Researchers from the University of Michigan have published a study on these phenomena felt just before dying. They try to explain the activity of the human brain thanks to examinations carried out on people dying of heart attack.
The testimonies are often identical: we see our life pass before our eyes, we see a light at the end of the tunnel or we feel ourselves floating above our own body. These sensations return regularly in the mouths of people who have been close to death. Faced with this observation, a team from the University of Michigan took up the challenge of finding a scientific explanation.
Their method was to analyze the brain activity of dying patients by electroencephalograms. This is not a medical first, but its results, published in the journal Proceedings of the National Academy of Sciences (PNAS) Monday are. These people were in a coma with no chance of waking up according to their doctors.
Heart attacks at the origin of scientific progress
At the time of disconnection, two patients saw their heart rate increase. The brain then developed a peak of gamma waves: they are produced by the cerebral cortex and are typical of the state of conscious wakefulness according to Stéphane Charpier, professor of neurosciences at Sorbonne University, for the RTS. This has already been confirmed by previous studies, but here the researchers were able to more precisely identify the area in question which is associated with “consciousness”.
For the main author of the study, Jimo Borjigin, this allows us to draw some lessons: “If this part of the brain is stimulated, it means that the patient sees something, can hear something and can potentially feel sensations outside of his body.”
The low number of people analysed, four, does not allow us to provide a very solid answer and identify robust hypotheses. But this will further guide future studies. In addition, the patients therefore died, which makes it impossible to know whether they saw or felt visions during their cardiac arrest.