near death experiences
Brain activity in rats while they’re fully conscious, sedated, and after their hearts have stopped (point 0). The top figures span 30 minutes in time; in the bottom figures, activity in the 30 seconds immediately following cardiac arrest is magnified. Borjigin et al./PNAS

A new study suggests that near-death experiences could be the result of increased electrical activity in the brain near the moment of death. The evidence suggests that electricity levels spike in the brain, possibly leading to visions of bright lights and other similar phenomena.

Published in the Proceedings of the National Academy of Sciences, the study examined the brain activity of several dying rats and found that in the 30 seconds after clinical death, the rats’ brains lit up with activity. Tests showed that the rats emitted extremely high levels of high-frequency brain waves known as gamma oscillations. These waves are often understood as a key component in human consciousness.

"A lot of people thought that the brain after clinical death was inactive or hypoactive, with less activity than the waking state, and we show that is definitely not the case,” lead author Dr. Jimo Borjigin, of the University of Michigan, told the BBC. "If anything, it is much more active during the dying process than even the waking state."

Borjigin believes that humans may experience a similar phenomenon, leading to many accounts of near-death experiences in those who have come close to death or experienced clinical death and been revived. Typically, these people report seeing bright lights and other strange experiences, which Borjigin attributes to a brain overstimulated by electrical impulses.

"This can give us a framework to begin to explain these. The fact they see light perhaps indicates the visual cortex in the brain is highly activated - and we have evidence to suggest this might be the case, because we have seen increased gamma in area of the brain that is right on top of the visual cortex," she said. "We have seen increased coupling between the lower-frequency waves and the gamma that has been shown to be a feature of visual awareness and visual sensation."

As interesting as this research is, however, Borjigin notes that similar tests would have to be performed on humans to truly confirm that near-death experiences are the result of electrical impulses. The proposed research would involve reviving human patients after they experience clinical death, which could be extremely dangerous and morally objectionable to some. Another hindrance is that researchers do not know exactly when the phenomena associated with near-death experiences occur.