Health

Why Some People See White Light When They Almost Die

To edge near the brink of death only to be yanked back to life can be a surreal process that sometimes produces what are known as near-death experiences. Some people report seeing a white light at the end of a tunnel, for example, as well as imagery that appears to involve religious themes and symbols and leads others to conclude that they've encountered evidence of the afterlife. While these episodes may seem fictitious, research shows that there are indeed scientific explanations for near-death experiences.

Near-death experiences and the brain connection

For a long time, people assumed that the brain stopped functioning when the heart stopped beating. But a 2013 study from the University of Michigan challenged that theory, revealing a surge in brain activity that lasted nearly a minute after scientists induced cardiac arrests in lab rats. The "hyper-alerted state" following clinical death could explain why people see white light during near-death experiences.

Dr. Jimo Borjigin, the lead author of the study, told ATTN: that parts of the rats' brains, including the visual and frontal cortex, experienced high levels of electrical activity after they were injected with potassium chloride, a chemical compound that has been used to stop the hearts of death row inmates during executions in the U.S. These "brain storms" may be responsible for the white light that 20 percent of cardiac arrest survivors report seeing.

There are other common themes of near-death experiences. Beside seeing white light at the end of a tunnel, people who have nearly died also report having out-of-body experiences and seeing visions of loved ones who've passed. Conventional religious wisdom would suggest that these experiences reflect encounters with the afterlife, but researchers contend that these encounters are the product of heightened brain activity — a fight or flight response of sorts — that cause visual hallucinations. "I think that I probably angered a lot of people who view the whole process [as a religious experience]," Borjigin said. "As long as we don't provide convincing scientific facts, people are going to continue to believe what they want to believe."

Of course, there are limitations to studies that look at near-death experiences in lab rats. Rats can't articulate what they're seeing or feeling; scientists can only measure their cardiac and neurological activity in the moments preceding death and speculate about the significance of that activity in terms of human near-death experiences.

But scientists are conducting more research on human subjects too.

A 2014 study on near-death experiences found that 40 percent of surveyed cardiac arrest patients were aware of the moments they were clinically dead before their hearts were restarted. One patient's story from this study is particularly fascinating, according to The Atlantic:

"A 57-year-old man described floating up to a corner of the room, seeing medical staff work on him, and watching himself be defibrillated. According to Parnia’s paper, several of the details he described checked out. What’s more, after triangulating the patient’s description with the workings of the defibrillator, the researchers think he may have seen things that happened for as long as three minutes after his heart stopped."

Borjigin says science has benefited from individuals coming forward with these unique episodes. "People who've had a near-death experience — who are unafraid to share their experience — are really teaching us a lot, because to them, it's a really real experience," she told ATTN:. "I'm learning as a scientist: If that were the case, then maybe this part of the brain or that part of the brain must be activated. If they didn't voice their experiences, I probably would have just imagined that the near-death experience is crazy."

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