“The feeling that you're no longer in your body can occur in many circumstances, the moment certain brain connections are altered or even simply modified", Vanessa Charland-Verville points out. “Sometimes, extreme fatigue is enough.” The researcher adds that the brain 'likes’ to create meaning. It is also inclined to construct highly coherent stories underpinned by highly complex imagery, which the subject, cut off from the outside world, tends to interpret as emanating from it and having all the characteristics of reality.

Well, in that case, how do we explain experiencers who tell us, for instance, what was happening in the room next to where they were being resuscitated by the doctors? Vanessa Charland-Verville’s answer is that the information is always reported after the event and that we have no proof of what exactly went on in the adjacent room. In short, there is no scientific rigour involved. “There is a group of researchers in the field of NDE who seem to work in a circular manner", she says. “They believe in life after death and hence allow this belief to affect their conclusions. Of course, there are still many unanswered questions to be explored, but is this a reason for formulating assertions that aren’t based on any rigorous scientific observations? As far as I’m concerned, I would like to see the elaboration of experimental protocols: in science, you can only conclude on what you can test.”

Indeed, reports of isolated cases carry little weight in science.  Especially because statistical probability has to be taken into account. Furthermore, we can’t exclude the fact that some patients may have had flashes of consciousness during which they saw, heard or felt things. “Their memories could be comparable to those you might have when waking up from anaesthesia”, Vanessa Charland-Verville explains.

Dysfunction of regions of the brain

Let’s turn the page on the spiritual interpretations of NDE. Several psychological interpretations have also been put forward. According to one of them, these experiences consist of a form of depersonalisation, a feeling of losing your sense of reality, which acts as a means of defence when faced with the threat of death. It is as though our subconscious creates a ‘story’ to deny the imminence of our death. But in that case, how can we explain the occurrence of NDE when we aren't in a life-threatening situation? This interpretation is fragmentary at best.

The third category of explanatory theories is neurological. They certainly aren’t lacking but, for now, the most relevant ones associate the various components of NDE (tunnel of light, OBE, etc.) with a dysfunction of specific brain regions that have been injured, especially as a result of a head injury or a lack of oxygen caused by cardiac arrest. The facts plead in favour of this hypothesis. Let’s look at the example of out-of-body experiences again. In 2002, surgeons at the university hospital in Geneva involuntarily provoked an OBE in an epileptic patient by stimulating the right temporoparietal region of the brain. And five years later, a team from Antwerp experimentally obtained the same result by stimulating the same region through magnetic transcranial stimulation and implanted electrodes.

Flashbulb memories of hallucinations?

Regarding the chaotic conditions during which NDE are likely to take place, it is very difficult to study them in real time. Therefore, the researchers from ULg’s Coma Science Group and Liège CHU are aiming to connect the characteristics of NDEs reported by experiencers taking part in their studies, with possible residual lesions in brain regions likely to be responsible for the unusual experience these people have reported. We have just mentioned the right temporoparietal region for OBE, but there are other regions that could possibly ‘support’ other components of NDE.

During a cardiac arrest, a brain haemorrhage or a head injury, some regions of the brain suffer more than others, especially in response to a lack of oxygen.  These are the ones the researchers at ULg suspect of being involved in NDEs. “Even years after an NDE episode, the sensitivity of imaging techniques allows us to look for minuscule scars, the slightest epileptic activity, small oedemas or minor blood deposits that could suggest the presence of microlesions in a particular area of the brain”, Steven Laureys, head of the Coma Science Group, explained to us in 2013.