(static cracking)
(wind swooshing) (bells chiming)
(chimes humming) - Thank you very much, Lisa. And thank you all for being here. I was going to say this evening, but I realized it's
not necessarily evening for all of you. So as you just heard,
I'm publishing a book. In fact, it's released
today in the United Kingdom, in a couple of weeks in the United States, with the same title as my talk, "The Hidden Spring: A Journey to the Source of Consciousness." Hopefully when I've
finished in an hour's time what I'm going to present to you, you will understand why
the book has this title. The book is of course about consciousness. And I'm quoting here what
the physicist Paul Davies recently wrote about consciousness. But I could have found
100 scientists saying basically the same thing. Davies says, "Among life's
many baffling properties, the phenomenon of consciousness leaps out as this especially striking. Its origin is arguably the hardest problem facing science today and the only one that
remains almost impenetrable even after two and a half
millennia of deliberation. Consciousness is the number one problem of science, of existence even." So our topic tonight is not a small one. It is widely regarded as the number one
problem of science today. So my book is about this
problem, but this is a lecture. And of course I can't begin to cover all the complexities that require a book-length treatment. So what I'm gonna say tonight is sort of extracting things
down to their essence, I'm going to simplify. And I'm gonna simplify by focusing on just one strand, although it is a sort of a red thread running through the book, one strand of the argument. And I'll state that argument upfront, it is that we have made so
little progress in terms of solving the problem that
Paul Davies identifies here, because we've been looking
in the wrong place. We've been looking for the explanation of how and why consciousness
arises in the cerebral cortex, the longstanding assumed
seat of consciousness. And I'm going to argue that we
should be looking elsewhere. We should be looking in a
far more primitive structure, the brainstem, in particular, the reticular activating system at the core of the brainstem. And not at these higher
cognitive functions that are performed by the cortex and, in
particular, by the human cortex, but rather at far more basic functions of the kind that are performed in the brainstem,
specifically raw feelings. I'm going to argue that raw feelings are the fundamental form of consciousness in all sorts of ways. And that if we shift our attention from higher cognition to
lower as it were feelings, the hard problem becomes less hard. In order to escape the risk of overly abstract ideas, I thought I would tell my story via a series of cases, some clinical case histories. I've lined up six for you. And I hope I get through all
six of them because as I say, I have only an hour, so let's
hope I get through them all, but at least it'll give you some flavor of the lived experience
of patients with disorders of consciousness who have been so helpful to me over the years in terms of my efforts
to unravel this problem. But let's start in the obvious place. I'm going to read you now the formulation of the hard problem by David Chalmers. In a paper in 1995, he coined that term and
this is what he wrote, "It is undeniable that some organisms are
subject of experience. But the question of how
it is that these systems or subjects of experience is perplexing. Why is it that when our
cognitive systems engage in visual and auditory
information processing, we have visual or auditory experience: the quality of deep blue,
the sensation of middle C? How can we explain, there
is something it's like to entertain a mental mage
or experience an emotion. It's widely agreed that experience arises from a physical basis, but
we have no good explanation of how and why it so arises." Now this is the way
the Chalmers formulated the hard problem. But of course, this is not a
new problem, as David said. It's something we've been
pondering for millennia. But in particular, I've
emphasized this phrase, something it is like, in order to make a link back to another philosopher, Tom Nagel, who wrote in 1974, "An organism has conscious mental states if and only if there is
something that it is like to be that organism, something it's like for the organism." And later in the paper,
that same paper he wrote, If we acknowledge that a physical theory of mind must account for the subjective
character of experience, we must admit that no presently available
conception gives us a clue about how this could be done. So my aim this evening in this brief talk is to give you a clue about
how this could be done. I told you I'm going to, well,
let me, first of all, sorry. I see what I have on the screen here is, I wanted to state as
succinctly as problem, as possible what this problem
is that I'm addressing. And you can think as I go along whether or not I am
answering this question. This is the hard problem. Why and how is there something
it's like to be an organism, something it's like for the organism? Now what I started to say is I told you I'm going to address this via
a series of cases in order to not get too lost in abstractions. Here's our first case. This is the case. He is, in fact, my brother. This photograph was taken
when he was two and a half, just short of three years old. And I, as you can see, was a baby. We were born in a small village and for all sorts of reasons,
we were rather isolated. So we were best of friends. And we got on famously. One day, four and a bit years after this photograph was taken, my parents were yachting and my brother climbed up
onto the clubhouse roof while I was waiting in the
waters of the lake below. And he tripped and he fell three stories and landed on his head on the paving stones
below, fractured his skull, and sustained an intracerebral bleed. He was flown by helicopter to a hospital in Cape town called Groote Schuur, to the neurosurgery
department where amazingly, but not entirely coincidentally
where I work today. That sort of hemorrhage is a
life-threatening emergency. But fortunately, in my brother's case, the bleeding stopped and the hemorrhage, the hematoma reabsorbed and he survived. And a few weeks later,
he was flown back home. He looked exactly the
same as he had before, apart from the fact that he had to wear a helmet to protect his fractured skull. But despite the appearance being the same, he was not the same. As a person, he was utterly different. And you can imagine to me as a four and a half year old, how uncanny, this is Lee. He looks Lee, but he isn't Lee. It was of course a terrible tragedy for him and for my family. For me personally, it
was extremely disturbing, especially for, in the way
that I've just described. I couldn't get my head around the fact that he was so changed. And so in this way, I was confronted, I
think, a little earlier than most of us are with this fact that we
ourselves are subjective beings, our personalities, our minds, are somehow also just a bodily organ. And if that organ is damaged then we're changed. And by implication, what
happened to my brother could have happened to me, could have happened to any one of us. If our brains were damaged in the way that his was, the hematoma reabsorbed
but it leaves damage, and also there's these
things called axonal shearing from the kind of injury that he had. If this were to happen to any one of us, we would not be ourselves. We would be somebody else. And by further implication, when our brains die,
we literally disappear. So this is the gravity of the problem that we are talking about. It wasn't obviously at the age of four, I didn't decide, okay, in
order to solve this problem. I better become a neuroscientist, but I have no doubt that those
early childhood experiences are what drove me to study neuroscience. And in particular, to be
interested in that branch of neuroscience that we
call neuropsychology. In other words, how mental functions
relate to brain functions. When I went to a university, which was in the, to study this, which was in the early 1980s, I was however quickly disabused of the idea that studying neuropsychology would provide the answers I was looking for as to how does it happen? This thing that Davies was talking about, that Chalmers was talking about, how does it happen that out of, how can it possibly be that
a physical organ is me? How am I produced by these
physiological processes in these anatomical structures? But this is not what I was taught. What I was taught rather
was how the cortex, and I emphasize here cortex, because in the 1980s, neuropsychology basically was the study of higher cortical functions. And neurologists study
the brainstem functions, those have to do with the body. Neuropsychologists study
cortical functions, they have to do with the mind. And I was taught how visual
information is processed in this part of the cortex and somatosensory processes here and auditory processes there. But when I asked my lecturers where does all of this information, where am I in the processing
of all this information? Where's the subject that
receives the visual and auditory and somatosensory and whatnot information? And I was kindly advised by my professors not to
ask questions like that. Those are not proper scientific questions. And they're bad for your career. But I wasn't studying this, because I was interested
in building a career. I really needed to
understand how this works. And so when I was taught, as I'm showing in the slide
on the screen at the moment, how visual information processing occurs in the visual cortex, and how incredibly elaborate all these different component processes are, how we go from the initial image in V1 to these various processing
streams whereby in, in one of them, you recognize color
and movement and faces. And another, if you're a human being, you're able to recognize letters and words and read. All of these things and
how ultimately all of this official information is encoded into the hippocampus
into long-term memory. All of these functional mechanisms were incredibly interesting, but the question, the problem for me was, visual information processing of this kind can be done
by your mobile phone. And in fact, what I have
on the screen for you now is not that different
from a circuit diagram, which describes the sorts
of information processing that your mobile phone does, performs. Your mobile phone can recognize faces, as you might've noticed when you're taking a photograph
and the way that it sifts through the stored images. It classifies them. These are faces. These are places, et cetera. Exactly the same sort of thing as I was being taught
about how our brains work. But the sentient subject who
receives this information, what it is like to see was
not a respectable question. It wasn't addressed at all. Around that time, I read this book by Oliver Sacks
called "A Leg to Stand On." It was before he became
so famous with his book, "The Man Who Mistook His Wife for a Hat." In this book, "A Leg to Stand On" in 1984, he wrote, Neuropsychology,
like classical neurology, aims be entirely objective, and its great power, its
advances, come from just this. But a living creature and
especially a human being, is first and last active, a subject, not an object. It's precisely the subject, the living eye which is being excluded. Neuropsychology is admirable but it excludes the psyche. It excludes the experiencing
active, living I." So that sentence,
"Neuropsychology is admirable, but it excludes the psyche," captured exactly my dismay and frustration with my field. Such was how things stood in the 1980s. And I think that this
has a great deal to do with why David Chalmers
formulated the hard problem in the way that he did. I'm now going to read
you a further passage from his book in which he clarifies that this hard problem pivots
on the question of function, on the function of visual
experience, for example. Let me read it to you, "The easy problems are easy, precisely because they
concern the explanation of cognitive abilities and functions. To explain a cognitive function, we need only specify a mechanism that can perform the function. The methods of cognitive science are well-suited for
this sort of explanation and so we're well-suited to the easy problems of consciousness. By contrast, the hard problem is hard, precisely because it
is not a problem about the performance of functions. The problem persists
even when the performance of all the relevant
functions is explained. What makes a hard problem
hard and almost unique is that it goes beyond problems about the performance of functions. To see this, note that even when we've explained the performance
of all the cognitive and behavioral functions in
the vicinity of experience, there may still remain a
further unanswered question: why is the performance of these functions
accompanied by experience? A simple explanation of the functions leaves
this question open. Why doesn't all this
information processing go on in the dark, free of any inner feel?" Just to make clear the gravity of the problem that Chalmers is identifying here, I want to tell you briefly about what another philosopher
said on this point. This was Frank Jackson in in his celebrated knowledge argument. The story revolves around a visual neuroscientist named Mary. And I'm going to tell the story in a simplified form in
the interest of time. Mary knows everything
that there is to know about the functional mechanisms of vision, but she's blind. So although she knows
exactly how light waves are transduced by the photosensitive rods and cones of the retina and transmitted to the
lateral geniculate body and from there to the visual cortex and how all those processing
streams that I showed you in the earlier slide further, in specialized modules, process that information,
exactly what those neurons do, exactly what the functional mechanisms of the different processing streams are. Despite all of that, she knows nothing about
what it is like to see. And then, thank God, one day, the gift of sight is bestowed upon her. And for the first time in her life, she actually experiences that deep blue that Chalmers spoke of, the actual quality of visual experience: redness, blueness, movement,
form, contour, and so on. And Jackson's point is at that moment, she learned something
utterly new about vision. something which was not predicted, not explained at all by her functional, her understanding of
the physical mechanisms whereby visual information is processed. And the point is that
because those mechanisms can be absolutely understood
without there being any, not only any need to understand what visual experience is
like, but also no bridge. It doesn't predict that there will have to be visual experience. And so this new thing, this new qualitative, experiential thing that Mary becomes acquainted with is not at all contained
within the knowledge, that's why it's called
the knowledge argument, that she had of the functional
mechanisms of vision. And the alarming conclusion that people like Jackson and Nagel
and Chalmers come to in consequence is that conscious experience, the actual something it is likeness of seeing, exists in some sort of parallel universe, some other dimension, some place other than
the physical universe in which causal mechanisms explain how one thing produces another. So this is what Chalmers is
talking about when he says, why is the performance of these functions
accompanied by experience? Why doesn't all this
information processing go on in the dark, free of any inner feel? The information processing accounts, the mechanistic functionalists accounts of visual processing in the cortex. And I'm using vision as my model example because that's what we do
in cognitive neuroscience when it comes to trying to understand the mechanisms of consciousness. That's where we've been looking, on the assumption that if we can, if we can isolate the mechanism
of visual consciousness, then we can generalize
from there to other forms of consciousness and explain
consciousness as a whole. Chalmers's point is that Mary who knew
everything there was to know about the functional mechanisms of visual information
processing knew nothing at all about what it is like to see. This seems to be an entirely
different order of things. So how are we to make sense of this? By the 1990s, John Kihlstrom was able to write
an article with this title. It's a review of the literature on unconscious, visual
and other perceptual, and other cognitive cortical mechanisms. The title says it all, "Perception Without Awareness
of What Is Perceived, Learning Without Awareness
of What Is Learned." The literature, the
research literature reviewed in this paper shows, in a nutshell, that you
can perceive visually, and in other ways, you can process this sort of information without knowing that you're doing so. You don't seem to have to know that you're doing so. The cortex and the brain as
a whole can process visual and other perceptual stimuli and act upon those stimuli without any awareness
that they've done so. The same applies to learning. You can learn things and remember things and they will influence what you do in the future without having any knowledge that you've learned those things and that you're remembering things. All of this can go on automatically, to paraphrase
Chalmers, in the dark. Just to give you some sense
of the kinds of evidence that Kihlstrom drew upon in
writing this review article and coming to the conclusions, which are sort of alluded to in the title, in one study research
participants are shown in the vajra paradigm called, an instrument called the tachistoscope, which flashes visual information so briefly for so few milliseconds that you don't even know
you've seen anything at all, let alone what you've seen. In this experiment, the participants were shown two faces. Face A, under which was
written the word rapist and face B, under which was
written the word philanthropist. Now remember they didn't know
they'd seen anything at all, let alone that they'd seen
a face and read a word. After the tachistoscopic
phase of the experiment, they're then shown supraliminally those same two photographs and asked which of the
two faces they prefer, which of the two people they prefer. And with a very high degree
of statistical significance, the research participants choose face B. When asked why are you choosing
this face over the other? They say, I don't know, because of course they
don't know consciously why they're doing so. They say it's just intuition or my gut feeling. I just prefer this chap. Now we know why they did it. They did it because of the words that were
associated with those faces. And that's precisely the point: that this kind of cognitive process, this higher visual cortical, because let me be clear that recognizing faces is a
uniquely cortical function, and indeed reading with comprehension is a uniquely human cortical function. So these sorts of functions can go on perfectly well without awareness. And this is the essence in a manner of speaking of what Chalmers is saying. He's saying, these things can go on in the dark, and that begs the
question that Chalmers asks, why doesn't it do so? Why do we have to be aware of these things at all? And the provisional conclusion
that I now want to state is that it's because they don't. Visual cortical processes
and all cortical processes and cognitive processes are
not intrinsically conscious as Kihlstrom's review shows. Therefore, it's no surprise that if we have focused our research efforts on trying to understand the
brain basis of consciousness, the physical mechanisms of consciousness, by looking at functions which are not inherently
intrinsically conscious, which can work just as
well without consciousness, then we're looking in the wrong place. If you remember my introductory remarks, this is the red thread
that's going to run through what I'm going to say to you tonight. So let's move on to my next case. I told you that when I was a student and I was taught about how
these different streams of information coming
from our sensory organs and projected onto our cortex
produce visual consciousness, auditory consciousness, et cetera. And I asked my professors,
"But where am I? Where is the subject who
receives all this information?" By the 1990s, 10 years after
I asked that silly question, which was considered silly,
it's a naive question, but many of the most naive questions are the most important questions, by the 1990s, neuropsychology was asking
those questions itself. And the answers that it came to was that visual and auditory and
somatosensory information, the sort of raw phenomenal
consciousness is not the main thing about subjectivity. It's where it all comes together, that question that I'd asked, where does it all come together? And one of the main answers
was it all comes together here in the prefrontal lobes. So for example, Bernard
Baars and Stanislav Kehaene were saying that there's
a global workspace, a sort of integrating of all of these different
information streams here. And this is where the
subject of the mind is, that remember consciousness, the global workspace in the sense of not just information
processing streams coming from our sensory end organs but rather the subject of
the mind that receives them. So I'm going to, remember, I'm just giving you an
impressionistic account in this brief lecture. I'm going to ask you, as scientists or people
who understand science, if there's a theoretical
claim that this is, this part of the brain is where
consciousness is generated in the sense of a subjective
sentient being of the mind, then if this part of the brain is damaged, then that function should be lost. So somebody who has no
prefrontal cortex should have no subjectivity in the sense that we are talking about here. No person who receives
all this information and knows, this is my vision. I am a sentient being, the sort of agent, or I, the active me, that Oliver Sacks was talking about. Damage to this part of the brain, complete damage to this part of the brain should completely remove the
thing that we are looking for. So I will now briefly describe to you a patient of mine
who I'm calling Patient W who due too complex pathology, basically a subarachnoid hemorrhage in the anterior communicating artery which needed to be operated on and the operation didn't go that well. And then there were sepsis. And then it wasn't
recognized early enough, et cetera, et cetera. Basically, after a series of operations, he ended up like this with
absolutely no prefrontal lobes. So there's the prefrontal
lobes. He doesn't have any. Here you see it again. But fortunately he has a little sliver of cortex here, language cortex, which enables him to
describe his experience. So I explained to Patient W that according to my colleagues,
he should lack a self. He should lack an overarching sense of sentient, receiving
this perceptual information and knowing it's me who's seeing these things,
that me should be missing. I asked him, "Is that missing." He said, "No, not at all." So I said, "Well, then bear with me. I'm gonna ask you a series of questions whereby I can illustrate, demonstrate to my colleagues
that they're wrong." I said to him, "Are you consciously
aware of your thoughts?" He said, "Yes, of course I am." I said, "In order to confirm that, I'm going to ask you to solve a problem that will require
you to consciously picture a situation in your mind." He says, "Okay." I say, "Imagine that you have
two dogs and one chicken." He says, "Okay." I said, "Do you see them
in your mind's eye?" He says, "Yes." So I say, "Now tell me how
many legs do you see in total?" You get the point that
if he's there looking at this visual information
that he's conjured up in his mind's eye, he should
be able to count two dogs, four plus four, one
chicken, two, turtles, 10. And that would show that
there's somebody there looking at the visual information. So you can imagine my
disappointment when I say to him, "Now telling me how
many legs do you see in total?" And he said, "Eight." And I said, "Eight?" And then he said, "Yes,
the dogs ate the chicken." Now that's not the best joke in the world, but it shows that
there's somebody at home. There's Mr. W was there thinking, looking at this information and even been able to take
this additional humorous step of imagining that the
dogs had ate the chicken. So the idea that it's the sentient being of the mind resides in
the prefrontal cortex, I don't believe it. And of course, it's not
based only on this case. I'm using that to illustrate a point. The other major theory
in cognitive neuroscience as to where the subject of the mind exists in the cortex is associated
with the name of Bud Craig. And he identifies the insula as the critical part of the cortex. The insular is not like
the prefrontal cortex where all the different information processing streams converge from your various senses, leading to your capacity
to make decisions about what are you going to do about it, but rather it's where the
visceral internal information from the vegetative body is transmitted to the cortex and integrated with this extra set of information. So very, very mainstream
theory that this is where the self resides in the cortex. So let's see what happens
if this part of the cortex is damaged as it was in
this patient, Patient B, a patient of Damasio's. Like I did with my patient W, Damasio interviews his
patient and asks him if he has a self, because the prediction
arising from Craig's theory is that he should lack such a thing. Damasio says, "Do you have," this is a dialogue, a conversation which
hasn't been published, but an article on this
case has been published. "Do you have a sense
of self?" Says Damasio. Patient says, "Yes, I do." "What if I told you that
you weren't here right now?" Patient says, "I'd say
you've gone blind and deaf." Damasio says, "Do you think that other people can
control your thoughts?" He says, "No." "And why do you think
that's not possible?" He says, "You control
your own mind, hopefully." Damasio said, "What if I were to tell you that your mind was the
mind of somebody else?" Patients says, "When was the transplant, I mean, the brain transplant?" Damasio, "What if I were to tell you that I know you better
than you know yourself?" Patient says, "I would
think you're wrong." Damasio says, "What if I were to tell you that you're aware that I'm aware?" He says, "I would say you're right." Damasio, "You're are aware that I'm aware? Patient, "I'm aware that
you're aware that I'm aware." Please note all these references to I, this is the very thing
that's supposed to be missing in such patients. So clearly the sentient being of the mind is neither in the prefrontal cortex, nor in the insular cortex, but these patients have some cortex left. What about a patient who
has absolutely no cortex? What if the cortex as a
whole word to be removed? Surely this would remove the sentient subjectivity
that we are seeking to explain with our cortical theory of consciousness. Well, here's a patient
three years old, this one, with absolutely no cortex. This is a condition called hydranencephaly where the patient is born with the brainstem and a cerebellum which hangs off the back of the brainstem, but no forebrain at all. Is she conscious? Yes, she is. Here she is. She's awake. She goes to sleep at night. She wakes up in the morning. Clearly she's conscious, but much more importantly, look at this. This is her reaction to her baby brother
being placed on her lap. She responds emotionally
to this experience. So it's not only that she's awake. It's not some sort of blank wakefulness, but a reactive mind with
feelings and content. It's not, it cannot possibly be representational cognition of the kind that the cortex performs, because she doesn't have any cortex She has only a brainstem. And yet she's conscious
and her consciousness has a particular quality and it doesn't have anything
to do with what's streaming in from the outside consciously, because remember the brainstem only processes sensory
information unconsciously. This has got to do with
her subjective response to that information, even
though she has no cognitive clue what that information is actually about. It's a pure, raw feeling. And it's not just her. Most of these kids are like
that. Here's another patient. Tell me this patient isn't conscious and that there's nobody home. Bjorn Merker wrote a review
article about these patients, whom he studied a great many of them. And I'm not gonna read
you this long quotation, but you can see the words that I've emphasized in yellow. They have a wide range of emotions and most importantly of all, those emotional responses are
situationally appropriate. In other words, the patient shows laughter or irritability or fear in response to stimuli, which would evoke those same
sort of feelings in you and me. So this is a weighty piece of evidence that the
cortical theory is wrong. The parts of the cortex
that are supposed to be the centers for consciousness,
the integrative centers, where a sentient self comes about it, even just the little
smatterings of evidence that I've given you this evening show that this is not the case. And even in patients in whom
there is absolutely no cortex, there's evidence that
there is consciousness. Consciousness, not of the cognitive kind that we've been focusing
on in our attempts to solve the hard problem, but rather consciousness of
a far more rudimentary kind, basic, raw feelings of
the type that you saw these two little girls and other children like them with the same
condition able to express. But of course, how do we know, how do we know what it's like to be such, is there anything it's
like to be such a child? These are just behaviors. We can't be sure what
they're experiencing. But let's just slow down. Although I'm anxious about the time I keep on looking to my left,
which is where my clock is, and I see that I must speed up, but let's just make sure that I'm conveying this
really essential point. You can remove the cortex, the supposed it's seat of
consciousness in its entirety. And I say, remove, of
course, in these children, it's not removed experimentally, in experimental animals, it is removed, and we find exactly the same thing. They are conscious with their wake and they display a full range of emotional and situationally appropriate
emotional responses. By contrast, with that lesion evidence, now we look at the brainstem, if there's damage in these structures, these tiny structures in the
primitive brainstem called the reticular activating system, then the lights go out. So the lights do not go
out if there's no cortex, but if there's tiny lesions in the reticular activating
system of the brainstem as small as two cubic millimeters, Fischer and colleagues
recently published a article in which they studied numerous patients with brainstem strokes and showed that a two cubic millimeter lesion in the parabrachial region
is all that's required to totally obliterate consciousness. So what that shows is that
cortical consciousness is dependent upon brainstem consciousness. What's generated here in the
reticular activating system is a prerequisite for
cortical consciousness. And what is more, remember
that critical consciousness is not always present. In other words, the cortex is able to process information
without consciousness. So what makes it conscious is activation by this reticular activating system. Now that's not controversial
what I've just said to you. Where I'm making the argument, we're looking in the wrong place. This is not intrinsically conscious. This is the foundation of consciousness. Why don't we look there? And I've showed you in
those hydranencephalic girls that the people who only have
a brainstem have consciousness of a particular type, and that
is affective consciousness. So is this not this intrinsic prerequisite for all of the other
forms of consciousness? Is this not the place
that we should be looking if we're trying to find out what the functional mechanism
of consciousness is? So let me now go to my case 5. And the reason I'm doing this
is because I'm very much aware that in the case of these
kids with no cortex, you can't be sure that
they have consciousness, because they can't speak. The one function which certainly
is cortical is language. And my patient W was able to
describe his mental states because he had the
sliver of frontal cortex, which enables us to produce language. Those children didn't. So we don't know. They can't tell us what
they're experiencing. Just like our pet dogs and cats can't tell us what they experiencing. We sense that they're conscious. They respond emotionally. We have relationships with them. But we can't know for sure. So in science, in such a situation, what we have to do is
rely upon multiple lines of converging evidence, we
have to make predictions. On the hypothesis that the
brainstem produces consciousness on the lesion study suggests that that's where the consciousness comes from. And I'm saying it is a consciousness of a particular type, it's feeling, it's affective consciousness. Then using another method, for example, deep brain stimulation, if we stimulate those structures, those deep brainstem structures in patients who do have intact cortex and can tell us what they experience, we might predict that they would
experience intense affects. And that's exactly what happens. If you stimulate the substantia nigra, which is a mid brain part of the reticular activating system, this is what happens in a patient, 65 year old patient with Parkinson's disease. That's why the stimulator
was put into her brain. But a patient who'd never had any psychiatric pathology in her life, that within five seconds of the stimulator being switched on, that had actually gone deeper
than the intended site, the intended site was
not in the brainstem, it went a few millimeters too deep into the reticular activating
nucleus that I mentioned, and she, within five seconds,
she falls into a depression. "I'm falling down in my head. I no longer wish to live, to see anything, hear
anything, feel anything." When asked if she's in
pain, she says, "No, I'm fed up with life. I've had enough. I don't want to live anymore. I'm disgusted with life. Everything is useless,
always feeling worthless. I'm scared in this world." Please note this, "I don't
want to live anymore," a suicidal depression. When asked why she's so
sad, she says, "I'm tired. I want to hide in a corner. I'm crying over myself,
of course, I'm hopeless. Why am I bothering you?" After the stimulation, within 90 seconds, the depression disappears. The patient very bravely or generously agreed to do a
double-blind trial after that where Blomstedt stimulated either in the higher structure
that he had aimed for or in the reticulate structure
that he had struck accidentally without the patient knowing
where he was stimulating. And every time that he stimulated in the reticulate nucleus, she
fell into this deep despair. So this is a second line of evidence. You can actually
stimulate intense emotions by stimulating those deep
brainstem structures. Here's a third line of evidence, functional imaging, PET
imaging in this case. These are normal subjects
with intense emotional states. They are feeling intensely
sad, angry, happy, or fearful. The PET imaging shows where in the brain the activity is that's
generating this mental state. And in all of these cases it's in the brainstem. Sadness, anger, happiness, fear, look at what's going on in
the cortex, next to nothing. So it's absolutely
clear by this method too that the affects are
generated in the brainstem. One last line of evidence is psychopharmacology. Psychiatrists tinker with
the neuromodulatory chemicals that are sourced in these very same brainstem nuclei. So antidepressants increase serotonin, which is sourced in the raphe nuclei of the reticular activating system. Antipsychotics block dopamine, which is sourced in the
ventral tegmental area of the reticular activating system. Some antianxiety drugs
blocking noradrenaline which is sourced in the
locus coeruleus complex of the reticular activating system. If all that this system
did was woke you up or produced a background
level of consciousness, which is the standard
view of what this part of the brain is doing, this is why when you lesion it, you go into a coma. Then anesthetists might be interested in these brain structures and these brain chemicals. But, no, psychiatrists are. Psychiatrists, doctors for feelings, treating emotional disorders. Clearly these neuromodulators sourced in the reticular activating system have something fundamental
to do with feeling. So let me just sum up, I'm gonna tell you about another one of these neuromodulators in a few minutes if I get that far. But let me just sum up what I'm saying. I'm saying that the
evidence is very strong that the source of consciousness, remember the subtitle of my book, is this hidden spring deep in, in the reticular brainstem or structures, which are prerequisite for consciousness to occur. Think of the the forebrain or the cortex as a sort of a television set. And think of this as the power supply. The standard view is, well, of course, consciousness
happens in the cortex, like televisual program
transmission happens in the television set, it
has to have a power supply. It has to be plugged in at the
wall, but that doesn't mean that the source of television
is the power supply. But as you've just seen, if you tinker with this power supply, you change the program. You change the actual televisual content. It's not just a power supply. It is literally the font of consciousness. And because it's prerequisite
for these cortical forms of consciousness, the
cortex isn't conscious unless it's aroused by the brainstem. And because I've, as I've showed you, the brainstem is generating
not some power supply, but rather consciousness
with a particular content and quality, a particular feel, a particular something
that it is likeness, that means the foundational
elemental basic form of consciousness is feeling. And feeling is prerequisite for all other forms of consciousness. Sigmund Freud, the discoverer
of the unconscious, even Freud who was the
person who taught us that the bulk of our
cognition is unconscious, what we rediscovered a hundred years later in cognitive science, that the bulk of our
cognition is unconscious, even he said, "It's surely of the essence of an emotion that we
should be aware of it, that it should become
known to consciousness. Thus the possibility of the attribute of unconsciousness would
be completely excluded as far as emotions, feelings
and affects are concerned. Now I've emphasized the word feelings, because the words affect and emotion mean different
things to different people. Some people claim you can
have unconscious emotions. They don't agree with Freud. So I want to be clear that I'm talking about
this thing, feeling. You cannot have a feeling
that you do not feel. And this is not just a linguistic point. As I've just showed you,
the brainstem mechanisms that generate raw feeling, they generate consciousness itself. But I say again this, this thing that I'm calling feeling cannot be other than felt. If you don't feel it, it isn't a feeling. And what I'm saying therefore
is that unlike cortex, the processes of which,
the information processing of which is not intrinsically conscious, shouldn't we be looking to the brainstem, the processes of which are
intrinsically conscious, in fact, are the source of all consciousness, If we want to understand the
function of consciousness, then surely we need to understand
the function of feeling. David Chalmers, one more time, he says, "This is not to say that
experience has no function. Perhaps it'll turn out to play an important cognitive role," et cetera. And he ends up saying,
"There's no cognitive function, such that we can say in
advance that explanation of that function will
automatically explain experience." This is, you can see a
reiteration of what I said to you earlier. But please note, it's the word cognitive. If you change the word
cognitive to affective, does his, I mean, would he
ever even have said this? "There is no affective function such that we can say, in advance, that explanation of that function will automatically explain experience." I'm saying, in advance, that
an explanation of the function of feeling will automatically
explain why it feels like something, because that
is the function of feeling. I hope you can see why this
is an important red thread in the argument of my book. If we're wanting to
understand consciousness, we should be focusing
on its most basic form: the form which is intrinsically conscious, that is to say feeling, because feeling has to be felt. Unlike vision, unlike
hearing, unlike memory, unlike all forms of cognition, for the most part, they're unconscious, but feelings are always conscious
and they are prerequisite for the higher forms of consciousness. So if we understand the
function of feeling, then we understand the
function of consciousness. That's where we should be looking. I say again, there is every possibility that if you can explain the
function of feeling, then you'll know why you feel it. So what is the function of feeling? Well, it's an extended
form of homeostasis. Homeostasis, as many of you might know, is the basic mechanism
that keeps us alive. Living organisms, unlike inorganic matter, they don't dissipate. They don't just, if the ambient temperature is 10 degrees, then we just sort of become
10 degrees ourselves. If we did, we would die. So we can't dissipate. We can't equalize with our environments. We can't allow ourselves
to obey the second law of thermodynamics, which states
that in any natural process, entropy will always increase. Homeostasis resists entropy. We say, no, I can't equalize. I have to maintain a
particular temperature range. I have to stay between 36 1/2
and 37 1/2 degrees Celsius. And if I deviate from
that, it's a problem. It's a demand for work. And I have to perform
work to get myself back into the temperature range
that is viable for life. And I speak here of temperature range. This applies across a wide range of physiological parameters. So you have blood glucose levels, blood oxygen levels, hydration levels, sodium levels, et cetera, that you have to remain within. Otherwise you die. And you note the word prediction here. There are algorithms built
into our brains, which say, if you're getting too
hot, that's a problem. So you've got to do something
and what must you do? The algorithm says, well,
sweat, that'll cool you down. Pant, that will cool you down. That's the work that you have
to do to get yourself back into your viable range. So that's how homeostasis works. And I said, feeling is an
extended form of homeostasis. And that extended form is that when you deviate from
your expected states, from your viable states, it feels bad. The value system that underpins all life is that it is bad to
die and good to survive. So if you're moving in
the direction of death, of a physiological state which is incompatible
with life, it feels bad. That is the function of unpleasure. That is the meaning of
unpleasant feelings. It means this is bad for me. And conversely, performing
the work that gets you back into your viable state feels pleasurable. And this is how you know that you're heading in
the right direction. Why is this important? I told you that you have
to have predictions here, algorithms built into the system that tell the system what to do. Demand for work, I know what I've gotta do,
gotta pant, gotta perspire. That's the work, gets me back to my
required temperature range. But the enormous adaptive
advantage provided by feeling is that if you are in a situation for which you do not have
a predetermined prediction for which there is not a
phenotypic algorithm built into your brain, then the
feeling tells you here and now whether you're heading in the right direction or wrong. Let me take, let me give you an example. You're in a, respiratory
control is an automatic process. You don't need to be aware of your need for oxygen
in order to breathe. It just happens automatically. But if you're in a building that's on fire and carbon dioxide is filling the air, then suddenly respiratory
control becomes conscious and you feel this demand for work in the form of an acutely unpleasant state of mind called air hunger
or suffocation alarm. Now you're in a situation
you've never been in before. You can't possibly predict, you've never been in a burning building, let alone this particular one, and you can't possibly predict what to do. So that's a state of uncertainty with no predetermined predictions. And the way in which
you solve that problem is to feel your way through it. So if I go this way and my air hunger gets worse, that's bad. It feels bad. That means it's bad. If I go the other way and my air hunger reduces, that's good. That means I must go that way. So the oxygenation in the air is felt without there being
any preordained solution to this particular problem,
you feel your way through it. So feeling tells you how you're doing within this basic
biological frame of values, scale of values which is that it's good to survive and bad to die. And you feel what is increasing and decreasing your chances, your probabilistic chances of surviving by feeling the feelings. So that enables you to make choices. And this too, I cannot emphasize enough, choices have to be
grounded in a value system. Something has to be better
and something has to be worse, otherwise you have no
basis for making a choice. And feelings provide the value system which enables choice in
unpredicted novel situations. So you decide which way
to go on the basis of what feels good and what feels bad without any cognitive
knowledge as to what, that drives the cognition and you feel your way
into your cognition so that what you're perceiving
and what you're thinking, flavored, colored, driven by the feeling that determines which choices you make. That is the function of feeling. That is what feeling adds to
basic automatized homeostasis. Now I've just identified one of the two most essential
properties of affect, that is valence. It feels good or it feels bad. But I must add that it also
has a categorical quality. Each affect feels, so air hunger feels
different from sleepiness, feels different from the need to urinate, feels different from fear, feels different from separation distress, feels different from thirst. Each of these has a flavor, a categorical quality of their own, because you need to know
what need is being met or not being met. So the color coding or
flavoring, the qualification of these different affective needs is is why consciousness has quality. So consciousness, in its basic
form, is inherently valuative and it's inherently qualitative. And it does something. What does it do? It enables you to survive
in unpredicted situations which is an enormous adaptive advantage over creatures who do
not have this capacity. So we're coming, I notice I really have to end earlier than I would have liked, but we're coming to
the crux of the matter, which is that this is
the function of feeling. So remember the question I was asking, why and how is there something
it's like to be an organism, something it's like for an organism? Well, affect feeling
explains why it's something, why it has to feel like something, the feeling, the quality of it, and the category of it
is its very essence. It's what it does is to
bring to the awareness of the organism for the
organism, how it's doing in terms of its literal, literal potential to exist, to continue existing, its
most basic design principle, the design principle that
homeostasis embodies. And this extended form of homeostasis, bringing to the level of awareness by the organism of its state, as it's navigating uncertain environments, is the function of consciousness
in its most basic form. And going back to Chalmers's claim that if you explain the function, it doesn't explain why
it feels like something, I'm saying that doesn't
apply in the case of affect. And affect is generated in the brainstem which is the source of all consciousness, all consciousness is contingent or dependent upon brainstem consciousness. Now I'm going to end here so that there's time for questions. I just want to let you
know that in my book, I then go on, based on work I did with Karl Friston, to explain how that mechanism
works mechanistically. Homeostasis is not complicated. It can be reduced to laws. And if affect, feeling, is an extended form of homeostasis, it too can be reduced to laws. And these laws are explicated in the book and it explains
how feeling governs, how voluntary action and learning from experience works in the brain. I was going to tell you
there's one last case, but I don't have time. So I'll just flick through and tell you, read my book, please. This is a complicated topic. I can't begin to do it justice in a
short talk like this. So why is the performance of these functions
accompanied by experience? Why doesn't all this
information processing go on in the dark, free of any inner feel? I hope you can see why I
believe that when it comes to feelings, that they
can't go on in the dark. They can't go on without any inner feel. They're very functioned. They're very causal contribution within the physical economy. Bodily economy of the
living organism is to feel and the feeling is what has the functional causal consequences
that Chalmers felt was so badly missing when it comes
to perception and cognition. Although he didn't realize
that his argument applied only to perception and cognition. I am sorry I've had to rush at the end. And I want to remind you in, for that reason that I
said at the beginning, only that I was going to give you a clue. Please read my book, "The Hidden Spring," out today in Britain and in a couple of weeks in America. Thank you very much. I look forward to your questions.
Cool.
Side note I find it fascinating that other cultures think the "I" resides in other organs