A sudden cardiac arrest has multiple potential causes, all of which have a common end-point, the cessation of respiration and the effective pumping of the heart and, for 90% or so, the end of life. For most survivors, paradoxically, the experience of having a sudden cardiac arrest was not really experienced. Few survivors have any memory of their actual cardiac arrest. In my case, I lost consciousness before my body hit the path on which I was running. While few can recall elements of their arrest, even fewer report having had a near-death experience. Most survivors of a sudden cardiac arrest report no memory of a near-death experience. If you are in that group, you are the rule, not the exception. Why is that? Why were we excluded?
First, just to get this off my chest, “near-death experience” seems to me an inappropriate or inaccurate term for what it is intended to describe. After all, is surviving a sudden cardiac arrest not itself a near-death experience? We survivors came as close to being dead as is biologically possible and if that does not describe being near death, well, I don’t know what does. I was found vital signs absent, given CPR for 15 or so minutes by bystanders and finally resuscitated by defibrillator in a speeding ambulance on the way to the hospital. I remember nothing of this rather typical near-death experience.
NDE: What a Person Recalls Experiencing During a Cardiac Arrest After the Arrest
But, as you well know, the term “near-death experience” describes something other than the precipitating medical event, the cardiac arrest or traumatic event itself. NDEs are about what is believed to have been experienced during the event, as recalled after the event. NDEs are memories. They are survivors’ self-reported memories, gathered at some point in time during or after their recovery from their sudden cardiac arrest.
Near-death experiences are what a person recalls experiencing during their cardiac arrest after their cardiac arrest.
NDEs are memories. In these memories, survivors recall scenes from their cardiac arrest, including visual and auditory memories of resuscitation attempts, or vivid encounters with people and things not physically present to others at the time of their arrest. The latter types of memories are as real to those who experienced them as the former. Whether the survivor recalls seeing people giving them CPR from a perspective above the action or recalls meeting a deceased relative in heaven, it is recalled as really occurring. Some survivors also report horrific and terrifying nightmarish memories, but this type of NDE is not talked about as much as are the others.
The interest and curiosity about near-death experiences is understandable. These hyper-vivid memories often defy physics and logic. They are so magical and surreal that some survivors who recall them are reluctant to discuss them for fear of being labelled or judged in a negative way. The reaction to sharing an NDE memory can be like that from trying to convince someone how you were abducted by aliens or were a queen in a past life. It is not every day that your heart stops functioning. It is even more rare and improbable to float above your own body, having an “out of body experience”, or to be told by a deceased relative that it is not your time to die.
It is easy to see why people want to share and validate their NDE memories in this group, where it is safe to do. It is also understandable why those outside this group are curious about these memories, especially in this age of growing skepticism of science. NDEs are a relatively infrequent and seemingly otherworldly phenomenon that seem to defy scientific explanation. Therefore, in addition to the curiosity of the public, there is also research into understanding NDEs that is heightening the curiosity and attention.
Does Consciousness Survive Death?
One area of NDE research is focused on answering the question: How can a brain that is shutting down, or is shut down in key areas, continue to process information? To generate an NDE, the brain must be functioning is the argument being tested. At its most extreme and perhaps most sensational, this research attempts to test the hypothesis that the mind or consciousness can survive and function separately from the physical brain. In other words, some researchers wonder whether consciousness survives the death of the body, much like the religious belief about the existence of a soul that is separate from, and survives, the physical body.
Early in the last century, in 1907, Duncan MacDougall, a physician in Massachusetts, weighed people as they died to calculate the mass of the human soul as it departed the body. His answer was 21 grams. His results were not widely accepted.
We know that brain cells begin to die shortly after the heart stops pumping blood to the brain, and the resultant lack of oxygen limits and eventually stops brain function. If these NDE memories can be shown to have been created during the arrest, when the person was clinically dead and the brain seemingly incapable of functioning, researchers want to understand how this is possible. Some researchers believe that perhaps the brain continues to process information longer than it has been given credit for, after the heart stops providing it oxygen. These questions provoke another: when do we determine the brain is dead?
Out of Body and Other Experiences
Another and perhaps more popular area of NDE research among the pubic is detailing and exploring the fantastic memories themselves, specifically those involving things or people not physically present at the time of the arrest. There is no shortage of books available from people who have reported these experiences, although one of the most popular was taken off the market by the publisher after its author admitted it was wholly fabricated malarkey (which was, oddly, the author’s surname). The memories recalled are very vivid and real, at least to those recalling them, and are often strongly associated with Christian and popular-culture imagery related to dying and going to heaven. A frequent theme in survivors’ recall is being guided back to life by a religious figure or someone deceased and important in their life (like a grandparent, parent, sibling, or friend).
When people refer to NDEs, this is what most are referring to, such otherworldly memories. Some people perceive these memories as evidence of the afterlife promised in the New Testament and this, especially in Western culture, makes NDEs topical. Elsewhere around the world, memories of NDEs are associated with the specific religious and cultural milieu of the person involved, and not necessarily centred on Christian imagery, but they do follow similar patterns and themes. Interestingly, the horrific menacing memories that haunt some survivors are rarely studied at all.
Reliability and Timing of the Memory
Near-death experiences are based on memories. The biggest challenge inherent in NDE research is the same as that of eyewitness testimony, that is, the reliability of memory. Psychologists, as well as police and lawyers, will tell you that memory is not an accurate mirror of reality. Memory is prone to confirmation bias and expectations. In addition to the reliability of memory is the challenge of determining the timing of the memory and when it was generated. Was the memory recorded by a hyper-active brain in the milliseconds before it shut down or was the memory somehow created when the brain was shut down (e.g., by a consciousness separate from the non-functioning brain) or was the memory supplied after the fact, when consciousness had been restored? There is no easy experimental way to answer the question, especially since the memories themselves are collected well after the fact.
The research challenge is determining when the NDE memory was generated: before the brain shut down, while the brain was shut down, or after brain functioning was restored. The second challenge is determining how to determine if the brain was ever shut down at all.
For the person doing the remembering, there is simply no accurate means of identifying exactly when the memory was created: at the beginning of or during the sudden cardiac arrest disabled blood flow and oxygen to the brain or after it was restored. The researchers are confronted with the same problem. If the memory was created before brain function was totally compromised or after it had recovered, the NDE phenomenon may become decidedly less interesting to study; it can be easily argued that the memory was created by a near-functioning or functioning brain. What was recalled might then be the result of the brain’s observations and/or its attempt to fill the gaps in understanding, drawing on prior memories, to make sense of the traumatic experience or to conform to expectations or a set of beliefs.
The question is, how can the research accurately place the creation of the memory at a specific time when it must rely on the person recalling the memory, well after the fact?
To get around this challenge, some clever researchers have placed objects out of view in the emergency room and later ask sudden cardiac arrest survivors whether they recall their resuscitation and, if so, whether they can recall any of these “hidden” items. There has been little success, so far, with only one survivor reportedly recalling a hidden item. This result is tantalizing but anecdotal and loaded with questions about rigorousness of the methodological controls in place.
Another challenge for the research is determining whether the brain was functioning in some capacity at the time the memory was created. If the brain is perceiving or processing information, current medical science says it must be functioning, but these researchers are attempting to prove that this is not the case with NDEs. Their assumption, therefore, is that the genesis of these memories was during the period when the heart was not pumping, while the person was absent vital signs (i.e., VSA) and the brain was essentially or at least temporarily dead. Researchers who rely on survivors’ memories need to accept at face value the survivors’ reports that the memory was created while the survivor was clinically dead. From the survivor’s perspective, their being in heaven seems proof enough they were dead. For the researcher, that is a big leap of faith. However, it appears to be an acceptable, if highly questionable, resolution for both some researchers and book authors.
Religion, Popular Culture and Expectations
Compounding the research challenges is that in North America, and perhaps elsewhere, there is a dramatic theme in popular culture (i.e., books, television, and movies) that dying people have an NDE. In the 5th season finale of the television sitcom, Curb Your Enthusiasm, Larry David dies after surgery to give one of his kidneys to the comedian Richard Lewis. Larry experiences the tunnel with the light at the end, meets two angels (Dustin Hoffman and Sacha Baron Cohen) in heaven but is sent back to earth when he starts arguing with everyone in heaven. My favourite is the dying character Mimi, from the 1996 musical “RENT”, who reports she was heading toward a bright light before being told to go back by the drag queen Angel, who died from AIDS earlier in Act 2.
“I was in a tunnel, headed for this warm white light. And I swear, Angel was there, and she looked good! She said, ‘Turn around girlfriend and listen to that boy’s song!'”
Rent by Jonathan Larson (1996)
The notion of dying people seeing a tunnel with a bright light or a light-emanating beckoning human figure at its end has become a cliché. When I woke after being in a 2-day induced coma, I announced to my concerned wife and gathered siblings and their spouses that I had seen my mother and father in heaven. I was being silly, a bit manic, and trying to break the tension. Some took me seriously.
People have expectations about the experience of dying and what the trip to heaven and back should be like. In fact, some survivors of a sudden cardiac arrest bemoan the fact they were denied the experience, even though they had died. Most of the reported NDEs replay a familiar scenario. The experience of dying and going to heaven is part of our cultural mythos and expectations. If NDEs are proof of an afterlife, the question remains: whose afterlife? Buddhists, Christians, Hindus, Muslims, and members of other religious groups have NDEs specific to their beliefs. It is a challenge for research to tease apart the influence of these religious and cultural expectations from the NDE memories recalled.
When might the memories have been generated and how?
The Milliseconds Before the Brain Shuts Down
Recent exploratory research indicates there is a significant uptick in brain activity immediately prior to brain death. While the research was conducted on rats, it is suggestive that our brains might act similarly. There is other compelling research that indicates the brain becomes extremely active and focused by life-threatening situations. For example, you may have had the experience of time slowing down, such as described below in one of my favourite fiction series, the Jack Reacher novels.
“Reacher twisted as he hit the ground. He was in that zone where his mind was fast but the physical world was slow.”
Bad Luck and Trouble by Lee Child (2007)
This happened to me when a driver turned his car in front of my front wheel while I was cycling, and I paralleled the arc of its travel into a parking lot, in slow motion. I still have a very vivid memory of my thoughts and perceptions during those seconds as the fingers of my left hand gripping my handlebars bumped against his door panel. Time does not really slow down, of course, but it certainly feels that way.
One theory is that the fear stimulates a flood of neurotransmitters in the brain, increasing focus and clarity of thought, attention to decision-making and behavioural responses and memory. Time feels like it has slowed down because cognitive processing has relatively sped up. Perhaps this happens to the SCA survivors who have vivid memories, either of their resuscitation or traditional NDE perceptions. Their brain is working extraordinarily fast in advance of shutting down, recording what it can and filling in the blanks with explanations from memory. Perhaps all this gets recalled later. There is also research suggesting the brain continues to function for some time after its oxygen supply is cut off. So perhaps the cessation of cognitive function is not like turning off your reading lamp before bedtime, but a more gradual process of cumulative brain cell death such as described below in another wonderful novel (in the box below).
“In the first minute following her death, Tequila Leila’s consciousness began to ebb, slowly and steadily, like a tide receding from the shore. Her brain cells, having run out of blood, were now completely deprived of oxygen. But they did not shut down. Not right away. One last reserve of energy activated countless neurons, connecting them as though for the first time. Although her heart had stopped beating, her brain was resisting, a fighter till the end. It entered into a state of heightened awareness, observing the demise of the body but not ready to accept its own end. Her memory surged forth, eager and diligent, collecting pieces of a life that was speeding to a close. She recalled things she did not even know she was capable of remembering, things she had believed to be lost forever. Time became fluid, a fast flow of recollections seeping into one another, the past and the present inseparable.”
10 Minutes 38 Seconds in this Strange World by Elif Shafak (2019)
While the Brain is (Apparently) Shut Down
New research investigating the state of being unconscious indicates that its primary result is slowing down and reducing communications between different parts of the brain. The brain has not shut down, as had been assumed, but rather its processes are fragmented and isolated from each other. Activity within these islands becomes tightly focussed, which also impedes efficient information transfer between them. Consciousness may be present – areas of the brain may be functioning — even though the individual is totally unresponsive. Other research, conducted on unresponsive people in a comatose state and using fMRI scans, showed responsive brain activity. In one study, a comatose woman with severe brain injury was asked to imagine playing tennis and those areas of the brain associated with that specific task showed activity, just as it did with conscious research subjects. The woman “heard” the verbal instruction and responded, neurally, as if she was playing tennis. This research speaks to the possibility that parts of the brain, or certain of its processes, may still be functioning during a cardiac arrest, unbeknownst to observers.
After the Brain Begins Functioning Again
And then there are the memories themselves, which are recalled days after the event and often when the survivor is brought out of an induced coma. Cognitive scientists will tell you that our memories just are not as accurate as we would like to believe they are, much to the chagrin of public criminal prosecutors. We are not objective when creating memories. Our expectations influence what we remember and confirmatory biases what we see. Our memories are fluid and change over time in line with our self-interest and ego needs. We remodel our memories each time we recall them, adding new details and deleting those contrary or damaging to our beliefs.
Our memories are also subject to a director, or perhaps a better analogy is cinematographer, that determines the perspective from which the memory is viewed. We either view memories as if seen through our own eyes or of those of an observer. Research indicates that highly emotional memories take on an observer perspective – you see yourself, in the memory, as an observer would see you, rather than what you would have observed through your own eyes (which is the field perspective). Changing the perspective from the field to observer perspective, from what you saw to how an observer would see you, can reduce the emotional impact of the memory, the research reports. It does not seem so surprising, then, that some survivors recall having out of body experiences, where they remember seeing themselves from above being resuscitated from the observer perspective. This could be how the mind wants to recall the experience, to mitigate its traumatic effect.
“Eyewitness testimony was suspect because of preconditions, and cognitive bias, and suggestibility. It was suspect because people see what they expect to see. Reacher was no different. He was human.”
Make Me by Lee Child (2015)
Perhaps the most interesting memory phenomena are those called the DRM illusion, named after the psychologists who discovered it, Deese (1959) and Roediger and Mc Dermott (1995), and an extrapolation called “imagination inflation”. The DRM illusion research initially focussed on asking people to remember a list of related words such as “bed”, “rest” and “awake”. When asked to recall the list, people falsely remembered associated words such as “sleep” that were not on the list. The research subjects were highly convinced of the veracity of these manufactured memories. Later DRM research extended these findings and has proposed that people may manufacture a new memory when a previously formed memory is highly associated with a particularly evocative external stimulus. In trying to find meaning in a situation, our brains might draw on older existing memories to create a new memory that matches the circumstances we are in, to help us understand it. The imagination inflation research discovered that if people imagine themselves in a situation they were never in, it strengthens their confidence they were in that situation (even though they were not). The act of imagining an activity never performed creates a memory, the memory becomes familiar, and the familiarity of that newly created memory increases the belief that the activity was indeed performed. Under certain circumstances and among some people, memories can be manufactured and confidently believed to reflect reality. Our memories seem very fixed and certain but are very fluid and untrustworthy. We are not cameras or computers. We are human.
Memories are formed through three processes: they are formed (encoded in the brain), strengthened (consolidated into long-term memory) and recalled (retrieval). Different parts of the brain are responsible for each. The shock and oxygen deprivation from a cardiac arrest affects memory formation, strengthening and retrieval. Many survivors lose memories of the days before their cardiac arrest, during the arrest and for some days after the arrest. How a sudden cardiac arrest impacts the reliability of memory is largely unknown.
NDEs are memories. Memories are unreliable mirrors of reality. Memories of near-death experiences are recalled well after the person has been revived, making it a challenge to pinpoint when they were created, encoded, and consolidated in the brain: before or during brain function cessation or after it resumed. Determining the timing of complete brain death is difficult and there is evidence the brain can function for some amount of time after respiration and blood circulation have ceased. It is a tough nut to crack, for the researchers. There is an expectation in our culture about what going to heaven might be like and we are delighted, sceptical and curious when this seems confirmed by people recalling these near-death experiences. Still, why didn’t I have one?
Summary Thoughts
I did have a near-death experience, coming as close to being dead as is possible, but none of the traditional NDE memories: no memory of witnessing the frenzy of resuscitation attempts nor memory of being turned around in heaven and directed back to earth by an otherworldly guide nor frightening nightmares. Most of my fellow survivors did not have any of these NDE memories either and the research is quite clear about that too. To me, this fact makes researching this phenomenon interesting, and for that reason alone: their relative infrequency among survivors makes near-death experiences an anomaly and worthy of understanding.
One of the exciting hypotheses from the NDE research is that perhaps our conception of death, or “being dead”, needs to be seriously revised. How long the brain continues to function and process information and store memories, after the lungs stop respiring and the heart ceases to pump, needs to be further explored. I might have been left for dead had my event occurred 50 or so years ago and I been found vital signs absent. Before the advent and communication of the effectiveness of CPR, that would have been the most likely outcome. The success of CPR changed our conception of what’s possible and what death means. Science and medicine need to take another leap forward. Death is not turning off the light; it is using the dimmer.
The brain is a wondrous organ, almost miraculous in how it functions and in the many functions it performs. It not only perceives but interprets and anticipates and initiates response. We can consume inert sugar pills (placebos) and, if we are told and believe they will reduce our physical pain, our brain will make it so, at least for some of us. In some cases, the brain’s response is as good as or better than a prescribed analgesic or pain killer. That our brain might record frantic scenes of resuscitation while its oxygen supply is depleting or provide existential comfort through a spiritual- or cultural-based explanation after a life-threatening event seems hardly surprising to me. Our brains are hard-wired to help ensure survival.
Whether our consciousness survives the death of the brain and body is a different matter and likely as answerable by the scientific method as whether heaven is real, God exists, or how much the human soul weighs. Some things are not questions for science but of faith.
“The heart has its reasons about which reason knows nothing. It is the heart which experiences God, and not reason. This, then, is faith; God felt by the heart, not by reason.”
Pensées by Blaise Pascal (1670)
My intention is not to discount the memories of sudden cardiac arrest survivors who report near-death experiences. There is no question in my mind that people have these memories. The consistency in form and content across what people recall, regardless of their religious belief, is striking. My goal was more personal – I wanted to try to understand why I did not have these memories and to do that I needed to understand how they might be created. At heart, perhaps, I’m jealous at being denied this experience, just as I was denied any warning sign of my impending cardiac arrest and denied any memory of the event itself.
So, why didn’t I have an NDE?
The effectiveness of CPR changed our conception of when death occurs and what it entails. People facing sudden cardiac death were suddenly now surviving. Death, it turns out, is not turning off the light. Death is using the dimmer. It is a progressive phenomenon with decreasing possibilities for recovery, without proper intervention. With my heart not pumping and my lungs not respiring, my brain quickly lessened its need for oxygen by reducing its activity, to preserve itself. I lay in that ephemeral abyss, the probability continuum between life and death. My brain remained alive but dormant, its cells extinguishing. Any cognitions I might have had at the time were sacrificed for its survival. My brain was simply doing its job and I did not die. It is a wondrous thing.
Requiem for a Sudden Cardiac Arrest
Amid the confusion and chest-thumping blows
I silently slipped to where nobody knows
Then the lights turned back on and time re-started
Though I returned not the same as when I departed
While I long to go back to where I don’t know
I just stare at the mirror wondering where did I go
Ted Gulloien
© 2021
