People in a coma still have thoughts and feelings – leading neurologist

SS: All right. So I'm going to jump right in. We say in everyday speech ‘knocked unconscious’, right, or ‘lost consciousness’. But speaking scientifically, can we actually measure lost consciousness? I mean, is someone who has been knocked out by Mike Tyson, for instance, really unconscious at that moment?

SL: Well, I don't know what it is like to be knocked out by Mike Tyson. But to answer your question about consciousness, and when we lose it, I think the historical error, Sophie, is that we have considered consciousness as all or nothing. You’re either knocked out, unconscious or comatose, or you’re conscious. And this black-white vision is very probably wrong with others showing that consciousness and losses of consciousness can be very gradual. And I think this is very important. Historically, when I started this research in the 90s, we had ‘coma’ and then there was brain that -  and what we at the time coined ‘persistent vegetative state’ where people looked awake but were considered unconscious and basically just waiting to die. Now we know that many patients we thought were unconscious, or so-called vegetative, were minimally conscious. And so this is very important that you can be more or less conscious, that consciousness is not an all or nothing thing.

SS: Okay, I think this talk will be about different gradations of how much we lose consciousness and what consciousness really is in different states. For instance, some people report seeing all kinds of wild things during a near-death experience, which we'd call an unconscious state of mind, I know that some scientists say, ‘Oh, these are just hallucinations’. But if my brain is hallucinating in this state, it means I still have consciousness, it's just, you know, tripping on something. So does that mean that even in the state of coma a human being possesses, like you say, minimal or some sort of consciousness? Do we have a notion of how much could that be or what  is it?

SL: I think you're absolutely right, that again, the error we've made is when trying to measure consciousness, how do we do that? We're having this discussion right now, we're talking. If you can't talk, we will use sign language or something. So the only person right now, Sophie, who knows what she's thinking, feeling is you and you alone, so you need to share that. And of course, people who are comatose, considered unconscious can no longer communicate. And so what do we do? We basically look from the outside, myself as a clinician as someone who tries to measure the unmeasurable consciousness, I'm going to ask questions. And so in intensive care with people with a severe traumatic brain injury who are bleeding, who survived a cardiac arrest, and over in this comatose states, I would ask him to do something, squeeze my hand, make any movement, and if I have an answer, I kind of have proof that they are conscious. But of course, when they don't answer, they don't really prove that they are unconscious. No. So this is very tricky. We're making inferences based on people's motor response when trying to measure consciousness after coma and sometimes we can get it wrong. And I think as you said, we have underestimated the capacity of the brain after coma when we think there's nothing going on, like in some patients after coma, like in people who have a near-death experience. This is very clear evidence that despite appearances, they can have very rich, subjective personal thoughts and feelings. 

SS: But also like, you know, we see this in the movies and sometimes we hear someone who has been in a coma or vegetative state for a long time, and the relatives, for instance, refusing to give up on that person everyday being by his side and talking to him believing that he can hear them. And then sometimes miracles happen, these people come out of vegetative states or comas, and they gradually start living normally. And most of them actually say that they could hear the people talking to them while they were unconscious. Did you see how that happens?

SL: Well, absolutely, I think with the team, we've contributed to a better understanding of residual brain function after coma. So within the European Task Force, and also now the American Academy of Neurology, we propose a more neutral term, which is ‘unresponsive wakefulness’.

SS: Ok, sure. 

SL: So from now, we'll try to refer to these patients, people no longer as ‘vegetative’, but as ‘unresponsive’, they just no longer respond to questions, and yet they look awake. And indeed, this is a difficult diagnosis. A substantial fraction of these patients do have thoughts, feelings, emotions, and it's often very frustrating because we can't have access to what they're actually perceiving. And that is the added value of the neuroimaging and that's the expertise of the team here, the Coma Science Group, where we use functional MRI, high density EEG, and you see some machines here behind me, all possible measures to try and document what's going on inside. So we no longer depend on the motor response, we can go and measure directly what's happening in the brain.

SS: Alright, so I read that you have located the area of the brain that is responsible for inducing these visions of the tunnel to the afterlife. So how real would you say these experiences are, I mean, if you can physically observe the impulses creating them?

SL: So it depends what do you mean by ‘real’. We have - it's a scientific challenge to define what is reality, but I think it's very real for them. And I think it's a physiological reality, where I don't think we should be too arrogant. This has been many years now that with the team we’ve been trying to understand these near-death experiences, but nobody truly can explain them. And maybe, if I can, Sophie, I have a little request for everybody watching us now in Russia, who maybe had such an experience, or who knows someone who had a near-death experience, please share it with scientists, share it with us, the email address is very simple: nde@uliege.be. Or visit our website, I created a foundation - Mindcare Foundation where including with our friends in Russia, all over the world, we try to reduce our ignorance when talking about consciousness, including the very fascinating topic of near-death experiences. But we need more testimonies, we have over thousands, but sometimes I feel frustrated because I never had one. So I should start by listening very carefully to the people who had and then try to understand this.

SS: So the temporo-pariental junction - as far as I understand is also linked to things like schizophrenia, Alzheimer's, amnesia – 

SL: Yes, let me maybe take a brain, it's my favourite organ. And you're absolutely right, we have a part of the brain right here in the middle, it's on the right side, and if I would stimulate it, even healthy people, one could provoke so-called out-of-body experiences. So this is interesting. Now, I don't think we should again say that just this part of the brain explains near-death experiences. It's too reductionistic. 

SS: Right. 

SL: But it is interesting to have some hypothesis. Another part here is important for this feeling of a presence. Then, of course, the occipital tracts that are quite sensitive to lack of oxygen can give this kind of tunnel vision, this bright, central light and we also know the stories about people having flashbacks of their lives. And this is a structure here, deep in the temporal lobe that is important for memory. We have patients with migraine or with stroke that sometimes tell me stories that are making me think of near-death experiences. But again, I think we're not there yet. We are making brain scans in people who had a near-death experience and trying to make correlations. But truly presently it would be too arrogant to say, ‘Well, this is just this or that chemical process in this or that part of the brain, we've understood it’. No, I think we need to be more curious and to study it, but also with an open mind, because consciousness truly is one of the biggest mysteries science is trying to solve.

SS: Okay, so let's say, if we stop dismissing near-death experiences as just fruits of imagination, right, and we accept them as important brain activity. What can we really say about them as of now definitely? What are they exactly from a neuroscience point of view?

SL: Well, the scientist will tell you, ‘Be careful’. What is true today is not necessarily true tomorrow. So it is about the scientific methodologies trying to confront what you think you understand with what you think you can measure. And so currently, yes, we have a couple of hypotheses, we've got a number of papers with the team that kind of reduce our ignorance. But it's still a challenge for science. I'm fascinated by the fact that people who have, for example, a cardiac arrest, when we know that the brain is using so much energy, there is no other organ in your body that needs so much energy, and then when suddenly, there is no more blood for no more energy. These people have these very rich and detailed thoughts and memories. So how is that? It's important to stress that they are not dead because for some people also, this is proof of life after death. I wouldn't agree. I think, currently, death is really a frontier that is difficult for us to study. We consider it in society, as, well, indeed binary, you're either dead or alive. But biologically speaking, this is a process. And now with modern medicine and technology, we can resuscitate some people, for example, with a cardiac arrest. And we need to increase our efforts to understand the process of dying. And at one point it becomes irreversible and that is what we consider death. We should, as a scientific community, as a medical community, be more curious and study this phenomenon more, and I think we're a little bit afraid, we consider this too complicated. And we suffer from auto-censorship. We consider this maybe as a taboo, which it shouldn't be.

SS: Steven, when you have that near-death experience, everyone has very different visions. I mean, some people see their dead parents, some see their lovers, some see tunnels. Is there something, anything from the people you've spoken to, who have shared their experience with you about this vision, that they have in common? For instance, if I'm an atheist, and I don't believe in afterlife, right, and my brain functions in a way that I don't believe there will be a tunnel after I died that I see, with light leaving me to heaven or whatever, will I see the same thing as a person that for instance, is very religious and believes in afterlife? Is there like a common thing, a common thread that all near-death experiences have?

SL: Yes, there is. I think there is something universal across all cultures. And we tried to give a kind of top 10. So what is the most common in our cohort, mostly Judeo Christian, Western? And the first one is that they all feel extremely good. Sometimes they don't have even the words to express how good they felt and actually difficult to come back. Next is this notion of a light, then the out-of-body experience, they lose track of time. And it was very interesting to me when having this discussion in St. Petersburg with Father Sergey, who is a religious leader in the Orthodox Church, but also discusses with people in the intensive care. And he said that, in his experience, about 50 or so of the patients had negative experiences. And that is something that maybe we should try to explore more. And hence, again, I would like more people from Russia to share this, and to compare it with what we see in Belgium, France and the United States, where we have now thousands of testimonies. Another example that strikes me is the interpretation of a tunnel, you mentioned already, which seems to be different when talking with my colleagues in the Muslim world, where it would be sometimes interpreted as a door or in India, where when I give conferences, and we also collaborate there, it's more like a river. So yes, something seems to be clearly universal. But also there are differences, individual differences, but maybe also cultural differences, but they currently are too anecdotal. We need more evidence. Maybe we can compare it with dreams, right? I don't know, Sophie, if you ever had a near-death experience? 

SS: No. 

SL: So it's difficult for us to talk about it, but you’ve had dreams, right?

SS:I have dreams all the time.

SL: And I think your dreams and my dreams somehow are similar in their surrealistic content. And we can, yes, say that there is something dreamlike. But of course, my dreams can be very different in their precise content than yours. So my answer about near-death experiences is - I think this is a physiological reality that needs more science, that has a shared common structure, but also with maybe a personal meaning that can depend on where we grew up. And of course, my friends and colleagues in India will hear much less frequently people talking about Virgin Mary or Jesus, and vice versa. Here we have fewer people talking about some Indian gods. But again, this needs to be documented in a more detailed manner. But when you ask me, ‘If I'm an atheist, will I have a near-death experience?’ Yes. And maybe you will even have a mystic experience. So far, when we look at the thousands of testimonies we have, it's very hard for me to predict. We have very religious people who have these experiences, sometimes they will indeed read this as something that brings them closer to God and they will become more religious, but not necessarily, and also vice versa. So I think it's not just ‘I'm a very religious person, so I have this or that near-death experience’. I think there really is a biological substrate.

SS: People often run out of options and we're talking about assisted death for those who lost consciousness forever. So in your opinion, does that mean that we equate being conscious with being alive in a sense so when my heart beats and my body functions, but my brain is unresponsive, cognitively dead... Am I still alive? 

SL: It's a very important question, where we have a definition for death, okay? When do you die? That is when your heart and lungs and brain cease to function and that's irreversible. Then things in the 50s got more complicated when a physician invented a new machine, the artificial respirator. Let me again show you such a machine. So this changed the course of history, it redefined death. This machine, by the way, is called ‘Osiris’ after the Egyptian god of the afterlife. So this machine for the first time, kept patients with a very devastating brain damage breathing through the machine, so their circulation could be ensured. And as medical community, we redefined death, not just on the heart and lung criteria, but now also on brain criteria. That is what we call ‘brain death’. So when your brain is dead, now, according to medicine, and according to law, you are dead, there's nothing we can do, we can decide. That's very important. And in my job, there is not much certainty. When I see a patient I try to give a diagnosis, it is what we call ‘probabilistic’, it is what I think this patient has. When we say someone is dead it shouldn't be probabilistic. It should be right, we don't want to get this wrong. And so maybe also I can reassure the Russian viewers, we have these criteria since the 50s and there is never ever been a single patient with the criteria of brain death who recovered consciousness. Now there have been diagnostic errors and medical professional errors. But if you do the job correctly, then brain death truly is death.

SS: So I read you managed to measure brain activity in seemingly unconscious patients by looking at brain metabolism. So basically, consciousness can be observed by counting how much energy the brain is consuming. But what about the future? What are the possibilities of brain scanning in the future? What will scientists realistically be able to see inside a human brain let's say in 10 years?

SL: Honestly? I don't know. So sometimes we make big claims. I listen to Elon Musk and his company, Neuralink, who's trying to plug in computers into the human brain. And that's great because he has wonderful technology. But I think the complexity of the human brain, and more importantly, the human mind is tremendous. So I don't know what's going to be possible in 10 years. And we don't even know what we don't know. So have we understood 50% when we talk about the human brain and mind? Or 5%? Or 0.005%? So truly, this is fascinating time. Yes, we have all these technologies that you see here, great machines that permit us to zoom in on the workings of the human mind. But again, we shouldn't be too arrogant. It's of a complexity that currently we're struggling with. And sometimes this goes very quickly. And sometimes, you know, it's terribly difficult and slow, like, when I read the science fiction books of my father, even my grandfather, we would be driving around in flying cars. It's not happening, we're still driving around in stupid cars with four wheels. So it's very, very difficult. And I think that the human mind is truly, trust us, - life itself, just as the origin of matter, something that at one point, it's been more than 25 years now I'm studying this and I'm dedicating my life to this, and there's just this part of mystery where I look with some kind of spiritual amazement because I can study as much as is possibly possible today and we don't know, do we? 

SS: Steven, it was so interesting talking to you. Thank you very much for your dedication to this very important topic. And you kept saying, ‘your Russian viewers’ - we’re actually watched all over the world, not only in Russia. 

SL: Wonderful. 

SS: Yes. So hopefully, you'll get lots of emails, people sharing their near-death experiences with you. Good luck with everything. And hopefully, we can know a little more about what consciousness is and how human brain functions in the nearest future.

SL: Yes, thank you so much.