Asked at ScienceDaily:
In order to examine the frequency distribution and chronology of different near-death experiences, the researchers collected and analyzed written accounts from 154 individuals who had gone through a near-death-experience. They took note of which specific near-death-experiences where present in each narrative and then examined the order of appearance of the different phenomena in each story. They found that on average, a person experiences about 4 different phenomena during a near-death-experience. The most frequently reported features were feeling of peacefulness (80% of participants), seeing a bright light (69%) and encountering with spirits/people (64%), whereas the two most uncommon experiences were speeding thoughts (5%) and precognitive visions (4%). In terms of chronology, they found that a third of the subjects (35%) experienced an out-of-body experience as the first feature of their near-death experience, and that the most frequent last feature was returning to the body (36%). “This suggests that near-death-experiences seem to be regularly triggered by a sense of detachment from the physical body and end when returning to one’s body,” says Charlotte Martial.
Overall, the most commonly shared experienced order of occurrences was: out-of-body experience, experiencing a tunnel, seeing a bright light, and finally feeling of peace. This sequence of events was reported by 6 (22%) of the participants. Although pairwise connections between different types of experiences were found in terms of how likely they were to follow each other chronologically, no universal sequence of events could be established in this sample of narratives, which suggests that each near-death-experience has a unique pattern of events.Paper. (public access) – Charlotte Martial, Héléna Cassol, Georgios Antonopoulos, Thomas Charlier, Julien Heros, Anne-Françoise Donneau, Vanessa Charland-Verville, Steven Laureys. Temporality of Features in Near-Death Experience Narratives. Frontiers in Human Neuroscience, 2017; 11 DOI: 10.3389/fnhum.2017.00311 More.
It’s worth noting that everyone who has given testimony about such an experience lived to tell about it. Apart from that, the actual relationship between the brain and consciousness is unclear, even in invertebrates, let alone humans.
See also: Does intelligence depend on a specific type of brain?
Scientific evidence that consciousness may not require a functioning brain