And heeere we go to the finale! My last episode of the NEAR DEATH EXPERIENCE series. I ended my last chapter with an argument that when our brains fail - like during fainting - they tend to create weird hallucinations. You might have experience of meeting supernatural being or seeing a tunnel etc.
So again, why is this happening?
Why are dreams so weird?
Our brains are practically never non-active. Unless you are dead of course. Even when you sleep, your neurons are very active - especially during one phase called the REM phase. REM is the phase of the sleep when you dream most intensively. The typical characteristic of REM sleep is that weird rapid eye movement behind the eyelids. That's the result of the fact that your visual cortex with brain stem is active. Along with these activations, there is also in-activation of dorsolateral prefrontal cortex. This area is responsible for logical thinking, planning, sorting thoughts and emotions. Taken together, this is the explanation why the dreams are so absurd with no logical narrative.
Waking up or if you want switch from REM state to awake state is under control of brain stem. There are not that many neurons (compared to the rest of the brain) yet they can change the activity of most of the brain. But of course, nothing is perfect and sometimes this switch doesn't work properly. It can happen that instead of direct transition from REM to AWAKE it sort of goes through this weird hybrid state between REM and AWAKE. This hybrid consciousness can resolve in all sorts of hallucinations.
One common hybrid state is so called sleep paralysis. During sleep your muscles are paralyzed which is the result of different area-activation under REM state. So when the switch in the brain stem doesn't work properly, it can just turn ON your awake conciousness while leaving your body paralysed. During this state is also very common having various hallucinations.
REM switch and NDE
It is long known that during stress conditions your brain is trying to stay awake as much as possible far remove from REM state. That makes sense, when you ancestors met a lion, taking a nap is probably not the wisest option. But under very extreme conditions like heavy loss of blood, extreme pain etc., specific neurons in brain stem shut down your awake state and you lose you conciousness. This inactivations is very akin to the inactivation during transition to REM conciousness.
It is just a hypothesis but when the scientists studied people with NDE they found out something very interesting concerning REM switch. It turned out that people's brains that had NDE tend to experience far more often this hybrid state we've talked about earlier.
So it is possible, that during extreme situations like cardiac arrest, loss of blood etc or maybe during awaking from them, their brains tend to create hybrid state full of hallucinations.
Well, we don't know, but I think this is pretty cool hypothesis. To close my NDE series, let me have a few words about Occam's razor. Occam's razor is a philosophical principle using for deciding between two hypotheses. If we have two hypotheses one of which is less complicated, it is also more likely that it is the right one. Sure, we might think that people having NDE are flying out of their bodies, meeting gods etc. But I think it is far less complicated to assume that NDE are just products of our brains.
Sources:
The God Impuls by Kevin Nelson
https://www.ncbi.nlm.nih.gov/pubmed/25377188
https://www.ncbi.nlm.nih.gov/pubmed/25958650