Raymond and Nadine, both from Belgium, had heart attacks. When oxygen was cut off from their brains, they had out-of-body sensations, Laureys said.

“I felt as if I were sucked out of my body at one point,” said Raymond. “I was going through a completely black tunnel, very, very quickly, a speed you cannot express, because you just don’t experience it.”

When Nadine’s heart attack came on, she could see herself from outside her body. “It’s as if you are on a cloud, even if it’s not really that,” she said.

It eluded her control, and that frightened her. She went into a dark hole. “You wonder if you will really return to your body,” she said.

A light appeared at the end of Raymond’s tunnel. He, too, was at first afraid and resisted. The light was female, and she “communicated” with him.