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SPEAKER: The future of science is, of course, an immense subject. It can be dealt with as a general problem-- the growth or regression of science, the economics of science, big science versus little science, the future of biology, the future of space science, and so on.

I decided to devote my talk to one very special aspect of the frontier of science, hence the title, "The Brain-Mind Problem as a Frontier of Science." I asked the question in the first place, can we define the limits beyond which science may never go, the final limits of science, or should we try to do so?

I attempt to illustrate the way in which we may be able to overpass what have hitherto been regarded as limits in the very special field that has been central to my scientific life. And that gives rise to this problem of frontier. I, by the way, don't think that I am a nut out on a limb. There are many other distinguished people in the past and at the present time who are asking these same questions.

And then I am heartened by a brief quotation I will give from the speech of Dr. [? Cook ?] yesterday. He says, "But I must at once assert that a future of science in which its present remains static is no future at all. An essential quality of science is its dynamism, the continuing search for new knowledge of nature, for new insights, for new formulations of ever-increasing inclusiveness, precision, and elegance."

And so I attempt, then, with these challenges, to see how I can approach this problem of the brain-mind and the frontier of science. The distinguished physicist Weisskopf made a valuable distinction in his concept of the two frontiers of science. The internal frontier is a very broad area where the basic scientific principles are not in question, but where the phenomena are so complex that they are not yet understood and explained.

Nevertheless, they appear to be encompassable by the present range of scientific hypotheses and investigations at the atomic, molecular, geological, and biological level. The external frontier borders on those realms of nature that lie beyond presently understood principles. That's his important distinction-- realms which, according to Weisskopf, comprise the nuclear and subnuclear worlds.

However, I would suggest that even incomplete solutions of the brain-mind problem will entail such revolutionary changes in existing science that the external frontier is transgressed also there. On the contrary, Weisskopf adopts the popular parallelist philosophy on the brain-mind problem in his statement, "Brain research is currently one of the most important internal frontiers."

That really worried me. Difficult problems, like the nature of thinking and memory, are approached from two directions, through neurophysiological methods, studying the physics, chemistry, and biology of the nerve systems, and through psychological methods, studying the observed phenomena in the brain.

This research can be thought of as boring a tunnel from two sides, from the physiological and through the psychological sides. The two approaches have not yet met, but hopefully, they will. Well, I'm sorry to say that I think this is a complete misunderstanding of the problem, and I don't worry about that too much, because how can we expect physicists to follow us in all our detailed conceptual developments?

It's reciprocal. I can't follow them either, you know. It appears, from that statement, that all we need is more neurophysiology and more psychology, which is curiously defined as studying the observed phenomena in the brain. That, of course, no psychologist would stand for that, I think, Dr. [? Kendall. ?] Hence, the frontier is internal.

But I think this is a mistake. And to make my objection explicit, I will briefly introduce the three-world philosophy recently formulated by Popper. I think this is one of the really great advances in conceptual thought in our time. The three worlds comprise everything in existence and in experience. Now, I've got to try-- I should have a slide for this, but I'll try and draw it. World one will be over on this side. World two here and world three there, if it was on the screen.

World one is the world of physical objects and states. It comprises the whole cosmos of matter and energy, and all of biology, including human brains. That is the total material world. The total world of the materialists, shall we say, is world one.

Now, world two is the world of states of consciousness and subjective experiences. It comprises, in totality, our sensory perceptions and cognitive experiences, even to creative imagination at the highest level, together with the self or ego, which, for each of us, is the basis of our unity and consciousness and continuity as an experiencing being.

You know, you went to sleep last night, and you wake up this morning, you're still the same self, although you've been unconscious for hours. This is the experience through our whole lifetime. And we each recognize it for one another. That's the self. But besides that, as I say, there is all of the perceptual experiences and all of these other highly memory, imagination and so on.

World two-- that's the world of conscious experience, is in the middle-- is initially private to each of us. So it is subjective. But it can become objective when it is revealed to other selves by linguistic or artistic expression, or by gestures, which may be at all levels of subtlety. That's the human relationship. You talk to people. You just make gestures. You communicate. You criticize, and so on. Or you may make diagrams or art or poetry and so on. All kinds of ways we have of communicating our thoughts to others. And that is the whole basis of society.

Finally, world three is what Popper calls the world of objective knowledge. And this is something much misunderstood by people. It is the world of culture that was made by man and that reciprocally makes man in his own lifetime. Each man. It comprises the whole of culture and civilization-- most importantly, language. World three includes all the expressions of human creativity that have been preserved in coded form on world one objects, such as the paper and ink of books.

That's world one, paper and ink. But the ideas coded there are in world three. And when you ask the question, what is physics or what is chemistry, that is a world three object. The whole coded information and systematization that has been created by man and which is available as an ongoing experience to any of us who want to examine one or other aspect of science.

And so a whole of science is, in world three, being created by the thoughts of men in world two and expressed on objects, like with books and so on and diagrams and so on, in world one. You will see how comprehensive this three-world philosophy is. The creative efforts to give a scientific account of nature constitute one of the most important components of world three.

Brain research is thus a world three activity, but the object studied, namely, brains, lie entirely within world one. So I would agree with Weisskopf that brain research itself can be classified as involving an internal frontier of science. We have an immense ongoing operation in what we call neurobiology, or what you will there, with conventional scientific methods studying putting up hypotheses testing and so on in the ordinary material mode.

So that is an internal frontier of science. Terribly complicated. But one doesn't imagine that there are new principles involved. Immense complexity. And a challenge. When you think of when will science find all of the answers? The answer is [INAUDIBLE] never. You can believe this is so complicated, so beyond our imagination altogether. We only know the tiniest little fragments of what is involved in the operation and construction of a brain. And can a brain understand a brain, might be the question you could ask.

It is otherwise-- I think the question is wrong, by the way. It's not a brain that understands a brain. It's a mind that understands a brain. Never mind. It's brain if you like.

[LAUGHTER]

It is otherwise with the brain-mind problem, because this problem concerns interaction between two different worlds, the world one, which is the world of material states physics and all the rest of it, and world two, the self-conscious mind. Hitherto, science has been restricted to problems arising within world one. It is evident-- or almost restricted. That's not true. There have been quite a lot of scientific studies on the world one-- world two when you come to examine it.

It is evident that if the mind-brain problem is to be subjected to a scientific attack, it will be an attack across an external frontier of science. We're moving out of the purely material mode into this other world, world two, and investigating the relationship between them.

Most brain scientists and philosophers evade this confrontation against such an horrendous frontier by espousing some variety of psychoneural parallelism. You see, you're up against something that's outside physics affecting physics. And this is, well, shall we say, it's a shocking concept at the best. The conscious experiences in this view of parallelism are regarded as being merely a spinoff from the neural events, every neural event being postulated, by its very nature, to have an associated conscious experience. Now, that is an incredible statement. Every little nerve cell ticking over-- I've got 10,000 million here in my brain-- and every one of those is supposed to be giving me or contributing to my conscious experience.

This simple variety of parallelism is certainly mistaken. It's never been thought out, actually. You cannot find, anywhere in the philosophy, anything more than a general coverover statement like that. It's mistaken because the great majority of neural activities in the brain do not give rise to conscious experiences. An immense lot of happenings are going on in my brain all the time, and I'm not conscious of them.

Even when you're asleep, you have almost as much brain activity as when you're awake, and you can be completely unconscious. But there are large areas of the brain, of course, in which no one-- say, the cerebellum, which is a field I've spent my life, or many years working in. And there, nobody ever thinks there's any consciousness in the brain events in the cerebellum.

Parallelism is unable to account for the experience that thought can give rise to action. That is, if you just have brain actions going on all the time, and a spinoff from those is consciousness, there's no way back. Your conscious experiences cannot get back, by parallelism, by the very tenets of parallelism, to brain action.

And so it's an illusion to think that I can, for example, if I want to move my finger or my shoulder and so on, they just move because of brain action, and I am eluded in thinking that I was the instrument in causing that to happen. You see, you never can accept parallelism as soon as you look at it in detail.

And then an even more pervasive experience is that we'll set in train neural machinery to recall memories, to bring them to consciousness. You know the way you have it-- as you get older, it's harder, recalling one name or another name, or one event or another, and you try to trigger it with strategies, and you get it back from the data banks in your brain and check it, and it may be correct or it may not.

And by your recognition memory, all of that sort of thing, according to parallelism, is played out by the brain, and the idea that you are deliberately examining your memories and checking them is simply an illusion.

Well, you can criticize this very effectively, this psychoneural parallelism, on philosophical grounds. And more recently, in a book that Popper and I are writing, we've had a very comprehensive attack upon it. There is really no seriously developed science or philosophy describing how this can happen, merely dogmatic statements. And that is what makes me feel that this is another kind of superstition.

Each age lives with its superstitions, which are unexamined beliefs held rigorously and defended with great emotion. And parallelism is in that class, I think. In part, I always regard myself as-- one of my missions in life is to discover superstitions and eradicate them, and in that way, move on to another age.

But you have to realize that each age, as it moves on, leaves behind its old superstitions, which are now recognized for what they are, and of course develops a new lot. The history of mankind will show that. And one has, necessarily, to be always on the guard with critical evaluation.

The only philosophy that consistently attempts this extraordinary problem of dealing with the assertion that every mental-- every brain action, every neural action, has a conscious experience associated with it is panpsychism, which says that that's in the very nature of things, that every object has some element of mentality in it, and it was more and more developed from atoms and molecules through to macromolecules and through to cellular structures at higher and higher organized levels, eventually, to the human brain. And there, it is fully flowering in our conscious experiences.

There's a neat little ironic attack on that. You could take, say, a glass of water, and you could say, this glass of water, for all we may know, may be in excruciating pain. And you only have to make the postulate that the excruciatingness of its pain is matched by the stoicism of its fortitude. And it--

[LAUGHTER]

Well, I think panpsychism is a refuge of people who don't want to see anything new ever introduced into the seamless web of the world they live in, that nothing like consciousness could have evolved because it was always there in the most primitive structures.

And the other thing is that if consciousness, as parallelism asserts, can do nothing, can never get back and cause brain actions, then it has no biological significance, and therefore, is something left completely out of the evolutionary story.

You see, I'm an evolutionist. I believe that consciousness came into existence because it had a considerable-- very importantly-- concerned in survival, in adaptation to conditions. And that has how it came, because it is a survival-- it gives you survival because of appropriate reactions to situations.

The most telling criticism against parallelism can be mounted against its key postulate, that the happenings in the neural machinery of the brain provide a necessary and sufficient explanation of the totality both of the performance and of the conscious experience of a human being.

For example, voluntary movement can be regarded as being completely determined by brain events, as I've been saying. But Popper, for example, makes the statement-- and I'll read it to you and you'll see how telling it is. According to determinism, any theory, such as, say, determinism, is held because of a certain physical structure of the holder's brain.

Accordingly, we are deceiving ourselves, and our physically so determined as to deceive ourselves, whenever we believe that there are such things as arguments or reasons which make us accept determinism. In other words, physical determinism is a theory which, if it is true, is unarguable, since it must explain all our reactions, including what appear to us as beliefs based on arguments, as due to purely physical conditions. Purely physical conditions, including our physical environment, make us say or accept whatever we say or accept, period.

Well, this is, of course, an untenable position. It's a reductio ad absurdum against determinism and parallelism. With this rejection of parallelism and panpsychism, we confront the great problem of the interaction of brain and mind, the world naught of Schopenhauer.

And this interaction occurs across a frontier between the world of matter and energy, world one, and the world of the self-conscious mind, world two. And you might wonder, what is the self-conscious mind? You know what I'm talking about. You're all prepared to talk about matter and energy, and apparently, the self-conscious mind cannot be observed. You can't turn a sense organ onto it. But it's directly experienced, of course. It doesn't even require the indirect observation for the matter energy. Well, it is directly experienced.

And such a thing as pain, color, light, sound, music, harmony, melody, memory, imagination, and so on, these are all in your self-conscious mind. There's no material-- there's a material counterpart in a sense, too, light, with vibrations and so on, but not to pain, and not to the more subtle experiences that each of us enjoys through our whole waking life.

So world two is a very real world to us. It is more real and more primary, as Eugene Wigner says, than the world one. It's the world of primary experience. How can we investigate, then, this problem of how brain events are related to mind events? By using scientific methods.

It would be a radical extension of the scope of scientific investigation, which, in the Weisskopf internal frontier thing, is investigating events in the material physical world with principles of physics governing the interactions.

Now, Weisskopf, though, goes on to say, "I believe that, at least potentially, science can justifiably claim the ability to understand every observable phenomenon." However, implicit in this claim to completeness is a very important qualification. If one asks the question, can, does, or will scientific insight cover every aspect of human experience, the answer must be negative.

To show that this statement does not contradict the completeness claim, let me give a simple example. And Weisskopf's example is a Beethoven sonata, but it could be any of the creative-imaginative performances of the human mind. The whole question of personal relations, ethics, aesthetics, and so on can become [? in-- ?] they are not covered by scientific investigation. Certain aspects only can be.

And so I agree with Weisskopf. He gets out from the completeness claim. And my story, my effort, is not to make a complete explanation of all of human experience, but to extend the frontier into special aspects of it that can be investigated scientifically.

Bronowski, too, distinguishes between two modes in which human beings attempt to understand. Firstly, there is what he calls the poetic mode, and secondly, there's the scientific mode. As expressed by Bronowski, modern physics also leads to an enlargement and a fundamental change in the relation of the human observer to the world of experience which he is trying to understand scientifically. And we have heard already, yesterday, expressed the beauty of a new scientific theory with its inclusiveness and its elegance.

These principles, as Bronowski states, express a far-reaching revision of the idea of knowledge. They shift the emphasis away from the impersonal record and put in its place a relation from which the human observer cannot be abstracted. I'll deal more with that in a moment.

The scrutiny of experience is no longer idealized as an activity that could be carried out by a machine. And that's a besetting error today, to think that machines can substitute for man in the essential nature of a scientific investigation. Bronowski goes on, "There is no reality, there are no laws, that can be separated from the process of their discovery. The human condition is also the necessary condition for the recognition of order in the world."

We are far removed from the inductivist philosophy of science in which the observer was thought of as collecting data and extracting therefrom the laws of science with a quite impersonal, machine-like exactness. That was the old error of science. This cleavage between the scientist on the one hand and the phenomena of nature on the other provided the operational conditions during the great advances of science from the 17th century on until the 20th century.

Scientists were deluded by the inductivist view of science so forcibly expressed by Bacon and Mill. Though the key role of creative imagination was overlooked in theory, it was exemplified in the achievement of the great scientists. That is to say, the scientists were far better in their performance than the theory that they thought they were working with.

The achievements of Galileo, of Newton, or of Darwin, for example, were imaginative-creative experiences and not inductive things. They just didn't sit on all these recordings and data and extract the ideas. Their mind was far beyond the material records.

Wigner, for example, says this in regard to a simple scientific measurement. "The measurement is not completed until its result enters our consciousness. This last step occurs when a correlation is established between the state of the last measuring apparatus and something that directly affects our consciousness. The last step is that the present state of our knowledge shrouded in mystery, and no explanation has been given for it in terms of quantum mechanics or in terms of any other theory."

This quotation focuses our attention back onto the brain-mind problem, because it now turns out that the very nature of all scientific investigations, we are crossing and recrossing backwards and forwards against across the frontier between world one and world two.

In the brain-mind problem, there are necessarily two completely different sets of phenomena to be related. On the one side, there is the study, in more and more detail, of the events happening in the human brain in relationship to self-consciousness.

So we come to develop concepts of organized complexity and subtlety in the neural machinery of the cerebral cortex that are of a different order from anything known to exist anywhere in nature. I want to stress that. It's very much misunderstood that here is something weighing, perhaps, 1.5 kilograms that you have in your head looking like a bit of cold porridge, and macroscopically, nothing very distinguished. And yet in its operation, it gives us everything. The incredible performance of this is the great challenge.

Now, there's been a great deal of work done on this-- far more than most people know-- relating, even, to this question. Where in this two hemispheres, which I assume-- I've never seen my brain, by the way, but I assume it's behind here somewhere, lying right back there, although it was revealed the other day by ultrasonic new ultrasonic investigations in Germany. They put me through and I found that it was there. But there it is.

And now, where, in my consciousness, where does it come out? Is it everywhere in the brain or in special places? Now, when they split the corpus callosum-- and I have all the slides for this, but I can't show them to you. You have to use your imagination. There, you can separate the two hemispheres from this great linkage of 200 million of fibers, one to the other side. Separate them. It's done therapeutically for some incessant epilepsies.

There are 20 cases in Los Angeles this has been done without serious disability. And they've given, though, a wonderful new insight, namely that-- and this is the first thing-- the speaking hemisphere is almost always on the left side. That is, events here. That part of my brain isn't speaking at all. It's going events here are causing it in special areas that we've known for over 100 years. And certain other parts of the brain, in addition, are the areas which are associated with consciousness.

The rest of the brain is processing information and so on, and concerned in, of course, my mental events, but only when it hands it on, and all parts of the brain are handing on information to other parts in a process beyond any concept we have. The intensity of operation, 10,000 million cells arranged in modules and organized and firing and perhaps 20 times a second or more than that each one of them in a pattern today is something beyond any concept that we ever could have. But that's what goes on in the human brain.

Now, we have it now that's the left side of the brain. And we can get more and more refined investigations about-- from the disorders of the brain and recording electrically from the human brain-- to give us some beginning concepts about what brain events lead on to conscious experiences.

Now, it is not in question that the happenings in the cerebral cortex are necessary for the experiences of consciousness by the subject. That, I will agree. But I do not think that they're sufficient. That is, brain events must be behind our conscious experiences, or for the ordinary ones that go on, say, perception, and so on.

But brain events are not sufficient for these conscious experiences, because what you have got to move into another world, the world two of the mind, the self-conscious mind. And that has another operative conditions, this new other entity beyond what the brain is giving. Now, that is where the problem starts to become, shall we say, very tricky indeed.

If you believe that everything in the brain was necessary and sufficient for consciousness, then you're in the parallelist position. If you don't want to fall into parallelism with this frustrating philosophy of determinism, you have to go beyond that, into this new world, cross the frontier, and consider, what is this world two, then, this world of consciousness that we all experience directly? How is it related to the brain and how does it have an independent life, some operative life, as well as the brain life? And that, I think, is essential in the new story.

So now, I go on. How can we have confidence that we can scientifically advance in this study of the brain-mind problem? You see, you might say, there, we're getting into all of this phony field of the psychic and so on and losing ourselves-- losing our scientific base.

But I would maintain that if our questioning is scientifically based, we must propose explanations or hypotheses that can be criticized by others in the light of known facts and the existent hypotheses. That is the way science advances, by formulating as precisely as you can the new theories, and then having them criticized by others, and so gradually gaining insight and understanding.

And these new hypotheses should serve as a challenge to further testing by experiments especially designed for the purpose. One must not naively assume that the complete explanation of this brain-mind problem lies at hand. But can we advance at all in a limited and provisional manner? And that is what I am trying to do.

I mentioned to you just now the tunnel analogy from Weisskopf, but that is too simple. It can serve all right, this boring of the holes from two sides. But this is always within world one, as he defines psychology, brain action. In this new adventure across the frontier, we can't have anything simple like boring the tunnel from one to the other.

But what we can do is we can do experiments-- scientific experiments-- on conscious experiences on the one hand. And there's a great deal of work being done in those things. And relate them, on the other hand, to what we know of brain actions. We should try to interlock many approaches on the great problem, being very modest in our expectations. There will not be one blinding flash of discovery, but we have to put up hypothesies. We have to dare to do this to try to move science into a new mode, if you like, and attempt partial explanations.

For example, in conscious perception, there's the whole of the visual experiences, for example, the whole of vision. There's a large amount of scientific investigation using inputs of standard patterns and waves of lights and colors and intensities and so on and using the observer consciously to report what he experiences.

There is even a whole power spectrum investigation by Stevens where he is investigating the intensities of inputs to sense organs on the one hand and the experiences of the subject on the other. And subjects can report light as being twice as bright, and twice as bright, and so you go right up and can build a scale. And it turns out to be a power scale that you do experience versus input in this way. The same with touch and sound or any other kind of sensory input.

So there is work being done on-- scientific work-- on this, problem today. And the thing is to bring it all together, though. That is what is lacking, i some overall comprehensive theory which would enable the picture to be brought together.

And then there's a wealth of data from clinical work, lesions of the brain, all kinds of lesions of that kind, or also drug actions and so on, from which one can, again, derive the experiences as reported by the subject and the brain actions on the other. There's the whole investigation on sleep and wakefulness, on [? unconsciousness ?] and all the rest of it, which is in this same mode.

Now, I come to, how can we develop hypotheses related to this? And you see, I'm committed to, having left aside parallelism and panpsychism, I am committed to a dualistic interaction hypothesis, the existence of the events in world one, the neural events in world two, the conscious experience events of the subject, and how can they relate to one another?

Because they do relate. Brain events gives you conscious experiences. Conscious experiences can modify, act on the brain, as they do when you want to, for example, move in response to your desire, or when you want to recover a memory, or any of the other countless ways in which you want to express your thoughts. Then your cognitive experiences have to give rise to neural events, and so, ultimately, to movements or expressions which others can observe.

That is what our life is all the time, and yet it's completely unknown how we can do it. Well, here are, then, some of the basic modes in which we can define our problem. I assume there's a relationship between events in the mind-- in the brain on the one hand, the neural events in the liaison brain. And we've got that now somewhat defined in its location. And some correspondence between those events and the conscious experience that's deriving therefrom, but not a rigorous relationship as there would be in parallelism, but a correspondence.

The other thing that is very remarkable is the unitary experience that each of us have all the time. Although there is an immensely disparate input into our brain, say, just to take vision. I look at this room here now, with all the varied faces in rows, and the colors, and the lights, and all the rest of it, and yet it's one picture to me.

Nowhere in the brain can this be seen. In the retina, yes, you could see the image made in my retina by the lenses of this picture. But never does it come together again. It's coded into the brain cells firing in this way and response to the most sophisticated lines of different orientations and lengths and so on. But that is all we ever find nerve cells responding to-- never a picture.

And of course, you don't have-- and the elusive thing is that the visual scientists go on looking for nerve cells to more and more complicated patterns of response. But it is terribly limited what you can find anywhere. And the answer I give is that they're looking the wrong way.

What the brain does-- its codes the picture up to a point, but it's the mind that reads it out. The picture reappears not in your brain, but in your conscious experiences. That's the way the unity the synthesis of sight and sound and touch and form comes together as an experience, not as a brain event. The brain event is necessary, but not sufficient, for your experience.

And a focusing comes on with attention. At any moment, you can concentrate on one minute object in the whole field, and the rest of the field becomes background. And so again, here is an action on the brain. I might mention the kind of ironic way in which the scientists working in this field speak about the problem.

There is the story of what's called the grandmother cell. The grandmother cell is, eventually, they'll find, in the brain, a cell which, every time your grandmother appears in your visual field, far or near in any kind of relationship, the cell goes ping, and you know it's your grandmother.

You see, it's with this kind of-- the only change I've heard in that story recently is Jack [? Cowan ?] calls it the Marilyn Monroe cell. But that is real fame. But this is the ironic way of saying how hopeless the task is to find the picture in the brain. The picture is in the mind, recognized by us.

Now, there are further, more complicated things I'll pass over quickly. There is, for example, not a complete correspondence in time between the neural events and the experienced events. There are very fine investigations by Libet in San Francisco on conscious perception on human subjects, by brain stimulation or by sharp stimulus to the hand, and so on.

And he can show there, in a remarkable way, with backward masking and antedating, that the conscious experience may be felt by the subject before the related neural events. It's antedating, as he calls it. And that's playing tricks with time.

And another one that you may have experienced is-- I've experienced it once, in a tragic situation of almost being killed with a truck accident. But as the event got closer and closer, time went slower and slower. And I saw this great hurtling truck, and the time seemed to be forever as I was getting the car slowly away and the truck was getting closer, and I thought it was going to hit me in the middle, and then the back of the car, and so on. And time ran so slowly in that emergency.

That is, again, the experience of time is handled by your mind quite differently from the brain events, which were the ordinary clock time events. I think most of you presumably have had that kind of experience. It shows you that there's something different in mind events from brain events.

And then there's, finally, of course, the effective thing I've been mentioning before, that mind events can work on the brain and bring about actions if, otherwise, you would be committed to being simply an observer of the ongoing brain actions that give rise to all your performance.

If you believe that there is any possibility of you, by taking thought, acting, speaking, resisting, and doing what you're-- arguing, communicating, if you believe that there is reality in that, then you are committed to the action of brain-- of mind upon brain.

So let us try to build a philosophy that relates world one and world two. And of course, the big problem you're up against is-- and you immediately ask the question-- here is the brain, with all the nerve cells, complex as you like, all of this operation going on in the matter-energy world, what is this other world two? Is it in matter energy, and so on?

And the answer is no. Then the answer can be, it's a different world. If it was in matter-energy, you're back in parallelism. It's outside the matter-energy world, world two, as we call it, the world of conscious experience, which is our most direct experience. Yet it is acting upon the matter energy world in certain special places in the brain.

Now, Popper makes, I think, a very good statement about this. You immediately will think, well, the only hope you've got in physics is in determinism, the quantum indeterminacy of Heisenberg and so on. But Popper makes this statement.

A closed, indeterministic world one would be a world ruled by chance. You see, if you have indeterminacy, it won't do as a little way into the matter-energy world to control it, because it's only a chance world, this indeterminism, at this level. It is necessary but not sufficient to allow for human freedom, and especially for creativity. I'm quoting Popper.

"What we really need is the thesis that world one, the matter-energy world, is incomplete, that it can be influenced by world two, that it can interact by with world two, or that it is causally open towards World 2 and hence further towards world three." That's the world of the whole of objective knowledge. "We thus come back to our central point. We must demand that world one is not self-contained or closed, but open towards world two."

And that is, I think, a very strong statement indeed. And now opening, this is how you're getting across an external frontier of science if you make demands of that kind. And so the statement of the hypothesis is, the self-conscious mind is actively engaged in reading out from the multitude of active centers at the highest level of brain activity in this liaison brain area.

There is displayed or portrayed before it, from instant to instant, the whole of the complex neural processes. And you have to think how immensely complex. There are what is going on in your brain. And somehow, scanning this, you have the mind-- self-conscious mind-- reading out from the brain, according to attention and choice and interest or drive, selecting from the brain, the total performance of it, small fragments of that performance to blend together into an experience from moment to moment.

In that way, the self-conscious mind achieves the unity of experience that we have. This hypothesis gives a prime role to the action of the self-conscious mind, an action of choice and searching and discovering and integrating. The neural machinery of the liaison brain-- that's this part of the cortex that is mostly-- sorry-- on this side-- is the world one component of the interface.

You've got the brain action on the one hand, brain action here, and interface, and above that, if you like, diagrammatically, world two. And the self-conscious mind not only receives from the neural centers, but also modifies them, in an interacting manner, backwards and forwards. Thus, we propose that the self-conscious mind exercises a superior interpretive and controlling role upon the neural events.

A key component of the hypothesis is that the unity of conscious experience is provided by the self-conscious mind and not by the neural machinery. The neural machinery is never brought together. No one, in neurobiology, can think of any plausible way in which the immensely disparate operations of the brain come together to give you this unity of experience from moment to moment.

The brain events remain disparate, being essentially the individual actions of countless neurons that are built into complex circuits, and so participate in the spatiotemporal patterns of activity. I mentioned that already with a visual experience. We've got all-- if you looked at my visual cortex now, in all the various areas of it, you would not find the picture. You would find little pieces of the picture in lines and contours and so on. And that is all you ever get. The thing has got to be brought together only in your conscious experience.

Our present hypothesis regards the neural machinery as a multiplex of radiating and receiving structures, but it does not itself provide the ultimate synthesis. The experienced unity comes not from the neurophysiological synthesis in the brain actions, but from the proposed integrating character of the self-conscious mind.

And we might say, then, what is the evolutionary reason for the self-conscious mind? And I would say that this came-- the consciousness came to animals further down than primates. But it came there to do this integration, when the patterns and pictures and complexities of input became greater and greater, then some kind of consciousness was evolved, superimposed upon the material operations, to give this unifying character, and consequently, appropriate responses to the total ensemble of performance.

You could imagine that the self conscious mind might be playing over this neural machine. Now, let me just give you some kind of picture. If-- maybe about an organized cells, as we know, in columns in the brain, about, what should we say, 10,000 cells in a column, is a little units of operation in the first place with their own internal life. And we have about at least a million of those, perhaps, in their left brain.

And this number of total performance of little columns. And you can think of a million columns. That means a square of thousand in each way, and that is the ticking performance, now, in my brain, 1,000 little columns-- 1 million, 1,000 by 1,000. And that would be a great area like that. And the mind is, as it were, scanning that whole thing like a searchlight or like a multiple scanning and probing device.

And that gives you the readout, which is then available for integration. It might be claimed that this hypothesis is just an elaborated version of parallelism, a kind of selective parallelism. However, that would be a mistake.

It differs radically in the important aspect that it is selectional, not taking the whole ensemble, but selecting from it-- patchy manner-- scanning it over from moment to moment, assembling it together in integration, and furthermore, reacting back on it. It's the both-way action of the mind upon the brain, the brain upon the mind, that is the essence of the theory, and which is, of course, denied by parallelism.

This is exhibited by all our experience by, for example, in memory, trying to probe into-- you're all familiar with the task of trying to recover a name or a picture or what you will, some experience, and you probe into your brain to try and get it and receive back and give to it and so on. I've mentioned that already. But this is all a deliberate action.

And then movement is, again, a very important aspect of this. And there have been beautiful experiments done by Kornhuber and [? Ullman ?] associates which show that when you are bringing about a movement, very carefully controlled so that it is not triggered by any signals-- this is heavily controlled-- and moving any-- just take a finger like this for a start.

When you do that, the subject lies there, and it's very heavily instrumented, averaging the responses of the brain and leading from the surface here. For example, when you're doing that, the subject lying at rest, and at long intervals without any triggering signal, moving once, and then the whole of the electrical response is recorded and stored. You do it again. You store it again.

And what you are doing is every time the movement occurs, you get the impulses in the muscle here. Those are electrically used to read back the responses in the brain to seconds in the computer. And so you have this backward integration. And so you add up 250 of these-- perhaps, the subject takes about an hour, the subject lying there.

And when you do that, you find out that up to 0.8 seconds-- and this is confirmed by others-- before the movement occurred, there was building up over the whole vertex here a negative potential reversed positive downwards here, and that this gradually mounts up and eventually comes through and concentrates on the actual area of the pyramidal cells that give rise to the pyramidal tract concerned in the movement. And it was another lot of cells-- it's another place.

But this is involved. This is the neural action which is triggered by the voluntary command to move the finger. And this is a scientific observation. And again, it's exactly in accord with the hypothesis. There's much more data that you can go into in all this field. I illustrate this one as a particularly relevant scientific observation which does show, establish, I think, that the command the willing to move the finger does act upon the brain and cause action.

It's very weak. It takes a long time. Presumably, this time is employed in building up this requisite spatiotemporal patterns in many millions of neurons. It's an immense neuronal operation here, which is-- and why is it so large and taking so long? It's because, I think, the influence of the mind upon the neural events is very weak and gradually has to be developed, amplified by the neural events, and eventually homing in on the right cells to cause that and not that.

You're all familiar that you can do that. If you want to move your finger, you don't do that. You move that. But when you were a baby, learning the very first movements, then you often did that instead of that, and you had to learn how to handle your brain to bring about the right actions. If you don't believe me, look at the nearest baby you can find and see what's going on-- I mean in the first few weeks of life. We've all learned these things, and we take them for granted. And we don't realize the immense learning experience there is in trying to make your brain do the right things.

Now, there's a complex story about what neural events are in relation to the mind in this giving and receiving in the columns that I've given you, these organized columns, which are known by histologists, described particularly by Saint [? Agatha. ?] I build upon all the very latest findings.

But we are still terribly ignorant of the detail, and also, the events, the life, the internal neuronal life, of the column. This is another approach to the problem. Both sides, you have to investigate, what are the neural events and what are the experienced events related thereto? This, I maintain, is the way in which you can advance scientifically in this problem, by testing out the hypothesis which I have very briefly outlined to you.

We have, of course, to make the postulates that, in these very special areas of the brain, under very special conditions, world one-- because that's a world one operation-- is open to the influences of world two as, for example, in a command performance to move.

Across that interface is the real problem. What goes on across that interface? And I want you to realize that I'm not making, as it were, big demands against the first law of thermodynamics. This is only under very special, dynamic conditions in a very special states of neuronal poise that it happens at all. And it happens very weakly indeed, taking a long time and requiring much neuronal amplification in order to eventually express itself as the firing of nerve cells and the movement.

But immense amount more work is required on what goes on in the human cortex in this way. Hitherto, we've only got these remote leadings of the brain. No one has opened the brain-- and it's not very nice to do. You have to have subjects under special conditions for experiments that will let you have so much of their brain time to lead from. And this will be done, though. And see, when you're doing these movements, exactly what happens to the nerve cells. There's only one brief report by [? Goldring, ?] so far, on that. But it is all in the field of command acting upon the brain.

They are very specially designed structures-- that is the theory-- but one doesn't know what the design is. You might say, well, why don't people go and look at the liaison brain in human beings with the electron microscope and see what's going on? The answer is that they wouldn't know what to look for. And if you don't know what to look for, you won't find it. It's like that in science.

You've got to have some highly sophisticated theories that would guide your imagination and intelligence in being able to look in the immense complexity of the brain. It isn't as if you're just looking for something very easy to discover. It's an organized complexity of a kind that is beyond our understanding yet.

But I would predict that progress will be made. Already, we are getting very fine electron microscopic studies and electrical recording studies of single neurons in, say, primate brains. And eventually, it will come through to human brains. And we may know what is going on much better. But this is an immense challenge for the future in which very few people are working.

I would like to close with a vision of the future expressed in an article "Quo vadis" by Bridgman, a distinguished Nobel laureate in physics. He says, "It seems to me that the human race stands on the brink of a major breakthrough. We have advanced to the point where we can put our hand on the hem of the curtain that separates us from an understanding of the nature of our minds. Is it conceivable that we will withdraw our hand and turn back through discouragement and lack of vision?" Thank you.

[APPLAUSE]