A fascinating (and somewhat macabre) new study may explain the so-called "near-death experiences" described by many people. Scientists studied the brains of nine rats as they were being euthanized and found that just after the rats' hearts stopped, their brains became more active than normal, NPR reports. This sort of "overdrive" or hyperconsciousness continued for about 30 seconds, gradually declining over that period of time, Smithsonian reports. The lead researcher says the results "blew our mind," and the findings are "consistent with what patients report" experiencing. Explains a co-author, "At near-death, many known electrical signatures of consciousness exceeded levels found in the waking state."
"When you turn off a light switch, the light immediately goes from on to off," explains a neuroscientist who was not involved with, but was impressed by, the research. "The brain doesn't immediately go off, but it shows a series of sort of complicated transitions." The BBC explains further: The scientists measured an increase in gamma oscillations, high-frequency brainwaves that connect information from one part of the brain to another. How to explain this? The lead researcher thinks the surge in brain activity may be "the byproduct of the brain's attempt to save itself," as well as to make sense of what's happening. Of course, the results will be difficult to replicate in humans, but the researchers say human brains are similar enough to rat brains that this could explain the "near-death" phenomenon. Of course, not everyone is convinced: "We have no evidence at all that the rats had any near-death experiences or whether animals can have any such type of experience, first of all," says one scientist. (A 2010 study found carbon dioxide may be a factor in the "heavenly lights" seen in near-death experiences.)