Crystal McVea from Altus, Okla., was in the hospital for pancreatitis. Then something went horribly wrong. She reacted badly to the medication and stopped breathing. Her heart stopped, too. Her mother called for help. For nine minutes, McVea was unconscious, but in her mind, she had a near-death experience. While many people see and talk to lost loved ones during near-death experiences, McVea said she saw God. Doctors managed to revive her, but she couldn't forget what God had told her: "Tell them what you can remember" [source: Kuruvilla]. McVea obliged, with a memoir and a few rounds on the talk-show circuit.
Rather than taking a detour to the afterlife, near-death experiences might just be a gaggle of neurons in your brain going berserk, according to a study published in the PNAS Early Edition in August 2013. Researchers from the University of Michigan hooked up nine anesthetized rats to an electroencephalogram, which measures the brain's electrical fluctuations. Those spikes, researchers say, are neurons firing at once. The scientists then gave the rats a heart attack. Within half a minute after their little hearts stopped, the brains of the rodents exploded with electrical activity. This, the researchers say, might be what is happening when people say they have had a near-death experience. In fact, 20 percent of cardiac arrest survivors report visions even though they are clinically dead [source: Kim].