Near death, explained

[kiri]

30. hynogogic and hypnopompic experiences

NDE's are almost surely related to hynogogic and hypnopompic experiences, which are fairly common as people fall asleep, or sometimes when waking up. Sleep involves a certain kind of brain shut down. Most people do not know about sleep paralysis. The hypno- experiences are "altered brain states" as the brain copes with shutting down the usual flood of sensory input.

It is also well-known now that states of feeling awe, 'the presence of another', usually attributed to a god, can be created by stimulating certain parts of the brain.
Our brains are quite good at fooling us in many ways, via optical illusions, auditory illusions, confirmation bias, distorted memories, false attributions (as to cause and effect), poor estimates of probability, dreams, and many other ways.

NDE and OBE have to fit into this overall understanding.

BTW, nearly all "alien abduction" tales are due to these near-sleep and near-awakening experiences.