My name is Laura Heisler, and I am the director of the Wisconsin Science Festival, and we are delighted to be partnering again this year with the Book Festival.  Just a few words about our author.  We are so delighted to have Anil Ananthaswamy here to talk about his latest book, "The Man Who Wasn't There: "Investigations into the Strange New Science of Self." Mr. Ananthaswamy is a consultant and the new scientist in London as well as a contributor to National Geographic News.  Years ago, he worked as a software engineer in Silicon Valley before training as a journalist at the University of California at Santa Cruz.  He is also a Ted speaker and is the author of "The Edge of Physics." So today we are delighted to welcome him to hear about his most recent book, "The Man Who Wasn't There." Please join me in welcoming Anil Ananthaswamy.  (applause)  - Thank you for that introduction.   Thank you, everyone, for coming.  This is a pleasure for me to be coming and speaking at the Wisconsin Book Festival.  The last time I was here in Madison it was in April, and it was really cold.  And it's lovely, it's lovely to be back here now. 

 Today, I'm going to speak about the human sense of self.  About who we are.  And specifically I'm going to talk about what neuroscience in general, and neuropsychology in particular, is telling us about our sense of self.  About when you ask the question, "Who am I?", the kind of answers we come up with.  What does neuropsychology have to tell us about how our self is formed our what that self is?  Normally, if you were to ask anyone, "Who are you?" you'll get a whole range of answers, and we all have an intuitive sense for what our sense of self is.  It's there when we wake up, and it kind of disappears when we go to sleep, reappears when we are dreaming.  And also, there's this sense we all have, in fact all of us will be experiencing this right now, the sense of being a body.  A sense of being in a body, occupying a volume of space that is taken up by this body.  Having a sense that we are viewing the world from within our heads, looking out.  Having a sense that whatever we are experiencing is private to us. 

 That there is a kind of first person perspective, that each perception that I'm having is somehow mine and mine alone and distinct from what somebody else might be experiencing.  There's also a sense we have of a continuity in time.  You can think back to your earliest memories, or you can imagine yourself 10 years from now, some future imagined self, and you have this sense that there's this same entity that is persisting over time.  All of these things, in some sense, go towards making up our sense of self.  So, if you were to ask someone, "Who are you?" you're going to get answers that tease out these various aspects of being human.  Now, when I pose it like that, you might wonder, so what really is the mystery? What is there to explain? We all know what this self is, and what's the big deal? In a larger set of the mystery, I just want to read this quote by philosopher Thomas Nagel, which says it very poetically "It seems outlandish that the centerless universe, "in all its spatiotemporal immensity, "should have produced me of all people.  "There was no such thing as me for ages, "but with the formation of a particular physical organism "at a particular physical place and time, "suddenly there is me for as long as the organism survives.  "How can the existence of one member "of one species have this remarkable consequence?" And that is the essence of the mystery, and any time philosophers, neuroscientists, theologians have wondered about the nature of the self, they ended up in debates.  It's not an easy question to answer in terms of what is the self, and the debates kind of, these are the broad brush strokes of the debate.  First of all, they argue about whether is there self or is there no self. 

 And it's as basic as that.  The other thing they wonder about is, can the self exist independent of all else? And what I mean by that is we know that the material world can be broken down eventually into fundamental particles.  We know that the material world is constituted of these fundamental particles like electrons and quarks and gluons.  And when it comes to the self, the question is, is the self independent of these material constituents of nature? Can it exist separate from the electrons and quarks and gluons that make up the material world? What philosophers call ontological reality.  Does the self have a reality that is separate from the material world, or is it something that comes about because of the interactions of the material world? And then you must have heard over the last year, last few years, the last few decades, about this idea that the self is an illusion.  Well, if the self is an illusion, then whose illusion is it? Is there somebody, something experiencing the illusion? What does that mean to be even saying the self is an illusion? So all of these things are the broad kind of debates that go on within philosophy, neuroscience, and theology about the nature of who we are.  And so I just wanted to, today, talk about a few things that can lead us to a point where we can appreciate what these philosophers are debating about.  And I can give you a spoiler alert right away that there are no answers.  We still haven't figured out what the answers are.  But it's still very hard to appreciate what the debate is about, what the philosophers and neuroscientists are wondering about. 

 So, in a sense, what my book tries to do and what I'll try to do in this talk very briefly is bring us to a point where we can understand what are they arguing about.  The first thing to look at is what are the key aspects of the self that concern philosophers and neuroscientists.  There are two things primarily.  One is called synchronic unity.  If you think about yourself right now, all of you are looking at the stage, you're getting a certain visual input through your eyes.  You're also hearing me speak, so you're getting a sensation of sound.  Most of you would be feeling like the perception that arises from sitting on your chairs, the tactile sensations of you clothes on your skin.  And what's interesting and not at all trivial to explain but might seem trivial is that all of these sensations, whether it's vision or sound or tactile, they're all being experienced by the same entity.  It's not as if one person is hearing the sound, another person within you is hearing or is seeing things, yet another entity is experiencing touch.  All of these sensations are being experienced by the same thing or, you know, same person. 

 You struggle for words at this point.  What is this thing, or what is this entity that is actually experiencing the various perceptions? And there is a kind of unity to everything that we experience in a given moment here and now.  Again, from an experiential point of view, from the point of just being a human being, it seems very trivial.  Yeah, of course that's how it is.  But trying to explain that philosophy, trying to explain that unity philosophically or neuroscientifically is not easy.  And, in fact, that's one of the things people fret about when they try to explain the nature of the self.  So there is this unity of experience of being here and now in a body.  There's also something called diachronic unity, and this is something I just touched upon when we think about our child or when we think to our earliest memories or any memories that we have of having existed.  And also if you imagine yourself in the future, certain perceptions are going to arise in your mind, some emotions are going to come up, and, again, if you think about it a little bit, no matter what you remember or what you imagine, all of the perceptions that arise from the remembering and the imagining seem to be happening to the same entity.  It's not as if when you think of your four-year-old self you are aware of somebody else, and when you imagine yourself 10 years from now, you're aware that it's happening to somebody else. 

 No, it all feels as if there is the same entity that is perceiving or is behind the whole thing.  Now, this is called diachronic unity.  And, again, it seems trivial, but it's not easy to explain philosophically and neuroscientifically.  How does this happen? In fact, it's because of the presence of this unity that some philosophers have argued that there must be something called a self that must be behind all these experiences.  That must be experiencing everything as if it happens to itself, and somehow it can put it all together and say, okay, here's a person that is experiencing existing over time.  But then there are other philosophers who argue otherwise And how do we make sense of all this? So, I'm going to just talk a little bit about the fact that this whole exploration of the nature of the self is not new.  It probably began the moment humans became self-aware.  The moment humans just realized that they were self-aware, the questions began.  Who am I? And on this screen I have an example of something that was, I don't know if any of you would actually recognize the script at the very top, but it's Sanskrit, which is an ancient Indian language.  This particular poem, I've just taken a stanza from a poem from the 8th century AD, which is trying to answer the question, "Who I am?" by trying saying what I'm not. 

 So it basically says, I'm not my mind.  I'm not my intellect.  I'm not my body.  I'm not by emotions.  I'm not my virtues.  And so on and so on and so on.  In trying to answer, "Who am I?" it's basically pointing out that I am not all these various things.  So what must be left must be I.  Of course, this particular tradition of asking the question, "Who am I?" belongs to a very specific philosophical tradition within India called non-dualism tradition, and they have their own answer for the question, "Who am I?" I'm not particularly interested in the answer right now because if you asked this tradition, you'll get one answer.  If you ask the Buddhists who go back 2,500 years, they'll have a slightly different answer. 

 If you go back to other traditions, whether in the east or the west, each one has a slightly different take on the answer to the question, "Who am I?" This is a quote from Scottish philosopher David Hume.  This is a very often quoted sentence from his writings.  He says, "When I enter most intimately into "what I call myself, I always stumble "on some particular perception or other, "of heat or cold, light or shade, love or hatred, "pain or pleasure.  "I never can catch myself at any time without a perception, "and never can observe any thing but the perception." And what he's saying is that all we are is a bundle of perception.  Bundle of perception.  So if you started trying to examine very, very deeply as to who is doing the perceiving, you would find nothing.  And so David Hume falls into the camp of philosophers who are called the bundle theorists.  And so on and so forth this debate goes on.  So somebody like David Hume is saying you can examine as deeply as you want, and at the end you will find nothing, and it is somewhat similar to what the Buddhists are saying.  The previous slide I showed you from the non-dualist tradition, they have a slightly different take on that. 

 So, for the rest of us who are not philosophers and not neuroscientists, how do we make sense of all this? You know, what are they arguing about? So that's what I tried to do in this book.  I look at eight different, I looked at eight different neuropsychological conditions, each one of which disturbs the self in a slightly different way.  So, by self I mean just the experience of being a human being.  We all know what that feels like, and sometimes, whether you are, you know, ill or not, sometimes during the course of your day you can perturbations of the self.  If you, for instance, are feeling slightly depressed, that is a perturbation of the self.  You feel differently when you're depressed than when you're not.  And similarly, each of these neuropsychological conditions change how one feels about one's self, and by looking at what changes, we can start asking questions about what the self is.  And so the conditions I looked at, Alzheimer's Disease.  Some of these you will be familiar with, and some may seem, you know, strange in terms of, by the fact that you may not have come across this even in regular readings.  Body integrity, identity disorder, schizophrenia, depersonalization disorder, autism, autoscopic phenomena which include out-of-body experiences, ecstatic epilepsy, and Cotard syndrome. 

 So I won't have, obviously, time to go through each one in detail, but what I want to do is kind of give you a sense for how by talking to people who are experiencing these conditions, how you might get an understanding of what might be happening, A, to their own experience of being a self and, B, what that tells us about how the brain might be, brain and body together, might be constructing the self in the first place.  And this tradition of looking at, you know, or asking questions and trying to answer them by looking at things that are not quite okay is not very different from how brain science has functioned over the last few decades.  For instance, when you think about how much we've learned about the brain and the way it functions, a lot of what, a lot of our knowledge has come about because we have studied people who have unfortunately have had a stroke or some brain trauma or lesions and they've lost some part of their functionality, like maybe language skills or motor skills, and by correlating that loss of functionality with the damage to the tissue we have understood how different parts of the brain might be doing what they're doing.  And this approach of looking at neuropsychological condition that change the self in some way is not very very different.  In a sense, you're looking at changes to the self and then trying to correlate that to changes in the brain and body and trying to understand what might be happening in a situation where the brain and body have to work together to create our sense of self.  Now, let me give you a couple of examples We won't have time to go through all eight, but maybe just by looking at a few you can get a sense for what, how this approach helps us understand the nature of the human self.  Now, Alzheimer's disease, unfortunately a lot of us will be familiar with because we will know someone who is actually suffering from it.  This is quite a relentless neurodegenerative disease that starts by affecting short-term memory formation.  So people start forgetting things that have just happened to them.  And eventually it causes complete cognitive decline. 

 People are unable to, you know, know anything about who they are.  They forget to recognize their loved ones, some people who are very near and dear to them.  And eventually they're unable to take care of themselves and have to be taken care of.  Now, this is quite, this is an extremely debilitating condition.  And when you talk to caregivers who are looking after people, especially with end stage Alzheimer's, they will say things like I don't think the person I knew is there anymore.  And this is a very common refrain.  They'll say that person is gone.  The person I knew is gone.  There is no one in there.  And so the question is, what really is happening in Alzheimer's? When you think about the first early stages of Alzheimer's, when you're losing short-term memory formation, what this is doing in the beginning is impacting what can be called our narrative or autobiographical self. 

 So, if I were to ask any of you, "Who are you?" you'll most likely give an answer that is going to be a narrative.  You're going to say, I was born here.  I moved from New York to Madison.  Maybe you did; maybe you didn't.  Just as an example.  You'll probably talk about your children, the work you do.  Essentially, you'll tell a story about who you are, and that's the story we all have in our heads.  It's a story about how we think about ourselves, about how we feel about ourselves, and when someone asks us who we are, that's the kind of response you will tell them.  You're very unlikely to tell them, "Oh, I'm a bodily self, sitting in a chair, "feeling my sensations." You're actually going to tell them about a story.  So, in a sense, already you can see that when you talk about the human sense of self you can talk of two different aspects. 

 One is the autobiographical self, the narrative self.  The stories in our heads.  The story.  Or something very physical and bodily.  And we usually don't refer to the bodily self when we're describing people and telling people about who we are.  So, in the case of Alzheimer's, what this does is it starts eating away at the narrative self.  So think about what happens.  You have short-term memory loss.  You can't remember what just happened.  And obviously if something is not going into short-term memory, it's also not going into long-term memory. 

 And when you think about the story that you are, when you think about who you are in terms of the episodes in your life, all of that is memory.  All of that is episodic long-term memory that's stored somewhere in your brain.  We don't exactly know how that works, but it's there in us.  And in order to have an autobiographical self or a narrative self, your memory systems, your ability to recall and sort of reenact those memories, all of that should be intact.  And when short-term memory formation stops, one of the things Alzheimer's does is it basically puts a stop to the formation of the narrative self.  So, in some sense, when the disease onset begins, the story that you are stops forming.  So that's the beginning stages.  And, unfortunately, as the disease progresses, it starts eating away at old memories.  It starts going in and scrambling the order in which you can tell your story.  So, for instance, there is a person that I write about in my book where when he was in the middle stages of his Alzheimer's disease and when I would ask him about his life, he would pretty lucid. 

 He would be able to tell you a whole range of things that had happened to him, but if you didn't know his real story, you wouldn't be able to tell that the order in which he was remembering things was all scrambled up.  So, in some sense, Alzheimer's has gone into his narrative self and somehow ended up just scrambling the sequence in which one remembers who one is.  So, middle stages basically starts scrambling and destroying the narrative.  Eventually it completely obliterates the narrative self.   And Alzheimer's poses a very interesting challenge to philosophers.  Like philosophers, there are some philosophers who have argued that our self is just a story in our heads.  In some sense, it's because we have the ability to be a story or be many stories and we have the ability to tell stories about ourselves, that is why we have the feeling of being an I.  Take away the stories and there is no I.  That's the philosophical argument that has been made.  Alzheimer's challenges that because we, you know, if you actually are with someone who has lost all narrative, basically has no story to tell because their brain now cannot recollect all those memories that formed them. 

 Does it mean that there is still no one in there who is capable of experiencing pain or hunger or any of the bodily sensations that we all take for granted to be happening to one's self? So basically the question is, even though they don't have a narrative or they don't have a story about who they are, does it mean that their other experiences just of being a physical body are unowned, that no one owns those experiences? It's a question that unfortunately we cannot answer with Alzheimer's because someone with end stage Alzheimer's is unable to communicate what it must be like to be without a narrative.  But more and more scientists, and social scientists especially, are beginning to argue that no, just because the narrative is gone doesn't mean that there is no one in there capable of experiencing pain or hunger or all the other emotions that we have as happening to someone.  Even though that someone is not the full person that we normally think of.  And Alzheimer's also challenges another view of the self, which is that the narrative self, philosophers again argue that it's just a cognitive thing, that it involves just the brain consciously recalling various memories that make us up.  So when we tell a story, we have to actually think about who we are and narrate that story.  And, of course, that ability is getting impacted in Alzheimer's.  There's no doubt about that.  But what's very interesting is that even in people who have lost the ability to cognitively tell a story about themselves, there is a lot of their narrative self left in their bodies.  When I say body, I'm always, remember that the body and brain are always working together.  So it's not like the body is separate from the brain or the brain is separate from the body, but there are things that we learn and we become and which become part of our narrative that are not necessarily recalled consciously. 

 That it's an ability that is there within the brain/body complex.  For instance, there's an example of the American composer Aaron Copland.  He suffered from Alzheimer's, and towards the end of his days he, if you left him at the, you know, at some street corner, he wouldn't know where he was.  Put him in front of his orchestra.  He could conduct his, you know, his signature orchestral suite, the Appalachian Spring.  I mean that memory, that ability of what he was, was there in his brain/body complex, but it was not open for conscious recall.  So there is something about our narrative being embodied.  It's basically part of who we are.  If you learn to ride a bicycle when you were four, now that is also part of your story even though you may not tell someone, Oh, I can ride a bicycle.  Of course you can tell someone, I can ride a bicycle. 

 But, actually, there might come a time when we're unable to tell someone, I can ride a bicycle, but you could ride a bicycle.  So, in some sense, that ability is embodied, and it's still part of your narrative So, again, Alzheimer's is challenging philosophers and neuroscientists about the nature of the self.  It's not purely a cognitive narrative self.  It has embodied elements to it, and it's not at all clear if both the embodied and cognitive narrative aspects of ourselves go away.  Whether there is still someone or something still left experiencing various perceptions.  So, this brings us to, like we just mentioned the bodily self earlier a little bit.  This experience of just being a body.  Again, we take this for granted.  We take the experience of being a body for granted.  If you were to look at your arms and limbs or just think about your arms and limbs right now, you would have no doubt that they are yours. 

 Again, this is, you know, completely natural.  But it turns out that there are situations in which the perception of your body can be altered.  And most of you will be familiar with the notion of phantom limbs.  If somebody has had an amputation, for instance, because of an accident or an injury or infection, a lot of people after an amputation will continue to feel the presence of their limb.  And these are called phantom limbs.  And some of them will even feel pain in this nonexistent limb, and that pain is called phantom pain.  Now, it's very, very clear in that context, and this is indisputable.  This is something that's been shown over and over again, and you can talk to people who have had amputations and many of them will tell you that, at least for a certain amount of time after the amputation, they continued to feel the limb as if it exists.  And for some, that perception continues long after the amputation.  It's very clear that what they're perceiving is not the physical limb because the physical limb is gone. 

 What are they perceiving? It turns out that one neuroscientific explanation for what might be happening is that the brain actually creates maps of our own body.  In order for the brain to control the body, which is the brain's primary task is to basically make sure that the body is fit for survival, it creates maps, various kinds of maps of the body.  And what we perceive as our body is actually the information content in those maps.  So when you've had an amputation, the physical limb is gone, but somehow the map in the brain has not got reorganized and you continue feeling that limb because that information persists in your brain.  So this is one way of showing that your bodily self is actually something not really that solid.  It's basically information in your brain that needs to be kept up to date with the actual physical body.  And this condition that I write about, body integrity identity disorder, is the opposite of phantom limbs.  So, phantom limbs, one neuropsychologist called it animation without incarnation, where, basically, the physical limb is not there, it's not incarnated, but it's animated in your mind because you can feel the limb.  BIID is the opposite, where it's incarnation without animation.  Where your limb is there, it's fine, it's physiologically healthy and there's nothing wrong with it in any normal sense of the word, but for the person experiencing this condition, they will feel as if that limb is not theirs. 

 So, in some sense, something about the map of the information in your brain about your limb is mismatched with your actual physical body part.  Now, what, from the point of view of trying to understand the self, what this forces us to ask is, "Am I my body parts?" Think about it, right? Here is a condition in which there is an I, a person who can say, "I don't feel like this hand is mine." Similarly, we can have another person saying, "I feel like this hand is mine." There is still an I.  There is still an I behind both those statements making this, you know, making a claim about some experience of being a self.  Now, what this tells you is that the I that is experiencing either ownership of a body part or the non-ownership of a body part is still something different from the body parts.  So you can almost say, just like the poem I showed you, "I'm not my body, I'm not my mind, I'm not my intellect." This is saying, "I," whatever that I is, we don't know that yet, "I am not my body parts." That I is capable of experiencing even non-ownership or ownership of body parts.  Similarly, when we looked at Alzheimer's, you can argue that I am not my narrative because, like someone with middle stage Alzheimer's, before Alzheimer's struck that unfortunate person, he or she would have said, "I am my narrative." But during the course of the disease, suddenly the same person can be a scrambled narrative.  There is an I.  They're still experiencing a narrative that is scrambled, and potentially experiencing a narrative that is completely gone.  We don't know the answer to that yet because we can't talk to people who have end stage Alzheimer's and get clear answers about what it must be like because the condition is so debilitating.  But, again, it kind of tells you that the I that experiences being a narrative or not being a narrative is slightly different from the narrative itself. 

 Similarly, the I here is different from the body parts.  There is still an I.   And I'll have to rush through the various conditions here, but just to give you an idea that each of these conditions changes something about our sense of self.  We can start asking similar questions.  Am I my thoughts? Am I the agent of my actions? So in schizophrenia, for instance, people can experience having thoughts in their heads that don't feel like their own.  Obviously it's their own thoughts, but it feels like it's not their own.  And they can feel like they're not the agents of their actions.  So if I were to lift this bottle of water, I have an implicit sensation that I am lifting this bottle of water.  And if you were unfortunately suffering from schizophrenia, you may lift the bottle of water and you may feel that, oh, this is not me doing it.  So it's basically telling you that even the sense of agency that you have, that I am the agent of my actions, which, again, we take for granted as being part of myself, is slightly different from the I. 

 There is an I that can experience either being the agent of an action or there is an I that can experience not being the agent of an action.  Who or what is that I? It's the same thing for thoughts.  We all have thoughts in our heads, and, again, it's an unquestioned feeling we have that they are our thoughts.  Each one of us thinks something inside and feels like it's my thought.  What about the situation where you can have a thought in your head and it feels like it's not mine? Again, there is an I that experiences both feeling like a thought is mine and a thought is not mine.  So I am not my thoughts in that context, in that way of analyzing what the I is.  And you can go on like this.  Depersonalization disorder estranges people from their own emotions, from their own bodily self.  So they feel their own body states and their own emotions much less vividly and feel a certain kind of distance from those things.  So, again, depersonalization disorder is telling us that I, again I'm not saying what that I is, it says whatever that I is, it's not emotions because the I here is just a subject of an experience, whatever that experience might be. 

 Sometimes experiences are feeling all your emotions really vividly, and sometimes, as in the case of depersonalization, it is being disconnected from those emotions.  But that I still persists.  What is that I? Autism, again unfortunately a lot of us now will be familiar with people who are suffering from autism, especially very young children, and in its serious form can be very debilitating.  One of the things that happens in autism is children with autism are unable to relate socially really well with other children.  And philosophers also, again, have long argued, not all but some, have argued that the experience of being a self is fundamentally a social phenomenon.  That if you interact with others and if you have relationships with others, it's the social self that is at the core of being an I.  I think autism challenges that because, you know, it would be very hard for a parent to look at their child who has autism and who is unfortunately unable to relate socially and say, Oh, there is no self there.  Of course there is a self.  It's just a slightly different way of experiencing social reality.  So there is still an I that is experiencing either social relatedness or experiencing or is having difficulty relating socially. 

 So whatever the social self is, there is still an I experiencing it.  Whether it's, you know, what would be called neurotypical or whether it's a child with autism.  So, who or what is that I? Again the question persists.  Am I my body? We just talked about body parts, but you can ask the same question about your entire body.  Now, all of us right now hopefully are having an in-body experience, which means we are all here in our body.  But when you have an out-of-body experience, you can have something called a doppelganger effect, where you have, and these are not paranormal experiences.  Science has very clearly shown that these are things that are happening because of the way our brains are misfiring or something is going organically wrong with the way the brain is integrating information.  But you can have a doppelganger experience where you can see a duplicate of your own self in front of you and interact with that self.  So, normally, what does in-body mean? In-body means I feel like I am, like I mentioned earlier, I occupy a certain volume of space that is my body.  We all have that feeling. 

 I have a sense of ownership about my own body.  You know, again, it's implicit. It's unquestioned.  I feel like this body is mine, and I also have a perspective.  I am looking out at the world and having a sense that everything that I'm perceiving is from behind my head and that it's all happening to me.  And that is the experience of being in-body.  It turns out when you have an out-of-body experience aspects of these various traits get changed.  So in a classic out-of-body experience you can have the sensation that you, whatever that I is, has left the body and is looking down at the body.  The body appears lifeless, on the bed, and someone will say, I am looking down at my body from the ceiling.  This has been replicated in, you know, in labs.  You can stimulate certain parts of the brain and recreate these experiences. 

 So it's not paranormal.  It's not like something is really leaving your body.  It's, basically, some kind of integration that the brain has to do.  You know, if you think about what the brain is doing, it's collecting sensations from outside the body.  So there's sight, sound, all the five senses that are giving the brain information.  There's also a lot of information coming to the brain from within the body.  From our viscera, about the temperature of the body, about blood pressure, all sorts of things.  And all of those things the brain has to integrate and somehow create this experience of being in-body.  And if you mess with that experience, and you can do that in the lab, you will create variations of these out-of-body experiences.  So, again, by looking at what happens when you're out-of-body, you can start understanding how the brain might create the experience of being in-body. 

  Ecstatic epilepsy, this is one form of epilepsy which, if people are suffering only from this kind of epilepsy, they will most likely not go to the doctor because it's such a pleasant experience.  It's called ecstatic epilepsy because they have feelings of bliss and mental well being when the seizure is happening.  They have a very heightened sense of their own body and the environment around them.  They have a feeling that time is slowing down.  The seizure might last one or two seconds, but it feels to them like an hour has gone by.  They have no sense of time.  They have a very strong sense of certainty about everything in the room.  I remember one person I talked to who used to have these seizures, he at that time was a student in Kalamazoo, and he said when the seizure happened everything about Kalamazoo seemed so perfect.  And I knew because I lived in Kalamazoo that it couldn't be so.  (laughter) But when the seizure was happening, he was, it was like divine order. 

  And also, paradoxically, they have a sensation of being one with something larger, some boundary between their self and the outside has blurred, even though they're feeling their own body and the environment very, very vividly.  So ecstatic epilepsy is a condition that actually also tells us a lot about how the brain creates our sense of bodily self.  The feeling we all have of being a body, sensing our body, our emotional state.  So, you can see that by looking at the way in which the self gets disturbed in these conditions, you actually start learning a lot about how we are what we are.  I finally want to come to the most intriguing condition, which is called Cotard syndrome.  Now, again, just like we all have an implicit feeling that are in-body, that we right now are in our bodies, that we own our bodies, etc, I hope we all feel that we exist.  None of us, hopefully, will stand up here and say, "I don't exist." But as it happens, there is a condition, which is called Cotard syndrome, where the primary symptom is the person saying, "I am dead," or "I don't exist." It's obviously a hallucination.  It's a delusion, but it's a delusion that you cannot convincingly argue with them about.  They are convinced that they don't exist.  Now, and there are studies beginning to happen that are telling us about why this delusion might come about. 

 But, basically, by studying something like Cotard syndrome, which is so stark, I mean, here's an obviously alive individual functioning in every sense of the word as an alive person would.  Of course, they are depressed and they have psychiatric problems, but you would not say that they don't exist.  But the person will insist that he or she is dead.  They will even do things like plan their own funeral, or there's one person I write about who used to spend time in graveyards because he felt more akin to people who were dead than he felt with people who were alive.  And there's also a very sweet anecdote about him.  When he was put in the brain scanner to figure out what was happening in his brain, he came out of the scanner and the PhD student who was working with him at the time in Belgium, she said, "Are you alive and kicking?" And he said, "Kicking." He would not accept that he was alive.   And, again, this challenges philosophers.  You know, here is, again, a situation where you can say, "I exist," or "I don't exist." So, in some sense, existence and nonexistence just become properties of the self.  The self is still something even more basic.  There is an I that can claim to exist, or there is an I that can claim not to exist. 

 What is that I? And that, in a sense, is what philosophers are worried about.  So, essentially, what philosophers are struggling to explain, what neuroscientists are struggling to explain is, where does this sense of an I come from? By I, I just mean the sense of being the subject of an experience.  It doesn't matter what that experience is.  It could be the experience of existing.  It could be the experience of not existing.  It could be the experience of having a narrative.  It could be the experience of not having a narrative.  There is an I that can experience just about anything.  What is that I? How does the brain produce that, if indeed it is the brain producing it? How does it come about? So, when you read philosophers arguing about the self, whether there is a self or no self and whether the self is an illusion or not, this is what they're arguing about.  They're arguing about whether the I is something that is just a feeling that appears because of all the other things the brain is doing or because there is something in the brain that actually is responsible for generating this I, and then everything else happens to that I. 

  And bundled here is like I pointed out earlier, David Hume, a lot of the Buddhist philosophy, will fall under this notion that there is no I.  That the I is just something appears to be so because of all the perceptions that we are having.  You take away all those perceptions and it all falls apart and there is no I at the center of it.  But there are others who will disagree.  There are self theorists who will say, no, it's impossible to have this kind of unity of experience if there wasn't something that the brain and body were doing together in order to create a very, very minimal self to which everything else can be referred, to which becomes the subject of all your experiences.  And then there are others who will argue that the self, the subject of an experience, is nothing but consciousness itself.  And there we hit a wall.  No one knows what, you know, how to, you know, what consciousness is.  They have trouble defining what consciousness is.  Neuroscientists debate among themselves whether science will ever adequately explain the nature of consciousness. 

 Philosophers disagree.  So it's a minefield, but it's interesting that even the question of the self eventually comes down somewhere to saying we need to understand consciousness in order to say what that I is.  And so for all the talk you will hear about illusions and whether there's a self or no self, I think it's fair to say that the debate is still open.  That there is something that is still unexplained, and that is the nature of the I.  And I'll leave you there for now.   That's the book.  (applause)