provide additional supportive evidence of consciousness in some people who were otherwise thought to be unconscious at the end of life, Parnia says.
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