New studies have something to say about the subject:

https://www.nbcnews.com/health/health-news/can-science-explain-what-people-see-feel-during-near-death-n1024316

'Kondziella is the lead author of new research on near-death experiences that is being presented Saturday at a meeting of the European Academy of Neurology Congress. His findings, which have not yet been published in a peer-reviewed journal, suggest that the typical hallmarks of such episodes, such as bright white light and a sense of tranquility, are most likely the result of neural activity in the brain, similar to what goes on during a phenomenon called sleep paralysis.

"I do think these experiences can be triggered in situations with imminent death," Kondziella told NBC News. "But while perceiving these experiences, brain networks are working to be able to store those experiences, to be able to be resuscitated, to retrieve those memories, and to tell us about them." '