Brain Story (2000) s01e01 Episode Script

It controls all our actions.
It's who we are It's the source of our emotions.
It contains a lifetime of memories, and a world of inner thought.
This series will take you inside the living, human brain.
We're going to get you counting and talking when I touch your brain with an electrode.
1, 2, 3, 4 7 and 8 later! I'm Susan Greenfield and my goal as a scientist is to discover how the brain works.
This is a unique form of scanning in that it enables us to actually see a thought.
We'll meet people who's extraordinary brains help us understand ourselves Joe's split brain allows him to draw two different objects, simultaneously.
Brain damage has left this woman unable to see anything that's moving We'll explore the surprising ways our brains play havoc with reality.
We'll delve into our darkest fears.
How can the terror of the battlefield physically change a soldier's brain? How can the web of living cells inside our heads, give rise to the stunning range of sensations we experience? Could love simply be a hormone surging through our veins? From birth to death, we'll see the amazing ways our brains are constantly changing.
We'll search for the routes of fabulous creativity unleashed in this man's diseased brain Even the most spiritual aspects of our lives will be dissected I don't feel alone The walls of Ancient Jerusalem have witnessed the ebb and flow of cultures for thousands of years.
And yet in all this time, the essential nature of what it is to be an individual human being has remained the same.
Every generation that's ever walked these streets must have come up against the same basic questions.
Why do we think and feel the way we do, what makes us who we are? And yet despite thousands of years puzzling over these fundamental aspects of human nature, we still seem to understand so little about ourselves.
People have always believed that there is more to the human spirit than mere flesh and blood.
But as a neuroscientist, my view is that we can explain everything about ourselves by looking inside.
I'm sure it has to be the brain that makes us who we are - our hopes, our fears, our thoughts our dreams are all somehow hidden away inside our heads.
I'm convinced there isn't a single aspect of our lives that doesn't reside in the sludgy mass of our brain cells.
I'm convinced that one day we will be able to interpret even our most intense, spiritual feelings in terms of the workings of the brain.
Research is finally bringing us closer.
We've already learnt an enormous amount about the basic physical processes going on in the brain.
But now I feel we're on the verge of being able to apply what we know, to take that knowledge and transform it into a true understanding of ourselves.
I think that science might be about to lead us into a place we've never been before - inside the human mind.
This is the challenge - to uncover what's going on inside a kilo and a half of pulsating brain, with it's network of a hundred billion nerve cells.
I've known neurosurgeon Henry Marsh for over 25 years.
But this is the first time I've seen him at work.
The first time I've been face to face with a living human brain.
Standing next to Henry, peering down at the surface of the brain, it is incredible to think that these nerve cells, somehow create the human mind.
We all think of mind and matter as being separate things but it is very extraordinary when you actually see the brain, particularly to operate upon it and if you think I'm actually operating upon thinking, I'm operating upon feeling.
Today, Henry is going to remove a tumour from Sarah Kitchen's brain.
It's a delicate operation because the tumour is near a region of the brain that is involved in language.
Damage a vital area, and Sarah might never speak again.
To avoid this happening, Henry has to do something extraordinary.
They've been going now for about an hour and the critical phase is coming where they're going to have to remove the tumour.
In order to do that, Sarah has to be awake.
Sarah, Sarah.
If you have a general anaesthetic and go into an operating theatre and have somebody operating upon your brain it's jumping into the deep end with a blindfold on, and you hope you're going to come out the other end in one piece.
But if you're actually awake while it's going on there's a much, in a sense a much greater sense of control, and in a way you're part of the team.
What we're going to do now is get you counting and talking when I touch your brain with an electrode, so we can work out where the speech area is.
OK.
Sarah, can you squeeze my hand? Once Sarah is awake, Henry begins to pinpoint the crucial speech areas.
By using tiny pulses of electric current he can jam temporarily the mental activity going on at a particular site in her brain.
Can you do some counting for me.
I want you to count up to 1 0 and then back down again.
1, 2, 3, 4 6, 7, 8, 9, 10.
That's great.
It wasn't that she knew the number 5 but couldn't actually say it she could think the number 5 but couldn't think of it as a number so to speak.
It's different, one's not paralysing the vocal chords one is actually paralysing the mental processes that turn a concept, a thought, whatever you want to call it into a word Carry on 1, 2, 3, 4, 5, 6, 7, 8, 9, 1 0 Ah Go on counting 1 1,1 2,13 (spoken in a slurred way) 12, 13, 14, 15 OK, wash please.
Sarah thank you very much.
Sorry to play games with you like that It's such a bizarre experience.
Talking to Sarah about her favourite recipes while Henry is prodding around in the very thing that makes her who she is.
I like spinach, cheese, pepper,spaghetti I like this menu Do you feel slightly drunk? A little bit, I like that feeling.
You sound fine, it's nice to see you smiling! Everything's going really well.
It is actual living proof of the fact that thought is a physical phenomenon.
We're all so brought up by, not just by our parents but by sort of thousands of years of culture to feel that thought is somehow as free as the air, it's mind as opposed to matter.
But to actually see somebody talking on one side of the screen and on the other side you see this blob of brain which is doing it, it's a very profound thought provoking experience.
I've spent 30 years of my life studying the human brain, and I'm still fascinated by the idea that this messy looking lump contains all our secrets, our thoughts and our feelings.
But the brain is doing much more than we're ever aware of.
We take so much for granted.
So how does the brain generate all the different aspects of our mental lives? Can we say where thoughts and feelings actually take place inside our heads? Well there is one mental function which does seem to be related to specific areas of the brain, - it's the feeling of having a body.
Our arms and legs are continually feeding back information to the brain, which then somehow creates a sensation of what our body is doing.
The brain constructs a body image.
It generates it in such a way that we attribute sensations when we feel objects to the part of the limb that's been contacted and that's very important.
Peter Halligan studies people with an intriguing disorder.
Five years ago, Angela Button had a blood clot in her right arm that meant it had to be amputated.
But Angela feels as though her lost hand is still there.
She has what is known as a phantom limb.
The phantom hand, just illustrate where it is.
My fingers feel, probably I would say about there, because the whole of my hand feels as if it is joint on to my stump.
Patients with phantom limbs feel the experience that they have such reality that they often, in the early stages at least, will attempt to make use of them.
And this is not surprising, people with phantom legs will get out of bed and assume the leg is there, and fall over.
Patients for instance who have maybe an itch on the nose will attempt to use the phantom limb to actually scratch it.
Angela can I just have a look at the actual stump at the moment, and test the extent to which you actually have sensations there, so just tell me what you feel as it were.
So if I touch you there what do you feel? Movement in my thumb and my little finger.
You're actually feeling it in your I'm feeling it in my fingers.
OK that's interesting.
Over to here.
How's that.
My two, these two fingers are going.
Movement, you feel movement? Hm.
For Angela, the phantom is very real.
Any physical contact with the end of her arm generates sensation in the missing hand.
But it's not her arm that is generating the phantom it's her brain.
Angela has not suffered any explicit demonstrable brain damage, so the brain area that represents the hand is still in tact, and therefore the idea would be that it would be capable of still representing an experience of that despite the fact that the hand isn't there.
Your brain contains a map of your body, and it is here that nerve signals from the legs, the arms, the face, are translated into sensations.
Even though there are no signals from Angela's amputated limb, her brain continues to generate the sensation of having an arm.
And in her case, something else has happened to the brain's body map.
Let's try here.
What do you feel? My little finger is moving.
That.
Tingling in my little finger.
Let's see down here now.
Experience any sensations? That's my thumb going.
OK, now if I combine those two.
Touching Angela's face seems to create a vivid sensation in her phantom hand.
As a result of the loss of the limb, the brain appears to restructure itself, such that information that now comes from the face is actually related or linked to the hand area.
With no incoming signals from her hand to keep her hand area working, the activity in the neighbouring face area spills over into this vacant territory.
Touching Angela's face now triggers the hand area in her brain as well.
Phantom limb seems to be suggesting that sensations in different parts of the body correspond to activity in particular areas of the brain.
It's intuitively appealing to think of the brain as having different specialised regions, and for certain basic functions this seems to be the case.
But what about the less physical aspects of our lives, our individual way of thinking? Is it possible that every nook and cranny of our characters can be traced back to an individual part of the brain? Two hundred years ago, scientists thought they had succeeded in doing just this.
The phrenologists believed that every single mental skill was controlled by its' own particular brain area.
Now we know the truth is far more complex, but to a certain extent the brain does seem to break down into areas specialised for different functions.
After an accident ten years ago, Isobel Rye has lost the ability to recognise music.
Isobel has a condition known as amusia, a subtle form of brain damage.
It allows us to explore whether even something as sophisticated as music, has its own specialised area in the brain.
She does hear that it is music, and not language or some noise But I don't have the slightest idea how music sounds in her brain.
I'd love to know.
No matter how many times lsobel hears a piece of music it always sounds like she's hearing it for the first time.
But there's nothing wrong with her hearing - it's inside her brain that her recognition of music breaks down.
What is spectacular about lsobel is that her musical functions or most of them seem to be so severely impaired, while her language is intact.
Here in Montreal, Professor Peretz has begun to explore exactly what happens in lsobel's brain when she listens to a piece of music.
Isobel has brain damage in areas known to be involved with processing the raw nerve signals coming from the ears.
But does her condition really prove that these areas are the brain's music centre? As Peretz has delved deeper into lsobel's mind it seems that the answer is not that simple.
Strangely, lsobel's ability to grasp the mood of a piece of music is intact.
Isobel is living proof that even something as abstract as the appreciation of music, can be traced to a physical activity in the brain.
But she hasn't completely lost the ability to respond to music.
So the brain processes involved in dealing with music must be much more complicated than just a single specialist area For complex experiences like this we rely on many parts of the brain and only when all of these parts are intact and working together, is the experience complete.
Every time scientists have tried to pin down a complete aspect of behaviour to a single brain area, they have failed.
Although there are undoubtedly areas specialised for different functions, we will never be able to say exactly what happens where in the brain.
My own research in Oxford is into degenerative brain disorders Iike Parkinsons and Alzheimers diseases Studying these devastating conditions, involves getting to grips with another aspect of how the brain works.
I've spent almost 30 years trying to understand what goes wrong in the brain in Parkinsons Disease.
We've known for a long time that the heart of the problem lies in a small brain region in the base of the brain called the substantia nigra.
But why is it that when the cells there are damaged we can no longer translate a thought into a movement? These patients illustrate the classic symptoms associated with damage to the substantia nigra.
They are fully lucid and yet the effects of the disease prevent their brain cells sending out the correct nerve signals to the muscles.
It turns out that this mental paralysis can be overcome by replenishing the brain with a chemical called dopamine Unfortunately, this dramatic effect doesn't last But it does reveal the powerful role chemicals play in the brain.
Dopamine works by allowing individual brain cells called neurones to communicate with each other, and there are dozens of other chemicals each like dopamine with their own role in the brain Between each neurone is a gap called a synapse.
When an electrical signal reaches the end of a neurone it releases a particular chemical.
This neuro transmitter then travels across the synapse and triggers a new electrical signal in the next cell.
All brain activity boils down to this.
So everything we do involves a frenzied web of chemical and electrical activity.
If we're ever going to explain how we work we'll need to keep track of all these microscopic interactions throughout the whole brain We know all the answers have to be in there, but how will we ever see inside? I'm about to be scanned in a machine called a magneto encephalogram, or MEG for short.
This device will come down over part of my head and actually pick up minute magnetic fields, and these fields are generated as a result of the electrical activity in my brain cells.
This is a unique form of scanning, in that it enables us to actually see a thought.
It can't measure chemical changes in the brain, but MEG is currently the most precise tool that exists for monitoring fast changes in electrical activity.
In this way it reveals how different areas of the brain work together.
At the moment scientists can only use MEG to explore what's going on during very simple tasks, because anything more difficult throws up patterns of activity that are far too complex to decipher.
In this experiment I have to count the number of times the small squares change to large ones.
It seems like a simple task, and yet MEG reveals something intriguing.
Massively slowed down, coloured patterns of electrical activity show what happens in my brain.
In the course of half a second different areas across my entire brain are pressed into service.
MEG is showing us how the brain functions as a whole.
It seems that for even the simplest of tasks many regions must work together.
But the big question is how does the brain do it? How does it integrate all this different activity into the seamless experience that we call life? For me, the challenge is not just to understand how the brain works in general, but also to explain exactly how each one of us comes to be the unique individual we are.
What is the basis of our own specific memories, emotions and thoughts.
What is the basis of our personality? Dick Lingham is not the man he once was.
Eight years ago his wife Lynne began noticing changes in Dick that she could not explain.
His personality has changed in that he is less aware of the effect his behaviour has on people.
There's no, there's much less empathy than there used to be.
He can get very agitated if things aren't going his own way, which he wouldn't have done before, he would have just sorted it.
I live with the husband I love dearly, but we can't even watch a film together on television because he can't follow the plot.
Dick's been diagnosed as having a degenerative brain disease.
It's slowly destroying the front of his brain.
My wife was given to understand that it might well just be two years before I was um in a mental, I suppose some sort of home anyway, and she would not be able to look after me.
But in point of fact we've had seven years and it's gone pretty well.
Um I must drive her to distraction but I'm unaware of it.
One of the strange by products of my illness is that you don't really mind, so from that point of view it's pretty good.
What's remarkable about this disease is that as cells are gradually dying off in the front of Dick's brain, his entire personality is undergoing a dramatic change.
Frontal lobes are the most sophisticated part of the brain, the part that makes us individually different from each other.
They're very important for our temperament, our social interaction, our personal style all depends very much on the frontal lobes.
Damage to his brain is turning the person Dick was into a very different individual, who is behaving in very different ways.
He's always been very good at telling jokes and stories but now he does upset people sometimes in some situations because the jokes are inappropriate.
Although he was told some of the things he'd been doing it didn't matter to him, he didn't see the significance of them.
And nor do I wish him to know some of the time, if he doesn't feel it in himself then what's the point of just always pointing out to him what he's doing, what he's saying.
But as Dick's condition has worsened, something incredible has happened.
The brain damage has released abilities that Dick never knew he had.
He has become overwhelmed with the urge to paint.
I've put diluted ink onto the paper and the idea really is to just build up a pattern which later I'll try to interpret into some reasonable picture.
As his brain continues to degenerate, this new skill sadly will fade, and this new personality will disappear.
I never reckoned I could paint anything in particular, I was never wonderful about that.
I've I enjoyed doing art at school but that was 40 odd years ago and I haven't done any art since then.
I think the only interesting thing is not whether the pictures are any good, that's almost an irrelevance but the fact that you are doing it for the first time in all that time.
I quite like that image although I'm a little unsure as to what's happening here.
We don't know why Dick's brain damage has changed him so dramatically.
But for me this tragic condition is proof that one day we will be able to explain individual personality and creativity in terms of physical processes within the brain.
I think one has to think of the brain as a number of interactive modules and that some perhaps inhibit or suppress the function of other modules, and so if you knocked out a module that's main role was inhibitory, then you could have a gain of function of other parts of the brain.
Maybe the disease has caused some widespread reorganisation in the basic circuitry of Dick's brain.
We can't yet say.
The neural routes of creativity must be complex.
Many other types of brain disease can also have striking effects on people's artistic imaginations.
In May 1 889 a young artist was admitted to this mental asylum in the small French town of St Remy.
He was suffering from severe mental delusions, and was quickly diagnosed as having epilepsy.
His name was Vincent Van Gogh.
Sitting among the very scenes that Van Gogh captured on canvass poses intriguing questions as to how he saw the world.
Is it possible that the physical upheaval in his brain somehow transformed his perceptions? Could it be that the epilepsy led not only to his crippling mental problems, but at the same time to his awesome creativity? I believe Van Gogh saw the world differently.
And we are so lucky that he was able to put it on the canvass and let us see it through his eyes.
For the last 30 years, Shahram Khoshbin has attempted to piece together the effect that Van Gogh's epilepsy had on his life and his art.
In the case of Vincent Van Gogh it was a type of seizure that had more to do with his ideas and rush of ideas and his behaviour than had to do with the traditional aspect of epilepsy where patients fall to the ground, jerk all over and foam at the mouth and lose consciousness.
Khoshbin believes that in Van Gogh's case the epilepsy affected the area of his brain just behind his temples, known as the temporal lobe.
The sensory integration takes place there - vision and hearing.
Because it comes in there and gets processed there.
So it's easy to see how a disturbance in this area could create a different sensory experience.
The epilepsy that Van Gogh probably suffered is not uncommon.
But in a small number of cases the resulting uncontrolled brain activity can permanently change the way a person perceives the world.
I see colours very vividly.
I love rainy days because it brings out the colour in the buildings around here and I can enjoy them even more.
Like Van Gogh, Reen Carter has had temporal lobe epilepsy all her life.
Dr Khoshbin has been working with patients like Reen to find out exactly how the epilepsy distorts their perceptions.
Colours are brighter, she describes that Shades are not grey, they're distinct, she describes that.
That experiences, other than visual also have the same connotation, things tend to stand out, become more separated, become more vivid, become more outlined if you wish.
And I hear this over and over again from my patients and I hear it from her.
When I was a student I'd go to visit the library.
I never checked out books but I would go to visit the elevator.
There was a red and a green arrow, I'm sure to everybody else very ordinary colours, even maybe a little bit muted but when the elevator was going and it was lit it would just make me feel so good to look at it, it was almost rapturous.
One day I made three hours of going up and down, just looking at those arrows, and changing, watching it change colours.
It was just so beautiful If epileptic seizures happen regularly in the temporal lobe a sufferers thoughts, emotions and actions can be altered permanently.
Malfunctions here may sometimes even be the trigger for our most intense spiritual feelings.
During his time at St Remy, Van Gogh began to display some extreme character traits.
Among his obsessive habits his religious beliefs suddenly became far more intense.
He studied to be an evangelist and then he was hired as a priest for a while.
And the reason why they discharged him was because they said his zeal was scandalous, imagine that how religious he must have been, he must have been too religious for the church.
On Sundays, Van Gogh would often visit three or four churches.
Religion was beginning to consume his whole life He was writing religious remarks on the walls, at one point writing "l am the holy spirit".
Um these are above and beyond the religious experiences one would have expected.
We'll never know for certain hether Van Gogh's w religious beliefs were triggered by his epilepsy.
But the very idea is fascinating, it raises the possibility that even our most spiritual experiences can some how be boiled down to the firing of neurones inside our heads.
Starting from a very early age I would have these sensations that would make me want to talk about things that the other children didn't want to talk about.
I just felt like I had a destiny to do something.
For most of her life, Reen Carter has experienced vivid religious hallucinations.
Her temporal lobe epilepsy seems to have been a key factor in her religious beliefs.
One day I had a vision of Jesus on the cross.
I was quite close to him, I was looking up His crown of thorns was not like the kind you always see.
It wasn't all dried up and brown, and it was very alive, it was green and had some leaves on it even.
That was a very big thing to me, to prove that this must be real.
I thought God was helping me to have this experience.
I don't think that I can for sure say that her entire belief system is based on this condition, but I can for sure say that this condition has affected it.
When I look back at the vision of Jesus on the cross I believe that I had a seizure.
My religion is more now in the practical sense, but I keep hoping that something will come back to me.
Cases of temporal lobe epilepsy give us an intriguing insight into the changes that can occur when the brain is disrupted.
But is it really likely that all religious experiences can be boiled down to the firing of neurones? For thousands of years we've looked to the heavens for answers that we couldn't find on earth.
In Jerusalem the importance of religion to Christians, Muslims and and Jews is powerfully evident.
For millions of people it remains a central pillar of life There are many questions about religion that aren't easily tackled by science.
What is the soul? Is there an after life? Does God exist? But surely that shouldn't stop us trying to explore what might be going on in the brain of someone who's having an intensely personal spiritual experience.
It may well be a very sensitive area of scientific investigation, but if we're going to try and understand every aspect of our lives in terms of brain function, then surely it's something that we can't simply ignore Whatever is going on in the brain is not beyond science, but that doesn't remove it's fascination or it's mystery or it's significance, it just tells us that the brain is generating it.
What we have to do as scientists is understand the pattern and what it means.
In Canada, a series of controversial experiments are taking place that explore how the brain might generate spiritual experiences.
The experiments are actually quite simple The individuals are randomly selected, usually volunteers OK the subject is brought into the laboratory, they sit in an acoustic chamber Close your eyes We blindfold them, so those neurones which would typically be engaged in surveillance in your environment can be recruited into the experience, to amplify it, so that the individual can experience it very vividly.
The volunteers have no idea what the experiment is about they are simply told to relax and describe what they experience I see like a forest fire, but it's really far away.
Persinger has designed a method for stimulating the temporal lobe It's a big hill or something, like a fire Coils in the helmet generate a magnetic field that amplifies the activity in this part of the brain and stimulates the thoughts and sensations produced there.
Yeah there it is it's way over there.
It's like an eye, it's moving and getting closer The experiences generated certainly seem out of this world.
It's black and there's a bigger eye.
Oh a bright light, nice purple Yeah it's not an eye anymore, it's gone.
The kinds of experiences, they're always related to temporal lobe themes, vibrations, movements, er experiences of being out of their body, of moving through tunnels or shapes or orifices of some type, seeing bright lights Tunnel, tunnel, I'm in a tunnel again.
A tunnel with a bright light.
Things are moving too fast.
Now I'm coming up the tunnel.
This is neat Now the tunnel's But Persinger can manufacture far more disturbing sensations than just visual hallucinations.
If we applied fields in a specific sequence we can induce the experience of a sensed presence, that there are some entities standing beside the person.
The idea of someone standing nearby.
I don't feel alone.
I'm going really fast over bumps and water His stimulation experiments have never yet produced a clear cut spiritual experience.
But Persinger's convinced that he has recreated many of the basic sensations that accompany religious belief.
In our laboratories context, I mean you know you're safe, you know it's a laboratory, you know that we're doing it, that an experimenter is doing it, or that something is involved with the experimenter.
I see a face Well suppose the same experiences, the same richness, and vividness, and feeling of a presence, something taking over your body occurred at 3.
00 o'clock in the morning when you're by yourself in your bedroom.
Somebody just shut the lid.
Then of course there would be a different explanation, you wouldn't have the easy pat explanation well the experimenters are doing it Instead you'd have to have an explanation given to you by culture, and most explanations for unusual phenomenon are attributed to gods.
One thing we do know is that the experiences that we call God in mystical experiences are from the brain, and now we know we can experimentally duplicate them, at least fragments of them in the laboratory.
That means we can understand them more and they're no longer the privileged experiences of a few, or individuals who have been anointed to interpret these experiences.
All people have them, it's a part of our brain, and like any talent some people will have more of these experiences than others.
The critical thing is that now science has the technology to find out how these experiences actually work.
Although experiments like this only begin to throw light on the physical basis of mystical sensations, they are part of a growing attempt to understand personal experiences that until recently, have been beyond the reach of science.
In the course of this series we will try to reveal the basic brain processes that lie behind every aspect of our mental lives.
Not just spirituality, but memories, intelligence and the very nature of conscious experience We'll be seeking a scientific explanation for who we are I don't think we should find this idea too upsetting, the idea that we might be reduced to a mere pile of neurones.
We shouldn't be any the less awe struck by life.
For me the real wonder is that a hundred billion brain cells working together can produce so much.
In the next programme, we find out what makes life worth living.
How does the brain brings the intense feelings of love, fear, anger and joy.
We're going to explore our emotions.