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- [Voiceover] There's always a strong temptation

to think of the brain or to call a brain a machine

or talk about it as a computer.

- [Voiceover] When I was in medical school,

we were taught that the brain is what it is,

and nothing really can change it.

- [Voiceover] I learned that the brain

was pretty much hard-wired,

and that what you've got by the age of 18,

you're left with.

- [Voiceover] All of this work suggests

that we need to radically change this old view of the brain.

- [Voiceover] I think we're now learning

that, in fact, the brain is changing all the time,

that the brain is changing with everything we think,

with everything we experience.

- My name is Dr. Norman Doidge.

I wrote a book called The Brain That Changes Itself.

(audience applauds)

- I'm here today to describe what I've come to believe

is the most important change in our understanding

of the human brain in 400 years.

This idea is revolutionary, because for four centuries,

mainstream medicine and science

have seen the brain as fixed

and described it as though it were a complex machine

with parts, each of which perform one mental function

in a single location in the brain.

This machine metaphor gave rise to what I have called

the doctrine of the unchanging brain.

A sense that treatment for many brain conditions

was impossible or unwarranted took hold,

and it spread through the culture,

even stunting our overall view of human nature.

But what if the idea of the brain as machine or mechanism

is not only wrong, but spectacularly wrong?

When I first heard reports that the human brain

might not be hard-wired, I had to investigate

and began a series of travels, and in the process,

met a band of brilliant scientists

at the frontiers of brain science,

who'd made a series of unexpected discoveries.

These scientific heretics began

to call this new brain property "neuroplasticity".

Neuroplasticity changes everything.

The brain is not a machine.

It has to be understood on its own terms.

And this is the remarkable story

of the brain that changes itself.

I went to Madison, Wisconsin

to meet with Mitch Tyler and Yuri Danilov,

two people who had worked with Paul Bach-y-Rita,

perhaps the most important pioneer of his generation,

the great visionary of neuroplasticity,

who, after some very personal experiences

with the death of his father,

figured out that the human brain is plastic

and then began to invent

all these extraordinarily ingenious devices

to help people rewire their brains.

- Given that Paul is a visual neuroscientist,

and that's what his training was,

he was looking for a way to demonstrate

this idea of this neuroplasticity,

or the brain's ability to rehabilitate itself.

And the logical extension of that

would have been in the blind population,

developing a blind prosthesis if you will,

or a sensory substitution device.

- Ok, now let's try something a little different now.

- Ok, it's a telephone.

And the receiver is to the right.

- In sensory substitution, he claimed that

brain is flexible, plastic, and smart enough

to analyze any information that you can deliver

accurately to the brain.

- Or you could actually take signals from a video camera

and presenting this stimulus on the back

of the patient who was blind

and have them be able to pick up that information

as though it was coming from their retina,

and treat that information the same way.

It's vision.

It doesn't matter where the signal's coming from.

- [Voiceover] How a sensation entered the brain

was not important to Bach-y-Rita.

What was important

was what the brain did with that sensation.

- The source of the signal really is almost immaterial,

as long as you provide that signal to the brain

and give it a context that it's being used in,

the brain will figure out how to use it

and use it to its own ends,

to both rehabilitate and also to perform the task

that it's trying to accomplish.

- Yea, I'm 54.

And I've been blind for 38 years, totally blind.

- Let's stay inside the lines, Roger.

- I see black, but I have no eyes whatsoever.

- [Voiceover] Over the years,

that big dentist's chair and massive computer behind it,

have all shrunk down so that it pretty well fits

into a pair of glasses with a mini-camera in it.

- The simplest way I've described it is when you're kids,

and you're laying in bed,

and one of your brothers or sisters are drawing on your back

with your finger, and you're trying to guess what it is.

It's kind of the same principle in a sense.

This device is drawing it on your tongue in vibrations.

- Roger, that turn was incredible.

- Yea, it was a sharp one.

I went, "Wait a minute."

It was foolin' me.

- You didn't cut it at all.

- It's drawing images onto your tongue,

and I try to get the whole image as much as I can

on this little one-inch-by-one-inch sensor.

It's tracing it like you do on your back when you're kids,

but it's now tracing it on your tongue electronically.

- And see if you can try and put your hand

on the top of the arrow.

Little higher.

- I mean definitely people think,

"Well, it's touch."

Well, not for me.

I mean, as soon as I put that on,

within a matter of seconds, I am seeing it.

I mean, I talk about seeing, because I am.

It's drawing pictures in my head.

- Perfect.

- I mean this was very emotional for me,

and I told my wife the same thing.

I said, "Maybe someday, I'll be able to see your face

"for the first time ever in my life."

- [Voiceover] We have senses that we don't know we have

until we lose them, and balance is one of them.

- In this helmet, we have a little two-axis accelerometer.

And what it does is converts your head-position information

into a little signal that's presented

on the tongue display here.

- [Voiceover] Once Bach-y-Rita realized

that you could get sensory modules

that seem to process one sensation to process another,

he turned to a very important problem,

the problem of balance.

- Now what I'm gonna have you do

is go ahead and just put it in.

And your job is to actually keep that little, red square

in the middle of the box.

So, it actually moves in response

to the position of the helmet.

- [Voiceover] Today, you can see Cheryl Schiltz

riding a bike, which seems like a very ordinary event.

But actually it's most extraordinary,

because Cheryl Schiltz is a woman

who had her balance apparatus almost completely obliterated

as a side effect from a medication she received.

- One morning when I tried to get out of bed,

I literally fell to the floor.

I tried to get up, tried to get on my hands and knees,

and I was just wobbling around,

and I just would fall again,

and I'd fall again,

and I remember looking,

and it was more of like a never-ending sense of tumbling.

And the doctor told me that it is a permanent condition,

but you'll learn to get used to it.

And actually the worst word of it all was "permanent".

"Permanent" made things stop.

It made it stop that

this is just the only way it will ever be.

- So how is Cheryl able to ride a bike?

- When we first met Cheryl, she was a wobbler,

a self-described person with a balance problem

and on disability.

But she was wobbling profoundly.

What I also realized is that this is her world.

This is something that she lives with every day.

- I always had this constant noise in my head,

and not a noise that, like, you hear noise,

but this feeling of noise.

If you could hear confusion, that's what it sounds like.

And my brain was really, really confused,

because it didn't know what to do.

It was so consumed with just trying stand up

and stay straight.

When I put that device in,

it was just like "Ohhhh."

It was like I stepped out of that room,

and I'm standing on the side of the ocean or something.

It was just like, "Oh my gosh. It's quiet.

"It's still, and it feels so good."

It's like I came back.

- [Voiceover] Bach-y-Rita thought

that the brain could rewire itself

by unmasking alternate pathways

or sprouting new ones.

What Cheryl's brain is doing,

is receiving the signals from her tongue

and sending them to the part of her brain stem

that normally processes touch.

It's then that her brain redirects this information

to the area that deals with balance

by unmasking dormant pathways.

- So the analogy, that I think I inherited from Paul,

is that, in the normal nervous system,

you have your major pathways.

They're sort of like the freeways in your brain

that handle large volumes of information

and do it very efficiently.

But if there's an accident on the highway,

you can either sit in traffic and not do anything,

or you can get off on the secondary road.

- [Voiceover] Over time, what the brain does

is it takes those back roads

and turns them into the superhighways

and reroutes the information

so that we're taking the existing pathways

and making them more efficient.

- By having that sensation on my tongue,

I had to reroute my patterns and my thoughts

and how my brain was functioning

to focus on that input, if you will.

- Cheryl was able to pick up that signal

within a couple of minutes

and learn how to move head left, right, front, back,

and pick up the signal and maintain upright posture.

Perfect posture.

She stood with military precision almost.

And we were amazed by that.

- And when we realized that she's stabilizing her body,

we decided to try to remove the device from the mouth

and see how long she can stay

and keep the balance afterwards.

- And what we found was,

when we took the strip from my mouth,

that there was a residual.

It would follow a little bit, you know.

The longer we did it, the longer the residual.

- So then when we continued the exploration

of this residual effect,

we figure out that the effect have ability to accumulate.

With each training session, it's getting longer.

- Suddenly, there was a profound realization

that these people don't have to use

this device all the time,

that there's something more than just sensory substitution.

It's a neuro-rehabilitation.

The brain is learning how to change itself

by use of this device.

That's the big breakthrough.

- The greatest thing is, is I'm not dependent

on the device anymore.

It truly, indeed, without a doubt, rewired my brain

in some fashion, how I honestly don't know,

but it did.

Hi!

- Hey, Cheryl.

- Good to see you.

- It's good to see you.

- The idea that the brain could change its function,

that it could morph, it could adapt

to new tasks was really radical.

And it took Paul some forty years

to demonstrate that that was possible.

And we're just at the front edge

of finally realizing Paul's vision

of being able to take this idea and run with it.

- So she'll do that for a while, and I'd like,

I think she'd like to do this as long as possible

so that she gets the long record.

- [Voiceover] Paul Bach-y-Rita's importance

lies in being a visionary, the first of his generation

to really understand the full potential of plasticity,

and to begin to apply it so that it could help people,

and to describe a new brain,

a brain that evolves in a changing world to change itself.

Sadly, Paul Bach-y-Rita is no longer with us.

A couple of years ago, he developed a brain tumor

and passed away.

- The first thing he said when he learned was,

"But oh, I have to hurry.

"I still have many things that I want to do."

He was a man with a mission,

and, I mean, he dedicated all his life to that.

- Did he have a sense that the wave was starting to break,

and suddenly plasticity was just on the brink

of becoming accepted for the first time?

- He said, "Well, you know,

"I just planted some seeds,

"and hopefully others will continue."

- So what we're realizing is,

we're still proving Paul right.

And Paul's visionary concepts from forty years ago

are just now being realized.

I think he got a glimpse of that realization.

And when you see the film clip of Cheryl dancing with Paul,

I think Paul finally got a glimpse of the realization,

the first instance of really seeing

his idea coming to fruition.

- [Voiceover] I already knew enough about the science

of the brain to know that brain plasticity was possible.

But then I had the extraordinary good luck

to meet an amazing neuroplastician,

Barbara Arrowsmith Young,

who, as it happened, was living in our backyard as it were,

in Toronto.

- What I'm doing here at Arrowsmith School

and in this program is actually changing cognitive capacity.

The students that I work with

are predominantly students with learning disabilities.

- Would that be 10 minutes before,

or would that be now?

- We're really walking

into the territory of their weaknesses.

We're going in and targeting the area of difficulty.

And do you know why you use the eye patch?

- No.

- 'Cause this eye right here

talks to this brain area over here.

- Barbara Arrowsmith Young

was one of the first neuroplasticians I met.

And she was a person who was born

with a devastating array of learning disabilities.

Many of her cognitive areas

were quite retarded, in fact, in development.

She had trouble speaking clearly.

She didn't know where her limbs were in space.

But her most devastating difficulties had to do

with a difficulty in understanding how to relate symbols.

This problem was so devastating for her

that she really couldn't understand conversations

as they were happening in real time.

- Growing up, I felt very stupid.

My teacher told my parents that I had a mental block

and that I wouldn't learn the way other children do,

and that I would have a struggle in school

throughout my schooling.

And being very, very literal, I actually thought

that I had a wooden cube in my head

that was making learning difficult.

I developed all sorts of coping strategies

to try to cover up.

Ok, fabulous. You were good.

- One day, one of her very close friends,

and a fellow student,

gave her a book by Alexander Luria,

called A Man with a Shattered World.

And it described a person who had deficits

that were very much like what Barbara suffered from.

It was the story of a Russian soldier

who had shrapnel in his head.

And he too had trouble with grammar and logic,

and cause and effect, and couldn't read a wristwatch.

- He talked about the person that couldn't tell time,

couldn't understand concepts,

the person that really felt that they were not able

to process or understand information in real time.

And it was an incredible ah-ha moment.

- [Voiceover] That soldier's lesion was caused

by the shrapnel that had been lodged

in the part of the brain that integrates signals

from the occipital lobe, which processes vision,

the temporal lobe, which processes sound and language,

and the parietal lobe, which processes touch.

So now she knew the junction, or area of her brain,

that was underperforming.

The problem was, Luria was never able to provide a treatment

for the poor soldier he was treating.

- Then I also came across a paper

by a neuroscientist, Mark Rosenzweig, out of Berkeley,

and he was looking at neuroplasticity

and that the brain wasn't fixed,

that the brain actually could change,

that through very specific stimulation and exercise,

you could change the brain at a physiological level,

which then allowed effective learning to go forward.

It made me realize,

"You know what?

"I don't need to be stuck with this learning disability.

"I don't need to live the rest of my life with it.

"There's a possibility here that I may actually be able

"to do something about it and rewire my own brain."

- Because she couldn't read clocks,

what she did for her first exercise

was very simple and elegant.

- [Barbara] I took a number of flashcards.

I made up a number of times,

and I drew the clock faces.

- Then she would add a minute-hand and a second-hand

and a hand for the week and the month and the year.

And a number of weeks into it,

she started to notice some extraordinary changes.

- It was incredible.

It was like blinders came off.

- Just by these incremental exercises,

she was building up new connections

in those processing areas

so that they could start to function,

eventually at an average level,

and then at an above-average level.

- What I believe this work does

through specific cognitive exercises,

is actually stimulate the function

of the underlying brain area to change it,

to rewire it, to strengthen it, to improve it,

and they can walk out of this program

and never have to look back.

- I was diagnosed with Stage 3 breast cancer

two days before my 35th birthday.

Happy birthday, you have cancer.

And I was told that I was gonna have to do chemotherapy.

I knew about the nausea, the fatigue, things like that.

And I certainly got those in spades.

But I also found that there's thing called chemo-brain.

So chemo-brain is almost like a fog

that just sort of descends on you.

And it makes it really difficult

to kind of process information.

I would struggle for a word in conversation,

so I didn't have that sort of word recall

that most people have.

It's major memory problems.

We take for granted that we know where we put our keys.

I mean, everyone's lost their keys, right?

But it's a much more profound thing than that.

It's this fog that descends on you,

and you can't make out the details.

- Well, in any case in which there's diffuse brain injury,

as a consequence of something like intensive chemotherapy,

basically the brain is operating with increasing noise.

Basically it's struggling to represent information

in detail with high accuracy.

- Mike Merzenich is the driving force

behind scores of innovations

of practical applications for brain plasticity.

Merzenich's special ability is training people

to think and perceive better

by working on brain processing areas

called brain maps.

Our brains represent the external world through these maps.

And their borders were believed to be fixed,

but Merzenich discovered that these maps

can actually grow and strengthen with exercise.

- Good morning.

Thank you for calling Scientific Learning.

How can I help you?

- Well, Scientific Learning focuses on problems in children,

and we're basically trying

to improve the capacities of children

through driving their brain plastically

in positive or corrective directions

and in ways that would improve their academic performance.

- One of the systems that he co-developed

is called Fast ForWord, and it's basically

a way of treating auditory learning disabilities,

disguised as a computer game.

- These exercises are game-like.

From the kid's perspective, they're fun.

(computer beeps twice)

But in fact, they're intensive, serious exercises,

and they're actually optimized to drive the child

as far as possible in a corrective,

or a more normal or more powerful, direction

as fast as possible.

- One of the things that's so powerful about Fast ForWord

is that, before the program, kids with reading difficulties

have very unusual scans, very, very different from normal.

But as they start to improve on the exercises,

and as they start to get better at reading,

Merzenich was able to show

that their brain scans also normalized.

- [Computer Voice] The fish are swimming.

- [Voiceover] But Merzenich's scientific work

is not just for children.

- Ready? So this exercise is called Bird Safari.

- [Voiceover] He has been able to prove

that plasticity exists from cradle to grave.

And studies show that the elderly can use

his brain fitness program to sharpen their memories

and function as well as they did

when they were from 10 to 25 years younger.

- Well, old brains slow down.

And old brains, again, represent information

in lower fidelity,

You can think of it as a little bit like a radio station

that's no longer quite tuned to the station.

Older brains forget most of what they hear.

Older brains forget most of what they see.

A younger brain remembers most of what it hears,

remembers most of what it sees.

This is machinery that also contributes greatly

to controlling how we feel about life,

how we operate in life,

how closely we can attend to the things

and enjoy the things of the world in life.

And it's really important that the average older individual

keep this machinery in good shape.

- [Computer Voice] Click the matching arrows in order.

If you hear,

(computer beeps twice)

click the Up arrow twice.

- [Voiceover] The brain fitness program

is this great computer program.

It's got several different, sort of games

that really press you to expand your memory.

- [Voiceover] What were the first changes

you actually noticed?

- I noticed my attention span lengthening.

That was the first thing that I noticed.

But after a couple weeks, and I started seeing changes,

then I thought there really is something to this.

This is really worth my time.

It meant that I was gonna be able to function

the way I used to.

It meant that I wasn't gonna be limited by chemo-brain.

- Well, it was a typical Friday morning.

I proceeded to go out to play tennis with a local pro

that I've played with for about 25 years.

And he says to me, "Mike,

"your game is not what it usually is."

And I said, "My balance is slightly off."

But I continued to play.

- Michael Bernstein was an eye surgeon,

who would work with very small instruments,

operating inside an eye.

And he was a classically trained pianist and a tennis buff,

who, in the prime of life, at the age of 54,

suffered an incapacitating stroke

that made it impossible for him to move half of his body.

- [Michael] The left hand, the left arm,

and left leg were paralyzed.

The speech therapist and the occupational therapist

said it would be very slow and not to expect too much.

- Michael Bernstein was one of the first people

to go to the newly-opened Taub Therapy Clinic

in Birmingham, Alabama, to try a new treatment

called constraint-induced therapy.

Dr. Edward Taub developed the therapy

for stroke victims.

It can even work on people

who have been paralyzed for years.

- Alright, go Molly, go.

Really let go of it.

- [Voiceover] The patient's good arm is constrained

in a mitt, so it can't be used,

forcing their paralyzed arm

to try rudimentary tasks.

- Keep going.

- The axiom in rehabilitation was

that there was nothing you could do with these people

that would make them improve,

that would enable them to use their affected extremities

any better than they could.

- Judy had trouble communicating.

She had a very serious stroke October 24th.

- One of the techniques that we use is called shaping.

It's a kind of training technique in which you get a person

to improve their motor response,

their motor function, in very small steps.

- The essence of the cure is this incremental training.

Concentrated practice helps rewire the brain

by triggering plastic changes.

After there has been massive brain death,

new neurons are recruited to take over lost functions.

- Pick that up, and back up.

- [Voiceover] You don't try and get a person

to perform a perfect movement

if they have just the rudimentary ability.

You just try to get them to improve just a little bit.

- Good, good. Stretch it out.

Stretch, stretch, stretch.

- They're children's games to us,

but to the patients,

they're major life challenges.

- Hello Mr. Taylor, how are you?

- Fine, thanks.

- Good effort, that's great.

Alright, show us what's on your other hand.

- This one?

- That's the mitt.

- He wears it all day here, and then when he goes home,

he wears it for as many of his waking hours as he can.

- So that he can't use his good hand?

- Right.

Alright, ready, set, go.

Really control it, really control it.

- People who've had stroke or traumatic brain injury

frequently don't use the more affected arm,

not because they can't use it.

They don't use it, because they've learned

not to try to use it.

- Nice.

Take it back.

31.74, that's better.

That's seven seconds faster.

- What we find after CI therapy

is that the healthy part of the brain

is recruited to produce movements of the affected arm,

and that is what we call neuroplasticity.

- Taub's technique developed

because he had spent years doing a form of research

that involved something called deafferentation.

Afferent nerves are basically like sensory nerves

that feed information from the limbs to the spine.

Ed Taub deafferented some monkeys

so that they couldn't use their arms.

Then he decided to take their deafferented arms

and put them in slings.

- This is a unilaterally deafferented animal.

The right hand is the afferented, the right arm.

And the left arm is normal.

- You deafferent one limb in a monkey,

and the monkey doesn't use that limb again.

However, on the basis

of this really rather short intervention,

one week of placing the animal in a restraining device

that prevented him from using the intact arm,

he began using the deafferented arm.

And then, when you removed him from the restraining device,

he would use the limb again for the rest of his life.

- When the animal is very hungry,

we can increase his motivation sufficiently

to try and force him to use the deafferented limb.

With adequate training, the afferented animals

were capable of carrying out

virtually every major category of movement.

- Taub was now very excited, because he wondered

if this thinking could now be applied

to human beings who suffered strokes.

- If you could get the same result

in human beings after stroke,

you would then have an enormously powerful

and effective way of treating stroke,

and traumatic brain injury, and other types of damage

to the central nervous system in human beings.

- Keep going.

- It turns out that Taub's technique is good

for many conditions beyond stroke victims.

He's used it with people with all kinds of brain damage,

including soldiers returning from Iraq,

people who have had their brains damaged

by chemotherapy and radiation.

It's even been used with children with cerebral palsy

and proven to be effective.

- Squeeze my finger, and let him out.

- Oh, get it, get it, get it.

- Good girl. We're almost done.

- Sometimes, the process goes slowly,

and sometimes it goes remarkably rapidly.

When it goes rapidly, it's almost like a miracle.

- [Voiceover] Michael Bernstein is now back at work,

using his hands in very fine motor activities.

- I only spent 10 days of therapy with Dr. Taub,

and the result was amazing.

Ok, sit back.

I could almost sense

that each hour of doing a different task,

I improved.

I couldn't make that movement, or that movement,

or that movement, or that.

Simple movements that are required in daily life

that you couldn't do because of the stroke.

Ok, sit back.

(classical music plays on piano)

I hadn't touched a piano in 41 years,

and I decided to get this performance together.

And I sent out invitations

and invited Dr. Taub and his wife.

- The bottom line is that you can teach

an old dog new tricks.

That principle is at the heart

of a revolution in rehabilitation.

(classical piano music plays)

(audience applauds)

- [Voiceover] Encore, encore!

- One of the most important lessons I learned

on this quest to understand neuroplasticity

is something I call the plastic paradox.

The paradox is this, that the same plasticity

that allows us to change our brains

and produce more flexible behaviors

is also the source of many of our most rigid ones.

All people start out with plastic potential.

Some of us, as we grow and develop,

enhance that flexibility.

For others, the spontaneity, creativity,

and unpredictability of childhood gives way

to a routinized existence that repeats the same behavior

and turns us into rigid caricatures of ourselves.

Anything that involves unvaried repetition, our careers,

cultural activities, skills repeated, and neuroses,

can lead to rigidity.

- For a while, people had this notion

that plasticity must be a good thing.

It's a good thing that the brain can change,

because we can learn new things.

And that's true.

But if plasticity is an intrinsic property of the brain,

it's neither good nor bad, it's just the way it is.

- Alvaro Pascual-Leone is elegant, charismatic, warm,

mellifluous, expressive, and whenever he does something,

he radiates a very serious sense of playfulness.

- I'm just going to start with a relatively low intensity

so you have a sense of what it feels like.

I've done this enough that I have a sense

of where your motor cortex is going to be.

TMS stands for transcranial magnetic stimulation,

and it is a way to stimulate, to apply currents

to specific parts of the brain,

but without having to cut open the skin,

crack open the bone, and expose the brain.

(machine pops loudly)

- Oh wow, that was my bicep.

(machine pops loudly)

- That's sort of more your little finger.

- You know, one of the things that we've learned from TMS

is that we can use it to map the brain.

We can use it to understand

how brain activity relates to behavior.

We can also use it to modify the brain.

We can use it, depending on the parameters of stimulation,

to actually increase activity in a part of the brain,

or to suppress activity in a part of the brain.

So I'm just going to target your language area.

Then, we'll give you a little feel of what it is like

when people are trying to speak and can't

because of a stroke in that area.

- Go ahead.

One, two, three, four, five,

(machine clicks rapidly)

six, seven, eight, nine. (voice shakes)

It's getting tough.

I was so slurring my speech.

- Mmm-hmmm.

- Pascual-Leone is now expanding his work

to look at the autistic spectrum, which includes

the childhood disorder of autism and Asperger's.

And his working hypothesis is

that they're both a product of hyperplasticity in the brain.

If the brain is plastic, and we believe it is,

can plasticity itself,

can the mechanisms of plasticity themselves

be abnormal in certain conditions?

Could it be that one has too much plasticity?

And we think that autism, autism spectrum disorders,

are exactly that.

- There are certain things in autism and Asperger's

that involve a hypersensitivity, and he's wondering

whether these hypersensitivities are related

to a very over-connected brain

that's formed many, many plastic connections.

- So that autism can generate an abnormal plasticity,

an excessive plasticity in fact.

When the brain is excessively connected,

it doesn't function well.

There is recurrent thoughts,

there is intrusions of thoughts,

there is repetitive behaviors, ritualistic behaviors.

If we are right, if the hypothesis is correct,

then we would be able to use

the capacity of brain stimulation to modulate activity

to suppress that plasticity tendency, and therefore,

hopefully, to help with the symptoms of disease themselves.

Pascual-Leone's remarkable experiments have shown

that we can change and restructure our brain anatomy

simply by using our imaginations.

- One of the things I became interested in

is the question of how do the maps change

when you simply think of things,

when you don't do anything other than thinking.

We took normal subjects,

and we sat them in front of a piano and asked them

to learn to do a five-finger movement exercise.

They just had to go from thumb to little finger,

back to thumb, back to little finger at a given rate.

And we found that over these five days of practice,

the part of the brain that controls finger flexions,

got larger and larger and larger.

But we had another group of subjects

who simply sat in front of the piano

and imagined themselves moving.

And we made sure that they did not move,

but simply mentally rehearsed the actions.

What we found in them is that the brain changed

in exactly the same way as in those

that actually physically practiced.

So the idea is that

just thinking will change your brain.

And what that ultimately means is

that one needs to be careful with what one thinks.

- This beautiful experiment complements the work

of Nobel Prize-winning psychiatrist Eric Kandel,

who showed that thinking actually turns on genes

inside neurons to form new connections between brain cells.

And this idea is further complemented by brain scans

which show that psychoanalytic, cognitive,

and other psychotherapies also change the brain's structure

through the use of thought alone.

- I think we're now learning that, in fact,

the brain is changing all the time,

that the brain is changing with everything we think,

with everything we experience,

that plasticity is an intrinsic property of the brain.

And it's not something you can switch on and switch off.

It's simply there.

And so the challenge is to learn enough about it

so that you can guide the changes.

- My name's Derek Steen.

I'm 41 years old.

Grew up here in San Diego.

And was involved in a pretty traumatic

motorcycle accident in 1985.

- When we wish to perfect our senses,

neuroplasticity can be a blessing.

But when it works in the service of pain,

it can be a curse.

- There's days where I just feel phantom pain in the hand,

and it feels like my hand's being crushed in a vice.

- Plasticity can also result in phantom pain

because of the reorganization that's taking place

after the amputation.

There is a mis-wiring.

Maybe some of the touch input

is going and activating pain areas in the brain.

- Our guide to neuroplasticity and pain

is one of the most intriguing of the neuroplasticians,

V.S. Ramachandran.

Ramachandran is the magical wizard of modern neuroscience.

He is the man who uses illusions to combat illusions

and imagination to change the brain and its contents.

- Many patients with phantom limbs can move their phantom.

But I found that in some patients,

maybe as many as a third,

the phantom is immobilized.

The patient will say things like,

"It's frozen in stone."

- After the amputation, my body actually,

I could still feel the left arm

in the sling sitting on my stomach.

When I would try to make that phantom hand move,

it created pain.

- Hey Derek, how are you doing?

- Good.

- Good to see you back here again.

- Thank you.

- No one really knew what triggered

the movement or pain in a phantom.

Ramachandran wondered, was it possible

that the face maps in people with amputated limbs

had somehow invaded the maps for their arms.

- What do you feel?

- I can feel a stroking across the phantom hand.

- Stroking right across the phantom hand?

- And my face.

- First of all, in normal people, the entire skin surface

is mapped onto the opposite side of the brain.

Now it turns out, there's a systematic map,

but the hand region on the map

is right next to the face region in that brain map.

- How about, let's go back there.

- It's towards the little finger.

- Towards the little pinkie, you said?

- After the arm has been amputated,

there's a massive sensory loss.

There's no sensory input to the hand region of the brain.

If you now touch the patient's face,

the message goes not only to the face area, as it should,

but also invades the vacated territory

corresponding to the missing hand.

- Here?

- Index finger.

- Here?

- Thumb.

- If I,

- I can feel the tapping on the hand.

- You feel the tapping on the hand.

- Mm-hmm.

- Here was striking evidence for plasticity

in the adult human brain.

In three weeks after amputation, the face input

now activates the original hand area of the brain.

- Ramachandran wondered if it would be possible

to fight one illusion, a phantom limb, with another.

What if he could trick the brain

to think that the limb was moving

by giving it some kind of false input?

- So I want you to look in the mirror.

Put your right hand there.

And look at the reflection of the right hand.

Position the phantom sort of, roughly,

so that it's kind of superimposed.

- He asked me to come down to his office one day

and said he had something new he wanted me to look at.

And he explained to me that he had a student

that had built a mirror-box.

- Do you feel anything in your phantom?

- I can feel my phantom.

And I sat down, I put my hand in the box, and I'm hurting.

The phantom pain's flaring up.

And I look in the box.

And he said, "Look at your right hand,

"and start moving your fingers,

"and imagine your phantom left-hand fingers moving."

- What you're doing here is using one illusion,

namely vision, to negate, quote-unquote,

the illusion of pain.

Because pain, too, is an illusion of sorts.

- Now I want you to tell me,

what do you feel when you do that?

- I can feel slow movement

and resistance in the phantom hand.

It was very shocking.

Imagine moving your fingers and having

(laughs)

a spirit go through and not touch.

- So what we saw in Derek was quite amazing.

Initially, he said the phantom was moving again

when he looked in the mirror.

When he closed his eyes,

of course the phantom was immobilized and didn't move.

When he opened his eyes again, it started moving.

So we immediately knew that vision provides a critical role.

You need to restore that whole visual-motor congruence.

And that's what seems to relieve the pain.

- So Derek, we want to try something

a little bit different, ok?

So, where's your phantom now?

- I can,

- Sort of roughly in that region?

- Yeah.

- Ok.

Another thing we have recently observed,

this is very striking, and it's absolutely amazing.

It blew my mind when I first saw it.

I'm gonna put my hand here.

- Ok.

- And I'm just gonna either stroke it, or tap it,

or do something with it, and I want to know

if you feel anything on your face, on your shoulder.

You have a patient with a phantom limb.

And the patient simply watching the normal person

being poked, and stroked, and touched,

he starts feeling the pokes, touches, and strokes

in his missing phantom hand.

- I can feel a vague tapping.

- And this blew my mind.

It's almost like X Files.

It's empathy carried to the extreme.

Now, why does it happen?

Again, it turns out,

there's a perfectly logical explanation

based on what we know of the anatomy of the brain.

If I am a normal person and somebody touches me,

sensory neurons in my brain fire.

- I feel tapping.

- You feel tapping on your phantom?

- Yes.

- Astonishingly, some of these neurons,

touch-neurons in my brain,

will fire when somebody touches you.

And these are called mirror neurons, for obvious reasons.

This neuron, which I call a Gandhi neuron,

is actually dissolving the barrier

between you and another human being.

That neuron doesn't know the difference

between whether he's being touched or you're being touched.

How 'bout if I do that?

Clinically they may be important,

because these neurons may be revived using visual input,

and it may be one reason

there's recovery from paralysis using visual feedback.

The idea of neural plasticity is quite beyond any doubt now.

There is a tremendous amount of malleability,

and we can tap into this,

maybe even to enhance brain function,

certainly to accelerate recovery of brain function.

It's essentially a new era of research

in brain plasticity and clinical applications.

- And this is a double letter.

Two, three, four,

eight, sixteen, twenty-four.

- [Voiceover] When Michelle was just a few weeks old,

I noticed that she didn't have all the normal movements

that the other babies had had.

And I remember telling Wally,

"Something's wrong with Michelle."

- I went to visit Michelle Mack,

because I wanted to test the upper limits

of human neuroplasticity.

Something catastrophic happened in Michelle's brain

when she was in the womb.

We don't know what it was,

but for some reason one of her hemispheres never developed.

Michelle Mack is a woman who was born

with just half a brain.

- I was born missing the left hemisphere of my brain.

My parents weren't given enough information,

because at that time, there were no MRI machines,

and that my brain would only progress

until I was about 11 and then stop.

- Carol brought Michelle

to the National Institutes of Health in Maryland,

because she'd read an article by Dr. Jordan Grafman

that contradicted everything she had learned about the brain

and been told about Michelle's prognosis.

- It's dramatic.

It includes not only the cortex, but her left thalamus,

it's all missing.

- Dr. Grafman had worked with people

who had severe brain damage,

including a lot of Vietnam vets,

and was able to show that brain development

could take place after a trauma.

- And it's important to merge

the sort of brain anatomy picture

with the person as a whole.

Michelle's brain works much in the same way

that our brains might work,

but the functions that are available to her

are somewhat more restricted.

- Some of the things she has trouble with

are when something is very vague.

- Anything that's not concrete.

- Grafman's theory provides a compelling explanation

as to how Michelle's right hemisphere

took over so many of the functions

that are normally governed by the left.

- We know that now that she can perform certain skills

that the left hemisphere ordinarily subserves,

they must now be located in the right hemisphere.

So we know she's had some dramatic plasticity

to enable her to have normal verbal skills,

normal verbal memory.

- You also have a number of special skills.

What are some of those?

- Memorizing dates.

- Do you remember when I came here last?

- Yes.

- When was that?

- That was in June of 2003.

- Do you remember what day that was?

- Yes, that was Thursday,

June 5th.

- Let's say we had a family reunion in Colorado.

- Sunday, July 9th to Sunday, July 16th,

2000.

- How about July 17th, 1989?

- That was a Monday.

- And how did you do that?

- I don't know.

- Hi. Hello.

- Hello, how are you doing?

- I'm fine.

- Well, we've learned from her

these general concepts about plasticity.

And I think now what we're going to try to do

is to study them in more detail.

You have part of your brain missing from that area,

but you talk pretty much - [Michelle] Normally.

- like I do.

Right, exactly.

So we want to see what the limits are of this plasticity

and whether, under some restrictions,

we can influence the plasticity in some way

to promote certain functions

that the family and the child would benefit from.

- I want people to see that I function on a normal level,

even though there's some things

that I'll never be able to do.

- When I think of Michelle, it's hard to imagine

a better test or illustration of the resilience

of human neuroplasticity.

It may be easy for some people to dismiss

these fantastic case studies

as anomalies that have little bearing

on the lives of the rest of us.

- Many people react by saying,

"But that's just one patient.

"It's an N of 1."

But my usual rhetorical response to this is to say:

Well, look. Supposing I bring a pig to this podium,

and I say, "This pig can talk."

You'll say, "Really?"

And I wave my wand and it starts talking.

What would your reaction be?

You're not gonna say, "Well, that's just an N of 1.

"Show me another pig."

You'd say, "My God, that pig is talking!"

And yet, the reaction of some of my colleagues is to say,

"Show me another talking pig."

- To understand that we have within our hands

this incredible power to drive changes in the brain

that accounts for our behavior,

that is in fact the very basis of what we are,

of the person that we are,

you know, what a gift.

- The brain that I met in my travels

turns out to be both a more resilient,

and a more vulnerable, brain that we had imagined.

By being more resilient,

it stirs up an incredible amount of hope for people

with all sorts of brain and psychological problems.

What we have been introduced to here

is the first generation of neuroplasticians.

They're just beginning to elaborate and elucidate the limits

and what neuroplasticity can do.

Much awaits us down the road.