Brain Story (2000) s01e06 Episode Script
The final mistery
At the start of each day, a profound change happens in the brain of every human being As we wake up, an inner world comes to life.
We become conscious.
From the mass of nerve cellsthat have been ticking over while we were sleeping, a strange, new sensation emerges.
The first hand feeling of being a conscious human being.
Somehow your brain creates the intangible, indescribable experience of being you.
It's not something most of us ever stop to really think about, but the fact that we each have an inner world of feelings and experiences is, to me, even more extraordinary than the fact that living things evolved at all.
As a scientist I cannot accept that consciousness is something mystical, beamed into our heads from outside - it has to come from physical processes within the brain.
But the question is - how? The ultimate goal of neuroscience is to interpret all our everyday experiences in terms of measurable changes in brain activity.
So where do we begin with something so elusive as consciousness? Something so utterly subjective and unique to each individual? The challenge is to explain how a kilo and a half of neurones and blood vessels inside our heads, with the consistency of soft butter can generate an extraordinary rich range of conscious feelings that we experience.
From taste of a good cup of coffee, to the satisfaction of solving a crossword puzzle, to the warm glow of remembering a summers holiday on a cold winter's morning.
We take it for granted the brain makes being alive feel the way it does, yet there's no reasons why it should.
The brain is made of the same biological ingredients as the rest of the body.
Yet somehow, it manages to generate the indescribable phenomenon of consciousness.
Understanding this tantalising paradox, is, I think, the ultimate quest for science.
Let's start as simply as possible.
We're always conscious of something.
What determines what it will be? Take driving.
You're going along a route you do every day.
You're changing gear and adjusting your speed and direction and you're not aware of any of it.
You're effectively somewhere else.
Then suddenly something happens and it becomes the focus of your consciousness.
Something switches inside the brain and the actions that were done automatically are now centre stage.
So what is happening inthe brain, when you switch out of auto-pilot and become actively aware of driving? Could there be some kind of higher Control Centre in the brain that determines what you're going to be aware of? Is there some kind of brain HQ which oversees all the activity in the rest of the brain? If so, this centre for consciousness would direct the different processes going on down below.
Whatever it happened to select at that particular moment would be the focus of your consciousness.
So is there any evidence that we have a consciousness control centre in our heads? One man's brain has played an important role in answering this question and it can often be found in the Gardener's Arms in Chester.
Graham Young has a very unusual brain and scientists are so keen to study it, that he's regularly flown, expenses paid all over the world.
It's almost a different life.
I live in Chester and I work in Chester and then I go away doing all this stuff and it's almost like - a separate identity's a bit strong - but it's two different existence's.
Graham became a hot property for Neuro-Scientists as a result of being hit by a car when he was a child.
I had a road accident when I was eight, resulting in some brain damage, so I lost all my vision to the right in both eyes.
As far as he was aware he was completely blind on the right hand side.
I mean I literally used to be walking around town, as an eight or nine year old lad and I'd walk into a lamppost or into a bin.
I just didn't see in and I would walk right into it.
I mean that doesn't happen any more; I've just got used to having half a field of view.
Twelve years later, while he was having his eyes tested in London, they discovered something extraordinary.
It turned out Graham's brain could actually process visual information on both sides, even though he wasn't aware of it.
Graham is an perfect case of a fascinating condition called Blind Sight.
Most people don't get brain damage in such a way as to satisfy the Research Scientist.
Graham fortunately has damage largely restricted to the visual cortex and not to the rest of the brain.
So that makes it a much more pure case.
Graham's road accident destroyed just a small area at the back of his brain.
If losing this area caused him to lose awareness of seeing, could his damaged area be the seat of consciousness? Weiskrantz experimented further.
He showed Graham moving lights on his blind side.
Right unaware, left unaware.
Right Bizarrely, although Graham says he can't see them, he can guess correctly what direction the dots are moving in.
I am completely unaware of an event occurring in my blind field and yet in terms of which way it's moved, I get it right 90% of the time.
That's a bit strange isn't it? And I don't know how I do it.
Right unaware.
Blind sight is a condition which one can respond to visual events without being aware of them.
Okay.
Now that means that as you know what the brain damage is, you can start to say something about what areas of the brain are necessary, are critical for awareness.
So what is going on inside Graham's brain? Scans suggest that when Graham is responding to the dots, but isn't aware of them, a very primitive visual pathway is active.
But when he is actually seeing them, a whole new range of brain regions lights up.
We need lots of different areas for conscience.
Just to receive the information isn't sufficient.
You have to do something with for it to become aware and the regions of the brain that are important for that lie quite far removed from the Visual Cortex in the frontal lobe, involving those regions of the brain that allow us to communicate the fact that we are conscious, that we are aware.
Blind Sight has revealed that there is far more to being aware than a single, central Control Centre.
Instead of some special area, devoted to consciousness, somehow the extraordinary feeling of awareness emerges from ordinary brain activity.
It may not feel like it, but changing patterns of nerve cells, firing in the brain are the basis of everything we experience.
Everything we imagine, all our thoughts and feelings.
Conscious awareness then, must somehow arise from this maelstrom of electrical activity in the brain.
So what could explain which of the many networks of cells firing away in our heads is heard above the background chatter? Neuro-scientists are now squaring up to the big question, which special property or process in the brain might cause consciousness? If there is no special centre in the brain, whose job it is just to generate consciousness, then somehow it must arise directly from the activity of ordinary brain cells, but then we have a problem.
In the brain there are thousands of networks of neurones, all firing away; what special property could a network of neurones suddenly acquire that's just for a moment made it responsible for consciousness? Imagine that your brain is like the surface of a lake in the rain.
Each new event is like a raindrop which triggers a spreading wave of nerve cell activity which then gradually fades away.
I'm suggesting that we're conscious of whatever happens to have caused the biggest ripple of activity in our brain at any one time.
I think of consciousness as something that grows as a spreading wave grows - the stronger or more significant the stimulus, the more extensive the ripples of activity, the more all your neurones are working together.
So the conscious thoughts and feelings that flit through your head, are a direct reflection of the ever-changing pattern of activity in your brain.
One attraction of this idea is that might help explain one of the great unsolved medical puzzles - what happens to the brain when we lose consciousness through anaesthesia? Good Morning Dr.
Artousio.
I hope we're on time.
Good Morning.
Yes, we've a few minutes yet.
Dr.
Nazir, would you go ahead and prepare this patient and I will join you in the lnduction Room in a few moments.
No one knows how anaesthesia robs the brain of consciousness, even though they've been used for many years.
Brain scans have shown that there's no obvious single area that's shut down.
Somehow, anaesthetics must affect the whole brain.
Have you listened? We have now made the transition into surgical anaesthesia.
Dr Bellrow what is the But the really interesting issue for me is that the effects are gradual.
It's like a sort of dimmer switch.
We usually take the patient through the analgesic stage, through the loss of consciousness and through a delirium phase into surgical anaesthesia.
In some intriguing studies in the 1950s, Dr Joseph Artousio investigated the semiconscious state.
Edna, are you comfortable now? Edna, are you comfortable now? Nod your head Edna if you are comfortable.
You see, Edna acknowledged that she was comfortable.
We have now entered the true third plain of the first stage.
Artousio was exploring the possibility of conducting major surgery without the complications of high levels of anaesthetic.
Here, he manages to find a dose which produces an astonishing semi-aware state, where the patient feels no pain, but yet she can still respond to commands.
So what could explain this gradual loss of consciousness? All anaesthetics dampen down electrical signals between the brain cells.
According to my theory, this would stop the waves of activity from spreading so far.
As the assemblies of cells become smaller, our consciousness gradually dims.
But anaesthetics also offer a further clue.
At doses too low to rob you of consciousness, they can nonetheless dramatically distort it, producing hallucinations.
In Zurich, Dr Frans Vollenweider is studying how low doses of an anaesthetic called Ketomene can affect the brain.
Ketomene can enhance your mood, it can give you feelings like euphoria.
It changes all the sensory modalities.
You can for instance hear or you can visualise things that you can't see it.
At first you have illusions, then maybe you have hallucinations, you can see things that do not exist in the real world.
Now it's coming.
It's coming now? Yes, definitely, taking off.
Are you able to close your eyes and focus on your inner experience? On my what, inner experience? The challenge for any theory of consciousness is to explain how minute doses of an anaesthetic can produce such distorted experiences.
Yes, everything is very different than usual.
The visuals effect and the audio effect, they are connected.
They melted? Yeah, they melted, so, by Is vision more auditory experience and vice versa? Yeah.
One gives the other food - that's it.
As I see it, the inputs from his senses would normally dominate his brain, creating a large, spreading wave of nerve cell activity.
The drug might weaken the signals coming from the senses leaving a hectic jumble of smaller ripples of activity, spontaneously generated in the brain, producing hallucinations.
Moving and moving and moving, a box in a box in a box or whatever, had this experience like I was, space was controlling no, my brain was controlling, my brain was controlling, my brain anyway Volunteers have been scanned while they're hallucinating.
Over several minutes a slight change in activity shows up in the front of the brain, but this time frame is too long.
Consciousness is too fleeting for the subtle and transient changes in cell activity to be detected by this kind of approach.
We think that Ketomene directly interferes with the communication between nerve cells and under Ketomene this communication is strange.
Some cell communication is blocked even, and Ketomene may lead to new assemblies between the nerve cells, so that a different kind of network gets established under Ketomene that is normally not working in that way.
And according to your experiences, what do you always see, or? Oh, what I did to today, yeah I travelled through the Galaxy.
Manipulation of conscious experience with drugs is nothing unusual; we do it all the time with alcohol, nicotine and caffeine.
But drugs, don't have to be involved.
I've come to the Palladium in Edinburgh to watch a group of performers who claim to have a unique ability to control the degree to which they are conscious of pain.
This is not the sort of thing, I'd normally go for, but I have to say I'm, quite excited by the prospect, because I gather I'm going to see people putting themselves through enormous agonies, but apparently completely unperturbed.
I'm going to be looking for whether I can apply my theory of consciousness to what I'm actually seeing before my very eyes.
Welcome, brothers and sisters of Edinburgh to the Jim Rose Circus, Secrets of the Strange.
This is a show dedicated to your brain.
The Circus has gained something of a cult following over the last ten years, with it's extraordinary feats of self-mutilation.
What I want to know is what's going on in their brains.
How can they block out, what to me would be unbearable pain? Jim Rose Circus is really dealing a lot with how to use your mind and your brain to empower yourself.
We do it as a warped seminar, it's kind of a comedy - Bibi The Circus Queen, The Amazing Mr.
Lifto and myself.
We basically kind of explain how to circumvent or to overcome what we would call discovery, I think you might, a lot of people might, call pain.
'Bibi's going to lie on this bed of nails, have a glass plate placed onto her stomach and a cannon ball will come down, crashing and smashing the glass.
A lot of people do the bed of nails and there is discomfort there.
Bibi's real fear is the shattering of that plate, because it's random and that's something that she can't prepare for.
Yes! Take a look at her back, take a look watch and register the shock.
Thank you Bibi - you're gonna love it.
' It seems that the way they control the pain is by preparing their mind for what's to come.
We all, throughout the Circus, use the same way of dealing with discomfort.
For example, if I'm doing the Human Dart Board, I put myself, I literally take my mind, which takes it's body, into another place - now where I like to go is into a nice warm watered pool and I like to be right up to my neck, and everything's feeling fine, everything's all nice and warm and relaxed.
With just a plank of wood to protect my Jim deliberately fills his mind with a persistent mental image to block out the pain.
I can take another one Edinburgh, can you? My interpretation is that a large assembly of cells in this brain generates Jim's overwhelming feeling of being in a warm pool.
This assembly is so dominant, it shuts out any rival stimulus like pain.
I feel nothing, I feel nothing.
Ow, I just felt something.
I don't feel the pain, but you see it's different now, 'cos I'm expecting what's happening.
If I stub my toe on my bed or something, at night, I'm going to scream just like you, because I didn't expect it, and I didn't put myself in the warm water.
'What's your name?' Susan.
Susan, I really screwed that up.
Susan from the BBC, give her a big hand.
There you go Susan.
Now then, this is how I shave.
Of course, we don't actually know what the brain cells are doing inside Jim's head.
My idea is still only a theory.
Thank you Susie, give it up for Susie, she's a star.
We may not know the exact brain process which gives rise to consciousness, but we do know that it must be produced by ordinary brain cells.
In other words, it must arise directly from sub-conscious mental activity and that has profound implications for how we view what it means to be human being.
We know that when we need to, our brains can trigger reflex responses without any conscious thought at all.
When facing a serve of over 100 miles an hour, professional tennis players don't have time to mull things over.
Their complex judgements and tactical decisions are all made automatically in the sub-conscious.
If they,by what's happened to me I may just take a look at a ball, I can see what my opponent is, I just hit the ball and sometimes don't even have the time for thinking, and you just have to hit the ball and that's it.
On the hard court and on grass you won't see any, you won't see many shots.
I mean that's why.
You won't ever think, you just hit the ball, the other side where you see the player, that's it.
If they try to become aware of what they're doing, they will fail.
The great players will serve the ball at about 1 00 miles an hour.
The only thing that the opposing player remembers that he can tell you about is watching the angle of the serve, so they're unconsciously carrying out that fast function.
Neuro-Scientist Professor Benjamin Libet has spent the last 50 years fascinated about the sub-conscious.
My own belief is that all our thoughts and all our actions are initiated unconsciously.
Any thought you have perceived very rapidly unconsciously and finally you become conscious of some result.
in 1958 Benjamin Libet began a series of experiments that challenged one of the basic tenets of human existence - that we are free to think whatever we choose.
Occasionally, brain surgery has to be conducted out on patients while they're awake.
Benjamin Libet realised that this gave him a unique opportunity to experiment on the conscious human brain We did not use General Anaesthesia, we used a Local Anaesthetic for cutting open the skin and drilling a whole in the skull and the subjects were very co-operative in general.
He began with a simple query.
How long would the patient's brain have to be stimulated with an electric current before they became aware of it.
We started by stimulating the Sensory Cortex, which is known to produce a sensation in the proper part of the body, usually the hand in our case and to ask the subject if they felt, anything and what they felt and so on.
He discovered that the brain had to be stimulated for at least half a second before the patient reported that they felt anything.
It seems it takes this long for the brain to generate a conscious experience.
That means that you do not experience the environment when it happens.
There's a delay of up to about half a second before awareness is produced.
This first experiment was proof that fast reactions must all be carried out subconsciously.
If you're driving a car and somebody steps in front of it suddenly, you'll slam on the brake in much less than a second and that's undoubtedly unconsciously performed.
If you had've waited for a second, you're liable to have hit the person.
The idea of living 1 a second//in the past may seem strange, but if consciousness depends on large numbers of cells working together, it makes sense that it takes time to develop.
It was his next set of experiments that that caused the real controversy.
This time he had a different question.
Does the brain start first, or do you start the brain? Because the traditional way of looking at voluntary action or free will is that you want to do something and you tell the brain to get going.
The results of his work have been debated for years.
Benjamin Libet may have now retired from the frame but others are continuing his work.
We all have this very strong belief that we have conscious free will and it's a central part of our idea of ourselves as individuals that we can want to do something, we can have an intention to do something and then we can do it, we can make our intention drive our actions and Benjamin Libet's work was one of the few experiments which made a truly innovative and courageous attempt to address that question.
I can't feel it being cold.
Patrick Haggard's team are going to measure my brain activity in the run up to a conscious decision, with electrodes placed on my scalp.
Okay Susan, you're all wired up and ready to go.
Absolutely.
We're going record from your left Motor-Cortex, your right motor Cortex and from the mid line.
I want you to watch the clock hand which is rotating on this small clock in the centre of the screen and then, at any time when you choose, when you intend and will to, I want you to press either this key, or this key, as the urge? -As the urge takes you.
-Fine, okay.
and then the computer will prompt you to type in the position of the clock hand at which you first felt the conscious will to press the button.
Fine.
Good.
-Any questions? -No.
Off we go.
It's very funny waiting for the urge isn't it? So, watching the clock I record the exact time that I make the decision to act, while the electrodes on my head, monitor the activity in my brain, Ieading up to this decision.
As I do this over and over again, a clear pattern starts to emerge.
So here are our results, which contain the same basic effect as Libet originally found.
The average time of the intention to move was where this arrow is here and you can see that the motor areas of the brain have begun to build up electrical activity in preparation for this willed action, 2000 milliseconds, at least, before the action actually occurs.
Just as in Libet's original work, this experiment seems to show that my brain appears to prepare for movement long before I felt like l'd consciously decided to move.
So, did I have any real choice about when I moved? Could the felling of having made a decision, just be an illusion? So, this looks like a real problem for our idea of conscious free-will, because our assumption that we work with every day, I think is that we decide what we want to do and then, or I should say, I decide what I want to do, and then I am able to get my brain to drive my body to make it happen.
The implications of Libet's findings are far reaching.
That our conscious mind, our free-will is merely an after effect.
The actions and decisions that we take every day, which feel like instant, conscious choices are actually the result of slowly emerging sub-conscious processes in the brain.
If everything really starts in the sub-conscious, do we have any freedom or are we sophisticated machines, our responses determined by the mechanics of our brains? There's no question that we are organic machines.
If we think of a machine as any physical system capable of performing certain functions, then of course the brain is a machine and we are, our whole bodies are biological machines, but the point I'm making now is, that doesn't show that we don't have free will, because this is a, the peculiarity of these machines is that they are conscious machines.
Since the 1960's philosopher, John Searle has been a passionate campaigner for free speech.
He believes that freedom, whether at the political or the personal level is an absolutely fundamental part of what it means to be human.
Now here's the problem.
There isn't any way we can think our way to freedom, that is, when you make a decision, when you take any action, you have to presuppose freedom.
If you go in a restaurant and they give you the menu and the guy wants to know what you want, you can't say 'oh well, I'm a determinist, que sera, sera, I'll just see what I order', cos even that is an exercise of freedom, the refusal to exercise freedom is already an exercise of freedom.
When you think about the things that some people do, there's no getting away from the fact that consciousness seems much more like an act of force than a mere after effect.
Mr Lifto is almost the living embodiment of free will at work, but do our minds really give us total freedom to control our thoughts and actions? It feels as though we've got free will, but how could a brain, made of ordinary matter give rise to a mind which floated totally free from physical reality? So here's where we are, at this stage of intellectual history.
We've got this awful problem of free will and people are refusing to look at it, the way they were refusing to look at consciousness, 20 years ago, but if you're looking at consciousness, you've got to look at freewill because it's one and the same set of problems.
All right, there's no way we can think away our own conviction of freewill.
We cannot abandon it.
It's a necessary presupposition of just living on a day to day basis, but we can't square it with the rest of the things we believe.
So we've got a straight contradiction in every lntellectual's conception of how the world works - that we got to resolve.
In the back woods of New Hampshire, Joe - known famously as 'the case of JW' has inspired some thought provoking ideas about where the illusion of free will comes from.
Twenty years ago Joe decided to submit himself to a drastic operation to control his epilepsy.
One day You'd have 2 or 3 seizures and when you do that long enough, you're willing to go through anything.
You say, what the heck, if they want to crack your head open and have an operation, what've you got to lose because everything's going wrong anyway, so might as well go for it.
So I just went for it anyway, because I thought I'd try it and see and it turned out it worked good.
The operation was to split his brain in two.
Having exposed his way into the top of the head, the Surgeon works his way into the cleft between the 2 hemispheres, revealing a white bundle of nerve fibres, connecting left and right sides of the brain.
Tearing apart these 50 million fibres in the Corpus Colossum, prevents epileptic seizures from spreading from one side to the other but it also prevents almost all information from your senses travelling across.
The operation has made Joe a valuable research subject for Neuro-Scientists.
After years of studying split-brainer's, Professor Gazzaniga believes he may have found the source of the illusion of conscious freewill.
He started by examining the linguistic abilities of the left and right sides of the brain.
Words on the right of the screen go to his left hemisphere and he calls them out easily, but when words are flashed to the other hemisphere he says he didn't see anything, but remarkably, he then draws a picture of the word.
Joe draws the telephone his right hemisphere saw, but strangely he can't tell what it is.
I can't exactly tell what it is.
I can't say what it is.
It looks like a shoe I guess.
What else? Coffee, tea I don't know, I can't tell what it is.
Because he thinks that speech comes from the left hemisphere, Mike Gazzaniga believes that the left must also be dominant in generating consciousness.
If you think about the consciousness differences between the left and the right separated hemisphere, the left hemisphere is an interesting, cognitive machine.
It has all these problem solving capacities, talk and language and speech, as you saw and the right hemisphere, basically, isn't a very interesting entity.
You would not want to have a date with a right hemisphere.
Despite having his brain split in two, Joe's life has been remarkably unaffected by the operation.
His personality and his interests have remained the same.
I've had them down there since I was a little boy, and I've been building them and saving them.
They've kept right with me all the time.
I feel pretty much like the same person I've always been, just chopped up a little bit I guess.
As far as the operation goes I don't think it really affected me too bad, just helped, but I don't think as far as making me worse, it made me worse or anything, it didn't do anything, and as far as two brains - I've only got one brain it's just not quite the same design as everybody else's.
The theory goes that if the conscious feeling of who you are came from both hemispheres, then Joe would feel changed by his operation.
Since he doesn't, Mike Gazzaniga's bold conclusion is that Joe's inner voice must come from just one side of his brain and since our inner thoughts are all words, they must come from the linguistic left.
The inner voice in the left hemisphere has got to be huge, robust - it's Pavarotti-like and this right hemisphere probably has a chirp; a little bird sound, because the devices that allow for the inner voice to really expand and express itself, are mostly located in the left hemisphere.
Experiments on Joe have lead Mike Gazzaniga to believe that the left hemisphere may also provide an explanation for the sensation of freewill.
Sun dial What did you say? Dial It's not dial.
In this test, Joe is flashed two words simultaneously.
Shown Hour and Glass he draws an Hour-glass.
With his left hemisphere Joe names it immediately, What's that? Hour glass but Joe's left only processed the word Glass, so he goes on to invent a reason why he drew a timepiece.
Did you see it? What did you see? I saw a glass.
Why did you draw that? I don't know.
Probably still thinking about the clock one, I don't know! It's as if Joe has been fooled by his own left hemisphere.
And so he basically makes up a story to explain the behaviour that he's carried out and he comes to believe that that's the reason why he did a particular act.
And you see those experiments, that kind of phenomenon time and again in these split studies, but the importance of it, is not that it is unique to split brain patients at all, it is a metaphor for what you and I do.
It's that we're constantly trying to figure out, and put a spin on what's coming out of our body.
Gazzaniga believes he's discovered why we think we've got freewill.
The feeling of being consciously in control of our minds, is just an illusion created by the left hemisphere.
Our conscious inner voice is merely a fiction to explain decisions made by the self-conscious.
It's got to be true that a huge amount of what we do in our awake conscious life is governed by unconscious processes.
I'm not conscious about the fact of how that last sentence just came out, it just came out because it's been some guys are down there with framing hammers putting this stuff together and Bingo out it comes, and it's more or less orderly.
So, so just think about the fact that the major management of your body walking through space, you're responding to auditory, visual, tactile events, all that's being done for you, it's just absolutely been done for you and you're not paying any attention to it at all.
You don't even know about it, but it does a wonderful job and it just turns out more and more of your cognitive acts are the same.
The work with split-brainers, like Joe is fascinating, but I'm not convinced that the experiments prove our consciousness emerges from just one half of our brain.
And this research doesn't actually get us any closer to answering the most important question of how brain cells can generate consciousness at all.
I think that the conscious thoughts and feelings that flit through your head is a direct reflection of the ever changing pattern of activity in your brain.
I'm suggesting that we're conscious of whatever happens to cause the biggest ripple of activity in our brains at any one time.
If I'm right, these patterns of activity would account for how the mass of protein and fat in our heads can create the richness of thought and feeling we each experience.
We know there's no such thing as a consciousness centre inside our heads, instead it's a result of the overall state of the whole brain and although it may feel special, consciousness must emerge from exactly the same processes as the brain's sub-conscious activity.
We may not yet be able to understand how consciousness is generated, but now that it's accepted as a physical reality and not some mystical phenomenon, I think we are on the road towards a scientific understanding of this age-old problem.
This new century will bring great advances in our understanding of the brain.
As imaging techniques improve we'll be able to monitor the brain's activity in all it's complexity as it flits from thought to thought.
And when we can match each of the many physical processes inside our brain with all our different thoughts, emotions and memories, the phenomenon itself may eventually be laid bare.
As we find out more about what goes on inside this incredible object, so our lives could be transformed.
If we could discover why, when certain brain cells degenerate, memory and personality fade along with them, then would could combat some of the devastating problems of old age, and as we gain insights into the brain processes that are necessary for happiness, then we may have powerful new ways to treat depression.
Whatever we learn about how the brain works, each one of us will continue to enjoy our own private world, Iocked away inside our heads.
I don't believe that neuro-science will ever undermine what it feels like to be a unique, individual human being.
We become conscious.
From the mass of nerve cellsthat have been ticking over while we were sleeping, a strange, new sensation emerges.
The first hand feeling of being a conscious human being.
Somehow your brain creates the intangible, indescribable experience of being you.
It's not something most of us ever stop to really think about, but the fact that we each have an inner world of feelings and experiences is, to me, even more extraordinary than the fact that living things evolved at all.
As a scientist I cannot accept that consciousness is something mystical, beamed into our heads from outside - it has to come from physical processes within the brain.
But the question is - how? The ultimate goal of neuroscience is to interpret all our everyday experiences in terms of measurable changes in brain activity.
So where do we begin with something so elusive as consciousness? Something so utterly subjective and unique to each individual? The challenge is to explain how a kilo and a half of neurones and blood vessels inside our heads, with the consistency of soft butter can generate an extraordinary rich range of conscious feelings that we experience.
From taste of a good cup of coffee, to the satisfaction of solving a crossword puzzle, to the warm glow of remembering a summers holiday on a cold winter's morning.
We take it for granted the brain makes being alive feel the way it does, yet there's no reasons why it should.
The brain is made of the same biological ingredients as the rest of the body.
Yet somehow, it manages to generate the indescribable phenomenon of consciousness.
Understanding this tantalising paradox, is, I think, the ultimate quest for science.
Let's start as simply as possible.
We're always conscious of something.
What determines what it will be? Take driving.
You're going along a route you do every day.
You're changing gear and adjusting your speed and direction and you're not aware of any of it.
You're effectively somewhere else.
Then suddenly something happens and it becomes the focus of your consciousness.
Something switches inside the brain and the actions that were done automatically are now centre stage.
So what is happening inthe brain, when you switch out of auto-pilot and become actively aware of driving? Could there be some kind of higher Control Centre in the brain that determines what you're going to be aware of? Is there some kind of brain HQ which oversees all the activity in the rest of the brain? If so, this centre for consciousness would direct the different processes going on down below.
Whatever it happened to select at that particular moment would be the focus of your consciousness.
So is there any evidence that we have a consciousness control centre in our heads? One man's brain has played an important role in answering this question and it can often be found in the Gardener's Arms in Chester.
Graham Young has a very unusual brain and scientists are so keen to study it, that he's regularly flown, expenses paid all over the world.
It's almost a different life.
I live in Chester and I work in Chester and then I go away doing all this stuff and it's almost like - a separate identity's a bit strong - but it's two different existence's.
Graham became a hot property for Neuro-Scientists as a result of being hit by a car when he was a child.
I had a road accident when I was eight, resulting in some brain damage, so I lost all my vision to the right in both eyes.
As far as he was aware he was completely blind on the right hand side.
I mean I literally used to be walking around town, as an eight or nine year old lad and I'd walk into a lamppost or into a bin.
I just didn't see in and I would walk right into it.
I mean that doesn't happen any more; I've just got used to having half a field of view.
Twelve years later, while he was having his eyes tested in London, they discovered something extraordinary.
It turned out Graham's brain could actually process visual information on both sides, even though he wasn't aware of it.
Graham is an perfect case of a fascinating condition called Blind Sight.
Most people don't get brain damage in such a way as to satisfy the Research Scientist.
Graham fortunately has damage largely restricted to the visual cortex and not to the rest of the brain.
So that makes it a much more pure case.
Graham's road accident destroyed just a small area at the back of his brain.
If losing this area caused him to lose awareness of seeing, could his damaged area be the seat of consciousness? Weiskrantz experimented further.
He showed Graham moving lights on his blind side.
Right unaware, left unaware.
Right Bizarrely, although Graham says he can't see them, he can guess correctly what direction the dots are moving in.
I am completely unaware of an event occurring in my blind field and yet in terms of which way it's moved, I get it right 90% of the time.
That's a bit strange isn't it? And I don't know how I do it.
Right unaware.
Blind sight is a condition which one can respond to visual events without being aware of them.
Okay.
Now that means that as you know what the brain damage is, you can start to say something about what areas of the brain are necessary, are critical for awareness.
So what is going on inside Graham's brain? Scans suggest that when Graham is responding to the dots, but isn't aware of them, a very primitive visual pathway is active.
But when he is actually seeing them, a whole new range of brain regions lights up.
We need lots of different areas for conscience.
Just to receive the information isn't sufficient.
You have to do something with for it to become aware and the regions of the brain that are important for that lie quite far removed from the Visual Cortex in the frontal lobe, involving those regions of the brain that allow us to communicate the fact that we are conscious, that we are aware.
Blind Sight has revealed that there is far more to being aware than a single, central Control Centre.
Instead of some special area, devoted to consciousness, somehow the extraordinary feeling of awareness emerges from ordinary brain activity.
It may not feel like it, but changing patterns of nerve cells, firing in the brain are the basis of everything we experience.
Everything we imagine, all our thoughts and feelings.
Conscious awareness then, must somehow arise from this maelstrom of electrical activity in the brain.
So what could explain which of the many networks of cells firing away in our heads is heard above the background chatter? Neuro-scientists are now squaring up to the big question, which special property or process in the brain might cause consciousness? If there is no special centre in the brain, whose job it is just to generate consciousness, then somehow it must arise directly from the activity of ordinary brain cells, but then we have a problem.
In the brain there are thousands of networks of neurones, all firing away; what special property could a network of neurones suddenly acquire that's just for a moment made it responsible for consciousness? Imagine that your brain is like the surface of a lake in the rain.
Each new event is like a raindrop which triggers a spreading wave of nerve cell activity which then gradually fades away.
I'm suggesting that we're conscious of whatever happens to have caused the biggest ripple of activity in our brain at any one time.
I think of consciousness as something that grows as a spreading wave grows - the stronger or more significant the stimulus, the more extensive the ripples of activity, the more all your neurones are working together.
So the conscious thoughts and feelings that flit through your head, are a direct reflection of the ever-changing pattern of activity in your brain.
One attraction of this idea is that might help explain one of the great unsolved medical puzzles - what happens to the brain when we lose consciousness through anaesthesia? Good Morning Dr.
Artousio.
I hope we're on time.
Good Morning.
Yes, we've a few minutes yet.
Dr.
Nazir, would you go ahead and prepare this patient and I will join you in the lnduction Room in a few moments.
No one knows how anaesthesia robs the brain of consciousness, even though they've been used for many years.
Brain scans have shown that there's no obvious single area that's shut down.
Somehow, anaesthetics must affect the whole brain.
Have you listened? We have now made the transition into surgical anaesthesia.
Dr Bellrow what is the But the really interesting issue for me is that the effects are gradual.
It's like a sort of dimmer switch.
We usually take the patient through the analgesic stage, through the loss of consciousness and through a delirium phase into surgical anaesthesia.
In some intriguing studies in the 1950s, Dr Joseph Artousio investigated the semiconscious state.
Edna, are you comfortable now? Edna, are you comfortable now? Nod your head Edna if you are comfortable.
You see, Edna acknowledged that she was comfortable.
We have now entered the true third plain of the first stage.
Artousio was exploring the possibility of conducting major surgery without the complications of high levels of anaesthetic.
Here, he manages to find a dose which produces an astonishing semi-aware state, where the patient feels no pain, but yet she can still respond to commands.
So what could explain this gradual loss of consciousness? All anaesthetics dampen down electrical signals between the brain cells.
According to my theory, this would stop the waves of activity from spreading so far.
As the assemblies of cells become smaller, our consciousness gradually dims.
But anaesthetics also offer a further clue.
At doses too low to rob you of consciousness, they can nonetheless dramatically distort it, producing hallucinations.
In Zurich, Dr Frans Vollenweider is studying how low doses of an anaesthetic called Ketomene can affect the brain.
Ketomene can enhance your mood, it can give you feelings like euphoria.
It changes all the sensory modalities.
You can for instance hear or you can visualise things that you can't see it.
At first you have illusions, then maybe you have hallucinations, you can see things that do not exist in the real world.
Now it's coming.
It's coming now? Yes, definitely, taking off.
Are you able to close your eyes and focus on your inner experience? On my what, inner experience? The challenge for any theory of consciousness is to explain how minute doses of an anaesthetic can produce such distorted experiences.
Yes, everything is very different than usual.
The visuals effect and the audio effect, they are connected.
They melted? Yeah, they melted, so, by Is vision more auditory experience and vice versa? Yeah.
One gives the other food - that's it.
As I see it, the inputs from his senses would normally dominate his brain, creating a large, spreading wave of nerve cell activity.
The drug might weaken the signals coming from the senses leaving a hectic jumble of smaller ripples of activity, spontaneously generated in the brain, producing hallucinations.
Moving and moving and moving, a box in a box in a box or whatever, had this experience like I was, space was controlling no, my brain was controlling, my brain was controlling, my brain anyway Volunteers have been scanned while they're hallucinating.
Over several minutes a slight change in activity shows up in the front of the brain, but this time frame is too long.
Consciousness is too fleeting for the subtle and transient changes in cell activity to be detected by this kind of approach.
We think that Ketomene directly interferes with the communication between nerve cells and under Ketomene this communication is strange.
Some cell communication is blocked even, and Ketomene may lead to new assemblies between the nerve cells, so that a different kind of network gets established under Ketomene that is normally not working in that way.
And according to your experiences, what do you always see, or? Oh, what I did to today, yeah I travelled through the Galaxy.
Manipulation of conscious experience with drugs is nothing unusual; we do it all the time with alcohol, nicotine and caffeine.
But drugs, don't have to be involved.
I've come to the Palladium in Edinburgh to watch a group of performers who claim to have a unique ability to control the degree to which they are conscious of pain.
This is not the sort of thing, I'd normally go for, but I have to say I'm, quite excited by the prospect, because I gather I'm going to see people putting themselves through enormous agonies, but apparently completely unperturbed.
I'm going to be looking for whether I can apply my theory of consciousness to what I'm actually seeing before my very eyes.
Welcome, brothers and sisters of Edinburgh to the Jim Rose Circus, Secrets of the Strange.
This is a show dedicated to your brain.
The Circus has gained something of a cult following over the last ten years, with it's extraordinary feats of self-mutilation.
What I want to know is what's going on in their brains.
How can they block out, what to me would be unbearable pain? Jim Rose Circus is really dealing a lot with how to use your mind and your brain to empower yourself.
We do it as a warped seminar, it's kind of a comedy - Bibi The Circus Queen, The Amazing Mr.
Lifto and myself.
We basically kind of explain how to circumvent or to overcome what we would call discovery, I think you might, a lot of people might, call pain.
'Bibi's going to lie on this bed of nails, have a glass plate placed onto her stomach and a cannon ball will come down, crashing and smashing the glass.
A lot of people do the bed of nails and there is discomfort there.
Bibi's real fear is the shattering of that plate, because it's random and that's something that she can't prepare for.
Yes! Take a look at her back, take a look watch and register the shock.
Thank you Bibi - you're gonna love it.
' It seems that the way they control the pain is by preparing their mind for what's to come.
We all, throughout the Circus, use the same way of dealing with discomfort.
For example, if I'm doing the Human Dart Board, I put myself, I literally take my mind, which takes it's body, into another place - now where I like to go is into a nice warm watered pool and I like to be right up to my neck, and everything's feeling fine, everything's all nice and warm and relaxed.
With just a plank of wood to protect my Jim deliberately fills his mind with a persistent mental image to block out the pain.
I can take another one Edinburgh, can you? My interpretation is that a large assembly of cells in this brain generates Jim's overwhelming feeling of being in a warm pool.
This assembly is so dominant, it shuts out any rival stimulus like pain.
I feel nothing, I feel nothing.
Ow, I just felt something.
I don't feel the pain, but you see it's different now, 'cos I'm expecting what's happening.
If I stub my toe on my bed or something, at night, I'm going to scream just like you, because I didn't expect it, and I didn't put myself in the warm water.
'What's your name?' Susan.
Susan, I really screwed that up.
Susan from the BBC, give her a big hand.
There you go Susan.
Now then, this is how I shave.
Of course, we don't actually know what the brain cells are doing inside Jim's head.
My idea is still only a theory.
Thank you Susie, give it up for Susie, she's a star.
We may not know the exact brain process which gives rise to consciousness, but we do know that it must be produced by ordinary brain cells.
In other words, it must arise directly from sub-conscious mental activity and that has profound implications for how we view what it means to be human being.
We know that when we need to, our brains can trigger reflex responses without any conscious thought at all.
When facing a serve of over 100 miles an hour, professional tennis players don't have time to mull things over.
Their complex judgements and tactical decisions are all made automatically in the sub-conscious.
If they,by what's happened to me I may just take a look at a ball, I can see what my opponent is, I just hit the ball and sometimes don't even have the time for thinking, and you just have to hit the ball and that's it.
On the hard court and on grass you won't see any, you won't see many shots.
I mean that's why.
You won't ever think, you just hit the ball, the other side where you see the player, that's it.
If they try to become aware of what they're doing, they will fail.
The great players will serve the ball at about 1 00 miles an hour.
The only thing that the opposing player remembers that he can tell you about is watching the angle of the serve, so they're unconsciously carrying out that fast function.
Neuro-Scientist Professor Benjamin Libet has spent the last 50 years fascinated about the sub-conscious.
My own belief is that all our thoughts and all our actions are initiated unconsciously.
Any thought you have perceived very rapidly unconsciously and finally you become conscious of some result.
in 1958 Benjamin Libet began a series of experiments that challenged one of the basic tenets of human existence - that we are free to think whatever we choose.
Occasionally, brain surgery has to be conducted out on patients while they're awake.
Benjamin Libet realised that this gave him a unique opportunity to experiment on the conscious human brain We did not use General Anaesthesia, we used a Local Anaesthetic for cutting open the skin and drilling a whole in the skull and the subjects were very co-operative in general.
He began with a simple query.
How long would the patient's brain have to be stimulated with an electric current before they became aware of it.
We started by stimulating the Sensory Cortex, which is known to produce a sensation in the proper part of the body, usually the hand in our case and to ask the subject if they felt, anything and what they felt and so on.
He discovered that the brain had to be stimulated for at least half a second before the patient reported that they felt anything.
It seems it takes this long for the brain to generate a conscious experience.
That means that you do not experience the environment when it happens.
There's a delay of up to about half a second before awareness is produced.
This first experiment was proof that fast reactions must all be carried out subconsciously.
If you're driving a car and somebody steps in front of it suddenly, you'll slam on the brake in much less than a second and that's undoubtedly unconsciously performed.
If you had've waited for a second, you're liable to have hit the person.
The idea of living 1 a second//in the past may seem strange, but if consciousness depends on large numbers of cells working together, it makes sense that it takes time to develop.
It was his next set of experiments that that caused the real controversy.
This time he had a different question.
Does the brain start first, or do you start the brain? Because the traditional way of looking at voluntary action or free will is that you want to do something and you tell the brain to get going.
The results of his work have been debated for years.
Benjamin Libet may have now retired from the frame but others are continuing his work.
We all have this very strong belief that we have conscious free will and it's a central part of our idea of ourselves as individuals that we can want to do something, we can have an intention to do something and then we can do it, we can make our intention drive our actions and Benjamin Libet's work was one of the few experiments which made a truly innovative and courageous attempt to address that question.
I can't feel it being cold.
Patrick Haggard's team are going to measure my brain activity in the run up to a conscious decision, with electrodes placed on my scalp.
Okay Susan, you're all wired up and ready to go.
Absolutely.
We're going record from your left Motor-Cortex, your right motor Cortex and from the mid line.
I want you to watch the clock hand which is rotating on this small clock in the centre of the screen and then, at any time when you choose, when you intend and will to, I want you to press either this key, or this key, as the urge? -As the urge takes you.
-Fine, okay.
and then the computer will prompt you to type in the position of the clock hand at which you first felt the conscious will to press the button.
Fine.
Good.
-Any questions? -No.
Off we go.
It's very funny waiting for the urge isn't it? So, watching the clock I record the exact time that I make the decision to act, while the electrodes on my head, monitor the activity in my brain, Ieading up to this decision.
As I do this over and over again, a clear pattern starts to emerge.
So here are our results, which contain the same basic effect as Libet originally found.
The average time of the intention to move was where this arrow is here and you can see that the motor areas of the brain have begun to build up electrical activity in preparation for this willed action, 2000 milliseconds, at least, before the action actually occurs.
Just as in Libet's original work, this experiment seems to show that my brain appears to prepare for movement long before I felt like l'd consciously decided to move.
So, did I have any real choice about when I moved? Could the felling of having made a decision, just be an illusion? So, this looks like a real problem for our idea of conscious free-will, because our assumption that we work with every day, I think is that we decide what we want to do and then, or I should say, I decide what I want to do, and then I am able to get my brain to drive my body to make it happen.
The implications of Libet's findings are far reaching.
That our conscious mind, our free-will is merely an after effect.
The actions and decisions that we take every day, which feel like instant, conscious choices are actually the result of slowly emerging sub-conscious processes in the brain.
If everything really starts in the sub-conscious, do we have any freedom or are we sophisticated machines, our responses determined by the mechanics of our brains? There's no question that we are organic machines.
If we think of a machine as any physical system capable of performing certain functions, then of course the brain is a machine and we are, our whole bodies are biological machines, but the point I'm making now is, that doesn't show that we don't have free will, because this is a, the peculiarity of these machines is that they are conscious machines.
Since the 1960's philosopher, John Searle has been a passionate campaigner for free speech.
He believes that freedom, whether at the political or the personal level is an absolutely fundamental part of what it means to be human.
Now here's the problem.
There isn't any way we can think our way to freedom, that is, when you make a decision, when you take any action, you have to presuppose freedom.
If you go in a restaurant and they give you the menu and the guy wants to know what you want, you can't say 'oh well, I'm a determinist, que sera, sera, I'll just see what I order', cos even that is an exercise of freedom, the refusal to exercise freedom is already an exercise of freedom.
When you think about the things that some people do, there's no getting away from the fact that consciousness seems much more like an act of force than a mere after effect.
Mr Lifto is almost the living embodiment of free will at work, but do our minds really give us total freedom to control our thoughts and actions? It feels as though we've got free will, but how could a brain, made of ordinary matter give rise to a mind which floated totally free from physical reality? So here's where we are, at this stage of intellectual history.
We've got this awful problem of free will and people are refusing to look at it, the way they were refusing to look at consciousness, 20 years ago, but if you're looking at consciousness, you've got to look at freewill because it's one and the same set of problems.
All right, there's no way we can think away our own conviction of freewill.
We cannot abandon it.
It's a necessary presupposition of just living on a day to day basis, but we can't square it with the rest of the things we believe.
So we've got a straight contradiction in every lntellectual's conception of how the world works - that we got to resolve.
In the back woods of New Hampshire, Joe - known famously as 'the case of JW' has inspired some thought provoking ideas about where the illusion of free will comes from.
Twenty years ago Joe decided to submit himself to a drastic operation to control his epilepsy.
One day You'd have 2 or 3 seizures and when you do that long enough, you're willing to go through anything.
You say, what the heck, if they want to crack your head open and have an operation, what've you got to lose because everything's going wrong anyway, so might as well go for it.
So I just went for it anyway, because I thought I'd try it and see and it turned out it worked good.
The operation was to split his brain in two.
Having exposed his way into the top of the head, the Surgeon works his way into the cleft between the 2 hemispheres, revealing a white bundle of nerve fibres, connecting left and right sides of the brain.
Tearing apart these 50 million fibres in the Corpus Colossum, prevents epileptic seizures from spreading from one side to the other but it also prevents almost all information from your senses travelling across.
The operation has made Joe a valuable research subject for Neuro-Scientists.
After years of studying split-brainer's, Professor Gazzaniga believes he may have found the source of the illusion of conscious freewill.
He started by examining the linguistic abilities of the left and right sides of the brain.
Words on the right of the screen go to his left hemisphere and he calls them out easily, but when words are flashed to the other hemisphere he says he didn't see anything, but remarkably, he then draws a picture of the word.
Joe draws the telephone his right hemisphere saw, but strangely he can't tell what it is.
I can't exactly tell what it is.
I can't say what it is.
It looks like a shoe I guess.
What else? Coffee, tea I don't know, I can't tell what it is.
Because he thinks that speech comes from the left hemisphere, Mike Gazzaniga believes that the left must also be dominant in generating consciousness.
If you think about the consciousness differences between the left and the right separated hemisphere, the left hemisphere is an interesting, cognitive machine.
It has all these problem solving capacities, talk and language and speech, as you saw and the right hemisphere, basically, isn't a very interesting entity.
You would not want to have a date with a right hemisphere.
Despite having his brain split in two, Joe's life has been remarkably unaffected by the operation.
His personality and his interests have remained the same.
I've had them down there since I was a little boy, and I've been building them and saving them.
They've kept right with me all the time.
I feel pretty much like the same person I've always been, just chopped up a little bit I guess.
As far as the operation goes I don't think it really affected me too bad, just helped, but I don't think as far as making me worse, it made me worse or anything, it didn't do anything, and as far as two brains - I've only got one brain it's just not quite the same design as everybody else's.
The theory goes that if the conscious feeling of who you are came from both hemispheres, then Joe would feel changed by his operation.
Since he doesn't, Mike Gazzaniga's bold conclusion is that Joe's inner voice must come from just one side of his brain and since our inner thoughts are all words, they must come from the linguistic left.
The inner voice in the left hemisphere has got to be huge, robust - it's Pavarotti-like and this right hemisphere probably has a chirp; a little bird sound, because the devices that allow for the inner voice to really expand and express itself, are mostly located in the left hemisphere.
Experiments on Joe have lead Mike Gazzaniga to believe that the left hemisphere may also provide an explanation for the sensation of freewill.
Sun dial What did you say? Dial It's not dial.
In this test, Joe is flashed two words simultaneously.
Shown Hour and Glass he draws an Hour-glass.
With his left hemisphere Joe names it immediately, What's that? Hour glass but Joe's left only processed the word Glass, so he goes on to invent a reason why he drew a timepiece.
Did you see it? What did you see? I saw a glass.
Why did you draw that? I don't know.
Probably still thinking about the clock one, I don't know! It's as if Joe has been fooled by his own left hemisphere.
And so he basically makes up a story to explain the behaviour that he's carried out and he comes to believe that that's the reason why he did a particular act.
And you see those experiments, that kind of phenomenon time and again in these split studies, but the importance of it, is not that it is unique to split brain patients at all, it is a metaphor for what you and I do.
It's that we're constantly trying to figure out, and put a spin on what's coming out of our body.
Gazzaniga believes he's discovered why we think we've got freewill.
The feeling of being consciously in control of our minds, is just an illusion created by the left hemisphere.
Our conscious inner voice is merely a fiction to explain decisions made by the self-conscious.
It's got to be true that a huge amount of what we do in our awake conscious life is governed by unconscious processes.
I'm not conscious about the fact of how that last sentence just came out, it just came out because it's been some guys are down there with framing hammers putting this stuff together and Bingo out it comes, and it's more or less orderly.
So, so just think about the fact that the major management of your body walking through space, you're responding to auditory, visual, tactile events, all that's being done for you, it's just absolutely been done for you and you're not paying any attention to it at all.
You don't even know about it, but it does a wonderful job and it just turns out more and more of your cognitive acts are the same.
The work with split-brainers, like Joe is fascinating, but I'm not convinced that the experiments prove our consciousness emerges from just one half of our brain.
And this research doesn't actually get us any closer to answering the most important question of how brain cells can generate consciousness at all.
I think that the conscious thoughts and feelings that flit through your head is a direct reflection of the ever changing pattern of activity in your brain.
I'm suggesting that we're conscious of whatever happens to cause the biggest ripple of activity in our brains at any one time.
If I'm right, these patterns of activity would account for how the mass of protein and fat in our heads can create the richness of thought and feeling we each experience.
We know there's no such thing as a consciousness centre inside our heads, instead it's a result of the overall state of the whole brain and although it may feel special, consciousness must emerge from exactly the same processes as the brain's sub-conscious activity.
We may not yet be able to understand how consciousness is generated, but now that it's accepted as a physical reality and not some mystical phenomenon, I think we are on the road towards a scientific understanding of this age-old problem.
This new century will bring great advances in our understanding of the brain.
As imaging techniques improve we'll be able to monitor the brain's activity in all it's complexity as it flits from thought to thought.
And when we can match each of the many physical processes inside our brain with all our different thoughts, emotions and memories, the phenomenon itself may eventually be laid bare.
As we find out more about what goes on inside this incredible object, so our lives could be transformed.
If we could discover why, when certain brain cells degenerate, memory and personality fade along with them, then would could combat some of the devastating problems of old age, and as we gain insights into the brain processes that are necessary for happiness, then we may have powerful new ways to treat depression.
Whatever we learn about how the brain works, each one of us will continue to enjoy our own private world, Iocked away inside our heads.
I don't believe that neuro-science will ever undermine what it feels like to be a unique, individual human being.