Near Death Experiences
Is an NDE Real or a Hallucination?
Near Death Experiences Series, Article 17 (Reviewed by the Editorial Board)
Is it true that when one has a cardiac arrest, after 4 minutes irreversible brain damage occurs? Although this is not quite the case, what is true is that the energy stores one has, only last 4 minutes. Stored oxygen levels (in the brain) for instance, are minimal and only last 2 minutes, whereas nutrients (stored in the brain cells) only last 4 minutes. After this cells start to undergo changes, they start to open up, calcium starts coming in and various chemical processes start to occur.
How the body responds during cardiac arrest
Also, when someone is about to die, the body initially responds by releasing certain chemicals and steroids to try and maintain the blood pressure and allow sufficient blood to get to the brain. After a while, however, the blood pressure drops and there is thus reduced blood flow to the brain, which will in turn activate certain parts of the brain and lead to the near death experience.
Are NDEs hallucinations
Because of these chemical process that take place, the most widely accepted scientific arguments to explain the causation of near death experiences, have largely centred around the concept that the experiences are hallucinations in response to changes in the brain at the time of death. It is a well-established fact that changes in the amounts of the chemicals or neurotransmitters in the brain can lead to 'abnormal' and disordered thought processes, or in other words a hallucination. These physiological and chemical derangements, accompanying the process of death, are thought to cause the near death experience. It has been argued that NDEs seem real to those who experience them, just like hallucinations often seem very real but do not correspond to objective reality.
Propose brain mediators
To support this argument many brain mediators had been proposed to account for the experiences, although none has yet been shown to be responsible experimentally. These included :
- a lack of brain oxygen
- increased carbon dioxide
- the release of endorphins (the body’s own morphine-like substance)
- mediators involved in specific type of seizure known as temporal lobe epilepsy
- various drugs and in particular drugs that were known to cause hallucinations, such as ketamine (which is occasionally used as an anaesthetic).
- A special mediator (psychedelic drug) claimed to be released near to death, called dimethyltryptamine (DMT)
Near death experiences: which parts of the brain are involved
Many scientists have debated which parts of the brain are involved in NDEs and have theorized that they may be due to brain cell activity in the limbic or temporal lobes. What we do know is that each area of the brain processes multiple functions and that "conscious” states such as seeing, thinking, feelings and emotions are mediated in many areas at the same time. Although we still do not know exactly which areas are involved, undoubtedly brain processes do mediate the experience. But the discovery of the exact areas will not explain the significance of near death experiences. Neither will it make a near death experience 'unreal' or a hallucination, in exactly the same way that discovering the areas of the brain involved in viewing pictures or experiencing maternal love doesn't make those sights or feelings hallucinations.
This is because all human experience is mediated through different processes of the brain, whether they are commonly understood experiences such as love or anger, or less commonly understood ones such as near death experiences and the activation of a specific area of the brain cannot allow us to determine that an experience is real and another area that it is not. For instance, feeling intense love is mediated by the same areas regardless of whether someone has the illusion of experiencing love or is really in love. The same is true for someone who experiences seeing a light; whether he or she is actually looking at a light or imagining looking at a light, the same areas of the brain become involved. (1)
....... If you want to read more, visit the near death experiences section of our web site (2).
(1) Parnia, S. 2013. Erasing Death. Harper One