Scientists confirmed the patients’ stories with doctors and nurses present at the time of death, and were stunned to hear what the subjects remembered.
Why is there still brain activity after death?
Brain death is a process. It takes up to 20 seconds before brain waves are no longer detectable. Once they aren't, a set of cellular processes take place that eventually result in brain death. And this could occur hours after the heart has stopped, Parnia said.
"If you manage to restart the heart, which is what CPR attempts to do, you'll gradually start to get the brain functioning again. The longer you're doing CPR, those brain cell death pathways are still happening — they're just happening at a slightly slower rate," he said.
The scientists are now expanding their ongoing experiment, which will be the largest of its kind, to investigate the occurrences of consciousness after death and how it may affect the rest of a person’s life if they are revived.
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"In the same way that a group of researchers might be studying the qualitative nature of the human experience of 'love.'” Parnia said.
"For instance, we're trying to understand the exact features that people experience when they go through death, because we understand that this is going to reflect the universal experience we're all going to have when we die."