A large study is to examine near-death experiences in cardiac arrest patients.
Doctors at 25 UK and US hospitals will study 1,500 survivors to see if people with no heartbeat or brain activity can have "out of body" experiences.
Near Death Experience survey
Some would say NDE's are a glimpse of the afterlife. Some would say it's a side effect of oxygen starvation of the brain. The other less publicised possibility view is the 'tunnel of light' is a trick of evil, as can be apparitions of angels - discernement and investigation is reqired
a devil changed himself into a bright angel and appeared to a monk. "I am the angel Gabriel," he lied, "and I have been sent to you." But the brother wasn't about to be taken in, and replied, "Think again - you must have been sent to somebody else. I haven't done anything to deserve an angel!"