What happens to our consciousness when we die? It’s perhaps the biggest question — and source of angst — when it comes to the human condition.
Those who report near-death experiences can offer a tantalizing glimpse of what our final moments feel and look like. Many of these experiences are strikingly similar, with people reporting vivid experiences that include visions of deceased loved ones, bright lights, and floating through the air.
While near-death experiences are often viewed through a religious or philosophical lens, researchers from the University of Michigan have studied the phenomenon on a scientific level, finding a spike in brain activity at the time of death.
Their findings were published this week in the Proceedings of the National Academy of Science. Study leader
Jimo Borjigin, associate professor in the Department of Molecular & Integrative Physiology and the Department of Neurology at the University of Michigan, led the study, which builds on earlier research that showed a neural surge in the dying brains of animal test subjects.
“We were postulating that [the surge] may represent neural correlates of consciousness that could potentially link the subjective experiences of people who survive cardiac arrest,” Borjigin told Medical News Today.
While the research has limitations, it’s a significant step forward in understanding the underlying reasons for vivid near-death experiences — and offers a glimpse at what our last moments may feel like.
While it’s simple enough to conduct experiments on animal subjects, it’s tough on both an ethical and practical level to study humans.
Borjigin told Medical News Today that she and her colleagues wanted to do justice to the earlier data to see if the human brain responded to death in the same way observed in a rat brain. To that end, the brain activity of four people who passed away in hospital while being monitored by an EEG (electrogram) device was studied.
“The data generated, even though it’s only four patients, is massive, so we were able to only report a fraction of the features that it’s actually showing on the data,” Borjigin said.
At the time of death, brain activity was detected in the TPO junction of the brain — named because it’s the hub between the temporal, parietal and occipital lobes in the back on the brain. The TPO junction already has a known association with dreaming, hallucinations, and altered states of consciousness.
“I really wanted to be able to define something in the brain that can potentially explain that subjective near-death experience,” Borjigin said. “Some of these patients might have if they had survived to tell their stories, but unfortunately they didn’t.”
While it’s impossible to know what the patients experienced during these brain surges, it makes sense that this increased activity in the TPO junction could help explain vivid near-death experiences.
Even though the patients weren’t visibly conscious, the uptick in brain activity shows covert consciousness — in other words, consciousness that can’t be detected using bedside exams because the patient is incapacitated.
“[People who’ve had near-death experiences] may remember seeing or hearing things, or having an out-of-body experience or motion perception as if they’re flying,” Borjigin explained. “I think that we have potentially at least defined or discovered minimum anatomical steps to neurosignatures of covert consciousness. We’d like to be able to study human subjects under less devastating circumstances, where the patients are known to be able to survive and then tell the story where they can correlate their brain signature with a subjective experience.”
In order to make this correlation, patients who survive cardiac arrest while being monitored by an EEG device could be interviewed to see if their brain waves line up with their experience.
In any event, studying the brain waves of dying patients can help us better understand the dying process, which is still somewhat shrouded in mystery. Exploring the interplay between the pulmonary system, cardiac system and brain may shed new light on the nature of consciousness.
“We’re interested in understanding more about the dying process,” said Borjigin. “If someone collapses to the ground, they might recover after a few minutes, or they might have a full blown cardiac arrest.”
“We’d like to understand how exactly dying takes place, so that we might be able to one day see more human sides rather than simply understanding the abstract.”
• New research shows a surge in brain activity at the time of death
• The activity takes place in a part of the brain known for dreams and altered states of consciousness
• This could help explain the vivid near-death experiences (bright lights, hallucinations) reported by people who were close to death
• Four patients were studied, and it’s impossible to correlate their brain activity with conscious experience
• Researchers would like to study more patients with EEG monitoring, in the hope that they can provide more data
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