An unexpected discovery made by an international team, examining the results of an EEG on an elderly patient, who died suddenly of a heart attack while the test was in progress.
What happens in our brain when we make the transition from life to death? What is the physiological basis for the accounts of those who have so-called ‘near-death experiences’, which have very similar features but are, according to some experts, merely the fruit of our imagination?
A study (the result of pure chance) just published in the scientific journal Frontiers in Aging Neuroscience by an international team of researchers is beginning to answer these questions.
Everything started, as mentioned above, with a coincidence. Neurologists were carrying out an electroencephalogram (EEG) on an 87-year-old patient who was brought to A&E after a fall and was operated on urgently to release the pressure of a cerebral haematoma. The man suddenly suffered a heart attack and died while the EEG was in progress.
However, EEG recordings went on for a total of 15 minutes before and after death. When researchers focussed on the 30 seconds before and 30 seconds after death, they observed something very specific showing changes in wave patterns (particularly in gamma waves, as well as in alpha, beta and theta waves) like those seen in people who are dreaming, experiencing flashbacks, processing memories or meditating.
A replay of life before death?
The waves emitted by the dead patient seem to suggest that, just before the heart stops and up to 30 seconds later, experiences like those reported by many survivors of near-death situations are triggered in the brain, i.e. (usually positive) memories and visions of their lives.
However, researchers have pointed out that it is clearly impossible to determine what kind of thoughts are formed from brainwaves alone, and in any case, processing memories is entirely subjective. The elderly patient examined by the international team was also suffering from brain trauma due to the fall, and from a series of epileptic seizures 'provoked' by neurosurgery, so he may have reacted in an unusual way.
However, “Albeit the influence of neuronal injury and swelling, our data provide the first evidence from the dying human brain in a non-experimental, real-life acute care clinical setting and advocate that the human brain may possess the capability to generate coordinated activity during the near-death period,” the researchers write.
Tests on animals confirm this
In reality, another experiment carried out on rats nine years ago in the U.S. and again focusing on 30 seconds before death, also showed the exact same type of oscillations. It is therefore possible, researchers suggest, that there is a neurological mechanism preserved throughout evolution, still present in human beings, specific to the moments before and after death.
Researchers have tried unsuccessfully to obtain other EEG recordings at the precise moment of death, while caring for the terminally ill. The hope, however, is that the study published in Frontiers in Aging Neuroscience will encourage other colleagues in similar situations to record and compare their findings.
It will only be possible to say something with certainty when there are more examples. In any case, even though the theory that the dying relieve their lives in a positive way is not yet proven (an idea that may perhaps comfort us), it is now maybe less abstract and more plausible.
