Category
📺
TVTranscript
00:00For six years, Harrison Ward-Mullis battled with uncontrollable epilepsy.
00:24His family faced a stark choice, let the fits continue or risk radical surgery.
00:31I was absolutely devastated, absolutely devastated, I mean I just could not take it in.
00:39When they were talking about surgery, I thought they would be taking a piece of the brain
00:44out.
00:45I had no idea that they were going to remove a complete half.
00:49Harrison has coped with the loss of an entire hemisphere.
00:52All our brains have this amazing flexibility.
01:22This splendid house has belonged to the same family for almost 700 years.
01:32Down the distant line of ancestors, many of the family's physical features have been transmitted
01:37in their genes.
01:38The familiar shape of the face, the eyes, looking at their portraits, I can see the
01:43likeness clearly, but I can tell very little about what kind of person each individual
01:52was or how their very different experiences shaped what was going on inside their heads.
02:03The lords and ladies of this ancient family, like all of us, must have been a mixture of
02:08the genes they were born with and the environment in which they were raised.
02:18Our surroundings, our memories, and everything we learn and experience throughout our lives
02:23will all influence who we become.
02:26This sculpting of our individuality takes place in a physical setting, our brains.
02:31I think it is the differences in our brains, the way the connections are configured and
02:34fine-tuned throughout our lives, that makes every one of us unique.
02:42I see each of us as an accumulation of experiences, with our brain constantly adapting to the
02:47unique world in which we live.
02:51We all like to think that life is about how we might leave our mark upon the world, but
02:55the question for me is how does the world leave its mark on each of us?
03:04The gross anatomy of the brain is laid down in our genes.
03:11Scans of the growing foetus reveal how the convoluted folds of the adult cortex gradually
03:16develop.
03:17But what about the brain's internal workings, all the detailed nerve circuits which are
03:23necessary for our mental skills to develop properly?
03:27How much of that is determined by our genes?
03:41Take a universal skill, like recognising another human face.
03:46You might expect a basic brain function, like this, to be hard-wired from birth, but it's not.
03:56At the Birkbeck College Baby Lab in London, researchers are investigating the changes
04:00in brain circuitry as a baby gradually learns to distinguish faces from other shapes.
04:06Surprisingly, they're really rather good at it.
04:14Very early on, the newborn is attracted by anything that has a face-like configuration,
04:20so two blobs for the eyes and a blob for the nose-mouth is enough to attract the newborn's
04:25attention and it will follow it.
04:27Over other shapes, quite interesting shapes, and over other scrambled face-like shapes,
04:31it wants this special configuration.
04:38Over several months, the electrical activity in a baby's brain is monitored.
04:42Then they're shown upright faces compared with upside-down ones.
04:55Newborns respond exactly the same way to both, but by 8 months old, Jessamine's brain seems
05:01to have changed.
05:08When babies are very young, one of the things you see is that they show different patterns
05:14of brain activity when shown a face the right way up and a face upside down.
05:19Now, those are the same features, if you like, just turned in different ways.
05:23So if they were just responding to features, they would show the same brain activity.
05:28The very fact that they show different brain activity with a special peak when it's the
05:32right way up suggests that they really are processing faces in a configurable way as
05:37a whole face and that the upside-down face is just seen as a collection of features.
05:45So how does a baby develop this special response to faces?
05:49What's guiding the change in nerve circuitry of Jessamine's brain?
05:53The researchers here believe that we don't develop these skills automatically.
05:58It's only the repeated exposure to faces which trains the brain.
06:08So genes give a child the potential for mental skills.
06:12Experience determines whether the skills actually develop.
06:20If you want to really understand how a brain emerges rather than is pre-programmed, you
06:25have to look at the child as, in a sense, structuring their own brain.
06:32And that way, the baby's brain is a function of what the baby does.
06:36So the baby is...
06:37One can say the baby builds its own brain.
06:39I don't think that's an exaggeration at all.
06:46So how does experience of the world shape the development of a child's brain?
06:51We're born with almost as many brain cells as we'll ever have.
06:55What changes are the connections between them?
07:08The brain is an ever-changing web of billions of cells.
07:13As each brain cell grows, it forms thousands of connections with its neighbours.
07:22In the first few years of life, there's an explosion of connections between brain cells
07:26as the brain wires itself up.
07:28Each experience, no matter how small, leaves its mark on the brain by stimulating more
07:32connections between brain cells.
07:35With each new experience, some connections are strengthened and others are weakened,
07:40in a constant process of wiring.
07:44Just as we develop connections with the right inputs, so we can also prune them back.
07:48The brain has no use for too many idle connections, so it cuts back on those that aren't continuously
07:53reinforced with experience.
07:57How our individual brains take shape depends on which connections are reinforced and which
08:02fail to stay the course.
08:04The result is a dynamic, flexible brain.
08:08Just how flexible, we're now beginning to understand, through remarkable cases like
08:13Harrison Ward-Mullis.
08:20Harrison is now six.
08:23Soon after he was born, a blood vessel burst in his brain, which left him with crippling
08:28epilepsy.
08:36Harrison was constantly having seizures, what they called a non-convulsive epileptic state,
08:43in other words, you wouldn't see him having seizures.
08:48And when I said, I used to say to people, my son's got epilepsy, well he looks alright
08:53to me.
08:59He had the sort of seizures that he would sit and chew, but nothing in the mouth.
09:05He would start rocking, and he would do this for about an hour.
09:09He was aggressive, he would all of a sudden see something in a room and aim it towards
09:14anything or anybody, and the behaviour gradually got worse over the years.
09:26The full extent of Harrison's epilepsy became clear when he was wired up for observation
09:32by Dr Frank Bizak at St Peer's Epilepsy Centre in Surrey.
09:37The stream of irregular spikes shows Harrison's brain is in constant turmoil.
09:42He's having small seizures, one after another.
09:45It's a situation that has been very frustrating for years.
09:52When we see it so dramatically on the television screen, it makes it seem real and tangible.
10:00You know, I've been in supermarkets where people have said, well if he was mine I'd
10:04thrash him.
10:05Yes, well thrashing isn't a recognised method of correcting brainwave abnormality to this
10:12extent I'm afraid.
10:13I think it's very difficult for us to put ourselves in Harrison's place, but looking
10:19at these little storms occurring every few seconds as they are right now, if we can imagine
10:24that his brain function for those few seconds is being quite significantly impaired, and
10:30yet people are having normal expectations of him.
10:34And he's switching in and off all the time.
10:46A scan revealed massive damage in the left half of Harrison's brain, but the right looked
10:52normal.
10:53These seizures were probably all originating from the bad brain on the left side of his
11:00head.
11:02So almost certainly the bad brain was sending a storm of abnormal electrical discharges
11:09into the good brain, preventing it from working as well as it would have been otherwise.
11:18Harrison's family were offered a radical treatment, surgery to remove the malfunctioning
11:23half of his brain.
11:26This would be a risky operation.
11:32The big thing for me in deciding whether to have the surgery was the fact that at any
11:40given moment I could have lost him in a seizure anyway.
11:44He could have gone into a major seizure where he could have died.
11:53Since it was the only way to tackle his epilepsy, Harrison's left hemisphere was completely
11:58removed.
12:02But normally, the left side of the brain is vital for speech, and it controls the movement
12:07of the right side of the body.
12:09How badly would its removal affect him?
12:15For three days after the operation, Harrison was unconscious.
12:21All of a sudden, he just made a movement to get up, and I just grabbed him, and he just
12:29started talking.
12:30I then knew that he was out of this almost comatized state.
12:35He spoke.
12:36When he finally came round, for the first time in six years, he put four words together
12:42as a sentence.
12:43And that was instant.
12:45His speech was so much better.
12:53His control of the right side of his brain was very limited.
12:57His control of the right side of his body has been affected by the operation.
13:01But with intensive physiotherapy, Harrison is improving steadily.
13:06It seems that if part of a child's brain is damaged, the rest will automatically rewire
13:11itself, so that vital functions are taken over by the remaining normal tissue.
13:19You can start us off then.
13:20Here we go.
13:21Twinkle, twinkle, little star, how I wonder what you are.
13:32Up above the clouds so bright, like a diamond in the sky.
13:41Harrison's story reveals the amazing dynamism of the nerve circuitry in the developing brain.
13:48How I wonder what you are.
14:07Our brains are at their most flexible in childhood.
14:11But throughout our lives, our grey matter is endlessly being shaped by experience
14:16and moulding itself to fit new circumstances.
14:22If you lose a large part of your brain as an adult,
14:25it's unlikely you'll ever fully recover any lost function.
14:28But it would be wrong to think of the brain as a fixed structure,
14:31which when it finishes growing, sets hard.
14:34At the microscopic level, the connections in our brain are constantly changing as we go through life.
14:39That's what learning and memory are all about.
14:42We never lose the ability to learn new skills.
14:46I may be making a hash of this now, but it shouldn't take too many lessons before I get the hang of it.
14:52As I keep trying to get the right pressure on the clay, the nerve circuits in my head are changing.
14:58It's very good. Keep your wheel going fast.
15:03Now I've picked up.
15:06Try and push it down first.
15:09How are our brains physically shaped by the experience of learning new skills?
15:14This issue is explored in some remarkable work with children who have difficulty with reading.
15:20So now all the words you're going to see in this game are made-up words, OK?
15:24And you just read for me...
15:26Cassie is unable to convert an unfamiliar group of letters into the sound of the word.
15:32Instead, she just guesses.
15:34OK.
15:35And just click the mouse when you're ready.
15:41Gloop.
15:42OK.
15:47Whip.
15:53Swag.
15:55Psychologist Bruce McCandless specialises in helping children like Cassie to learn to read.
16:01You didn't like those? Those were hard, huh?
16:03Our brains automatically decode the letters that they see into the sounds of the language
16:09and blend them together into whole words.
16:12If you don't catch on to this skill early on in the reading process,
16:16oftentimes you might get stuck trying to compensate with other strategies.
16:23The word on the screen is pen. Make a new word by taking away the N and add a T.
16:28Bruce is interested in the changes that occur in his students' brains
16:32when they finally learn to read properly.
16:37How about down here, though? What's the end of this word look like?
16:42T and S. How would you say T and S together?
16:51Yeah, that's it.
16:52OK, let's just run through a couple of them and make sure we have that down.
16:56Best.
16:57Yeah.
16:58Best.
17:02You've got to look really carefully at the letters there.
17:04The letters will tell you what word it is.
17:06Bets.
17:07There you go. Great.
17:09Reading is a complex skill which involves hearing, vision, memory and speech.
17:16But Bruce has scanned the brains of good readers and identified one key area
17:21which seems to be active specifically during reading.
17:25He believes this area is involved when we're converting letters into word sounds.
17:30Said Mike, Grace led Mike to the spider club.
17:36Inside the club...
17:39With Bruce's help, Mark has just learned to read in the last few months.
17:44Not me, said Grace. I like spiders.
17:48Mark came in reading at a very low level
17:52and we struggled with a couple of very key letter sound identification concepts with him.
17:58But over the course of the 24 sessions, he started to really catch on
18:03and started to very actively start to decode words on his own,
18:08start to correct his own errors and start to realise the role that each letter played in a word.
18:13OK, great. Come on in here.
18:14Just like last time, you remember the MR centre.
18:17Come up on the bed here and we'll crank it up.
18:20Mark had a brain scan before he did the reading course
18:24and his brain showed no activity in the key area Bruce believes is involved in reading.
18:30Now that he can read, he's having a second scan to compare the pattern of activity.
18:35He's got to be one of our best.
18:37Inside the scanner, Mark does a reading test.
18:40Oh, those are beautiful. Great.
18:42The second scan of Mark's brain, when he was reading well, reveals a clear change.
18:48As he learned the new skill of decoding letters into sounds,
18:52he made new connections in his brain.
18:55I can show you some of the results of what we've found so far.
18:58So first I want to show you...
19:01Check this out right here.
19:03We did the same exact scan with the same exact words
19:07a little while later and look what happened.
19:09What do you see there?
19:11The red dots?
19:13Yeah, that's right. You know what the red dots mean?
19:16That it was working?
19:18That's right. That part of your brain was working pretty hard when you were playing the word game.
19:22So we're really excited about that.
19:24It's an example of learning, changing the pattern of your brain activity.
19:28So what do you think about that?
19:30Seeing the inside of your brain and what's going on as you're thinking about stuff.
19:34Pretty neat.
19:36Yeah?
19:37Yeah.
19:47As we develop into adults, our brains gradually acquire a unique individual personality.
19:54I believe that much of who we become is the result of our brains absorbing what's going on around us.
20:01Mostly we're unaware of this process,
20:04but occasionally something is so significant we know it's altered our brains.
20:10It's become a memory.
20:22Memory, like other aspects of brain function, develops as we grow.
20:27Our entire system for storing and retrieving memories is evolving in the first few years of life.
20:34None of us remember the events from early in our life.
20:38And in fact, if you ask most people how old they were for their earliest memory,
20:42generally it's between two and four years of age.
20:49At his lab in Minnesota, Charles Nelson is testing children of different ages
20:54to see how their brains change as their memories develop.
20:57Our data suggests to us that a baby's memory system is present at birth.
21:02It is far from as developed as it will be,
21:05but the fact is they show evidence of memory at birth.
21:09And the best example of that is they recognise their mother's voice.
21:15This one-month-old baby is hearing short segments of her mother's voice,
21:20alternating with a very similar stranger's voice.
21:23Mommy's baby.
21:25Mommy's baby.
21:27Mommy's baby.
21:29Mommy's baby.
21:31Mommy's baby.
21:33Mommy's baby.
21:35Her brainwaves are different for the two voices.
21:39Even at this age, a baby can store a clear record of the sound of her mother's voice.
21:47You're putting the honey on his forehead?
21:49Lucas is three.
21:51His brain is capable of storing more complex visual and emotional information.
22:00Even though these faces are all unfamiliar,
22:03he's able to remember whether he's seen the same expression earlier.
22:19The research shows that as our brains develop,
22:22they respond faster to something familiar
22:25and more areas of the brain become involved in storing and retrieving a memory.
22:34The final triumph is that we become aware of what we remember.
22:38By age nine, Andy has a different brainwave for a familiar image
22:43and at the same time, he indicates that he has a memory of it.
22:49So babies do one thing, and three and four-year-olds do another,
22:53and children of, say, seven or eight or nine do yet another,
22:56and adults do yet another.
22:58And that's the magic of recording brain activity
23:01because we are now able to do the same thing at all these different ages
23:04and track the development of how the brain responds
23:08to a stimulus that should be recognized as familiar.
23:11Andy's brainwaves are very similar.
23:14His brainwaves are very similar.
23:16And the stimulus that should be recognized as familiar.
23:19In the brain, the essence of a memory is always the same.
23:23When we become familiar with something,
23:26the connections between a circuit of neurons are reinforced
23:29as they fire in synchrony.
23:32Each time we trigger the memory, the same circuit is activated.
23:40Why is it then, if basic memories are being formed
23:43long before we're aware of them,
23:44that we can't retrieve them later in life?
23:49One possibility is that they're erased,
23:52that they're formed initially, but then they just disappear.
23:55And we know that occurs in the brain, and adults do the same thing.
23:58Another possibility is that they still exist,
24:01but they're transported to some part of the brain
24:04and we no longer have the key to unlock the location,
24:07akin perhaps to storing something in a filing cabinet
24:10and forgetting where in the filing cabinet you stored it.
24:12It's a fascinating idea
24:15that my brain might still carry traces from earliest infancy
24:19in a form that my adult memory system can't now access.
24:27These films from my childhood bring back strong memories.
24:34When I recall a birthday party like this,
24:37or an outing to the beach,
24:39I'm doing far more than remembering bare facts.
24:52Retrieving a memory of a specific event in the past
24:55is an impressive mental achievement.
24:58It means reliving the moment
25:01with all the emotional force
25:04and personal connotations attached to it.
25:07How does the brain do this?
25:18So, Claire, what is it that you want me to do?
25:21OK, I'm going to ask you to learn some names first.
25:24I'm going to ask you to learn the names of four people.
25:27A minister, a doctor, a postman and a paperboy.
25:31This is a very simple test,
25:33but it illustrates the intriguing way the brain stores memories.
25:37I'm not going to test your memory for the photograph.
25:40The photograph is just there to help you remember the names.
25:43I just want you to concentrate
25:45on remembering the forename and the surname.
25:48This is the doctor. His name is Jim Green.
25:54This is the minister. His name is Cuthbert Catamon.
25:59This is the postman.
26:01His name is Tom Webster.
26:04And this is the paperboy. His name's Philip Armstrong.
26:08Now, let's see if you can remember them.
26:11What was the name of the doctor?
26:14Jim Green.
26:16And what was the minister's name?
26:18Cuthbert Catamon.
26:20What was the postman's name?
26:22Tom Webster.
26:24What was the paperboy's name?
26:26Philip Armstrong.
26:28Very impressive.
26:29I'm all right now.
26:31You're all right. You passed that one.
26:33Superficially, it seems that I've just stored the names as bare facts.
26:38But in my mind, each memory exists as a combination
26:42of their face, clothes,
26:44and the particular sound of Claire speaking their name.
26:47We could call it a mini-event.
26:49Only by pulling together all these fragments
26:52can we remember the name.
26:54His name is Cuthbert Catamon.
26:55John Forbes has been shown these cards many times before.
27:00This is the postman.
27:02His name is Tom Webster.
27:05OK, so one more time.
27:07What was the name of the doctors?
27:12I can't remember his Christian name now.
27:14Green.
27:15Green.
27:24The doctor.
27:32What was the minister's name?
27:41Pass.
27:42John has a very rare kind of brain damage,
27:45which has helped reveal how memories are normally stored.
27:48Pass.
27:50And what was the paperboy's name?
27:52Tim.
27:55Pass.
27:57OK, well done. You're doing really well.
28:00It's really tough, like that.
28:02Let's try it one more time.
28:08John's brain was damaged as a baby.
28:10But it was only several years later,
28:13around the time of this video,
28:15that he became aware that he had virtually no memory.
28:19Normal people, they can just...
28:21They've got several things milling around in their head
28:24and they can store something and not forget about it
28:26and just have their mind completely on something else
28:29and then when they're asked about this other thing,
28:31they can just, boom,
28:33oh, yes, that was with me
28:35because my memory's so much less.
28:39It's very difficult for me to remember something.
28:50It's like having a cabinet of memories
28:55and losing the back pages every now and again.
28:58Someone just leafing through,
29:00what shall we chuck, chuck that, chuck that, chuck that
29:02and being left with like a skeleton of memories.
29:04His family first noticed John's amnesia
29:07when they saw that he couldn't cope
29:09away from the familiar surroundings of home.
29:13I think we first realised
29:15there was a problem with John's memory
29:17when we were on holiday one year
29:19and he was about nine
29:21and he would permanently keep getting lost.
29:23We went to a holiday camp
29:25when his younger sister,
29:27who's three years younger,
29:29would be able to find her way around quite easily.
29:31John would have problems
29:32every time he came in the room.
29:34In the dining room,
29:36he wouldn't know where we were sitting.
29:38If he went out to the toilet midway through,
29:40he'd come back in and not be able to find us again.
29:42And even at the end of the first week,
29:44he was still doing that.
29:46That's how we realised
29:48that he couldn't find his way around
29:50and he couldn't remember as much
29:52as we thought he should be able to.
29:57John still has virtually no ability
29:59to navigate his way around
30:00even familiar situations.
30:03His memory has no structure to it
30:05so he can't piece together
30:07fragments he remembers
30:09to see the bigger picture.
30:12Things that come out of the blue
30:14are really difficult to handle.
30:16They just throw me completely
30:18whereas most people can adjust.
30:20It's very difficult for me to adjust.
30:22So it's like being a train.
30:24Slam!
30:26And I'm thrown completely
30:28and it can be really
30:29it can really get unbalanced.
30:31John came to us first
30:33when he was
30:35around 13 or 14 years of age
30:37and at that time
30:39he had been seen by a neurologist
30:41and the major complaint
30:43really was his memory problem.
30:47John is now 22
30:49and he's been visiting Dr Varga Kadem
30:51for several years.
30:54He still needs to follow
30:56precise step-by-step instructions
30:57to find his way.
30:59Even though John
31:01can function very well
31:03for example
31:05the route from his home
31:07to here involves a train change
31:09and he's been taught
31:11how to cope
31:13but if for example
31:15the platform changes
31:17for one reason or another
31:19on that particular day
31:21then that's enough
31:23for John to get completely lost.
31:25His system only works
31:27when you try and change
31:29one element
31:31and then John is completely lost
31:33and he has to start
31:35all over again
31:37from the very beginning.
31:41What John has lost
31:43is the ability to bring together
31:45the different components
31:47of a memory.
31:49This is because of damage
31:51to one particular area
31:53of his brain.
31:55And as you can see
31:57in this view
31:59you can see
32:01the full length
32:03of the hippocampus
32:05and you see
32:07how full and fleshy it is.
32:09So let's have a look
32:11at yours now.
32:13The effects of the damage
32:15to John's hippocampus
32:17shed light on the workings
32:19of the brain's memory systems.
32:21And here,
32:23that's right.
32:24It seems that the hippocampus
32:26plays an essential role
32:28in orchestrating
32:30the storage and retrieval
32:32of all the emotional
32:34and sensory aspects
32:36of an experience.
32:38Without a normal hippocampus
32:40John can't form
32:42truly vivid memories
32:44with personal meaning for him.
32:46His jumbled storage system
32:48won't allow him to travel
32:50back in time
32:52to relive his past.
32:53It allows us to go back
32:55and look at
32:57the particular episodes
32:59that are meaningful to us.
33:01We really
33:03do not get any indication
33:05from John
33:07that he's doing this
33:09when he's trying to tell us
33:11about events that have
33:13happened to him in the past.
33:15They seem to be
33:17renditions of stories
33:19that he has listened to
33:21about himself
33:22and he's trying to
33:24recreate the situation
33:26because when he
33:28tells you
33:30of these events
33:32and episodes
33:34there is very little
33:36emotional involvement.
33:38It's almost like
33:40he's reading a story.
33:42I'm very cautious
33:44personality-wise,
33:46very defensive
33:48and I think that's
33:50part of
33:52how you link
33:54into relationships
33:56because they're not there.
33:58That then
34:00puts me at a disadvantage.
34:02It's hard to imagine
34:04what it's like
34:06to look back at your life
34:08as isolated facts
34:10with no sense
34:12of ever having been there.
34:14We take lots of
34:16photographs
34:18and keep showing him
34:20them and we could
34:21remember occasions
34:23and incidents.
34:25We continually talk about
34:27them if they're
34:29important to him.
34:31This is our way
34:33of being able to
34:35give him memories
34:37that when he looks
34:39back on his life
34:41he has something
34:43that he can remember.
34:51One of the most
34:53remarkable aspects
34:55of the brain's memory
34:57systems is that
34:59they select
35:01what we remember.
35:03After all,
35:05storing everything
35:07would be as
35:09unhelpful as
35:11storing nothing.
35:13Somehow our brains
35:15automatically keep
35:17the memories which
35:19are important to us
35:20as a special
35:22significance.
35:24It was in this very
35:26room that I first
35:28dissected a human
35:30brain. I was even
35:32sitting at this very
35:34bench and I remember
35:36it really clearly.
35:38For example,
35:40I had the thought
35:42as I held the brain,
35:44what if I got a
35:46bit under my
35:48fingernail? Would
35:49my brain have isolated
35:51this event and kept
35:53it fresh in my memory
35:55because it was so
35:57important to me?
35:59But our brains
36:01don't just accumulate
36:03memories of significant
36:05events. We're all
36:07equipped with a second
36:09very different kind
36:11of memory system
36:13which forms the
36:15basis of our
36:17knowledge.
36:19We learn from all
36:21our experiences,
36:23extracting information and
36:25developing insights about
36:27the world around us.
36:29Our brains build up
36:31huge databases about
36:33our personal
36:35environment. We
36:37can't say how or
36:39when we learn
36:41these truths but
36:43we gradually
36:45absorb them.
36:47And knowledge of
36:48how our brains make
36:50sense of the world.
36:52It's a living
36:54database, our
36:56accumulated knowledge
36:58of the difference
37:00between a flower
37:02and a tree, a
37:04bike and a car,
37:06a dog and a cat.
37:08It's how we cope
37:10with the endless
37:12stream of new
37:14objects and experiences
37:16which we encounter
37:17every day.
37:19And this wealth
37:21of knowledge must
37:23somehow be stored
37:25in the constantly
37:27updating pattern
37:29of neuron connections
37:31in our heads.
37:33Tragically,
37:35those very
37:37connections are
37:39unravelling in
37:41Ivor's brain.
37:43This long process
37:45started ten years
37:46ago.
37:48Physically,
37:50fortunately,
37:52he is fine
37:54and quite
37:56dexterous and not
37:58clumsy. He still
38:00plays some golf
38:02and walking.
38:04And, you know,
38:06these problems
38:08regarding fitness
38:10are intact,
38:12they're fine.
38:14Ivor has semantic
38:15loss. He is
38:17slowly losing
38:19the part of his
38:21memory that
38:23allows us to
38:25distinguish one
38:26thing from another.
38:28Dementia is
38:30the term we give
38:32to any kind
38:34of progressive
38:35deterioration in mental
38:37function. And
38:39one of the big
38:41conceptual developments
38:43of the last
38:45thousand years
38:47is that
38:49Ivor's
38:51dementia
38:52is the result
38:54of a specific
38:55area of cell
38:56death in his
38:57left temporal
38:58lobe. The
38:59millions of cells
39:00here are the
39:01core of the
39:02brain's physical
39:03system for
39:04storing knowledge.
39:05As these cells
39:06die, Ivor's
39:07loss of
39:08understanding is
39:09exactly the
39:10reverse of
39:11the stages a
39:12child's brain
39:13goes through
39:14when they
39:15think of
39:16an animal,
39:17for instance.
39:18They're quite
39:19happy to say
39:20it's a dog
39:21or it's a
39:22cat for
39:23any animal
39:24because there
39:25is some
39:26preservation of
39:27knowledge,
39:28enough to
39:29identify it as
39:30an animal,
39:31and the most
39:32prototypic
39:33first-acquired
39:34concept of
39:35animals tends
39:36to be dog,
39:37cat and
39:38horse.
39:39This test
39:40reveals how
39:41Ivor's grasp
39:42of the world
39:43is changing.
39:46It's not that
39:47Ivor has forgotten
39:48the words.
39:49He's actually
39:50lost the
39:51knowledge of
39:52what each
39:53animal is.
39:54This is
39:55a cat.
39:56This is
39:57a horse.
39:58This is
39:59a horse.
40:00This is
40:01a horse.
40:02This is
40:03a horse.
40:04This is
40:05a horse.
40:06This is
40:07a horse.
40:08This is
40:09a horse.
40:10This is
40:11a horse.
40:12This is
40:13a horse.
40:14This is
40:15a horse.
40:16This is
40:17a horse.
40:18This is
40:19a horse.
40:20This is
40:21a horse.
40:22This is
40:23a horse.
40:24This is
40:25a horse.
40:26This is
40:27a horse.
40:28This is
40:29a horse.
40:30This is
40:31a horse.
40:32This is
40:33a horse.
40:34This is
40:35a horse.
40:36This is
40:37a horse.
40:38This is
40:39a horse.
40:40This is
40:41a horse.
40:42This is
40:43a horse.
40:44This is
40:45a horse.
40:46This is
40:47a horse.
40:48This is
40:49a horse.
40:50This is
40:51a horse.
40:52This is
40:53a horse.
40:54This is
40:55a horse.
40:56This is
40:57a horse.
40:58This is
40:59a horse.
41:00This is
41:01a horse.
41:02This is
41:03a horse.
41:04This is
41:05a horse.
41:06This is
41:07a horse.
41:08This is
41:09a horse.
41:10This is
41:11a horse.
41:12This is
41:13a horse.
41:14This is
41:15a horse.
41:16This is
41:17a horse.
41:18This is
41:19a horse.
41:20This is
41:21a horse.
41:22This is
41:23a horse.
41:24This is
41:25a horse.
41:26This is
41:27a horse.
41:28This is
41:29a horse.
41:30This is
41:31a horse.
41:32This is
41:33a horse.
41:34This is
41:35a horse.
41:36This is
41:37a horse.
41:38This is
41:39a horse.
41:40This is
41:41a horse.
41:42This is
41:43a horse.
41:44This is
41:45a horse.
41:46This is
41:47a horse.
41:48This is
41:49a horse.
41:50This is
41:51a horse.
41:52This is
41:53a horse.
41:54This is
41:55a horse.
41:56This is
41:57a horse.
41:58This is
41:59a horse.
42:00This is
42:01a horse.
42:02This is
42:03a horse.
42:04This is
42:05a horse.
42:06This is
42:07a horse.
42:08This is
42:09a horse.
42:10This is
42:11a horse.
42:12This is
42:13a horse.
42:14This is
42:15a horse.
42:16This is
42:17a horse.
42:18This is
42:19a horse.
42:20This is
42:21a horse.
42:22This is
42:23a horse.
42:24This is
42:25a horse.
42:26This is
42:27a horse.
42:28This is
42:29a horse.
42:30This is
42:31a horse.
42:32This is
42:33a horse.
42:34This is
42:35a horse.
42:36This is
42:37a horse.
42:38This is
42:39a horse.
42:40This is
42:41a horse.
42:42This is
42:43a horse.
42:44This is
42:45a horse.
42:46This is
42:47a horse.
42:48This is
42:49a horse.
42:50This is
42:51a horse.
42:52This is
42:53a horse.
42:54This is
42:55a horse.
42:56This is
42:57a horse.
42:58This is
42:59a horse.
43:00This is
43:01a horse.
43:02This is
43:03a horse.
43:04This is
43:05a horse.
43:06A study in Berlin reveals just how adaptable older people's brains can be.
43:13The participants, who are all over 60, walk an obstacle course while memorising a list
43:18of words they hear through headphones.
43:21The lines on the track and handrail record how steadily each person walks.
43:29When they have completed the circuit, they must recall the words in the order in which
43:34they heard them.
43:35I still remember how I got the idea for this experiment. It was watching in the Swiss Alps
43:42older people walking up a hill, talking to each other, and coming to a corner where there
43:49was some stone, and they were talking to each other.
43:55And coming to a corner where there were some stones in the way, some rocks, and they stopped
44:00talking. And why did they stop talking? I thought because they needed all their mental
44:06resources now to navigate around the rocks. And after they had done that, they started
44:11talking again.
44:12So in this particular instance, in early adulthood, our bodies, the way we move, does not need
44:21much cognitive support. We do it automatically, without thinking very much about it.
44:27When we grow older, however, suddenly these bodily movements take more resources, they
44:33take more of our mental bank account. So we were looking for an experiment where we could
44:39look at this in an exemplary fashion, walking and thinking.
44:46Professor Balthes measures the volunteers' ability to walk and memorise at the same time,
44:52compared with their ability simply to memorise. When they're walking, they have much more
44:58trouble remembering the words. When there's nothing to distract them, their recall is
45:03almost perfect. Younger adults easily do both at the same time.
45:16What that experiment shows, basically, is that if you want to optimise walking, you've
45:22got to allocate the resources to walking. And if you want to optimise memorising, you've
45:28got to allocate the resources to memorising. The worst you could do is to switch back and
45:34forth, to try to here and there, optimise walking and then memorising. In the end, you
45:41may not produce, or you may not be able to produce either.
45:53So perhaps the much-vaunted wisdom of old age comes from our brain's ability to process
45:59information in a more selective way. As it has done throughout our lives, the world is
46:07still leaving its mark on our brains. But as we grow old, the world we choose to deal
46:12with becomes more personalised.
46:20In very old age, it happens much more frequently that the world becomes smaller. And that actually
46:27is really what ageing is all about. You have smaller parts of the world, and the art of
46:33life is how do you make smaller parts more beautiful?
46:45Right until the very end, our dynamic brains are changing in response to the world. The
46:52physical matter in our heads reflects the journey on which life has taken us. Our abilities,
46:58our memories and our knowledge are all built up through the fine-tuning of billions of
47:04connections between our brain cells. It is this personalisation of the brain that I call
47:11the mind.
47:15Our brains are permanently in dialogue with the outside world. They assemble knowledge
47:19and experience, and this process lasts a lifetime.
47:24I think we are nearer to understanding the neural processes that take place in our brains
47:28as we develop these highly personalised minds. How every significant moment, everything we
47:34learn, leaves its biological mark.
47:42The wonder of the brain is that somehow, despite all the changing microcircuitry, the essence
47:49of who we are, our very sense of identity remains.
47:57Within our dynamic, adaptable brain, a unique individual personality is constantly evolving.
48:04In the final programme of the series, the most intriguing question of all, how does
48:10your brain create the conscious experience of being you?
48:33www.microsoft.com
48:36www.microsoft.com
48:39www.microsoft.com
48:42www.microsoft.com