Author Interviews
1:51 pm
Thu February 21, 2013

'Erasing Death' Explores The Science Of Resuscitation

Originally published on Thu February 21, 2013 2:39 pm

What happens when we die? Wouldn't we all like to know. We can't bring people back from the dead to tell us — but in some cases, we almost can. Resuscitation medicine is now sometimes capable of reviving people after their heart has stopped beating and their brain has flat-lined; Dr. Sam Parnia, a critical care doctor and director of resuscitation research at the Stony Brook University School of Medicine, studies what these people experience in that period after their heart stops and before they're resuscitated. This includes visions such as bright lights and out-of-body experiences.

Often described as near-death experiences, Parnia prefers the term "after death."

"What we study is not people who are near death," Parnia tells Fresh Air's Terry Gross. "We study people who have objectively died. ... And therefore what we've understood is that the experience that these people have of going beyond the threshold of death, entering the period after death for the first few tens of minutes or hours of time, provides us with an indication of what we're all likely to experience when we go through death."

In his new book Erasing Death: The Science That Is Rewriting the Boundaries Between Life and Death, Parnia examines the experiences patients describe, but whereas much discussion around the experience of death has been philosophical or personal, Parnia is looking at the subject scientifically.

"One of the big problems that we have," Parnia says, "is that because we've never had a science, we've never had an objective method to go beyond the threshold of death and study what happens both biologically and from a mental and cognitive perspective. Therefore everything that we deal with is basically hearsay and people's own beliefs."

He specializes in people who survive cardiac arrest. Eighty to 90 percent of these patients do not have stories of bright lights, tunnels, out-of-body experiences and luminous beings. Parnia says this could be related to the degree of damage and inflation that is occurring in the brain and how this affects memory. Ultimately, Parnia's concern is the quality of care patients are receiving.

The question that drives his research, he says, is: "Is there a reason why people are having these experiences? For instance, could it signify that somehow these people had had better-quality resuscitation of the brain?"


Interview Highlights

On a Hieronymus Bosch painting that depicts an image similar to images described by people who have had near-death experiences

"There's a very interesting painting by Hieronymus Bosch from the 15th century where he's actually painted what looks like a classical near-death experience, but in reality people didn't know about near-death experiences at that time and it certainly isn't what classical Christianity would have taught of what people would have experienced when they've died."

On why most people who are resuscitated do not have memories of lights or tunnels or mysterious beings

"We've certainly found in our studies ... that if we manage to get to patients immediately after waking up — which is not easy at times — and talk to them, they tend to remember more, and if you go back and reinterview them within a couple of days, they tend to have forgotten their experiences, possibly. So we think that probably many more people have these experiences — if perhaps not even everyone — but somehow their memories get wiped in the same way that most of us — if not all of us — dream every night, but somehow there's a disruption to the memory circuits that allow us to recall our dreams the following day."

On why doctors often put a patient on ice when trying to restart a heart

"If we cool people down by a number of degrees Celsius ... we slow down the rate by which cells — particularly brain cells — are undergoing their own process of death, because we have to remember that cell death takes place through chemical steps. So, from our high school chemistry days we all know that chemical reactions need heat, and if you take away the heat, that slows down the chemical reaction."

On questioning the things people report having seen during near-death experiences

"The experience that people have is very personal and it's very real to them. So, for most people who've gone through these experiences, as far as they're concerned, what they've experienced is absolutely real. They've described and seen something of the other side. Now, for those of us who haven't had the experience, it's impossible to verify that, but in the same way that, for instance, if a patient comes to me and says, 'I have depression,' it would be completely unacceptable for me as a physician to simply discard that experience and say, 'Well, I don't think [so]. You may feel that you're depressed, but actually it's an illusion of having depression or you're hallucinating. Your depression, it's not really real.' So we have to remember that to the people who've had the experience, it's real to them."

On how the variation in quality of care drives him to this research

"There is enormous, enormous variation in the quality of care that our patients receive across the country and in different countries, and the reason for that is because there is absolutely no regulation on the quality of care that our patients receive. Therefore, at the same institution doctors may provide care completely differently, and therefore your chance of coming back from a cardiac arrest is completely potluck and, more importantly, that means that your chance of ending up with brain damage is completely potluck. Now, we have to remember that cardiac arrest is the only condition that will affect every single one of us. I will definitely have a cardiac arrest in my lifetime. You, unfortunately, will definitely have a cardiac arrest, and so will everybody who's listening to your show. And so do we want to have the best level of care provided for us so that we can be brought back without brain damage, or are we willing to just take a chance?"

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross. What happens when we die - wouldn't we all like to know? We can't bring people back from the dead to tell us but in some cases, we almost can. Resuscitation medicine is now sometimes capable of reviving people after their hearts have stopped beating and their brains have flat lined. And some of those people report being conscious during the period after their heart stopped, before they've been restarted.

These experiences are popularly known as near-death experiences. But my guest, Dr. Sam Parnia, prefers to call them after-death experiences. He's a critical-care doctor who is the director of resuscitation research at the Stony Brook University School of Medicine. He's conducting research into optimal cardiac arrest care, and into the experiences some cardiac arrest patients report they have brought back from the other side of death. He says whether these experiences are psychological phenomena or actually happen, they've been reported so routinely they warrant further study. Dr. Parnia is the author of the new book "Erasing Death."

Dr. Sam Parnia, welcome to FRESH AIR. As a doctor who specializes in resuscitation research, what is your interest in what people have experienced after they technically died; after cardiac arrest, when their heart has stopped?

SAM PARNIA: Well, I've been interested in this field for many years now. And the reason I got interested, really, was because I had a patient who I had taken care of, who - when I was a medical student, many years ago, now - who I saw essentially die; have a cardiac arrest in front of my eyes, and nothing could be done to save this person. And I remember thinking to myself, what is this person experiencing as they're going through this period of death?

Now, this was more than 15 years ago, and at that time there was very little work carried out in this field. But as I have begun to grow in this field myself, I have come to realize that we have a very strong need to study what happens to the brain after people die, because R-remed(ph) - a physician like myself, who specializes in resuscitation science - R-remed is to bring people back to life after they've died.

And therefore, inadvertently, we have to study what happens to the brain in the minutes to hours after someone's dead but also, not forgetting that there's a human being in there; and that they have a consciousness, they have a mind, what classically used to be called the psyche or the soul. And what does that person experience, and what's it like for them? And that's why we combine both together.

GROSS: So since we're talking about what people experience after cardiac arrest, after their heart has stopped, and then they are subsequently revived - so what they experience between the time their heart has stopped, and the time that they're resuscitated - how has medicine changed the length of time you can be technically dead after cardiac arrest but still be resuscitated?

PARNIA: Traditionally, when somebody died - and that's true of today - when somebody died it was really the point where the heart has stopped beating. And as a consequence of the heart stopping beating, a person would stop breathing immediately and would lose consciousness immediately. And the reason for that was that there was no blood getting to the brain, and the brain would stop functioning.

So today when we define someone as being dead, we look at those three criteria - no heartbeat, no respirations, and we check the pupils of the eye for a reflex that when it's absent, it tells us that the brain stem and the brain is no longer functioning. The person is motionless - and they're dead, and we define them as dead.

However, what we've now discovered - in the past decade or so - is that actually, it's only after a person dies. So in other words, when someone has actually reached that point and they've become a corpse, that the cells inside the body start to undergo their own process of death, and that the period in which the cells die is variable depending on the organs, but it certainly goes on to hours of time.

So for instance, brain cells will die at about eight hours; again, there is some variation, but around eight hours after a person has died. And therefore, our work in resuscitation science is to try to study the processes that are going on in a person after they've died, but before they've reached the point of complete, irreversible and irretrievable cell damage such that no matter what we do, we can't bring them back.

And if we manage to restore oxygen and nutrients back to those cells before they've reached that point, we are able to successfully bring someone back to life. And that's why today, with numerous advances that have taken place in the field of resuscitation science, we have managed to push back that boundary to well beyond the 10-, 20-minute time frame that had been perceived in the past, into many hours of death.

GROSS: So in resuscitation medicine, one of the goals, as you're saying, is to keep the cells alive while the doctors are trying to restart the heart. And that's why - and I guess I maybe should have known this, but I didn't - in a lot of resuscitation medicine, the person is put on ice, or a technological version of chilling the body, while doctors try to revive the heart.

PARNIA: That's absolutely correct. One of the biggest discoveries in the last 10 years has been that actually, if we cool people down by a number of degrees Celsius that actually, we slow down the rate by which the cells, particularly brain cells, are undergoing their own process of death - because we have to remember that cell death takes place through chemical steps. And so from our, you know, high school chemistry days, we all know that chemical reactions need heat and if you take away the heat, that slows down the chemical reactions. So actually, that is one of the things that's enabled us to prolong that gray zone after death and bring people back many hours after they've died.

GROSS: So let's talk about what most people describe as near-death experiences, which is what you've been studying except you don't think of it that way; you think of it as actual death experiences. And why don't you explain the distinction.

PARNIA: Well, after physicians discovered CPR and were able to push back the boundaries of death for the first time - in 1960, interestingly by the mid-1970s, a book was published in which people's accounts of having had a critical illness and been close to death - including people who survived cardiac arrest and essentially, had been brought back from death - their experiences and their accounts were documented. And it was found that people who'd been in that situation had these very unusual but yet interesting experiences where they felt incredibly peaceful; they weren't afraid of death. They often described seeing a bright, warm, welcoming light; going through a tunnel. Sometimes they described a sensation of having a loving, compassionate being with them that would guide them through the experience. Sometimes they described seeing deceased relatives. Sometimes they described going to a point where, if they'd gone beyond that, they couldn't come back. And some of them described getting to a place that was very beautiful.

Now, the most interesting aspect of what these people described was a sensation of detaching from the body and looking down at resuscitation efforts that had been ongoing. And these were termed near-death experience, at that time. Now, they led to a lot of interest but also a lot of skepticism. And one of the biggest problems with the term near-death experience, which is why I don't like to use it anymore, is that it - from a scientific perspective, it is very vague. There is no definition to what near-death really means, and that's why it's led to a lot of controversy.

And the main reason for that is because what has happened is, different people have lumped together experiences that were taking place under very many different circumstances where the human body has a completely different physiology, a different biological process that has been going on. And therefore, people don't agree, and they've been very emotional about this, and it's created a lot of debate - and in my opinion, not necessary.

Now, what we study is not people who are near death. We study people who have objectively died. These people have been dead for tens, sometimes hours - tens of minutes and sometimes hours of time. And therefore, what we've understood is that the experience that these people have of going beyond the threshold of death, entering the period after death for the first few minutes, tens of minutes or hours of time, provides us with an indication of what we're all likely to experience when we go through death.

And that's why I call these an actual death experience, because the physiology and the biology of the human brain is very well-studied, it's very well-understood, and it's standardized, which means that we can study it in a scientific fashion.

GROSS: What are some of the questions you're asking?

PARNIA: Well, at one point, we're simply interested in documenting what people have experienced when they've gone beyond that threshold of death. For us, it's very much - we tend to like to use an analogy. It's a little bit like if you look back 100 years ago, and if someone had said that one day we'll be able to get into space, go to the moon and come back, it would have seemed completely implausible. Yet somehow by, you know, 1969, we were able to go to the moon and come back and tell us - tell other people what it was like to look at Earth from space.

Now, if you look at death, it's very similar. Throughout history, humankind has never perceived it possible to go beyond the threshold of death. And that's why if you look at every discussion that takes place about death, it tends to be philosophical or personal. So we find that we have a unique set of patients who have actually, by analogy, gone to the moon and come back and were able to document what they've experienced. And that's the first level of what we do, is just document that.

The second level, though, it looking to see - is there a relationship, is there a reason why people are having these experiences? For instance, could it signify that somehow these people had had better quality resuscitation of the brain? Was it something that was going onto their brain at that time that may be indicative of these, and so on and so forth.

GROSS: So for people who have had these actual death experiences, what are some of the themes that you've heard, experiences that are similar in many patients?

PARNIA: Well, I think that interestingly, although - as I describe - the limitation or the problem with the term near-death experience is that it's too vague, that in general, people who have undergone cardiac arrest and a period of death and been brought back to life, actually have very similar experiences. And what I find most fascinating about the experiences are the cases where people have come back and described to their physicians, with astonishing detail, of what had been going on. And they described watching things, and described hearing conversations - and recalling them incredibly accurately.

GROSS: When you say what had been going on, you mean going on in the hospital room after the patient's heart had stopped, while doctors were trying to resuscitate them?

PARNIA: Absolutely. So they may describe events that were going on while they were being resuscitated. They may describe events that were going on outside their room, family members' conversations that were going on that were not even in the room they were in, but things that have been verified.

And although a lot of people had traditionally tended to discard these experiences - and possibly for the right reasons because we didn't have a science to explain it. But if you look at it scientifically, there are now millions and millions of people around the world who have had these experiences, sometimes children less than 3 years old, who have had very accurate descriptions of what was going on that were similar to what adults have described. And therefore, it's important for scientists like ourselves to bring them into the mainstream and study these objectively.

The general trend of what they describe, aside from the sensation of being very peaceful, is seeing a bright light; sometimes a very warm, welcoming, loving being that they describe as being full of compassion, that guides them through their lives.They often describe having a review of their lives, everything that they had done from early childhood to that point. And interestingly, the way they describe their review is very much like they experience, sometimes, everything that they had done. So for instance, if they had hurt somebody's feelings, even inadvertently, without purpose, they feel the pain that they had given somebody else. And therefore, they judge themselves, in effect, and their actions. And that's why when they come back, many of them are motivated to lead their lives in a completely different way. I remember one person who said that, I particularly wanted to make sure that I don't fail again; and I want to make sure that I at least end up with a C, when I get back there again.

GROSS: So I have like, two opposite reactions to these stories. One is they sound like theatrical cliches; you know what it sounds like? The Rogers and Hammerstein musical "Carousel," in which the main character is dead and comes back to Earth with his angel, who shows him everything that's happening and reviews his life. It sounds like a lot of - like a lot of the more simplistic visions of heaven. But the other side of that is maybe some of these things have emerged because people have experienced this, like maybe there's a reason that there are those kinds of themes. And also, how do you argue with people who say that they've experienced this?

PARNIA: Well, I mean, this is a wonderful point that you've brought up because if you think about it - and we touched on this earlier - one of the big problems that we have is that because we've never had a science, we've never had an objective method to go beyond the threshold of death and study what happens both biologically and from a mental and cognitive perspective. Therefore, everything that we deal with is basically hearsay and people's own beliefs. And that's why if you were to poll, I'm sure, 1,000 people, you may get up to 1,000 different opinions, but possibly even - maybe a slight exaggeration, but you may well get many different opinions.

Some people have actually suggested that it may be that our perceptions of what it's like to die may be related to people who come close to death and been - somehow come back to life and told others. For instance, there's a very interesting painting by Hieronymus Bosch, from the 15th century, where he's actually painted what looks like a classical near-death experience. But in reality, people didn't know about near-death experiences at that time, and it certainly isn't what classical Christianity would have taught of what people would have experienced when they've died. So what we're doing is, really, going through and systematically and scientifically studying what people experience. And what we're hoping to do is to enable science to guide our opinions and belief systems, as it's done with other aspects of human knowledge in the past.

GROSS: If you're just joining us, my guest is Dr. Sam Parnia. We're talking about his new book "Erasing Death: The Science that is Rewriting the Boundaries Between Life and Death." And he's the director of resuscitation medicine at the Stony Brook University School of Medicine. Let's take a short break here, and then we'll talk some more. This is FRESH AIR.

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GROSS: My guest is critical care doctor Sam Parnia, author of the new book "Erasing Death." We'll get back to the research he's conducting into the so-called near-death experiences some cardiac arrest patients report. But first, some more about state-of-the-art resuscitation medicine.

So what is the most technologically advanced and effective way of restarting a heart?

PARNIA: Well, traditionally, what doctors have been doing since the 1960s and '70s is essentially, doing chest compressions and providing breaths to a person; that's what we call CPR. But really, we've now advanced beyond that and therefore, there are various other technologies available, which include automated CPR machines that will deliver both breaths and chest compressions at the correct depth.

But also, more advanced systems are in place, which are particularly prominent and used commonly in Southeast Asia, in Japan, South Korea, where they actually will take a person who's been found dead, effectively, brought to the emergency room; and attach them to a type of bypass machine that takes the blood out of the body, provides oxygen into it, and then circulates it and pumps it around the body again. And that way, they give the doctors number of hours of time to try to figure out what caused the person to die, and fix the underlying problem before restarting the heart and bringing the person back to life again.

GROSS: So while we're talking about resuscitation medicine - which is your specialty - you've said that death isn't a moment; it's more like a process in which the heart stops and then slowly, the cells die. And you say resuscitation isn't like, a 10-minute process. It's something that goes on even after - like, resuscitation medicine continues even after a person's heart has begun beating again. Tell us a little bit about that process of resuscitation medicine.

PARNIA: Well, after CPR was discovered, there was a lot of excitement because for the first time, physicians could actually bring back someone who died. However, after this was put into practice and it was spread around the world, it became very clear that even though physicians were getting better at restarting the heart in people who'd died, most of the people whose heart had been started once would die again in the subsequent hours to days, such that the overall ability to have survival - and ensure patients go home and remain without brain injury - remained very, very low.

And the discovery that really has helped us to shift that balance was the understanding that actually, the fact that someone has died once and been brought back to life, is a completely unnatural state. And it leads to a number of complications in the brain, in particular, but also other organs; where the brain becomes inflamed and swollen and acidic and damaged. And therefore today, the way that we have tried to function is to also optimize resuscitation for the subsequent 72 hours after we've even restarted the heart, to ensure that people don't end up brain-damaged and can get home safely.

GROSS: And just tell us, briefly, what are some of the things you can do to try to prevent that brain damage.

PARNIA: Well, one of the biggest discoveries has been that if we cool the brain, we slow down the rate by which brain cells require oxygen. Because one of the biggest difficulties is that after you restart the heart, the brain starts to swell up. There is - no matter - even if the heart's beating, we can't get quite enough blood and oxygen into the brain. So that while there is a deficit in the amount of oxygen getting into the brain, the brain cells continue to undergo damage and eventually, will lead to severe disability. By cooling the brain down, we essentially slow down the rate of their activity and therefore, they need less oxygen. So we try to match the amount of oxygen to what they need.

Furthermore, we also take away the swelling itself by cooling the brain. And then other things that we have to do, which are very important - is to regulate the correct level of blood pressure, which traditionally has been too low. And we found that actually, by making sure the patient has a higher blood pressure, we can get more blood into the brain. We need to regulate the oxygen very closely, the carbon dioxide; and there are a number of other nuances that we have to work on. But it's by putting together these multiple, intricate links, into the chain of resuscitation that we can ensure that things that are potentially toxic are removed.

For instance, another important point is that we've discovered recently that actually, oxygen itself, if in excess, is toxic to brain cells; and it causes them to die. And so that's why it's very subtle, and very important, to manipulate these different parameters.

GROSS: Dr. Sam Parnia will be back in the second half of the show. He's the author of the new book "Erasing Death," and is the director of resuscitation research at the Stony Brook University School of Medicine. I'm Terry Gross, and this is FRESH AIR.

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GROSS: This is FRESH AIR. I'm Terry Gross, back with Dr. Sam Parnia, the director of resuscitation research at the Stony Brook University School of Medicine, and the author of the new book "Erasing Death." He's a critical care doctor who is researching optimal ways of caring for cardiac arrest patients and restarting their hearts. He's also researching the experiences some of these research patients report having in the period after their hearts stopped, before they've been restarted; what is popularly known as near-death experiences, but which he describes as after death experiences. These patients sometimes report having seen a bright light or a luminous being, or having had a review of their life.

Now, although you specialize in resuscitation medicine, you know few people who have actually reported these kinds of experiences - people who have been your patients. And you write in your book that 80 to 90 percent of people who survive cardiac arrest don't have these recollections. So the overwhelming number of people who have these actual death experiences, don't tell stories about bright lights and tunnels and out-of-body experiences and luminous beings - and everything. So what do you make of that; that the people who do report that are really, in a minority?

PARNIA: Well, you see, it's important to remember that people who've died - as I said, even when they're getting CPR, their brain is completely flat lined. The brain does not function, which is why they are in a complete coma. That's why if you test their reflexes, their brain reflexes are absent and therefore, we would expect there to be no memories whatsoever from anybody because even if you were to have some sort of experience, you don't have the apparatus to carry the experience back and allow you to describe it to other people - because that apparatus is completely nonfunctional. So what we don't understand is, why is it that 10 to 20 percent of people do somehow, paradoxically, despite a non-functioning brain and going through the process of death, recall these incredibly vivid experiences.

What we do believe, though, is that it may be related to the degree of damage and inflammation that is occurring in the brain afterwards. So, for instance, if I were to resuscitate a patient now, after an hour of chest compressions, and bring them back to life again, we realize that that's not the end. They still have significant swelling of the brain, inflammation, damage ongoing to the memory circuits as well as other parts of the brain for the subsequent 24, 48, even 72 hours. So now, if I were to get this person back to life and they can fully become conversant and try to remember their experiences, it may be that the swelling has actually erased their memory from that time.

And I think there's some evidence to support that. What we've certainly found, in our studies, is that if we manage to get to patients immediately after waking up - which is not easy, at times - and talk to them, they tend to remember more. And if you go back and re-interview them within a couple of days, they tend to have forgotten their experiences, possibly. So we think that probably, many more people have these experiences, if perhaps not - even everyone; but somehow, their memories get wiped in the same way that most of us, if not all of us, dream every night but somehow, there's a disruption to the memory circuits that allow us to recall our dreams the following day. And some people certainly are more vivid dreamers; they can recall more of their dreams than others. And that somehow - to do with the circuitry of their memory recall.

GROSS: I'm glad you bought up dreams because I'm sure a lot of skeptics say what people are experiencing with the luminous being and the light, and the out-of- body experience is basically a chemically induced dream; a hallucination of some sort, induced by a chemical. What's your answer to that?

PARNIA: Well, essentially, what you're referring to is broadly talked about, and considered, as the dying brain hypothesis; and that being that essentially, as a person is dying, there are various chemical changes going on in the brain, and there may be activation of certain parts of the brain that can lead to hallucinations - for instance, the same parts of the brain that say, LSD or other drugs may act upon. The problem with this theory is that one, there is no scientific evidence to support it. There have been numerous studies carried out looking at very - oxygen levels, carbon dioxide levels, drugs, etc.; and there is no relationship that has ever been discovered with any such factor and people having experiences.

But the more important point that we need to highlight is that when we're studying people who've had a cardiac arrest - which is why I like to separate them out from the vague entity of near-death experience, is that we understand the physiology of what happens to the brain in very precise detail. After someone dies and the heart stops, the brain stops functioning within moments. And you have a complete flat-lined state. There is inadequate blood getting into the brain, so the brain circuits can no longer function. And therefore, there should be no memories. So in order for someone to even hallucinate, they have to have a normally functioning brain. And so what our discoveries have started to do is to question the way we consider the relationship between the human mind, what has classically been called the psyche or the soul, and the brain itself. And it may be that the human mind, consciousness or soul may be able to function when there is no brain function at all.

GROSS: Well, that leads to the question that so many people have asked, and failed to answer; which is, where is the seat of consciousness?

PARNIA: Well, obviously that question goes back many centuries and millennia before our time. And certainly, the classical Greeks had addressed this and tried to address this in detail. Plato and many others considered that the human mind, the psyche or the soul is an entity that is separate from the body whereas others, such as Aristotle, considered that it must be produced from the body - somehow, the soul is a product of bodily processes. And if you now fast forward to modern-day science, in a sense we have no answers, either. There is not a single shred of scientific evidence that shows us how a brain or a brain cell could generate thoughts, consciousness, feelings, emotions, everything that makes us into who we are.

And therefore, scientists have also been broadly divided into two opinions. Some tend to follow Aristotle's belief system; that although we have no idea how consciousness, the psyche, the soul may come to be, it must somehow be generated by bodily processes and particularly, in the brain. And there are others who think that perhaps no matter what we do, we will never be able to explain the entity of the human mind through activity of electrical and chemical processes in the brain and therefore, that entity that we consider the soul or the psyche or the self is a separate, undiscovered scientific entity that works with the brain but is not manufactured by brain cells.

GROSS: You write in your book that because of what you've learned about people's actual death experiences - and you've learned this from them, after they've been resuscitated - you say we can be certain that we humans no longer need to fear death. And granted, a lot of people have been telling these stories. But a lot of people don't have these stories to tell. A lot of people who have been resuscitated, we don't know what they've experienced. Do we know what people experience when they knowingly commit suicide, or when they've been the victim of a terrible crash or a bomb blast, or a murder or something, where there is no hope of, you know, restarting the heart because the body is just so shattered? Like, we have no idea what that experience would be like even if we believe the testimonies by those who say they've seen - you know, a beautiful light or a luminous being.

PARNIA: Well, I think this is a point that is definitely worth, you know, thinking about a little bit more. Obviously, as you said, we have certain limitations at any time where there are some people that we cannot bring back. I mean, if someone's been a victim of a bomb blast and - as horrific as it sounds, you know - because we don't have a body to bring someone back to, then we simply, we can't work miracles today. Maybe in the future, things will be different. However, what is interesting though, is that generally - and the reason why I think we can draw some conclusions that are applicable to all of us - is that the experiences where people have looked - have described when they've gone through death, the initiating factors have been variable and different amongst the people. And in other words, what I mean, the thing that caused them to die hasn't been the same. It's been very different.

And furthermore, these experiences have been described from all over the world; people with different cultures, different backgrounds - whether they be atheists, whether they have a particular religious faith, or somewhere in between - and even children who are sometimes too young to have any concept of what - or understanding of, you know, the concepts of an afterlife or what happens when we die, etc. Yet the message of the experience is remarkably universal, and it tends not to be frightening to people. It tends to be very positive and upbeat, certainly for those who've gone through a natural process of death.

Now, where I do like to definitely highlight caution is in the case of people who've tried to commit suicide who somehow, we've managed to bring back - and believe me, we get those. Those people tended to have had, in my experience, very frightening and disturbing experiences that I would definitely warn people off doing that. But those, at least, who've died through natural causes, they - I don't think they should be afraid of death. We understand what happens when people die, and that's the one conclusion that I think we can make.

GROSS: So you've said that you think that the positive feelings, the luminous beings, the sense of light and peace that some people report having experienced after their heart has stopped during that period of resuscitation, that you don't think that that would be true of people who commit suicide. Why would suicide be different?

PARNIA: I couldn't tell you why suicide should be different. I can simply tell you that from my experience of talking to people and interviewing people who have gone through suicide, that the experiences have been universally painful and distressing and certainly, they wouldn't want to go through it again. And therefore, I'm simply sharing that observation. I don't know what the processes could be, but I certainly would not suggest someone to try that.

GROSS: My guest is Dr. Sam Parnia, author of the new book "Erasing Death." He's the director of resuscitation research at the Stony Brook University School of Medicine. More after a break. This is FRESH AIR.

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GROSS: If you're just joining us, my guest is Dr. Sam Parnia, and he is the director of resuscitation research at the Stony Brook University School of Medicine; and is the author of the new book "Erasing Death: The Science That Is Rewriting the Boundaries Between Life and Death."

So one of the things you're trying to empirically test is, you know, when people say they've had an out-of-body experience, can you actually prove that. And so you're trying to study that. How are you trying to study that?

PARNIA: The whole - sort of experience that people have had has really fascinated many of us, for many years. And one of the things we have to remember - and you actually highlighted this in one of the questions you asked me, but I didn't address it - is that the experience that people have is very personal, and it's very real to them. So for most people who've gone through these experiences, as far as they're concerned, what they've experience is absolutely real. They've described and seen something of the other side. Now, for those of us who haven't had the experience, it's impossible to verify that. But in the same way that, for instance, if a patient comes to me and says, I have depression, it would be completely unacceptable for me as a physician to simply discard that experience and say, well, I don't think you - you know, you may feel that you're depressed but actually, it's an illusion of having depression; or, you're hallucinating your depression, it's not really real. So we have to remember that to the people who've had the experience, it's real to them.

Now, how can we scientifically test these experiences? Well, most of what they describe is very subjective. You know, if they describe seeing a being of light or a tunnel, I can't test that. But if they do come back and describe in specific details watching me or my colleagues working on them, recalling their conversations, then that is potentially more objectively testable. And so what we have done as part of our work is to try to install images that are only visible from a point above - at the ceiling, in areas where patients are getting resuscitated in order to see if they also can describe seeing this - images that they would not have known about beforehand.

And obviously, if we can get, you know, a series of hundreds of people who claim to have been at the ceiling looking down, and they do describe the images, then we have to probably accept that what they say is real. If, on the other hand, none of them describe seeing the images, then we have to perhaps question their perception of what they're seeing.

GROSS: So have you tried that yet, and what have the results been?

PARNIA: We have been trying it. We started a very small, pilot study at my hospital in England a number of years ago. However, what we've come to realize - and that's ongoing - what we've come to realize is that we have numerous challenges. The first challenge is that most of the patients who get resuscitated, unfortunately, don't live long enough to talk to us. So this is one of the big problems we have - is that the standard of care for resuscitation is not universal, and people don't all receive the best level of care so as a result, we may be lucky if only 10 or 15 percent of people who go through resuscitation actually come back and can then talk to us. And of these people, most of them have had their memories completely wiped out. And only about 10 percent will actually have any memories whatsoever. But the occurrence of the out-of-body experience is even more rare. So we found that actually, only about 1 percent of patients who survive a cardiac arrest actually have any memories that are consistent with an out-of-body experience.

So that means if you start out with a thousand cardiac arrest events, you may end up with one person who has - who's lived long enough to also have an out-of-body experience and therefore, as the data is now coming through - and I've tried to describe some of these in our book because people are fascinated by it, and we get numerous requests for updates, etc. They don't realize how challenging this is. We've had a number of people who've had out-of-body experiences, but their out-of-body experiences have occurred in areas where they actually did not have images installed. And they've tended to recall looking at the events from a different angle to where the images have been installed

So for instance, we have started out by putting images at the head of the bed. But the patients come back and told us that, you know, I was looking from the foot of the bed; and then goes through and describes all kinds of accurate details. So we're having to readdress - and as we learned, we're having to adjust the study, to incorporate the realities of what's happening on the ground.

GROSS: So if I may ask, what do you ultimately hope to learn before you die?

PARNIA: Well, I'd like to rephrase that and say, what would I like to achieve?

GROSS: (LAUGHTER) OK.

PARNIA: (LAUGHTER) If I may. And what I'd like to achieve - and this is what really drives me on; and we haven't talked a lot about that, but it really does drive me on, and it really is something that bothers me - is that there is enormous, enormous variation in the quality of care that our patients receive, across the country and in different countries. And the reason for that is because there is no - absolutely no regulation on the quality of care that our patients receive. And therefore, at the same institution, doctors may provide care completely differently. And therefore, your chance of coming back from a cardiac arrest is completely potluck. And more importantly, that means that your chance of ending up with brain damage is also completely potluck.

Now, we have to remember that cardiac arrest is the only condition that will affect every single one of us. I will definitely have a cardiac arrest in my lifetime. You, unfortunately, will definitely have a cardiac arrest, and so will everybody who's listening to your show. And so do we want to have the best level of care provided for us so that we can be brought back without brain damage? Or are we willing to just take a pot chance? So that's my overall goal and ambition.

Now, an inadvertent consequence of that work is that we've - constantly pushing back the boundaries. And what we're beginning to learn scientifically, which is what I'd like to continue to learn - to address your actual question - is, what does happen to us when we die? What is the relationship between the human mind, the psyche, consciousness, or what people have classically called the soul? And I use that term on purpose because I want people to understand what it really means. It's the self. What happens to it, and how does that interact with the brain? And what does that tell us, and how can we use that to better our lives while we're on Earth? Inadvertently, through science, we're starting to answer questions about what is life, what is death, what is the real afterlife that people have talked about; does it really exist. And I think we'll continue to have more answers in the coming years.

GROSS: So this might be too personal, but are you giving this a religious interpretation?

PARNIA: Not at all. You know, I didn't come from religion; I don't particularly have a religion. So I just want to be clear about that. I came to this - again - for some crazy reason. I was a 19-year-old who was fascinated by what makes us into who we are, and then I started to see people being resuscitated in hospitals. And I began to see that we don't have the right standards of care, there's enormous variation in care; and that really provoked me into getting involved in this field.

And as now - you know, many years have gone by, and I'm still interested in this, and I continue to push forward. I'm beginning to learn things that I'm simply sharing with others - because we have to remember that, you know, until a few hundred years ago, everything that was "known" - and I say in quotation marks, "known" - was described to us by philosophers or theologians, OK? But it was only through the advent of the scientific method, which is, in essence, the objective method of learning about the world around ourselves, that gradually, things started to fall out of philosophy or theology, and into the realm of science. So for instance, you know, astronomy, the idea of the stars, was always a religious thing. And now, it's science. Well, I believe that death should also be studied by science, and that's what I do.

GROSS: Well, thank you so much for talking with us.

PARNIA: It's been a pleasure, and I've really enjoyed being on the show.

GROSS: Dr. Sam Parnia is the director of resuscitation research at the Stony Brook University School of Medicine. His new book is called "Erasing Death." You can read an excerpt on our website, freshair.npr.org. This is FRESH AIR. Transcript provided by NPR, Copyright NPR.

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