It’s relatively common for people who come close to death to report seeing bright lights and experiencing strange sensations, in what’s commonly known as a “near death” experience. In fact, around 20% of people who survive a heart attack report something like this. But researchers have found that those things are most likely not the result of other-worldly mysticism; rather, they posit that near death, the brain has a surge of hyperactivity that brings on the weird sensations and lights.
In a rat study, the University of Michigan scientists found that right as a rat clinically died, the rat’s brain showed “a widespread, transient surge of highly synchronized brain activity that had features associated with a highly aroused brain.” The researchers note that this final burst of activity could easily sway the senses into perceiving bright lights, levitation, or other oddities.
For more details, you can read an interview with the researchers who are working on this in National Geographic.