Brain Story (2000) s01e05 Episode Script

For six years, Harrison Ward Mullis battled with uncontrollable epilepsy.
His family faced a stark choice, let the fits continue or risk radical surgery.
I was absolutely devastated, absolutely devastated.
I mean I just could not take it in, When they was talking about surgery I thought they would be taking a piece of the brain out, I had no idea that they were going to remove a complete half.
Harrison has coped with the loss of an entire hemisphere.
Do all our brains have this amazing flexibility? This splendid house has belonged to the same family for almost seven hundred years.
Down the distant line of ancestors, many of the family's physical features have been transmitted in their genes - the familiar shape of the face, the eyes.
Looking at their portraits I can see the likeness clearly.
But I can tell very little about what kind of person each individual was, or how their very different experiences shaped what was going on inside their heads.
The Lords and Ladies of this ancient family, Iike all of us, must have been a mixture of the genes they were born with and the environment in which they were raised.
Our surrounding, our memories and everything we learn and experience throughout our lives will all influence who we become.
This sculpting of our individuality takes place in a physical setting, - our brains.
I think it is the differences in our brains, the way the connections are configured and fine tuned throughout our lives, that makes every one of us unique.
I see each of us as an accumulation of experiences, with our brain constantly adapting to the unique world in which we live.
We all like to think that life is about how we might leave our mark upon the world, but the question for me is how does the world leave its mark on each of us? The growth anatomy of the brain is laid down in our genes, Scans of the growing foetus reveal how the convoluted folds of the adult cortex gradually develop.
But what about the brain's internal workings, all the detailed nerve circuits which are necessary for our mental skills to develop properly? How much of that is determined by our genes? Take a universal skill, like recognising another human face.
You might expect a basic brain function like this to be hard wired from birth, but its not.
At the Birkbeck College Baby Lab in London, researchers are investigating the changes in brain circuitry as a baby gradually learns to distinguish faces from other shapes.
Surprisingly, they're really rather good at it.
Very early on the new born is attracted by anything that has a face like configuration, so two blobs for the eyes and a blob for the nose, mouth is enough to attract the new born's attention and it will follow it, over other shapes, quite interesting shapes.
And over other scrambled face like shapes.
It wants this special configuration.
Over several months the electrical activity in a baby's brain is monitored when they're shown upright faces compared with upside down ones.
New borns respond exactly the same way to both.
But by eight months old, Jessamine's brain seems to have changed.
When babies are very young, one of the things you see is that they show different patterns of brain activity when shown a face the right way up and a face upside down.
Now those are the same features if you like just turned in a different way, so if they were just responding to features they would show the same brain activity.
The very fact that they show different brain activity, with a special peak when it's the right way up suggests that they really are processing faces in a configural way as a whole face and that the upside down face is just seen as a collection of features.
So how does a baby develop this special response to faces? What's guiding the change in nerve circuitry of Jessamine's brain? The researchers here believe that we don't develop these skills automatically.
It's only the repeated exposure to faces which trains the brain.
So genes give a child the potential for mental skills, experience determines whether the skills actually develop.
If you want to really understand how a brain emerges rather than is pre programmed you have to look at the child as in a sense structuring their own brain.
And that way the baby's brain is a function of what the baby does, so one could say the baby builds its own brain.
I don't think that's an exaggeration at all.
So how does experience of the world shape the development of a child's brain? We're born with almost as many brain cells as we'll ever have.
What changes are the connections between them.
The brain is an ever changing web of billions of cells.
As each brain cell grows it forms thousands of connections with its neighbours In the first few years of life there's an explosion of connections between brain cells as the brain wires itself up.
Each experience no matter how small leaves its' mark on the brain by stimulating more connections between brain cells.
With each new experience some connections are strengthened and others are weakened in a constant process of wiring.
Just as we develop connections with the right inputs, so we can also prune them back.
The brain has no use for too many idle connections so it cuts back on those that aren't continuously reinforced with experience.
How our individual brains take shape depends on which connections are reinforced and which fail to stay the course.
The result is a dynamic flexible brain.
Just how flexible we're now beginning to understand through remarkable cases, Iike Harrison Ward Mullis Harrison is now six.
Soon after he was born a blood vessel burst in his brain, which left him with crippling epilepsy.
Harrison was constantly having seizures, what they called a non convulsive epileptic state, in other words you wouldn't see him having seizures.
And when I said, I used to say to people "My son's got epilepsy".
"Well he looks all right to me" He had the sort of seizures that he would sit and chew, but nothing in the mouth.
He would start rocking, and he would do this for about an hour.
He was aggressive, he would all of a sudden see something in a room and aim it towards anything or anybody and the behaviour gradually got worse over the years.
The full extent of Harrison's epilepsy became clear when he was wired up for observation by Dr Frank Bizak at St Piers Epilepsy Centre in Surrey.
The stream of irregular spikes shows Harrison's brain is in constant turmoil.
He's having small seizures one after another.
It's a situation that has been very frustrating for years When we see it so dramatically on the television screen It makes it seem real and tangible.
You know I've been in supermarkets where people have said "Oh if he was mine I'd thrash him".
Yes well thrashing isn't a recognised method of correcting brain wave abnormalities of this extent I'm afraid.
I think it's very difficult for us to put ourselves in Harrison's place but looking at these little storms occurring every few seconds, as they are right now If we imagine that his brain function for those few seconds is being quite significantly impaired, and yet people are having normal expectations of him.
And he's switching in and out all the time.
A scan revealed massive damage in the left half of Harrison's brain, but the right looked normal.
These seizures were probably all originating from the bad brain on the left side of his head.
So almost certainly the bad brain was sending a storm of abnormal electrical discharges into the good brain, preventing it from working as well as it would have been otherwise.
Harrison's family were offered a radical treatment - surgery to remove the malfunctioning half of his brain.
This would be a risky operation.
The big thing for me in deciding whether to have the surgery was the fact that at any given moment I could have lost him in a seizure any way.
He could have gone into a major seizure where he could have died Since it was the only way to tackle his epilepsy, Harrison's left hemisphere was completely removed.
But normally the left side of the brain is vital for speech, and it controls the movement of the right side of the body.
How badly would it's removal affect him? For three days after the operation, Harrison was unconscious.
All of a sudden, he just made a movement to get up and I just grabbed him and he just started talking.
I then knew that he was out of this almost comatised state.
He spoke, when he finally came round for the first time in six years he put four words together as a sentence.
And that was instant.
His speech was so much better.
Here we go Harrison, that's very good.
His control of the right side of his body has been affected by the operation, but with intensive physiotherapy Harrison is improving steadily.
It seems that if part of a child's brain is damaged the rest will automatically rewire itself so that vital functions are taken over by the remaining normal tissue.
Are you going to start us off then? Twinkle twinkle little star, how I wonder what you are, up above the clouds so bright, like a diamond in the Harrison's story reveals the amazing dynamism of the nerve circuitry in the developing brain.
How I wonder what you are.
Our brains are at their most flexible in childhood, but throughout our lives our grey matter is endlessly being shaped by experience, and moulding itself to fit new circumstances.
If you lose a large part of your brain as an adult it's unlikely you'll ever fully recover any lost function.
But it would be wrong to think of the brain as a fixed structure, which when it finishes growing sets hard.
At the microscopic level the connections in our brain are constantly changing as we go through life.
That's what learning and memory are all about.
We never lose the ability to learn new skills.
I may be making a hash of this now, but it shouldn't take too many lessons before I get the hang of it.
As I keep trying to get the right pressure on the clay, the nerve circuits in my head are changing.
How are our brains physically shaped by the experience of learning new skills? This issue is explored in some remarkable work with children who have difficulty with reading.
So now all the words you're going to see in this game are made up words.
Just read for me the words Cassie is unable to convert an unfamiliar group of letters into the sound of the word.
Instead she just guesses.
Just click the mouse when you're ready.
Gloop.
Wip.
Swag.
Psychologist Bruce McCandliss specialises in helping children like Cassie to learn to read.
Our brains automatically decode the letters that they see into the sounds of the language and blend them together into whole worlds.
If you don't catch onto this skill early on in the reading process often times you might get stuck, trying to compensate with other strategies.
The word on the screen is pen, make a new word by taking away the N and add a T.
Bruce is interested in the changes that occur in his students brains when they finally learn to read properly.
How about down here though? What does the end of this word look like.
It's T and S.
How would you say T and S together? St Yeah that's it.
Okay lets just run through a couple of them make sure we have that down Best.
Ha ha.
You've got to look really carefully at the letters there.
The letters will tell you what word it is.
Bets.
There you go, great.
Reading is a complex skill which involves, hearing, vision, memory and speech.
But Bruce has scanned the brains of good readers and identified one key area which seems to be active specifically during reading.
He believes this area is involved when we're converting letters into word sounds.
Said Mike.
Grace led Mike to the spider club.
Inside the club were With Bruce's help Mark has just learnt to read in the last few months.
Not me said Grace I like spiders.
Mark came in reading at a very low level and we struggled with a couple of very key letter sound identification concepts with him.
But over the course of the 24 sessions he started to really catch on, and started to very actively, started to decode words on his own, started to correct his own errors and started to realise the role that each letter played in a word.
Right come on in here.
Just like last time.
Mark had a brain scan before he did the reading course, and his brain showed no activity in the key area Bruce believes is involved in reading.
Now that he can read he's having a second scan to compare the pattern of activity.
Inside the scanner Mark does a reading test.
Those are beautiful great.
The second scan of Mark's brain, when he was reading well, reveals a clear change.
As he learned the new skill of decoding letters into sounds he made new connections in his brain.
I'll show you some of the things we've found.
We did the same exact scan with the same exact words a little while later and look what happened.
What do you see there? The red dots.
Yeah that's right.
Do you know what the red dots mean? That it was working? That's right, that part of your brain was working pretty hard when you were playing the word game.
So we're really excited about that.
It's an example of learning changing the pattern of your brain activity.
So what do you think about that, seeing the inside of your brain and what's going on as you're thinking about stuff? -Pretty neat.
-Yeah As we develop into adults our brains gradually acquire a unique individual personality.
I believe that much of who we become is the result of our brains absorbing what's going on around us.
Mostly we're unaware of this process.
But occasionally something is so significant we know it's altered our brains.
It's become a memory.
Memory, like other aspects of brain function develops as we grow.
Our entire system for storing and retrieving memories is evolving in the first few years of life.
None of us remember the events from early in our life, and in fact if you ask most people how old they were for their earliest memory, generally it's between 2 and 4 years of age.
At his lab in Minnesota, Charles Nelson is testing children of different ages to see how their brains change as their memories develop.
Our data suggests to us that a baby's memory system is present at birth.
It is far from as developed as it will be, but the fact is they show evidence of memory at birth, and the best example of that is they recognise their mother's voice.
This one month old baby is hearing short segments of her mother's voice, alternating with a very similar stranger's voice.
"Mummy's baby, Mummy's baby" "Mummy's baby, Mummy's baby" Her brain waves are different for the two voices.
Even at this age a baby can store a clear record of the sound of her mother's voice Lucas is three.
His brain is capable of storing more complex, visual and emotional information.
Even though these faces are all unfamiliar, he's able to remember whether he's seen the same expression earlier.
The research shows that as our brains develop they respond faster to something familiar and more areas of the brain become involved in storing and retrieving a memory.
The final triumph is that we become aware of what we remember.
By age 9 Andy has a different brain wave for a familiar image, and at the same time he indicates that he has a memory of it.
So babies do one thing and 3 and 4 year olds do another, and children of say 7 or 8 or 9 do yet another, and adults do yet another.
And that's the magic of recording brain activity because we are now able to do the same thing at all these different ages and track the development of how the brain responds to a stimulus that should be recognised as familiar.
In the brain the essence of a memory is always the same.
When we become familiar with something, the connections between a circuit of neurones are reinforced, as they fire in synchrony.
Each time we trigger the memory, the same circuit is activated.
Why is it then, if basic memories are being formed long before we're aware of them, that we can't retrieve them later in life.
One possibility is that that they're erased, that they're formed initially but then they just disappear.
And we know that occurs in the brain and adults do the same thing.
Another possibility is that they still exist but they're transported to some part of the brain and we no longer have the key to unlock the location, akin perhaps to storing something in a filing cabinet and forgetting where in the filing cabinet you stored it.
It's a fascinating idea, that my brain might still carry traces from earliest infancy, in a form that my adult memory can't now access.
These films from my childhood bring back strong memories.
When I recall a birthday party like this, or an outing to the beach, I'm doing far more than remembering bare facts.
Retrieving a memory of a specific event in the past is an impressive mental achievement.
It means reliving the moment, with all the emotional force and personal connotations attached to it.
How does the brain do this? So Clare what is it you want me to do? I'm going to ask you to learn some names first.
I'm going to ask you to learn the names of four people - a minister, a doctor, a postman and a paper boy.
This is a very simple test, but it illustrates the intriguing way the brain stores memories.
I'm not going to test your memory for the photograph, the photograph is just there to help you remember the names.
I just want you to concentrate on remembering the fore name and the surname This is the doctor, his name is Jim Green.
This is the minister his name is Cuthbert Cattermole.
This is the postman his name is Tom Webster And this is the paperboy, his name is Philip Armstrong.
Lets see if you can remember them.
What was the name of the doctor? Jim Green.
And what was the minister's name? Cuthbert Cattermole.
And what was the postman's name? Tom Webster And what was the paper boy's name? Philip Armstrong.
Well done! Very impressive, I don't need to show you them again.
So I'm all right then? You're all right, you passed Superficially it seems that I've just stored the names as bare facts, but in my mind each memory exists as a combination of their face, clothes and the particular sound of Clare speaking their name.
We could call it a mini event.
Only by pulling together all these fragments can we remember the name.
His name is Cuthbert Cattermole John Forbes has been shown these cards many times before.
This is the postman his name is Tom Webster.
OK so one more time, what was the name of the doctor? I can't think of his christian name, now, Green.
Er, the doctor, OK.
What was the minister's name? Pass.
John has a very rare kind of brain damage, which has helped reveal how memories are normally stored.
Pass And what was the paper boy's name? Tim Pass.
OK, well done you're doing really well.
Let's try it one more time.
John's brain was damaged as a baby, but it was only several years later around the time of this video, that he became aware that he had virtually no memory.
Normal people they can just, they've got several things milling around in their head and they can just store something and not forget about it, and do stuff their mind completely on something else and then when they're asked about this other thing, they can just boom, oh yes that.
Whereas with me, because my memory is so much less it's very difficult for me to remember something.
It's like having a cabinet of memories and losing the back pages every now and again.
Someone just leafing through them, what shall we chuck - lets chuck that, chuck that and being left with like a skeleton of memories.
His family first noticed John's amnesia when they saw that he couldn't cope away from the familiar surroundings of home.
I think we first realised there was a problem with John's memory when we were on holiday one year and he was about nine.
And he would permanently keep getting lost.
We went to a holiday camp when his younger sister who's three years younger would be able to find her way around quite easily.
John would have problems, every time he came in the room, in the dining room he wouldn't know where we were sitting.
If he went out to the toilet mid way through he'd come back in and not be able to find us again.
Even at the end of the first week he was still doing that.
That's how we realised that he couldn't find his way around and he couldn't remember as much as we thought he should be able to.
John still has virtually no ability to navigate his way around even familiar situations His memory has no structure to it, so he can't piece together fragments he remembers to see the bigger picture.
Things that come out of the blue are really difficult to handle.
They just throw me completely, whereas most people can adjust it's very difficult for me to adjust.
It's like being a train slam I'm thrown completely and it can be really, I can really get unbalanced.
John came to us first when he was around 13 or 14 years of age, and at that time he had been seen by a neurologist, and the major complaint really was his memory problem.
John is now 22, and he's been visiting Dr Kadem for several years.
He still needs to follow precise step by step instructions to find his way.
Even though John can function very well, for example the route from his home to here involves a train change and he's been taught how to cope.
But if for example the platform changes for one reason or another on that particular day then that's enough for John to get completely lost.
His system only works if every unit within that system functions in a very repetitious and routine way.
You try and change one element, and then John is completely lost and he has to start all over again, from the very beginning.
What John has lost is the ability to bring together the different components of a memory.
This is because of damage to one particular area of his brain.
And as you can see the structure that we're particularly interested in -You know the name of it very well.
-The hippocampus, yeah.
The hippocampus, and you can see it over here, you see it.
You see it, in this view you can see the full length of the hippocampus right.
You see how full and fleshy it is.
So let's have a look at yours now.
The effects of the damage to John's hippocampus shed light on the workings of the brain's memory systems.
There And here, that's right.
It seems that the hippocampus plays an essential role in orchestrating the storage and retrieval of all the emotional and sensory aspects of an experience.
Without a normal hippocampus John can't form truly vivid memories with personal meaning for him.
His jumbled storage system won't allow him to travel back in time to relive his past.
Mental time travel allows us to go back and look at the particular episodes that are meaningful to us.
We really do not get any indication from John that he's doing this when he's trying to tell us about events that have happened to him in the past.
They seem to be renditions of stories that he has listened to about himself, that has been told to him and he has learnt those, but there isn't this element that he can recreate the situation, because when he tells you of these events and episodes there is very little emotional involvement.
It's almost like he's reading a story.
I'm very cautious personality wise, very defensive and I think that's part of how I've matured with my memory, because I'm missing information a lot of the time.
And all the little things that you pick up and you link into relationships because they're not there, that then puts me at a disadvantage.
It's hard to imagine what it's like to look back at your life as isolated facts, with no sense of ever having been there.
We take lots of photographs and keep showing him them and we go back over his early years Because he doesn't remember occasions and incidents, we continually talk about them if they're important to him.
This is our way of being able to give him memories that when he looks back on his life he has something that he can remember One of the most remarkable aspects of the brain's memory systems is that they select what we remember.
After all storing everything would be as unhelpful as storing nothing.
Somehow our brains automatically keep the memories which are important to us and discard the rest.
For me the anatomy lab here at Oxford University has a special significance.
It was in this very room that I first dissected a human brain.
I was even sitting at this very bench and I remember it really clearly, for example I had the thought as I held the brain what if I got a bit under my finger nail, would that be the bit that someone would have loved with, or would that have been a particular memory.
I can remember who was standing next to me and the whole moment is preserved really clearly.
But I can't remember what I'd done the day previously, or indeed what I did subsequently.
My brain had isolated this event and kept it fresh in my memory because it was so important to me.
But our brains don't just accumulate memories of significant events, we're all equipped with a second very different kind of memory system which forms the basis of our knowledge.
We learn from all our experiences, extracting information and developing insights about the world around us.
Our brains build up huge databases about our personal environment.
We can't say how or when we learn these truths but we gradually absorb them, and knowledge of these facts which we call semantic memory is stored in the circuits and neurones in our brains.
Semantic memory is memory for facts, it's how our brains make sense of the world.
It's a living database, our accumulated knowledge of the difference between a flower and a tree, a bike and a car, a dog and a cat.
It's how we cope with the endless stream of new objects and experiences which we encounter as we go through life.
And this wealth of knowledge must somehow be stored in the constantly updating pattern of neurone connections in our heads.
Tragically those very connections are unravelling in lvor's brain.
This long process started 10 years ago.
Physically fortunately he is fine, and quite dextrous and not clumsy.
He still plays some golf and walking, and you know these problems regarding fitness are in tact, all fine.
Ivor has semantic dementia.
He's gradually losing the part of his memory that allows us to distinguish one thing from another Dementia is the term we give to any kind of progressive deterioration in mental function And one of the big conceptual developments of the last few years in dementia really has been the realisation that different kinds of dementia cause very different types of breakdown.
Ivor's dementia is the result of a specific area of cell death in his left temporal lobe.
The millions of cells here are the core of the brain's physical system for storing knowledge.
As these cells die lvor's loss of understanding is exactly the reverse of the stages a child's brain goes through as it builds up its network of neurone connections.
If you show patients a picture of an animal for instance, they're quite happy to say it's a dog or it's a cat for any animal, because there is some preservation of knowledge, enough to identify it as an animal, and the most prototypic, first acquired concept of animals tends to be dog, cat and horse.
This test reveals how lvor's grasp of the world has regressed to the level of a child.
OK and what about this one.
It looks like a dog as well.
OK what's this called? Is that a little cat? A little cat? OK What's this called.
I don't know, a little cat is it? A little cat, all right.
It's not that lvor has forgotten the words, he's actually lost the knowledge of what each animal is.
Is that a dog? A dog, OK.
And have you seen dogs with these bits on? Yes I saw another one this morning, looking virtually the same as that.
Right, and it had those lines on it? That's right.
Well it had it tremendously different when I saw it, that's right yes.
Right.
What's that one called? It's not a dog is it really? OK if it's not a dog, what would you call it.
A cat.
A cat you think, a cat or a dog.
OK that's well done lvor, that's lovely.
I think we've learnt a lot about the organisation and the representation of knowledge from how it breaks down, giving us clues as to how it must be built up, in terms of features.
And also how particular categories are organised, because the condition doesn't effect all aspects of knowledge equally.
Ivor's problems are very specific.
His recall of past events is still in tact.
And he can remember the rules of many games.
Cards, cards lvor was always very good at.
He plays patience by himself a lot and that's not a problem.
We still play bridge with some understanding friends and family Though he probably does not get contracts correct always, but as far as memory of the cards, or what has been played, that's OK, that's fine still.
Sadly lvor's dementia is at the moment untreatable.
But for the time being he's still able to get some pleasure out of life.
Although dementia scars the later years of some people, ageing itself does not need to be a story of relentless decline We may be losing brain cells but for most of us there's no reason why we can't make the most of the connections that remain.
Though our ever flexible brain's resources may decline it seems that in old age more than ever we can turn the experience the brain has accumulated to our best advantage.
A study in Berlin reveals just how adaptable older people's brains can be.
The participants, who are all over 60 walk an obstacle course while memorising a list of words they hear through headphones.
The lines on the track and hand rail record how steadily each person walks.
When they have completed the circuit, they must recall the words in the order in which they heard them.
I still remember how I got the idea for this experiment it was watching in the Swiss Alps older people walking up a hill, talking to each other and coming to a corner where there were some stones in the way, some rocks, and they stopped talking.
And why did they stop talking? I thought because they needed all their mental resources now to navigate around the rocks and after they had done that they started talking again.
So in this particular instance, in early adulthood our bodies, the way we move does not need much cognitive support, we do it automatically without thinking very much about it.
When we grow older however suddenly these bodily movements take more resources, they take more of our mental bank account.
So we were looking for an experiment where we could look at this in an exemplary fashion - walking and thinking.
Professor Baltes measures the volunteers' ability to walk and memorise at the same time, compared with their abilities simply to memorise.
When they're walking they have much much more trouble remembering the words.
When there's nothing to distract them, their recall is almost perfect.
Younger adults easily do both at the same time.
What that experiment shows basically is that if you want to optimise walking, you've got to allocate the resources to walking and if you want to optimise memorising you've got to allocate the resources to memorising.
The worst you could do is to switch back and forth, to try to here and there optimise walking and then memorising.
In the end you may not produce, or you may not be able to produce either.
So perhaps the much vaunted wisdom of old age comes from our brain's ability to process information in a more selective way.
As it has done throughout our lives, the world is still leaving its mark on our brains but as we grow old the world we choose to deal with becomes more personalised.
In very old age it happens much more frequently that the world becomes smaller and that actually is really what ageing is all about.
You have smaller parts of the world, and the art of life is how do you make smaller parts more beautiful? Right until the very end our dynamic brains are changing in response to the world.
The physical matter in our heads reflects the journey on which life has taken us Our abilities, our memories, and our knowledge are all built up through the fine tuning of billions of connections between our brain cells It is this personalisation of the brain that I call the mind Our brains are permanently in dialogue with the outside world, they assemble knowledge and experience and this process lasts a lifetime.
I think we're nearer to understanding the neural processes that take place in our brains as we develop these highly personalised minds.
How every significant moment, everything we learn leaves its biological mark.
The wonder of the brain is that somehow despite all the changing micro circuitry the essence of who we are, our very sense of identity remains.
Within our dynamic adaptable brain a unique individual personality is constantly evolving.
In the final programme of the series, the most intriguing question of all - how does your brain create the conscious experience of being you?