WASHINGTON — You feel yourself float up and out of your physical body. You glide toward the entrance of a tunnel, and a searing bright light envelops your field of vision.
Rather than an ascent into the afterlife, a new study says these features of a near-death experience may just be a bunch of neurons in your brain going nuts.
"A lot of people believed that what they saw was heaven," said lead researcher and neurologist Jimo Borjigin. "Science hadn't given them a convincing alternative."
Scientists from the University of Michigan recorded electroencephalogram (EEG) signals in nine anesthetized rats after inducing cardiac arrest. Within the first 30 seconds after the heart had stopped, all the mammals displayed a surge of brain activity that had features associated with consciousness and visual activation. The burst of electrical activity even exceeded levels during a normal, awake state.
In other words, they may have been having the rodent version of a near-death experience.
"On a fundamental level, this study makes us think about the neurobiology of the dying brain," said senior author and anesthesiologist George Mashour. It was published Monday online by the Proceedings of the National Academy of Sciences.
Near-death experiences have been reported by many who have faced death, worldwide and across cultures. About 20 percent of cardiac arrest survivors report visions during clinical death, with features such as a bright light, life playback or an out-of-body feeling.
"There's hundreds of thousands of people reporting these [near-death] experiences," said Borjigin. "If that experience comes from the brain, there has to be a fingerprint of that."
An unanswered question from a previous experiment bothered her. In 2007, Borjigin had been monitoring neurotransmitter secretion in rats when, in the middle of the night, two of the animals unexpectedly died. Upon reviewing the overnight data, she saw several unknown peaks near the time of death.