This isn’t as morbid as it sounds. Scientists are beginning to be able to document the brain’s reaction to dying or near-death episodes, and they’re beginning to wonder if the brain’s reaction to death gives us humans our ideas of heaven.
Newsweek published an interesting article on the phenomenon based on the book Heaven: Our Enduring Fascination With the Afterlife by Lisa Miller.
Before brain-scanning and brain imaging techniques, patients had to write down or illustrate their experiences to explain to people what they saw/heard/experienced. The Newsweek article included some of those drawings in a slideshow.