Brain Signaling Behind Near-Death Experience Revealed
A near-death experience can be a scary occurrence. Now, scientists may have found out what might cause these experiences in cardiac arrest survivors. They've examined what happens to a person biologically during near-death and have discovered that shortly after clinical death, there are brain activity patterns characteristic of conscious perception.
About 20 percent of cardiac arrest survivors report having a near-death experience during clinical death, which is when the heart stops beating and blood stops flowing to the brain. These visions and perceptions have often been called "realer than real." However, it's still remains unclear whether the brain is capable of such activity after cardiac arrest.
"We reasoned that if near-death experience stems from brain activity, neural correlates of consciousness should be identifiable in humans or animals even after the cessation of cerebral blood flow," said Jimo Borjigin, one of the researchers, in a news release.
In order to examine near-death experiences a bit more closely, the researchers looked at rat brains. More specifically, they examined them after clinical death, which is when the heart stops beating and blood stops flowing to the brain. More specifically, they analyzed recordings of brain activity called electroencephalograms (EEGs) from nine subjects. What they found, though, was surprising.
Within 30 seconds after cardiac arrest, all of the rats displayed a widespread, transient surge of highly synchronized brain activity that had features associated with a highly aroused brain. The researchers found nearly identical patterns in the dying brains of rats undergoing asphyxiation.
"The prediction that we would find some signs of conscious activity in the brain during cardiac arrest was confirmed with the data," said Borjigin.
The findings reveal that the reduction of oxygen or both oxygen and glucose can actually stimulate brain activity. This provides not only the scientific framework for near-death experiences, but also paves the way for future studies concerning the science of near-death.
The findings are published in the journal Proceedings of the National Academy of Sciences.