Please enjoy this transcript of my interview with Dr. Bruce Greyson (brucegreyson.com), the Chester F. Carlson Professor Emeritus of Psychiatry & Neurobehavioral Sciences and Director Emeritus of the Division of Perceptual Studies at The University of Virginia. He is also a Distinguished Life Fellow of the American Psychiatric Association and one of the founders of the International Association for Near-Death Studies.
Dr. Greyson’s research for the past half century has focused on the aftereffects and implications of near-death experiences and has resulted in more than 100 presentations to national and international scientific conferences, more than 150 publications in academic medical and psychological journals, 50 book chapters, and numerous research grants.
He is a co-author of Irreducible Mind: Toward a Psychology for the 21st Century; co-editor of The Near-Death Experience: Problems, Prospects, Perspectives and of The Handbook of Near-Death Experiences: Thirty Years of Investigation; and author of After: A Doctor Explores What Near-Death Experiences Reveal about Life and Beyond.
Transcripts may contain a few typos. With many episodes lasting 2+ hours, it can be difficult to catch minor errors. Enjoy!
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Tim Ferriss: Dr. Greyson, thank you for making the time today. It’s very nice to meet you.
Dr. Bruce Greyson: Thank you, Tim. I’m delighted to be here with you today.
Tim Ferriss: So I thought we would start more or less at the beginning in terms of chronology of your life, and we’re not going to do an A, B, C, D linear recap of your whole life, because that would be an epic, multi-day affair. But perhaps you could tell us, as a setting of the table, a bit about your childhood. How were you raised? What did the environment foster in terms of thinking, in you, frameworks for understanding the world, that type of thing?
Dr. Bruce Greyson: Sure, Tim. Well, I was raised in a scientific, non-religious household. My father was a chemist, and as far as he was concerned, what you see is what you get. There’s nothing beyond the physical. So that’s how I was raised. Being a scientist, he stimulated in me a desire to gather information, and I often participated in some of his experiments. He had a lab set up in his basement.
He also taught me, though, that if you study things that we pretty much understand already, you can make little inroads here and there about fine points. If you really want to make some impact, you need to study things we don’t understand at all. And he gave me examples of that. So I grew up with that idea that I wanted to be a scientist and discover new data, and try to figure out what’s going on with it.
Tim Ferriss: Did you have, at that point, an innate fear of death? These seem like some questions that might be important to touch upon before we get into the meat and potatoes of what we’ll dive into shortly. Was that inbuilt or experienced by you?
Dr. Bruce Greyson: No, that’s a fair question, but actually, the answer is no. I didn’t have any fear of death. We certainly had family relatives that died. And as far as I could tell, when you die, that’s the end. What’s to be afraid of there?
Tim Ferriss: Lights out.
Dr. Bruce Greyson: Lights out.
Tim Ferriss: What attracted you to psychiatry? What was your path to psychiatry from the experiments in the basement? What led you there?
Dr. Bruce Greyson: Well, when I went through medical school, I had no idea what I wanted to do. I thought I would be a family doctor. But I found that when I did my psychiatry rotations, there were so many more unanswered questions, so many things that we had no idea how to explain. Much more so with the brain than with the kidneys or the heart or the lungs. I thought, “This is where I need to go, to look at what’s going on in the brain, to have these thoughts and ideas and feelings.” So I went in that direction.
Tim Ferriss: Were there any particular conditions that fascinated you? This is predating the NDE investigations.
Dr. Bruce Greyson: Yes. There was.
Tim Ferriss: Were there any particular conditions?
Dr. Bruce Greyson: I found myself really drawn towards psychoses, people who had hallucinations and delusions, and just didn’t think the way the rest of us do. Most of the things that psychiatrists deal with are common everyday things like anxiety, depression, which everyone has to some extent. But I really was fascinated by the more extreme conditions, schizophrenia and manic depressive illness. People who just had totally different views of the world than I did.
Tim Ferriss: So I suppose this is as good a time as any to segue into some of I think what most would consider stranger terrain, even beyond psychoses, although that’s a Pandora’s box we could certainly get into quite separately.
Dr. Bruce Greyson: Sure.
Tim Ferriss: And I suppose that the stain on the tie on the story surrounding that may make some sense to tell. Would you mind sharing that with the audience?
Dr. Bruce Greyson: I went through college and medical school with this strict materialistic mindset that the physical world is all there is. And in one of my first weeks as a psychiatric intern, I was asked to see a patient who was in the emergency room with an apparent overdose. I was in the cafeteria having my dinner when this call came through. And being a green intern, I was startled by the beeper going off. And I dropped my fork and spilled some spaghetti sauce on my tie. So again, being a new intern, I didn’t want to embarrass myself, so I put on a white lab coat and buttoned it up so nobody could see it. Then I went down to see the patient, and she was totally unconscious. I could not revive her, but there was her roommate who had brought her in, who was in another room about 50 yards down the hall.
So I left the patient. There was a sitter there with her, as happens with all suicidal patients, and I went down to see the roommate. And I spent about 20 minutes talking to the roommate, trying to understand what was going on with the patient, what stresses did she have, what drugs she might’ve taken for an overdose, and so forth. It was a very hot Virginia late summer night, and I was starting to sweat in that room. There’s no air conditioning back in the ’70s, so I unbuttoned my coat so I wouldn’t sweat so much, inadvertently exposing the stain on my tie.
When I finished talking to the roommate, I stood up to leave and I saw that it was open, so I quickly buttoned it up again, said goodbye, and sent her on her way. Then I went back to see the patient, and she was still unconscious. I confirmed with the sitter who was with her that she had not awakened at all during the time I was gone. She was admitted to the intensive care unit, because she did have some cardiac instability because of the overdose.
And when I saw her the next morning when she had awakened, she was just barely awake. And I went into her room and I said, “So-and-So, I’m Dr. Greyson from psychiatry.” And she opened one eye and said, “I know who you are. I remember you from last night.” That just blew me away, because I knew she was asleep at best, and unconscious at worst. So I don’t know how she could have known that.
So I said to her, “Gee, I’m surprised. I thought you were out cold when I saw you last night.”
And then she opened her eye again and said, “Not in my room. I saw you talking to Susan down the hall.” That made no sense to me at all. She was lying there on the gurney. The only way she could have done that is if she had left her body and come down, and that made no sense. You are your body. How can you leave it? So I didn’t know what to do. I thought, “Is she pulling my leg? What’s going on here?”
She saw that I was confused, and then she started telling me about the conversation I had with her roommate: what questions I asked, what Susan’s answers were. And then finally said, “And you had a red stain on your tie.” That just blew me away. I didn’t know what to make of this. I was really getting flustered at this point. I thought, “Were the nurses somehow colluding with her to trick this poor intern?” But no one knew about the stain except the roommate.
So I realized that I was having trouble keeping my composure then, but my job was to deal with her mental status, not mine. So I pushed things into the back and just dealt with her about “What made you take the overdose? What are you thinking about suicide now?” And so forth. And thought, “Well, I’ll think about this other stuff later on.”
So she was admitted to the psychiatric unit, and I was a busy intern. I didn’t have time to think about this stuff. I didn’t dare tell anybody. They’d think I was crazy. So I pushed it on the side, and just didn’t think about it for a while. But it was very, very emotionally upsetting to me to think, “This bizarre thing happened, but it can’t happen. It can’t have happened. There must be some other answer to it.”
It just sat there in the back of my mind for about five years, until I was now on the faculty at the University of Virginia and we had a young intern join us, Raymond Moody, who wrote a book called Life After Life, in which he gave us the term “near-death experiences,” and described what they were. I had never heard of this type of thing before. And when he described it to me, I realized that’s what this patient was talking about. She was talking about a near-death situation, leaving her body, seeing things accurately from another location.
And I thought, “Well, I need to understand this.” So I started collecting cases. And it wasn’t hard to do. These are very, very common phenomena, but nobody talks about them. But if you start asking patients who have been close to death, they will tell you about them. And here I am, 50 years later, still trying to understand them.
Tim Ferriss: Did you expect it was going to last five decades, or did you think this was going to be a short project of collecting case studies?
Dr. Bruce Greyson: I assumed, Tim, that in a couple of years, I’d have a simple physiological explanation for this. And that would make me satisfied and be the end of it. But the more I learned about them, the harder they seem to understand. So I’ve gotten more comfortable with not knowing all the answers.
Tim Ferriss: So just a clarifying question on the case study of this particular woman who had overdosed, attempted suicide.
Dr. Bruce Greyson: Right.
Tim Ferriss: Was that, I guess, based on all you know now or what people would consider it, a near-death experience, an NDE? Or was it some close cousin? Because presumably, she was not intubated and flatlined at the point that you were talking to her roommate. She was alive, but either comatose or asleep, or otherwise cognitively offline.
Dr. Bruce Greyson: Right.
Tim Ferriss: How do you think about that?
Dr. Bruce Greyson: Well, they were measuring her heart function, her EKG. And her heart had not stopped, but she was having erratic arrhythmias, erratic forms of her heartbeat. So I don’t know how close to death she was. I mean, it’s always hard to tell how close to death someone is. Whether she had a real near-death experience or not, I don’t know, because I didn’t investigate it. At that time, I didn’t know anything about near-death experiences. I didn’t know what questions to ask, so I just wanted to get it out of my life and push out of the way. So looking back on it, it’s certainly not proof of anything, except how unnerving this was to me emotionally to have this happen.
Tim Ferriss: So I suppose that as part of investigating the overall context for thinking about these things, it might be useful to talk about — this is, I’m sure, out of order in terms of the questions you might usually get asked, but — the NDE scale. And the reason I want to ask about the NDE scale that I believe you developed, maybe it was in collaboration with colleagues, is the high internal consistency, and maybe you can just describe these things. Split-half reliability, that one I’m actually not familiar with. And then test-retest reliability, which is seemingly a critical component of this.
And the reason I bring all this up, as the crow flies — it doesn’t really need to fly, hops — about 20 feet away, I have an Encyclopedia Britannica set that was bought by Richard Feynman when he was, I believe, 42. And I’m going to butcher this paraphrase of a quote of his. But in effect, “It is most important not to fool yourself, and you’re the easiest person to fool,” I believe is one of his quotes. Hence, we have the scientific method, the structured way for investigating and testing hypotheses.
So could you speak to the scale? And we’re going to get to other questions around the perhaps common criticisms or forms of skepticism speaking to the biological underpinnings. But let’s talk about the scale first. Because I’m sure a lot of people listening would think to themselves, “Well, number one, there have to be a lot of people who just make up stories. And they want to sell books, and they do this, this, and this.” Not in your case, I’m just saying those who have experienced or claim to have experienced NDEs and seeing X, Y, or Z.
Dr. Bruce Greyson: Right.
Tim Ferriss: And then there are people who would love to misrepresent and become a messiah of this, that, and the other thing. So how do you make sure you’re not fooling yourself or being fooled? Could you just perhaps describe the NDE scale, or speak to that in whatever way makes sense to you?
Dr. Bruce Greyson: Back in the late 1970s, after people had read Raymond Moody’s book, several psychologists and physicians started getting interested in studying this phenomenon. So we assembled a meeting at the University of Virginia with about two dozen of these people, researchers who wanted to study it, and tried to agree on how to do that. And it turned out that everybody had a different idea about what a near-death experience was.
Tim Ferriss: Makes sense.
Dr. Bruce Greyson: Depending on their background, some thought it was an out-of-body experience. Some thought it was a sense of feeling of bliss. Some thought it was a communion with God. All sorts of different interpretations people had, and they didn’t agree on what should be included as part of a near-death experience.
So I surveyed a large number of researchers who had published about this, and asked them to give me a list of the most common features you see in a near-death experience. I had some 80 features, which is ridiculous. So I took that list, and I gave the list to a bunch of near-death experiencers and said, “Which ones of these do you think are really important in defining a near-death experience?” And they whittled it down a bit.
Then I took the whittled-down list and gave it back to the researchers and said, “Which ones of these do you think are the really important ones?” And they whittled it down again. I went back and forth between the researchers and the experiencers until I had a consistent list of 16 features that they all agreed were the important parts of a near-death experience. And they included changes in your thought processes; thinking faster and clearer than ever before; having your past flash before you; strong feelings of emotions, usually joy and bliss; and a sense of being unconditionally loved by a brilliant light. Not always. Sometimes there’s fear, also.
So we developed this scale of these 16 items, and I’ve used that for the standard of deciding which ones of these phenomena are near-death experiences and which ones are not. And it’s been now translated into more than 20 different languages. It has been used in thousands of studies around the world. There have been attempts to refine it, to improve it. There are things we know now that I didn’t know back then. And people have tried to add things to it, but basically, all the additions don’t make much of a difference. You still identify the same experiences as being NDEs with or without them. So that’s where it was. That’s where the scale came from.
Tim Ferriss: Could you speak to some of the elements that might help you separate out, for lack of a better way to phrase it, true experiencers versus people who have false positives or who want to tell a story?
Dr. Bruce Greyson: Yeah. Well, I actually published a paper about false positives where we had people who claimed we had a near-death experience, but did not score very highly on that scale. And we wanted to look at why they think they have near-death experiences. And you are right when you said before that some people are making things up. Do they want the publicity? They want to be held as messiahs? That’s true. But I think they’re a small minority of people who claim to have near-death experiences, and they’re usually very easy to identify by what they do with the experience.
Tim Ferriss: Right.
Dr. Bruce Greyson: If you immediately go on the talk circuit, and talk to Tim Ferriss and other people like that, and want to brag about how enlightened you are now, we say, “Well, let someone else study those. I’m not going to deal with those.” But the majority of people who I think were false positives are people who had some less intense form of mental illness. If people are blatantly psychotic, we don’t include them in the studies. But there are people who have personality disorders who seem on the surface to be perfectly fine, but have exaggerations of our traits that make them function differently in the world. And some do have this incredible need to get confirmation of what’s happening to them. They feel different, and they don’t know why. So they hear about near-death experience of things and think, “Maybe that’s why I’m different. Maybe I had a near-death experience.”
Tim Ferriss: What we’re going to do in this conversation, and I’m just scratching my own itch from a curiosity perspective, but we’re going to bounce all over the place. I like to frame that as a feature, not a bug, but it’s going to be pretty nonlinear. So I want to zoom in and out from the clinical skeptical side to the hopefully, and I think we’ll get to quite a few of these, examples that could be corroborated in some fashion. And those may overlap with those that are described as out-of-body experiences. They might not. And we’ll probably come back to that term as well. But could you tell the story of — tell me if this is enough of a cue — the red MBG?
Dr. Bruce Greyson: Many people in a near-death experience say that they encountered deceased loved ones in the experience, and that can easily be explained as wishful thinking, expectation. You think you’re dying, and you would love to see your grandmother once more, so she comes to you. And there’s no way to prove or disprove that.
However, in some cases, the person having the near-death experience encounters someone who had died, but nobody yet knew they had died. So that can’t be dismissed as expectation and wishful thinking. This is not a new phenomenon. Pliny the Elder wrote about a case like this in the 1st century AD. But we’re hearing about a lot of them now.
About 12 years ago, I wrote a paper that had 30 different cases from recent years. Jack was one of those. He had an experience, actually, he was in South Africa back in the ’70s, and he was a young technician at that time and had very serious pneumonia. And he repeatedly stopped breathing and have to be resuscitated. So he was admitted to the hospital with a severe pneumonia. And he had one nurse who was constantly working with him as his primary nurse, a young pretty girl about his age. He flirted a lot with her when he could.
And one day she told him she’s going to be taking a long weekend off, and there’d be other nurses substituting for her. So he wished her well, and she went off. And over the weekend, while she was gone, he had another respiratory arrest where he couldn’t breathe. He had to be resuscitated. And during that time, he had a near-death experience. And he told me that he was in this beautiful pastoral scene, and there out of the woods came his nurse, Anita, walking towards him. And he was stunned, because he was in this different world. What’s she doing there? So he said, “What are you doing here?”
And she said, “Jack, you can’t stay here with me. I want you to go back, and I want you to find my parents and tell them that I love them very much, and I’m sorry I wrecked the red MGB.” He didn’t know what to make of that, but she turned around and went back into the woods. And then he woke up later in his hospital bed. Now he tells me that back in the ’70s, there were very few MGBs in South Africa, and he had never seen one. When the first nurse came into his room, he started to tell her about his experience and seeing his nurse, Anita. She got very upset and ran out of the room.
It turned out that she had taken the weekend off to celebrate her 21st birthday, and her parents had surprised her with a gift of a red MGB. She got very excited, hopped in the car, and took off for a test drive, and crashed into a telephone pole and died instantly. Just a few hours before his near-death experience. I don’t see any way he could have known or wanted or expected her to have an accident and die, and certainly any way he could have known how she died, and yet he did.
And we’ve got lots of other cases like this. They’re called “Peak in Darien” cases, based on a book that was published in the 1800s with cases like these, where people encounter deceased individuals who were not known to be dead. And I don’t know how to explain those.
Tim Ferriss: Now, just to put my skeptic’s hat on, I could say, “Well, if I were Jack…” Was it Jack? Let’s just say it’s Jack. That would make one hell of story if there wasn’t a third party to independently verify it with.
Dr. Bruce Greyson: Right.
Tim Ferriss: But there are other cases, and for people listening, we’re going to come back to some of the common questions, I would say, forms of discussion around these related to possible biological mechanisms, or lack thereof. We’re going to come back to that in a second. But there are, then, cases that are seemingly characteristically quite different, and perhaps can be, and I’d be curious to know if this has been done or not, but verified with third parties.
And one that comes to mind that I’ve heard you discuss is related to the surgeon flapping like a bird, and I was hoping that you could give a description of that particular case study. Before we get to that, how many near-death experiences have you documented, studied, or otherwise read about, put into the archives yourself? How many instances would you say you have encountered in your —
Dr. Bruce Greyson: I’ve got slightly more than a thousand in my database at the University of Virginia where we have validated as much as we can that they were, in fact, close to death, and this is what happened to them. I’ve talked to many more people about their near-death experience that I haven’t included, because I wasn’t confident that they really fit the criteria for being in the study. But it’s really much more common than you might think it was, because people don’t talk about these things. You mentioned people wanting the publicity of this. That may be more true now, but back in the ’70s and ’80s, nobody wanted to talk about these things.
Tim Ferriss: Yeah, you see what I’m saying.
Dr. Bruce Greyson: I mean, if you talk about things, you got ridiculed, you got referred to a psychiatrist. You were called crazy. You were shunned by people you knew, both materialist and religious folks. They didn’t want to hear about these things. So people did not talk about these events.
Tim Ferriss: And what of this surgeon flapping like a bird?
Dr. Bruce Greyson: This was a fellow, Al, in his mid-50s, who was a van driver, and he was out on his rounds one day. And he had chest pain. And he knew enough to stop his rounds and drive to the emergency room. And they did some evaluations and found that he had four arteries to his heart that were blocked. And they rushed him to the emergency room for urgent quadruple bypass surgery.
So he’s lying on the table, fully unconscious, the drapes over him, so forth. And he tells me that in the middle of the operation, he rose up out of his body and looked down and saw the surgeons operating on him. And he saw the chief surgeon, who he hadn’t met before, flapping his arms like he was trying to fly. And he demonstrated for me. At that point, I laughed, because I thought, “This is obviously hallucination. Doctors don’t do that.” But he insisted that I check with the doctor. He said, “This really happened. Ask him.”
So he told me lots of other things about his near-death experience, but that’s the one that I was able to verify. So I talked to the surgeon, who actually had been trained in Japan, and he said, “Well, yes, I did do that. I have a habit of letting my assistants start the procedure while I put on my sterile gown and gloves, and wash my hands and so forth. And then I go into the operating room and watch them for a while. And because I don’t want to risk touching anything with my sterile hands now, I point things out to them with my elbows.” And he pointed things out, just the way Al was saying he was trying to fly.
I don’t know any other doctor that’s done that. I’ve been a doctor for more than 50 years now. I’ve never seen anyone do that. So it’s an idiosyncratic thing. Is there any way Al could have seen that while he was totally anesthetized? His heart was open. I don’t think there’s any way he could have seen that, and yet he did.
Tim Ferriss: All right. So many questions. And let’s start with the question of how rational materialist skeptics, and that’s not meant as a criticism of those people at all, might try to explain this. They might say, “It is a lack of oxygen, or a diminishing amount of oxygen. It might be a cascade of neurotransmitters that are released when A, B, or C happens. It might be the introduction of drugs.” I certainly know when I’ve had surgeries, when I’ve had Versed, or God knows what else introduced to my bloodstreams, some very strange things happen, although I haven’t experienced the type of thing you’re describing when I’ve been anesthetized. How do you respond to those, or how do you think about those explanations?
Dr. Bruce Greyson: I’m sympathetic with them. I started out as a materialist skeptic. After 50 years, I’m still skeptical, but I’m no longer a materialist. I think that’s a dead end when it comes to explaining near-death experiences and other phenomena like this. When I started out, I assumed, Okay, we’ll look at things like heart rate, oxygen level, drugs given and so forth, and each thing we tried to study turned out not to explain anything. For example, the most obvious thing was the lack of oxygen, because no matter how you come close to death, that’s the last common denominator, you’re going to lose oxygen to the brain. But when you actually study this, what you find is that people who have near-death experiences actually have a higher oxygen concentration than people in similar situations who don’t have a near-death experience.
Tim Ferriss: Can you say more about that? How is that? How do we know this or how do we surmise that?
Dr. Bruce Greyson: They don’t measure what’s going on in the brain, but they measure in the peripheral blood system how much oxygen is flowing through.
Tim Ferriss: With a pulse oximeter or something like that?
Dr. Bruce Greyson: Yes.
Tim Ferriss: In a hospital setting, okay.
Dr. Bruce Greyson: They also can draw blood and measure it more directly than the pulse ox. But what they find is that when they draw blood from people who were in a near-death situation, those who have a near-death experience have a higher oxygen level than those who don’t. So what that means is that lack of oxygen is not causing the experience, in fact, it seems to be inhibiting it in some way. And what that mean may be that many people have a near-death experience, but if you’re lacking oxygen, you can’t remember it later on. And that only if you have good enough oxygen, do you remember it later on. So it may be related more to their memory of the experience than the experience itself.
Likewise, with people given drugs as they’re approaching death, the more drugs you’re given, the less likely you are to report on near-death experience later. Now, there are some drugs that can mimic parts of a near-death experience, they’re not drugs that are given to dying patients, but things like ketamine, various psychedelic drugs, people using psilocybin now, and they can produce things that mimic in some ways, some features of near-death experiences. They don’t produce the whole phenomenon. They don’t, for example, reliably have the blissful feelings, and they certainly don’t have the accurate out-of-body perceptions that many near-death experiences have.
I shall say that Jan Holden at the University of North Texas studied about a hundred cases of people who claimed to be out of their bodies and seeing things. And what she found when she sought third-party corroboration was that in 92 of the hundred, they were completely accurate. In six cases, they were partly accurate and partly inaccurate, only one or two were completely wrong, so the vast majority were actually corroborated by other people.
Tim Ferriss: What are some other examples of hospital setting? And part of the reason I mentioned that specifically is that you have multiple credible witnesses in some cases, I would imagine?
Dr. Bruce Greyson: Yes.
Tim Ferriss: Which makes it interesting because you could independently, at least in theory, verify, confirm various occurrences while a patient was sedated, was suffering from cardiac arrest or otherwise. What are some examples that come to mind that you think are the most defensible in those environments or otherwise, but where you have the ability to independently confirm or have denied X, Y, or Z that happened?
Dr. Bruce Greyson: The ones that come to mind are the ones where people see deceased individuals who no one knew had died yet, I can give you more examples of that, and they’re often corroborated by other people. And also people who claim to leave their bodies and see things from an out-of-body perspective that they shouldn’t have known about. And we’re not talking about seeing things like, “I saw the doctor in green scrubs,” or “I saw a dust on the lamp.”
Tim Ferriss: Something you would expect.
Dr. Bruce Greyson: We’re talking about really unusual things like, the nurse had mismatched shoelaces, things that you wouldn’t expect, or the doctor flapping his wings. So we have corroboration for a lot of these cases.
Tim Ferriss: And what is the most fertile ground from a pathology perspective for near-death experiences? For instance, cardiac arrest, are cardiologists those most likely to hear reports of NDEs? And then the secondary question is, does the manner of death influence the nature of the NDE reported?
Dr. Bruce Greyson: Let me take the second one first, that’s the easiest one to answer. The matter of death by and large does not affect whether you’re going to have any near-death experience or what kind you’re going to have. Now, there are some exceptions to that, for example, if you are intoxicated at the time, you’re less likely to have an experience, and if you do have one, it’s going to be fuzzier and harder to remember.
Most of the research has been done with cardiac arrest patients, and that’s done because, number one, you’ve got a large population of people who we can document we’re close to death. And number two, many of those people have no or very few complicating physiological problems with them. If you study people who are on dialysis, they’ve got many other problems going on that can complicate what’s going on in the brain. But there are a lot of people who have a sudden cardiac arrest who are otherwise fairly healthy, so they’re a clean population to work with. So for that reason, most of the research has been done with cardiac arrest patients.
But the vast majority of people who spontaneously come to me and say, “Let me tell you about my experience,” did not have cardiac arrests. I’d say maybe 20 or 30 percent have had a cardiac arrest, a heart stop, a lot of them are accidents or injuries or so forth. We have a large collection of people who were injured in combat who have near-death experiences, people who fell from great heights and that sort of thing, people who drowned.
Tim Ferriss: Has the nature of reported NDEs changed over time or does it vary widely across cultures? And the reason I ask is that, for instance, the observation of the placebo effect and how it manifests has changed quite a lot over time. There’s actually a great piece in Wired magazine about this, depending on culture, depending on how widespread readings and reporting about the placebo effect is in terms of strengthening or decreasing the strength of placebo effect. And you see examples of this also in reports of, say, in some cases alien abduction or UFO encounters, et cetera. And there’s a homogenizing of the experience or reporting of it in some cases that one could attribute to mass media coverage discussions on podcasts and so on. So how does that apply or not apply to reports of NDEs?
Dr. Bruce Greyson: Great question, Tim. In terms of knowledge about near-death experience, whether that affects what you’re going to say, we’ve done some research looking at people who reported their near-death experiences to us before Raymond Moody published his book in 1975 when nobody knew what these things were. Working at the University of Virginia, I had access to the files of Ian Stevenson, who’d been there for many, many years collecting unusual phenomena. And he had maybe 50 of these cases, they weren’t called near-death experiences, some were called deathbed visions, some were called out-of-body experiences, some were called apparitions, but when you look at them, they were just like the near-death experiences we call today.
I collected 20 of those that we had enough information about and then matched them on age, sex, religious belief, so forth, with 20 recent cases that I studied. And we compared what phenomena they reported and what things they didn’t, and what we found is that before Moody told us what a near-death experience was like when no one had heard of these things, people reported the same things they report now. So knowing about a near-death experience does not affect whether you’re going to have one or report it.
Now, you also asked about culture, and that’s an interesting point because most near death experiences start by saying, “Well, there aren’t any words to describe it, there aren’t any words in this, I can’t tell you about it.” And I say, “Great, tell me about it,” so they use metaphors. They often will say, “Well, then I saw this God-like figure — I’m saying God because I don’t know what else to call it, but it’s not the God I was taught about in church, it was much different from that, but this all-loving, all-knowing entity, whatever it was.”
And what you hear from people in different cultures is based on what cultural or religious metaphors they have available to them. For example, people in Christian cultures will say that they may have seen God or Jesus. People from Hindu and Buddhist countries don’t use those words, they may say they met a Yamdoot, the messenger from Rama, or they may say, “I just saw this white light.” Also, the tunnel, we have tunnels in the US, so when people say, “I went through this long, dark enclosed space,” they will say, “tunnel.” Well, people in Third-World countries don’t use that word. They may talk about going into a well or into a cave.
I interviewed one fellow who I hear was a truck driver who said, “Then I got sucked into this long tailpipe.” So whatever metaphor comes readily to them is what they use to describe the phenomena. If you look at the actual phenomena they’re reporting, it’s the same all around the world. And in fact, we can find cases from back in Ancient Egypt and Rome and Greece that have the same phenomena we talk about today, but the metaphors they used to describe them are different from culture to culture.
Tim Ferriss: When you’re sitting at, say, dinner or you meet a scientist outside of your field of study who’s well-intentioned, they’re not coming at you in some type of malicious or cynical way, they’re genuinely curious because I think really good scientists are open-minded, but they also ask for proof or they look to demonstrate proof or disprove hypotheses. If you had to steel man against a non-materialist explanation for NDEs, are there any, if you had to pick them, compelling ways to interrogate this experience from a materialist perspective?
Dr. Bruce Greyson: I myself, as a skeptic, tend to doubt everything I think as well as everything else that you think, so I’m not happy with the lack of evidence we have for some of these things. I’m still looking for it, but I went into this thinking there’s going to be a simple physiological explanation, it’s been 50 years and we haven’t found any explanation yet. That doesn’t mean we won’t, so we’re still looking, we have some technologies now that can study the brain in ways we didn’t have before. We have very sophisticated neuroimaging, we have much better computer algorithms for analyzing EEGs. And we have a wider range of psychedelic drugs to use to try to replicate parts of the experience in some ways. So there’s a lot going on in physiological research now that was not available 50 years ago, and we may someday have a physiological answer to explain near-death experiences.
But let me give you two questions, one is that if you find something that has always correlated with a near-death experience, a brainwave activity or a chemical, that doesn’t mean it’s causing the experience. For example, right now, people are listening to us and there’s electrical activity in parts of their brain that process hearing, it always happens when they’re hearing us, this part of the brain always lights up. That doesn’t mean that electrical activity is causing our voices, it’s just a reflection of it. So when you find these physiological concomitants of a near-death experience, you’re finding perhaps the mechanism for it, but not the cause of it.
The second question was that, even though I’m a skeptic and part of me still wishes we could find a physiological explanation, I’m still looking. You need to remember that this is what has been called promissory materialism, we don’t have the answer yet, but we will someday. That’s a perfectly fine philosophical position. It is not a scientific position because it can never be disproven. You can always say, well, we haven’t got it yet, but we’ll get it in 50 years, we’ll get it in a hundred years. So you can never disprove it, so it’s not scientific. So saying that that’s a scientific way of dealing with things, promissory materialism is not the way to go, we need to deal with what we have right now and how we interpret what we have right now.
And I think most people who study near-death experiences, whether they’re spiritualists or materialists or neuropsychologist or philosophers, they agree on the phenomena, they don’t agree on the interpretation of it, of what’s causing it and what its ultimate meaning is. I think that’s fine, that’s not where I am, I’m not a philosopher, I’m not interested in the ultimate cause or the meaning of it. I’m actually a clinician, so what interests me most about near-death experiences is how they affect people’s lives and what people do with the experience. And that’s the same regardless of what’s causing it, whether it’s a hallucination or a spiritual experience, it affects people in the same way, and that’s, I think, what interests me most.
Tim Ferriss: We’ll probably come back to this, but just maybe as a teaser for folks, and please fact check me if I get any of this wrong, but it seems like some of the common after effects for those who experience NDEs are increased altruism, a feeling of connectedness. If they had a profession involving some degree of violence, for instance, not necessarily ill intention, but law enforcement, if they were in the mafia, I know there’s a case of this specifically, they’re no longer capable or willing to perform those jobs. Those who have attempted suicide and have the experience of an NDA counterintuitively are less suicidal after the fact, so I’ll provide those as teasers.
But just to scratch my own itch, I’m going to pick up on a thread from quite a few minutes ago where I was asking about possible differences in reported NDEs. Do children and adults report the same phenomenon, obviously using different metaphors for trying to convey the ineffable perhaps, do they differ in any notable way?
Dr. Bruce Greyson: They don’t really differ. The one difference is that children don’t have the elaborate life review that most adults do, they haven’t had as much of a life —
Tim Ferriss: It’s a short form.
Dr. Bruce Greyson: They also tend to have as many deceased relatives that they might encounter. They have some, but you’re more likely to hear from children encountering a deceased pet, a dog or a cat. But by and large, people who have studied children’s near-death experiences find the same phenomena, they often have difficulty—even more than adults do—in putting it into words, so they will often ask the children to draw what happened, and they produce artwork to explain the near death experience.
Tim Ferriss: You’re mentioning new tooling, new equipment and technological capabilities that we have, whether that be fMRI or some type of advanced brain imaging, the use of computers, algorithms, certainly AI at some point, if not already, to analyze EEG/ECG data and so on. How might you use something like brain imaging if you could design a study? Because presumably, if someone’s about to flatline, you’re not going to slide them into an fMRI machine because the clinicians would not be able to get to them. So would that mean you would be putting someone into, say, an fMRI and then doing your best to simulate an NDE with exogenous compounds such as psychedelics or otherwise? How might you use the brain imaging?
Dr. Bruce Greyson: People have studied brain imaging with psychedelic drugs. We used to think that psychedelics work by stimulating the brain to hallucinate, and what the studies have shown is that the psychedelic trips that are associated with more elaborate mystical experiences are associated with less brain activity and less coordination among different parts of the brain. It’s as if the brain is getting pushed out of the way by these drugs allowing whatever it is to come in all this mystical experience.
People have tried to look at brain function during a cardiac arrest. It is not easy. Several papers have been published in leading neuroscience journals claiming they’ve done this, but they have not done that. For example, one study was published of people who were comatose and on life support, and they said it was happening in the brain when they stopped the artificial ventilation. And what they found was that there was a change in the brain function when they did that. It was reported as an increase in gamma activity, it was actually not, all the brainwaves were decreased when they stopped the ventilation, but the gamma waves were decreased less than the alpha, beta and delta. So it looked like there was more, relatively speaking, of the gamma, it was actually less than it was before, but these people were not dead.
They also reported heart function during this time, and when they were reporting these changes in brainwaves, the people’s hearts were still beating, they were still having a normal sinus rhythm, normal heartbeat. When the heart did stop, they didn’t continue doing the EEG, so you couldn’t continue to see what’s going on in the brain after they actually died. But they reported it as electromagnetic activity in the brain in dying patients, well, they weren’t dying, the artificial respiration was stopped, but their hearts were still beating.
Similarly, there were other studies like this where they claimed to be reporting on dying patients, and they really were not dying patients, there were people who were approaching death. There was a study done in Michigan where they sacrificed rats and measured what’s going on in the brains when they do that. And they reported a 32nd burst of activity after their heart stopped, that’s what they said they found, it actually wasn’t a burst. If you look at the traces they give you, it was a slight increase, but far less than the brains were showing before, and they sacrificed them. So it was a tiny blip, it wasn’t a surge like they said it was.
Furthermore, if they anesthetized the rats, they didn’t show this at all. And obviously, people have NDE, near-death experiences under deep anesthesia, so that’s not the same phenomena. There were several other things that were untypical of near-death experiences, for example, every single one of the rats they tested had this burst of activity. But if you ask people who come close to death, only about 10 or 20 percent have near-death experiences, and probably most significant, they didn’t bother to interview the rats to see what they were experiencing.
Tim Ferriss: Yeah.
Dr. Bruce Greyson: I will mention one researcher who has actually measured EEG’s brainwaves during cardiac arrest, and this is Sam Parnia at NYU. When you’re resuscitating somebody, you press on the heart, you compress the heart, heart compressions for a while, and then you stop and give them a break to see whether they spontaneously breathe or not, and then you continue it again. Or they’re shocking them with electricity, and then you stop and see what’s happened. And he measured the brainwaves during that period when they stopped thinking, this is going to tell us what’s going on. Well, I’m not sure it is because it’s only for a few seconds that you’re stopping and the body is still suffering from the shock of the electricity or the chest compressions.
Furthermore, he reported some increase in several different wavelengths of brain activity in about half the patients. He also reported that there were some six patients who reported near-death experiences, and he said, “Well, obviously the increased brain activity is causing the near-death experience.” But if you look at this data, the six who had the near-death experiences did not have the increase in brainwaves, and those who had the increase in brainwaves did not report near-death experiences. So I’m not sure if we learned anything from that.
Tim Ferriss: All right. So I’m going to ask you to make some sort of theoretical leaps to answer the next few questions. But first, because I have to ask this, when people see or claim to have seen deceased relatives, and I don’t know if you have this level of granularity in the reports, how old are those deceased relatives? Are they last they saw them? Because presumably, some of these people who died would’ve had a slow decline with neurodegenerative disease and so on, so do they appear much younger? Is there any pattern in the reports whatsoever in terms of the age that these people seem to be when they are observed?
Dr. Bruce Greyson: Yeah, there is a pattern, but again, I need to follow back on the fact that most people say there weren’t any words to describe it. So when you ask them to describe what they saw, you’re describing what the brain interpreted of what they saw. And most people say that they saw the deceased loved one at the prime of their lives when they were young and healthy, not when they were dying. I have had some people say, I didn’t really see a human figure, I just saw my grandmother. Well, how did you know it was your grandmother? I felt her vibrations, I knew it was her, it had her essence. So they may have just seen this blob of light and knew by the way it felt to them, this is grandma. There’s no way of validating this type of thing, it’s just their impression.
Tim Ferriss: Let me ask a tactical, practical question and then we’ll get into the stranger stuff.
Dr. Bruce Greyson: Sure.
Tim Ferriss: Let’s say there’s someone listening and they’re like, “I’m not sure I want my name on it, but as an anonymous donor, I’m willing to give Dr. Greyson some sum of money.” Or maybe some secret agent at the NIH is like, “You know what? I know a way to liberate some funds. What studies would you like to design and see done?” And they don’t need to be specifically related to NDEs, but if they are, I suppose that’d be more germane to the conversation. Any types of studies that you would love to see performed related to this?
Dr. Bruce Greyson: I can answer that from my personal perspective, which is not what I’d like to see the field do.
Tim Ferriss: Sure.
Dr. Bruce Greyson: What I would like to see the field do is what they’re doing right now, looking at all the different possibilities, looking at cross-cultural comparisons, looking at neurophysiological changes, the types of things they’re doing now, looking at other phenomena that seem to mimic parts of the NDE like psychedelic drugs. But that’s not where I am right now, I’m nearing the end of my career and I’m falling back on, “What does it all mean?” And for me, what that means is, how does it affect people’s lives? So I would like to see more research into the practical applications of near-death experiences.
We’ve done some studies now with near-death experiences who say they needed help readjusting to “normal life” after a near-death experience. And we’ve surveyed them about what did they need help with? What was so disturbing about the experience for its after effects? What type of help did you seek? What type of help did you receive? What type of practitioner did you go to? A psychiatrist, a doctor, a spiritual healer, a pastoral counselor? And what types of help were actually helpful and which ones were not helpful? And we’re finding some interesting findings from that. We’re also surveying physicians about their attitudes towards near-death experiences, and we pose them the question, if a patient comes to you and says, I had this experience that I want to tell you about. Would you feel comfortable talking with them about it, and what are the barriers you feel to open up and talking about them? And we had a list of some 25 possible barriers we thought might be things they said, and we were very pleased to find that almost none of them said, “I don’t think it’s worth talking about. It’s not important.” Or, “It’s just a neurological artifact. Doesn’t mean anything.” Or, “It’s just a type of psychosis.”
By far, the most common response doctors gave was, “The barrier is I don’t know enough about the experience to talk to patients about it.” The second most common was, “I don’t have time to talk about this with my patients. I’m just too busy.” Now, those are both things that we can correct. We can certainly give more training to physicians, and we can restructure the schedule so they do have time to talk to patients.
Tim Ferriss: What are the most, if any, reliable ways to simulate an NDE or NDE-like experience? And it makes me think back to a movie. It may not age well, but I enjoyed it at the time. With Kiefer Sutherland, 2000 — no, it was prior to that. 1990 something, called Flatliners, where there are medical students who would take turns putting themselves into a brief period of death, and then they get into this arms race of competing with one another and pushing it further and further and further.
But my understanding based on some of what I’ve read, you do have familiarity with some of the psychedelic-related science, is that these NDEs seem to produce more what had been described as out-of-body experiences, perhaps more, I don’t want to say reliably, but more frequently than psychedelic experiences. We will come back to that point. But are there any ways to simulate it in such a way to make it more studyable, even if it’s not the exact phenomenon? Since I’m sure the IRB would have a tough time accepting temporarily killing patients or subjects that are recruited for a study.
Is there anything that approximates it or any thoughts on how we might do that? Keeping in mind, and this is an imperfect example, but long ago, decades ago, psychedelics were viewed as psychotomimetics, so they can be used as a tool for effectively eliciting a psychotic episode, so it could be better studied. Now, that ends up not being quite right, but how would you think about approximating an NDE?
Dr. Bruce Greyson: Yeah. I don’t think there’s a good way. I think the tool we have that comes closest are certain psychedelic drugs in a very supportive environment. I don’t think people who are just taking drugs on their own can necessarily replicate a near-death experience. But in a supportive environment, in the lab, with low lighting and good music and someone there to help you with it, you can replicate some of the features of a near-death experience. Not all of them. And you tend not to have all the after effects. I think that’s understandable because if you have an experience under drugs, you can say, “Oh, that’s just the drugs. It wasn’t real.” Whereas if it happens spontaneously, it’s harder to dismiss.
Now, one of the issues with the drugs is that we can find out what’s going on in their brain when people are given these drugs, and that’s fine. But then, you make the leap to saying, “Well, this is the same change in the brain that occurs during a near-death experience.” And that’s an assumption. We don’t have the evidence for that yet. It tells us how we might look for places in the brain where we might look and what types of changes. But that work hasn’t been done yet, so it’s all speculative. And certainly, the drug-induced experiences are not identical to near-death experiences.
Many near-death experiences have tried drugs afterwards to try to replicate the experience. And they universally tell me it is not the same thing. One person told me, “When I was on psilocybin, I saw Heaven. When I was in my near-death experience, I was in Heaven.” That was the way he explained it. But they tend not to have the same after effects. And one caution of that, I would say, is that the recent work done at Johns Hopkins with psilocybin has found a marked decrease in fear of death after short experiences with psilocybin. And they’ve done some follow-up in at least a year after the experience. They still have that decreased fear of death, and that’s very encouraging.
Tim Ferriss: Yeah, it’s surprisingly durable, it directly correlated with the strength of the mystical experience, which is measured using an assessment much like your scale for NDEs. What other characteristics seem to be hard to replicate with drugs or are less frequent in occurrence? And perhaps this is an opportunity to speak to what exactly an out-of-body experience is as you would define it. And I think we already gave, perhaps, an example of this with the wings flapping, but could you say more about that?
Dr. Bruce Greyson: It’s tricky to define an out-of-body experience. There’s a large body of evidence looking at people who have their temporal lobe of their brain stimulated electrically. And these would claim they produce out-of-body experiences. They do not. They may produce a sense of not being aware of your body anymore, but they don’t produce a sense of leaving your body and being able to turn around and look at your body and seeing it from an out-of-body perspective.
They often say that with this stimulation, you can see a double of yourself. But you’re seeing it from inside the body, you’re not outside the body. And the double you see is static. It’s not moving around. Whereas people who have real out-of-body experiences talk about moving around the room, going to distant places. People who have out-of-body experiences sometimes can report things accurately that can be corroborated later on. That doesn’t happen with stimulation of the temporal lobe.
So, there are a lot of differences between these artifacts that are produced by temporal lobe stimulation and real out-of-body experiences. When you read some of the papers that have been published about temporal lobe stimulation, they say things like, “Well, my legs were getting shorter, or I felt like I was falling off the gurney.” And they’re called these out-of-body experiences. They’re not. They’re somatic hallucinations, but they’re not out-of-body experiences.
You can get out-of-body experiences with other types of mystical experience and with psychedelic drugs. Whether they’re the same or not is open to question right now. We don’t have examples of people having drug-induced out-of-body experiences having accurate perceptions of what’s going on around them, whereas you do with near-death experiences. Now, that may be because we haven’t looked deep enough yet and we may find them, but at this point we don’t have that.
Tim Ferriss: I’ll share a strange experience and then we’ll get into the, as promised to the listeners, some of the stranger stuff, but not that this is just a plain vanilla walk through the DSM. So I have a fair amount of flight time with different psychedelic compounds, and the one time I would say I consistently experienced what you would describe or might describe as an out-of-body experience was in using, and I highly discourage anyone to use this, a terpenoid called Salvinorin A, which is found in Salvia divinorum, otherwise known as diviner’s sage, used by the Mazatecs in Mexico for centuries, probably millennia.
And part of the reason I don’t recommend it — well, first of all, you could go on YouTube and just search “Salvia freak out” and you’ll get lots of video footage for why you should probably steer clear of it. But it’s, as I recall, a κ-opioid agonist and that is — consuming an agonist of the κ-opioid receptors typically is described as acutely dysphoric. What is dysphoria? Well, it’s the opposite of euphoria. It’s horrible. Terrible, terrifying experience for most people. So I don’t recommend using it.
But these experiences are notable for two reasons. Number one, I had no expectancy. I didn’t know anyone who had consumed a purified Salvinorin A. Secondly, I was observed by clinicians. And in one case, was inside an fMRI machine, so I could not see anything outside of the machine. But in both cases, the experience was effectively a flattened, abstract experience, devoid of time, space, a sense of self. Nonetheless, there was an observer, but an incredibly bizarre experience even compared to, say, a psilocybin or an NDMT or something else.
And in each instance, I had two experiences in, at some point, mid-abstraction, I effectively had the view of a CCTV camera in the upper corner of each room, and I was able to see what all the scientists were doing, all the clinicians, and was able to corroborate those after the fact. Now, in the first instance, I was not in an fMRI machine, so people might say, “Well, you could have had one eye open and you could have been watching.” Now, I would challenge anyone in the depth of this experience to attempt to report anything visual with their eyes open. But the fact that I was literally strapped down inside an fMRI machine would preclude any ability as we currently understand it, to use my eyes to see anything.
And that raises some questions for me because I do have a reasonably broad palette of experience with different molecules, but that was two for two, and I haven’t experienced that in anything else. This is slowly meandering into the stranger territory. So it seems to be the case that certainly, we can occasion very strange experiences with the ingestion or inhalation of different compounds. So the brain has some role as a mediator of experience in the world. But then you seem to document in your experience these phenomena that seem to reflect a mind beyond brain, for lack of a better descriptor. And I don’t want to put words in your mouth.
How do you begin to even think about this? And is the brain, I suppose we could make an argument for this on a whole lot of levels, a reducing valve, as Aldous Huxley might put it, that is filtering for information that is optimized for survival and procreation. And when you do something that I suppose opens the aperture of that reducing valve, then suddenly you have these experiences. Is the brain acting like a receiver of some type?
Now, the argument against that would be, well, if you damage the brain, you can observe all of these effects on perception and cognition and so on. How, at this point, given all of your documentation, discussions with colleagues in and outside of this area of expertise, think about mind versus brain, with the understanding that there’s a lot more we don’t know than what we know? But how do you think about this?
Dr. Bruce Greyson: Well, I was taught in college and medical school that the mind is what the brain does, and all our thoughts and feelings and perceptions are all created by the brain. And I cannot believe that anymore. I’ve seen people whose brains were either offline or severely impaired telling me they had the most elaborate experience they’ve ever had. So I’m inclined to think that the mind is something else and the brain filters it, as you said.
This is not a new idea. 2,000 years ago, Hippocrates said this, that the brain is the messenger of the mind. And this is not surprising because we know that the brain has these filters. There’s the default mode network and the thalamocortical network. If people are listening to us now, they don’t really care what we look like. They want to hear what we’re saying. So, their thalamocortical circuit tamps down the visual input and focuses on the auditory input. And likewise, we’re not hearing the train go by outside or the traffic outside because you’re focusing on this, and that’s your brain doing that. It’s filtering out what stimuli are you going to pay attention to.
And it starts even beyond the brain at our sense organs. You don’t see all the visual light that’s out there. You just see the small portion that is in our visual spectrum. We don’t see infrared and ultraviolet. And likewise, we only hear a small fraction of the frequencies of sound available. We don’t hear the sounds that dogs and bats hear, or elephants and dolphins. So, our brain and the associated sensory systems that we have with that filters out things that are not important to our survival.
Now, we think about the things that happen in near-death experience, seeing deceased loved ones, leaving the body, contacting. That’s not essentially for survival. You can get food and shelter and a mate and avoid predators without all that. So it makes sense that the brain would normally filter that stuff out and not pay attention to it. And if in a near-death experience or similar experiences, the brain is shutting down selectively so that that filtering mechanism is put on hold or being weakened, then you have access to this other consciousness.
Now, that raises the question of what is this other consciousness? Where is it? In a way, that’s a bogus question, because if it’s a non-physical entity, how can it have a where? It can’t be any place. But I’m not a philosopher. I’m an empiricist. And when people say to me, as many do, “If you have this non-physical mind, how does it interact with a physical brain?” And I have no idea. On the other hand, if you take a materialistic perspective and say, “How does the brain, the chemical and electrical changes in the brain, create an abstract thought?” We have no idea about that either.
So, whether you’re an empiricist, a materialist, or not, we can’t explain how thoughts arise and how they get processed to us. What we do know is that all our experiences are filtered to us through the brain. You can have the most elaborate mystical experience in the world, but to tell me about it, you have to be back in your body with words created by your brain and filtered through concepts that your brain puts on it. So obviously, the brain is involved in perceiving and processing and relating the near-death experience. You can’t get around that. But that doesn’t mean it’s creating it.
Tim Ferriss: Also, I just wanted to add that, and I’ve heard you discuss this, just because something is currently unexplainable does not mean it’s fundamentally unexplainable. If we look back at the history of science, and certainly this will continue to be the case, we would laugh at some of the presuppositions of 200 years ago. And there’s no reason to think that 100, 200 years from now, certainly with the rate of technological change, maybe five, 10 years from now, almost with certainty, we will look back at many of the things we took to be true now and laugh at them similarly. And that in science, everything is provisional in a sense. It is until proven otherwise, which it almost inevitably is, is there’s something that’s added to it.
It would seem to me that studying this field, documenting these cases, doing your best to make sense of these things is not without career costs. It would seem to me, and certainly this was the case with psychedelics, say, a few decades ago, to try to scientifically study psychedelics. Putting aside all of the nightmares of logistics with dealing with the FDA and handling Schedule I compounds and so on, to take that path was viewed as career suicide. And I don’t know if that’s a fair label to apply to your field of study with respect to NDEs, but what have the cost been, if any, and why have you persisted despite those costs?
Dr. Bruce Greyson: It’s less of a problem now than it was back in the 1980s when no one knew about these things. Most academic centers assumed this was just a few crazy patients telling us stories and they weren’t worth investigating. And I was told in one university that if I continued to study these things, I would not get tenure. So, I’ve ended up leaving that place and go to a different university before they came up for tenure. I wasn’t willing to risk that, but I did now get tenure at two subsequent universities where it’s become more acceptable to study unusual phenomena as long as you’re doing it in a scientifically respectable way and publishing your material in mainstream medical journals.
So, I think it’s less of an issue now. But you still see a lot of, I wouldn’t say it’s professional suicide, but certainly professional barriers being raised to people who study these things. I think why people do it, partly because they’re intellectually curious about it, there’s a challenge here. I don’t understand it, and I want to. And probably more importantly for me is these experiences have profound effects on the people who have them. And as a psychiatrist, I want to understand that and help them deal with those effects if they need help with it. So, I think it is irresponsible to just ignore it and say it doesn’t exist.
Tim Ferriss: Let’s talk about some of your other interests, research interests, and I have a note here, genomic study of extraordinary twin communication. Could you elaborate on this?
Dr. Bruce Greyson: This actually was not my project originally. An Israeli psychologist, Baruch Fishman, contacted me and said, “I’ve got this great study I’d like to do, and I found a twin genomic database in England where they’ve got 15,000 pairs of twins and the entire genomic platform all laid out. So if we can survey these twins they have, about what they’ve had some type of communication when they’re at distant locations, whether you call it telepathy, you can call it extrasensory, you can call it coincidental, but they have reliable communication with each other when they’re far away from each other. Can we find out from the genomic analysis what genes are associated with this ability?” And I thought, “That sounds interesting. It wouldn’t be something I would pick, but sure, I’m game to try that.”
So, we did apply for a grant, and we got the approval of the group in England. The study hasn’t actually started yet, but it makes me wonder about the genetics that goes into having a near-death experience. We’ve been studying what’s going on in the brain, what’s going on in the heart and lungs. We haven’t scratched the surface of what’s going on in your genes that may make you more likely to have a near-death experience or a certain type of experience. Now, we know that when our hearts stop, between 10 and 20 percent of people will have a near-death experience, and we haven’t found any way of predicting who’s going to have one or not. But maybe the answer is in the genes. So, I think it’s worth doing a genetic study of people who have near-death experiences and those who don’t.
Tim Ferriss: I’ve had a handful of guests on this show who have identical twins, and they have all, maybe off the record, I think in some cases on the record in conversation, shared with me stories that certainly defy any current conventional explanation of communication with their twins. And it’s 100 percent at this point, and I’ve only had a handful of individuals with identical twins. But in several cases, these are scientists, these are people who are otherwise as rational materialists as you could be, but they are not going to refute their own direct experience, continued direct experience with their identical twin.
It does raise a lot of questions. And if we wanted to get really sci-fi, you think about genetic engineering, you think of CRISPR, you think of gene therapies. If we were to, in some capacity, determine which code is responsible, which light switches are responsible, would it be possible to increase someone’s ability to express those capabilities in the same way that we might, say, toy with myostatin inhibition or something like that to catalyze increased muscle growth in the sense we might see in Bully Whippets or in Belgian Blue cattle as an example. So it certainly seems like a study worth doing. Why not? I mean, worst case, you find no correlation.
Dr. Bruce Greyson: There’s a lot of ifs in that question. If we could do this, if we could do that, if you could show this.
Tim Ferriss: Lots of ifs, yeah.
Dr. Bruce Greyson: Frankly, I’m not encouraged by what I’ve seen so far with genetic engineering. Well, we can make tomatoes with a thick skin that can travel better across country, but they don’t have the flavor that a normal tomato does. So you’re always paying a price when you genetically modify something. You may gain something you’re looking for, but you may lose something else. And when you start messing with human genes, you don’t know what you’re going to come up with.
Tim Ferriss: Oh, for sure. How much funding are you seeking for this particular twin communication study, the genomics study?
Dr. Bruce Greyson: That’s a small one. Just $50,000 or so.
Tim Ferriss: Yeah. In the realm of science, that’s very inexpensive. What other studies outside of NDEs would you like to see done? Are there any that are shovel-ready, so to speak, or close to shovel-ready?
Dr. Bruce Greyson: Well, I would like to see — no, we’ve mentioned people who claim to leave their bodies and see things accurately from out-of-body perspective. I would like to get a more controlled version of that, and people have tried that. Sam Parnia at NYU has tried it a couple of times. I tried it once. There have been a total of six published studies of attempts to do this, and none of them have been successful. Usually, you’ll study things for a year or two and find no near death experiences in your sample, or people who have an NDE but didn’t describe seeing things from an antibody perspective. So there really hasn’t been any test of this yet.
Now, a determined skeptic would say, “Well, that shows that it doesn’t really happen, and that people who spontaneously have this experience and tell you about it are misinterpreting what’s happening to them or just making it up.” And I would desperately like to find some objective way of measuring this, but we haven’t had that yet. So, it would be nice to try to hone down that and try to find a good way of studying this in a mess — I mean, the stuff that Sam Parnia’s done, I was participating in one of his studies that had 2,000 patients in it from a variety of hospitals and we found nothing in that group. So you need a huge study to do this.
Tim Ferriss: This was related to out-of-body experiences, specifically?
Dr. Bruce Greyson: Yeah. I think there’s a lot to be learned from the neurophysiological research that’s going on now. There’s a very active group at the University of Liege in Belgium that’s making headway with this. There are other people around the world who are studying it. This group at University College in London. But I think we’re a long way from having an answer yet. We’re just starting this type of research. And it may be certainly not in my lifetime before we find a good answer.
Tim Ferriss: Is there a study design that you think would be a more intelligent way or a better way to approach controlled study or assessment of out-of-body experiences? And part of the reason I ask is that if you look back at, for instance, I could give a famous example, the Amazing Randi, who had this outstanding prize, I think it was a million dollars or a hundred thousand dollars for anyone who could demonstrate PSI abilities or extra sensory perception or fill in the blank under controlled conditions. And to my knowledge, no one ever claimed that prize.
Now, at the same time, if you look at a documentary like for instance, I believe it’s called Project NIM, which looked at the, in retrospect, ill-advised idea to try to raise a chimpanzee as you would a human child. The chimpanzee demonstrated all sorts of learning behaviors and so on that could not be replicated in the lab simply because the chimpanzee would shut down, would not demonstrate those behaviors in a laboratory setting. That doesn’t mean they didn’t exist, but there were challenges in studying it in a controlled environment. What is your best explanation? Again, understanding that for a lot of people, if you can’t verify it under double-blind placebo-controlled conditions or the equivalent in this setting, then it doesn’t exist. Right?
With extreme claims comes the requirement of extreme levels of proof. But how would you, based on everything that you’ve studied, colleagues you’ve spoken with, explain why it is so difficult to produce or replicate or study these things in controlled settings? Why is that?
Dr. Bruce Greyson: It’s essentially a spontaneous experience that does not happen under controlled conditions. When you put someone in a lab, they’re not the same as they were when they’re out on the street. And we’ve learned this with sleep studies. When you bring someone into the lab to measure their brainwaves during sleep, it takes a day or two usually to have them adapt to the situation before you can actually do it and get something that’s at least a bit like what their normal sleep is. So I think you have to take that into account that people have these experiences out in the wild, so to speak, and it’s hard to tame it without clamping down on the controls to their brain that would shut it off maybe.
So I don’t know whether you can do that, whether you can have a really controlled circumstance where you have this experience. Now you can certainly do it with mimics that mimic part of the experience, for example, with drugs or with brain stimulation that can mimic a part of it. And then by implication, develop metaphors of what might be going on in the brain during a near-death experience, but it’s not the experience itself.
Tim Ferriss: What are some of the, for you personally, open questions that you would love to see answered before lights out onto the next adventure after death if there is a next adventure, what are some of the open questions in this field or in other fields that for you, you would most like to see answered? Are there any burning questions that come to mind?
Dr. Bruce Greyson: Well, the big question of course is how the mind and brain interact and that certainly you get some hints of that from a near-death experience. But there are other phenomena that also address the mind and brain seeming to separate. And one of these is the terminal lucidity phenomenon where people who have had dementia for a while and cannot communicate or recognize family suddenly become completely lucid again and carry on coherent conversations and express appropriate emotions. And then they die usually within minutes or hours. And we don’t have any explanation for this.
Tim Ferriss: I have a few friends, not just one. A few friends who’ve directly seen, observed this phenomenon. And I do not have any way to explain that.
Dr. Bruce Greyson: If you believe the brain-as-filter mechanism, that could play a role in this, that when the brain is shutting down in the last hours before death, it releases this filter that allows the consciousness to fully flourish. Now a big problem with that is the person is still able to speak and communicate. So obviously parts of the brain are still functioning just fine. So if you have this experience of heightened lucidity at death, how do you let people know that unless your brain is still functioning? But it is a dilemma because we don’t have a medical explanation for how someone with a debilitating disease that is irreversible like Alzheimer’s disease can suddenly regain function again. Now there are speculative theories about this, but none of them really make a whole lot of sense and none of them have been corroborated by evidence.
Tim Ferriss: Now there are other facets of some of the reported NDEs, past life review as an example. You might also have, as I understand from listening to a number of your presentations, recall or re-experiencing an event through the perspective of someone other than yourself. When you consider all of these reports, how has that affected, if at all, how you think about time? And I ask that it might seem incredibly broad, but I think most of us tend to think of time as this fundamental constant. But if you talk to the Carlo Rovellis of the world, if I’m pronouncing his name correctly, if you start really digging under the hood, it’s difficult to automatically take that as static, known fact. And I’m wondering how you think about time if these reports and your research and experiences have changed that at all.
Dr. Bruce Greyson: Most near-death experiences say there was no time in this other realm, either that time stopped or just time ceased to exist. And when they say that, I reflect on what they’ve told me about the experience, I say, “Well you’re telling me that this happened and then this happened and this happened, but that implies a linear time. So how can there be no time if you’ve got things happening in sequence?” And they just shrug and say, “Well, when I tell you about it now in this body, in this world, it’s a paradox. Over there, it wasn’t. Everything was happening all at once and there wasn’t any linear flow. That’s just the way it is.” I can understand that as an abstract concept. I can’t relate to it in my real life. I don’t know what that means to not have time because so much of our life is controlled by what we think of as the linear passage of time.
Tim Ferriss: Yeah, it’s a slippery one this time thing when you have some of these non-ordinary experiences. Let me ask about another perhaps non-ordinary experience, and this is something I found in the footnotes of a footnote of a footnote. So you may have some ability to explain this. Auditory hallucinations after NDEs, and I only read the very top, abstract in a PDF, so I did not dig into it. But what does this refer to?
Dr. Bruce Greyson: A psychiatrist in Colorado, Mitch Liester and I, did this study. We surveyed a large sample of near-death experiences about what they seem to be, what seemed to be hearing voices long after the near-death experience. And we also looked at schizophrenics who were hearing voices and compared the experience of those two groups and they were quite different. The near-death experiences, who claimed to still be hearing voices almost universally said these were helpful guiding voices. They enjoyed hearing them and they found them making their lives richer. They gave them some guidance and they were reassuring to them. On the other hand, these schizophrenics almost universally said, “These are terrifying hallucinations. I wish I didn’t have them. They make my life much harder. I don’t like them at all. Wish they would just go away.” It’s not experienced in the same way. Is it the same phenomenon? I don’t know.
Tim Ferriss: Among the people who reported the auditory hallucinations, was there any degree of overlap in terms of structural brain damage or otherwise? In the NDE group.
Dr. Bruce Greyson: We don’t have the measures of brain function to answer that.
Tim Ferriss: To know. Yeah. I could keep going for many, many, many hours. Let me ask you this just as a way of branching out a little bit. In terms of researchers who in your mind demonstrate a compelling combination of both open-mindedness but rigorous skepticism, who would you, not to ask you to pick among favorites, but who are a few names that come to mind?
Dr. Bruce Greyson: Sam Parnia at NYU.
Tim Ferriss: How do you spell his last name?
Dr. Bruce Greyson: P-A-R-N-I-A.
Tim Ferriss: Got it.
Dr. Bruce Greyson: There are retired physicians who are still involved in this field. Peter Fenwick in England and Pim van Lommel in the Netherlands. There’s a brilliant psychologist in New Zealand, Natasha Tassell-Matamua, who’s doing a lot of interesting research in this area. She is part Māori and she’s doing work with the cross-cultural comparison of Māori versus English near-death experiences, but also looking at a lot of the after effects. There’s that large group at Liège that I mentioned to you before that’s doing a lot of research into this.
Tim Ferriss: This is Belgium?
Dr. Bruce Greyson: Yeah. Many of them are quite confirmed materialists. That’s fine. They’re still doing good research. The head of that lab though, Steve Laureys, is much more open-minded. He still is a materialist, but he’s more open-minded about what these things might mean. And he is certainly compassionate about how it affects the people who have these, which is probably more important to me than what they think is causing it. So there are a number of people around the world who are doing good research with this area.
Tim Ferriss: You have written a number of books and co-authored, co-edited others. One of them is Irreducible Mind: Toward a Psychology for the 21st Century. What does the irreducible mind refer to?
Dr. Bruce Greyson: That basically means a mind that’s not reducible to chemical processes and electrical processes in the brain. It’s a mind that can be independent of the brain. And that book, without ever mentioning anything paranormal or parapsychological, goes through a series of phenomena in everyday life that point to mind and brain not being the same thing. And it does include near-death experiences and other experiences near-death, and it includes exceptional genius, it includes psychosomatic phenomena, a variety of things that have occurred to perfectly normal people over the centuries and have been well-documented and don’t seem to be compatible with the idea that the brain creates all our thoughts and feelings.
Tim Ferriss: Which of your books, whether solely authored, co-authored, or co-edited, would you suggest people start with if they wanted to?
Dr. Bruce Greyson: I would suggest my most recent book, After, because that’s really geared towards the average person, the layman, and is written in language like we’re talking right now. I tried to minimize jargon, whereas the other books I’ve written have been primarily for academicians, which are much harder to read, much denser. Still excellent books, but not for the average person.
Tim Ferriss: And that is After: A Doctor Explores What Near-Death Experiences Reveal About Life and Beyond.
Dr. Bruce Greyson: Right.
Tim Ferriss: All right, so that’s where people should start.
Well, Dr. Greyson, this has been a very wide-ranging conversation. Is there anything that you would like to discuss, mention, or a request you’d like to make of my audience, something you’d like to point them to? Anything at all that you’d like to say before we start to wind to a close?
Dr. Bruce Greyson: I think that things I want people to know about near-death experiences are number one, that they’re very common. About five percent of the general population or one to every 20 people has had a near-death experience. And secondly that they are not associated in any way with mental illness. People who are perfectly normal have these NDEs in abnormal situations that can happen to anybody. And third that they lead to sometimes profound, long-lasting after-effects, both positive and negative that never seem to go away over decades.
Tim Ferriss: People can find all things Bruce Greyson, it would seem, at brucegreyson.com, if I’m not mistaken. So Bruce Greyson, G-R-E-Y-S-O-N, dot com. And you have quite a few books to your credit, but the one to start with would be After subtitle, A Doctor Explores What Near-Death Experiences Reveal About Life and Beyond. Is there anything else?
Dr. Bruce Greyson: That’s it. You covered it pretty well, Tim.
Tim Ferriss: All right, well thank you very much for the time and for everybody listening, we will link to everything that we discussed in the show notes as per usual at tim.blog/podcast, then you just search Bruce, probably, and he’ll pop right up. And as always, until next time, be just a bit kinder than is necessary, not only to others but to yourself. And thank you for tuning in.
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