Ever since a reputable neurosurgeon made the claim that he had experienced the afterlife, a wave of experiments now seek to explain the phenomenon behind a near-death experience.

NPR recently reported that a brief spike in brain activity that occurs shortly after the heart ceases may be the cause of near-death experiences. Nine lab rats were hooked up to machines and analyzed by a team of neuroscientists at the University of Michigan. The scientists found that the rats’ brains experienced an electrical burst that lasted about 30 seconds after their hearts stopped.

Theoretically, if human brains work like rats (after all, we are both mammals) then our perception of the near-death experience is actually a last ditch attempt by our brains to keep itself alive before it shuts down for good. Jimo Borjigan, leader of the research team and a scientist at the University of Michigan at Ann Arbor, is excited that “science tells us the experiences really could be real for these individuals, and there is actually biological basis for… [the near-death experience]… in their brain. It’s all really happening in their brain during this very early period of cardiac arrest.”

Near-death experiences have always been considered a highly spiritual phenomenon, with many reporting visiting a variety of afterlifes, or even Heaven to speak with God himself. Borjigan and his team “were just so astonished” at the “continued and heightened activity” that was “much, much higher after the heart stops — within the first 30 seconds.”

The findings are so revolutionary that the National Academy of Sciences is publishing the research. A neuroscientist with the Allen Institute for Brain Science in Seattle, Christof Koch, said of the research that “it shows us in considerable more detail than ever done before what happens when the brain is dying… When you turn off a light switch, the light immediately goes from on to off… The brain doesn’t immediately go off, but it shows a series of sort of complicated transitions.”

In spite of the findings, not all scientists agree that the discovery applies to human physiology. Sam Parnia, an expert on dying and near-death experiences with the Stony Brook University School of Medicine in New York, has said he doesn’t believe “this particular study helps in any way to explain near-death experiences in human beings… We have no evidence at all that the rats had any near-death experiences or whether animals can have any such type of experience.”

The BBC reported Dr. Chris Chambers of Cardiff University as commenting that “we should be extremely cautious before drawing any conclusions about human near-death experiences: it is one thing to measure brain activity in rats during cardiac arrest, and quite another to relate that to human experience.”