Nelson’s finally pinpointed when the NDE occurs! We’ve determined what its neurophysiologic cause is. The symptoms of a NDE generally crop up due to a lack of blood to the brain. Even a reduction in blood flow can cause a NDE.
Nelson has noticed a correlation between the amount of blood flow to the brain and the experiences that follow. The “tunnel” phenomenon actually occurs because of lack of blood flow to the eyes (an extension of the optic nerve of the brain). The retina is particularly sensitive to blood availability. When blood is in low supply peripheral vision suffers first, therefore the patient with limited blood flow feels as though they are looking through a tunnel. They are only able to see a small circle of their usual field (right in the middle where the concentration of rods and cones are higher).
As it turns out, when blood deprivation occurs, the first function to fail is the visual system (peripheral vision being the absolute first). This explains why people blackout before a NDE and remain semiconscious before losing consciousness completely.
This phenomenon was discovered through the work of Dr. Lambert using a machine simulating G-force for research participants and specialized goggles that would allow blood flow to the eyes for a longer period of time than without them.
When exposed to 2Gs of gravitational force (without afore mentioned goggles) the eyes lose blood and the subject is temporarily blind. When that force is increased or lasts too long (just a few seconds) the person loses consciousness/faints.
During experiments the specialized goggles allowed the subjects to keep their vision, that is, until they passed out (then it didn’t matter whether they had blood flow to the eyes because the brain couldn’t process visual information anyway).
People regularly have NDEs during a faint (this cause was at the top of the list for Nelson’s fifty-five subjects during his research experiments, making it possibly the most common cause for NDEs).
20% of the blood that the heart pumps goes to and feeds/oxygenates the brain. If a third of this blood is reduced the brain stays active for about ten to twenty seconds before it loses consciousness.
Unfortunately, if the brain’s blood flow is reduced by 90% for 30 minutes or more there will be permanent damage. If no blood reaches the brain for a minute or two, the patient will fall into a coma that may last longer than a few hours. If no blood goes to the brain for 4 minutes or longer the temporary brain problems become permanent damage.
The portions of the brain that are most sensitive in this scenario are memory structures (limbic system/hippocampus). This (product of selection during evolution) is another way the body is able to keep itself alive under dire circumstances.
The brain structures that keep the body operational will be the absolute last thing to go.
Let’s revisit fainting.
Our own Dr. Nelson involved himself in a game where he and his friends decided to make themselves safely (theoretically) pass out and see what happened. Nelson was successful and had an experience in which he pictured his father calling him home. This turned out to be somewhat of a premonition because Dr. Nelson was supposed to be home for a family outing he’d forgotten about. However, he realized (later in life) that something triggered his memory about the plans his family made while he was under his intentional unconsciousness.
Experiments for NDEs involve subjects safely fainting in laboratories and recording what happens on a high speed video camera. Then the subjects are asked about their experiences. The research team then compared their descriptions to what Raymond Moody (the first person to record his patient’s near-death experiences in the 1970s) described as the near-death experience. The team “found no real difference between the two types of experiences.” Nelson determined that this would be a great system for his research strategy; making people faint would give the same results as any experience that resulted from lack of blood flow but would be much safer for the subjects when done correctly.
Have you ever had a NDE while unconscious or having fainted?
Personally, I’ve had an experience in which I fainted and felt as though I was surrounded by people when there was really only one person around. I saw a white concentrated light right at the center of the beings I envisioned. It seemed to last much longer than the faint actually occurred (I know this now).
I encourage anyone who reads this blog to remember any such experience and try to compare and contrast the details of it with what we’ve learned because of Dr. Nelson’s research.
To be continued…
Wait for my next post for the rest of the story. I hate to make you wait too long so I’ve decided to do each chapter in parts. It should also make it more pleasant to read as well!
See you next time!