You’ve heard the stories countless times. Someone has a brush with death but survives and later reports some very odd happenings. A bright light that pulls them forward, or pushes them away. A floating sensation where they hover near the ceiling and look down on their own rescue or surgical procedure. They might report seeing images from their past or people they’ve known who have passed on, beckoning them to join them in heaven.
Is this what is happening? Are these events a glimpse at what lies beyond the curtain that separates life and death? Or is there a physiological explanation for these phenomena?
In an excellent article that appeared in a recent issue of New Scientist, this phenomenon was discussed by neurologist Dr. Kevin Nelson. He points out that we basically have three states of consciousness: Awake, Non-REM Sleep, and REM Sleep. He emphasizes that these three stages are not distinctly separate but rather overlap one another. And it is in these gaps that near-death experiences live.
Such experiences are most often reported by those who suffer cardiac arrest. A cardiac arrest occurs when the heart ceases to function, either because its electrical activity has stopped or it has become extremely chaotic usually in deadly rapid rhythms that we call ventricular tachycardia and ventricular fibrillation. In either case, the heart is no longer and effective pump and blood circulation ceases. The brain requires a constant supply of oxygen and nutrients. If this is interrupted it begins to malfunction and if severely interrupted, as with a stoppage of the heart, brain death begins almost immediately.
So how does this relate to a near-death experience?
One of the areas of the brain that will begin to malfunction early are the eyes and the visual cortex near the back of the brain. As vision begins to fail it does so in an out to in manner. That is, from the periphery to the center. This results in a tunneling of the vision so that it appears as though you’re looking down a gun barrel or a hallway or perhaps a pathway to heaven. What is left of the vision is typically a vague light that is enhanced by all the adrenaline running around in the brain as it fights to survive. This might make the light appear much brighter and this will enhance the victim’s tunnel-like vision and create the bright-light image.
Other areas of the brain are concerned with body position and location in space and when these malfunction the perception of where you are can be altered. This leads to a feeling of floating and in some people their brain constructs the image of their surroundings as if they were looking down on everything, including themselves. Interestingly, PCP (phencyclidine or Angel Dust) can cause a similar reaction, as part of a Depersonalization Syndrome.
This level of consciousness is similar to what psychiatrists and neurologists have called Lucid Dreams. These are dreams that occur in that zone between wakefulness and sleep. They are often extremely real and when someone awakens from them they’re not sure if the events really happened or not. The brain is capable of constructing all types of images and scenarios. Some of these may indeed be the faces and forms of past love ones and when coupled with a loss of spatial orientation and tunnel vision, it can look as though they are ghostly apparitions from heaven.
Near-death experiences are not common but they are often dramatic. In my nearly 40 years of practicing cardiology I have seen this phenomenon many times.