For a long time, it was believed that the human brain was fixed or hardwired
and most forms of brain damage were therefore permanent and irreversible.
However, scientists have since come to realize that far from being fixed,
the brain has remarkable powers to regenerate itself even in old age.
Norman Doidge is a psychiatrist and medical researcher.
In his new book, he explores the impact of this revolutionary discovery on all of us.
It's called "The Brain That Changes Itself."
Stories of personal triumph from the frontiers of brain science.
For years, we've been told that the human brain is like a machine,
a computer that there are different parts
that they're responsible for different functions.
And if those parts break or wear down or damaged, we lose that function.
Now, in your new book, you throw this all on its head and you say that in fact,
the brain is plastic,
explain what that means.
Well, plastic means plastic in the sense of Plasticine,
modifiable, adaptable.
The plastic brain is a brain that can
change its structure and its function depending on
both...
Without drugs or invasive...
Without drugs. Just depending on what you do with your brain.
The task at hand that you are working on,
what you're perceiving can cause you to change the structure of your brain
on many levels
and this is the most fantastic part,
what you think and imagine actually can change the structure of your brain
down
to the very connections between the brain cells, down into the genes
even for instance.
One of the most,
you know,
staggeringly interesting discoveries of the late
20th century was the discovery that learning
changes the number of connections between the neurons,
the nerve cells in a nervous system.
You can go, for instance, from having perhaps 1300
connections between
nerve cell A and nerve cell B to 2700
with several hours of training. By virtue of more brain activity occurring,
By virtue of learning and brain activity. So,
what happens is thoughts
or activities that you do with your brain
actually turn certain genes on and others off inside the nerve
cells, which then make proteins which then change the structure.
Now,
why is this discovery considered so revolutionary and more particularly what
are the implications of this discovery for people with brain dysfunction?
A stroke for example. When you had a stroke, the general assumption was
your brain got swollen, the chemicals were kind of deranged and after a few weeks,
whatever you were left with was what you would have
to live with for the rest of your life.
You basically lost that brain
function that was damaged. The cells died, they couldn't be replaced,
the healthy ones around it couldn't reorganize.
And so,
we were kind of waiting for the swelling to
go away and rehab was just sort of focused on
getting you over that period. Now, we know that rehab can actually
reorganize the brain if it's done properly and bring many new functions back.
But if I could just say it, it also meant
that
as you started to get older and your brain started to decline.
It was like a machine that was wearing out
and the attempt to exercise your brain in the second half
of life was really kind of unwarranted or waste of time.
And so, we just
accepted a view of human development in which
the second half of life is a period of necessary mental decline.
And then, of course, the whole view of human nature that we have, you know,
since the rise of modern science, most
educated people see human nature in some way is emerging from the human brain.
And if the human brain was fixed, immutable
and a rigid structure,
it made a lot of sense to think of human nature as fundamentally fixed.
And so,
we have to re-examine all that and I begin to do that in this book.
Well, you do it by way of story and that there's some remarkable,
almost logic defying, remarkable,
given what our traditional notion of what the brain is,
probably the most remarkable.
And it is the story of a woman who was born with half a brain. Tell me about Michelle.
I went to visit Michelle because I thought that
I knew that she was born with one hemisphere alone,
just half a brain.
And,
I thought that whatever changes that she was able
to undergo would really test this notion of
plasticity, certainly, at least in early life.
And
basically, when she was in the womb, some catastrophic event occurred, so
her left hemisphere never developed.
And
based on what, you know, the usual view of
that
the brain basically has certain areas which in the left
hemisphere which are responsible for speech and other functions,
someone with that level of damage you would imagine
would be unable to speak, unable to think, they might be alive, but on a respirator.
And it turns out that that's not the case with Michelle.
In fact,
if you met Michelle,
you would detect some subtle things like one of her arms is a little twisted,
et cetera
and
her speech when she's upset, it's a little repetitive,
but you would never dream.
And nor did the people who examined her for a number of years dream
that she had half a brain. Well, explain to this
now, if we had thought that
this part of the brain is responsible for speech
and I don't have this part of the brain,
How is Michelle speaking?
We know that there's a lot of plasticity early in life.
But we also know and I make this very clear in the book,
there's plasticity from cradle to grave.
But you know, there are waves of increased plasticity
and it turns out that what the brain does is
it learns how to do what it's got to do at the time. So,
parts of the brain that might have been
devoted to other things will learn how to move.
If it has to see to survive, they'll be devoted to vision.
And so
all
these things can actually be organized and move around,
these higher mental functions. To give our viewers even more
kind of appreciation of the extent to which
that's possible.
Retell the story that's in the book that
you dub the woman who is perpetually falling.
Cheryl Schiltz
was a woman.
She had a hysterectomy and she was given
a medication because she developed an infection called gentamicin
and
it poisoned the vestibular apparatus, which is the balance apparatus in her brain.
And if you lose your sense of balance,
you will feel like you're perpetually falling. When I was with Cheryl at one point,
I asked her, "What's it like when you've finally fallen to the floor?
What do you feel at that point?"
And then she says,
"Sometimes, I just feel the floor opens up and I fall into a perpetual abyss."
So that was her life and she ended up on disability.
And one of the great
people
who were at the cutting edge,
I call these people "neuroplastician" to coin a phrase,
Paul
Bach-y-Rita
invented a mechanism
and I was there when she was using the mechanism for one
of the first times that basically was attached to an accelerometer.
An accelerometer is like a gyroscope.
And
she would...
The accelerometer would be in a hat on her head. Like a construction hat.
Like a construction hat.
And it would give signals that went into her tongue of all places
telling her where she was in space. I tried it on.
So when you lean forward and you feel like champagne bubbles,
they're really little electric shocks, tell you you're forward, you lean back,
it goes back
and she would put this hat on.
And
immediately
she would... Normally, she'd be holding herself like up on a table lest she fall
and immediately her whole body relaxed.
And this seemed like a miracle. Why? Because
the sensory
apparatus, the
sense of touch on the tongue goes to a
different part of the brain and the balance apparatus.
So
somehow or rather these signals coming in
were making new pathways or strengthening very dormant pathways between
her sense of touch and her sense of balance,
so that was the first miracle I saw that happening and she had tried it on.
But
then there was a second miracle which
is as she started to use the machine more,
she found she had a residual period
where
she would take the hat off.
And at first, the residual period lasted
30 seconds. Residual period being that she still had balance. (MULTIPLE VOICES).
Exactly.
That's
right.
It lasted for, you know, a few seconds and then
it lasted longer and longer.
And as she started to use the hat and take it home and use it,
she would be going for days. And
that was a true miracle because what was happening was
a miracle. I mean,
it's only a miracle
if you think that the brain is fixed, it's actually not a miracle.
because
she now no longer considers herself a
wobbler. Because the brain reordered itself and put
the balance in a different part of the brain that wasn't then.
Yeah. And, it developed new paths. Now, is this sensory substitution?
I mean, this is again,
another fascinating notion he introduces. This is what
Paul
Bach-y-Rita called sensory substitution. He did
this
as well for people who had been congenitally blind,
they've never seen anything.
And,
he rigged up a camera to a computer and then attached it originally just to the back
and there were vibrating pixels that were on the back.
And then he put it in to the tongue
and he found that he could train a human tongue
to function like a retina.
And they would be able to see Twiggy.
They would say, "Well, that's a picture of Twiggy."
That's a picture of a vase...you've just moved a vase in front of a telephone,
they could read certain things.
If you threw a ball at them, they would duck, they could see perspective.
I mean, so this is remarkable.
They could see through the tongue.
What was happening is the tongue is like a two-dimensional surface
just as the retina,
the retina is.
And yeah,
basically...
The images would be...
Images would be on the tongue.
And then, we've recently learned, actually, this was some work also done
in Canada,
Bach-y-Rita was from the states
that
the input coming into the tongue was processed in the back of the brain,
which we tend to call the visual cortex.
So it was all being rerouted
and
Paul
Bach-y-Rita has found different ways to do sensory substitution, which is
lay the groundwork for the notion of a retinal implant, but,
you know, helping other people who have
literally lost the ability to sense certain things.
We touched on the whole issue of stroke victims.
And that you can tell a great story here about a surgeon in
his mid 50s had a terrible debilitating stroke.
Tell me how he came back. Michael Bernstein,
yeah, out, he was playing tennis. He was a tennis...
He spent the morning doing surgery on the eyes,
so he needs a lot of fine motor skills. It's microscopic surgery.
It's in a small confined space.
Then, he was playing tennis,
then he developed a stroke and he couldn't move one side of his body.
He went for conventional rehabilitation,
they gave him whatever it was the 4 to 6 weeks.
And basically, they said you're on your own and he had very,
very little control of his arm at that point and very little control of his leg,
and then he tried a new
form of treatment. He
happened to be from Birmingham,
Alabama where a man named Edward Taub had
developed this new treatment called constraint-induced therapy.
And
one of the things that neuroplasticians have shown in hundreds of experiments
now is that it's use it or lose it brain.
If you don't use something,
it's that cortical real estate is taken over by something else.
Now,
what happens when a very common form
of stroke is you have a stroke in the left
hemisphere and you can't move your
right hand. You're paralyzed.
You can't move it well, et cetera.
And so people try to use their arms,
it doesn't work
and
so they stopped using them.
Now,
what Taub did ingeniously was,
he got people to put their good hands in slings.
Constrain them. He constrained them
and then if a person could just do this,
he would give them small amounts just to get
a little more control over that very incremental,
and he worked them very, very hard.
And they would have to do things like, you know, try to wash pots. And,
you know, people would come in, they couldn't dress themselves, they
couldn't eat, they couldn't put food on a fork.
They literally would have been dependent for the rest of their lives.
And Michael Bernstein was one of the first to go
through this and after two weeks of very intensive training,
and that's not a long time. No. No.
It
isn't,
He was able to function, get back to work and function as a surgeon.
And there are people who went to Taub clinic, there was one person
I spoke to had
a stroke almost 50 years before. He had been
a little boy playing baseball when he had a stroke.
They
could help him. All these years,
after the fact, I mean,
that's just so remarkable because that plasticity
and the ability to reorganize
is in the brain.
And it has even helped people who've had traumatic injuries,
traumatic brain injuries.
I think that's the kind of thing that would be very helpful
for
anyone who's got those kinds... Well, not anyone but many people with
traumatic brain injuries, for instance,
think of the soldiers getting back from Afghanistan.
Is this kind of therapy or are these kinds of treatments now finding their way
into medical practice?
Not quite.
No, because normally when someone has a stroke or any kind of brain damage,
I mean, we really do look on it very,
very fatalistically and if the evidence is what we should, they don't improve.
Yeah look.
We look on it fatalistically in part because studies that have been
done in the past and people with brain damage and strokes showed that
interventions didn't work.
But now that the neuroplasticians have laid out the laws of this new science,
there's reason to be hopeful for a number of kinds
of brain injuries.
I bet,
the notion of phantom pain again
documented that people who lose limbs that they continue to
to hurt.
You again claim that
neuroplasticity both explains this and that researchers
using the theories of neuroplasticity have been able to cure phantom pain.
Tell me about that.
Well, phantom pain was one of the great mysteries of medicine.
How is it possible to feel pain in a limb that isn't there?
And what a neurologist named
Ramachandran discovered was
that in patients who've lost their arms and then
get pain or in one case in scratch or itches,
What happens is
if you remove an arm,
there's cortical real estate if you will, that had been devoted to
moving that arm and feeling for that arm, it's now dormant.
In the brain.
So adjacent cortical real estate takes it over.
And
in the typical human body map,
an area that's very close to the arm is actually the face. And
we now know that phantom pain is often caused because the face maps in the brain
say, "Hey, there's more cortical real estate for us and they start to move in there
and
reorganize
the brain." There was one patient he had who had an unscratchable itch,
so that was a terrible affliction for him.
And
Ramachandran eventually figured that if you just scratched the man's cheek,
the itch went away. And
Ramachandran was able by the way to sort of trick the brain
into rewiring itself using this same neuroplasticity.
One of the reasons that people would
have these frozen pains is because once the input is stopped into the brain
from,
you know, from the arm,
it's as though
that's the picture that remains in the brain, there's no
new input to say. Now the arm is moving again.
Many people who had phantoms
felt their arms were frozen and in pain.
So, he set up a mirror device where you would look at what your real arm,
let's say this arm had been cut off.
You'd look at your real arm and then you look into a mirror right here.
The brain would be tricking you thinking that your arm was...
Think that your left arm was moving, that which, of course, didn't exist,
you'd kind of put your stump near it
and
that rewired the map so that the frozen phantom could move.
Now,
I understand that neuroplasticity also tells us something
about the nature of sexual attraction and love.
What is that?
There's tremendous variation, of course, in what people are turned on by,
let's say sexually, I mean,
you know, take
situations in other cultures
seem unnatural sometimes.
And we learned that people can develop attractions. If you think of
the whole idea that Chinese men 100 years ago in the aristocracy were
totally turned on by women who had their feet broken and bound up.
Okay.
We start to realize that sexual tastes can be acquired and we
we can acquire sexual types.
And we're seeing a lot of this happening now actually
with the internet and internet porn in a way.
You know, there are a lot of stories that started to
become
public in the nineties about men
who would get on the internet
and they'd sort of just be searching
around and then they fasten on to certain images
that would really turn them on, that really surprise them.
And then they would practice them over and over and over again
and they would have orgasms and when a person has an orgasm, they secrete a
brain chemical called dopamine, which actually reinforces the circuit
and rewards them.
So, dopamine is a neurotransmitter or a brain chemical
that's very involved in consolidating a new circuit.
And these men would start to develop new sexual attractions
that at times seemed bizarre to them,
sometimes they dipped into childhood things.
I mean,
one story I talked about in the book is
a man who developed an attraction to spanking sites.
And if you think about it, spanking would seem to have to do with early childhood.
But the other thing that was happening for these men and this
was reported over and over and I saw it in clinical practice
is
they said that for a mysterious reason, they were losing
interest in
their own
partners, even though objectively they found them to be attractive.
So, here was a case where
because of plasticity, people were inadvertently rewiring
their brains.
And plasticity isn't always a good thing. That it can lead to rigid behaviors (VOICE OVERLAP).
And in this case, it leads typically or very frequently to a kind of an addiction.
And if you think about it, addictions are about plastic change in the brain.
There are certain people who, if they have alcohol,
they have a chemical
sequence that's fired in their brain and a chemical called delta
FosB
is released
that changes their brain permanently.
That's why sometimes it does make sense for a person to say,
even though they haven't had a drink for years, I'm an alcoholic.
It's in plasticity terms,
my brain has been structurally altered by my interactions with alcohol.
Now, interesting you say that because they also point out that psychoanalysis
can be used
to open up the brain's pathways and reorder
the brain's function too. I think you call this
neuroplastic therapy.
Explain to me what that is and how it would work.
It turns out, you know, based on what I told you before about,
you know, thoughts altering genetic behavior
that thoughts in therapy are actually changing brain structure as well.
They change different brain structures.
But the major therapists that we know that are successful
and that includes psychoanalytic therapies, cognitive behavioral therapies,
it's something called interpersonal therapy.
They're all for slightly different conditions,
all
rewire the brain, all change the balance in the brain's department.
So,
they are as every bit as biological, if you were
in intervention as the use of drugs and the advantage of psychotherapy is if
you don't absolutely need drugs.
And I want to say, I mean, I use drugs sometimes
but the advantage of them is
they
don't have as many side effects
in general. And,
if you think about it, drugs
as they are today are very blunt instruments, you take a pill and it goes
and it bays every cell in your brain and in fact, in your body,
and that's why we get so many side effects.
And it would be
to a certain extent, if you're using thoughts for the intervention,
you're like more like a micro surgeon
going into the thought patterns that are probably...
Do you know enough about the brain to be that precise in terms of psychiatry
and psychoanalysis.
In other words, if I make an interpretation about the meaning of behavior, do
I know where in the brain
it's going?
Well if we're treating, let's say an anxiety problem, right?
We now know that if you use psychoanalytic psychotherapy
and
you take a person before the therapy
and
you
take the thing that's making them anxious and you
make them think about it or attend to it,
the part of the brain that's likely to light up and trigger these
sort of bolts of anxiety.
And after they go through the therapy, if the therapy works,
those parts of the brain aren't triggered. Now you
have an absolutely horrifying statistic here about our generation,
the baby boomers,
those between 40 and 60 that they have over a 50% chance of reaching the age of 85,
and that 85-year-olds have a 47% chance of having Alzheimer's.
We're going to have a population full of dementia. I mean, what can baby boomers do
to enhance their brain power and ward off that disease?
Okay.
So, there's two things that we worry about when
we think of mental decline as we get older.
One of them is a more benign thing and more common,
it's called age-related cognitive decline.
The senior moments that begin in our 50s that
frighten people
and then there are the serious dementias.
So, the good news is that we know for a fact
now that age-related cognitive decline is reversible through brain exercises.
And I met with a man Stanley
Karansky who was 90,
who started to have some difficulties
with senior moments. His handwriting was sloppy.
He was no longer alert, he wasn't socializing much.
And
in six weeks
and
roughly
an hour a day, he was able to reverse all of that. What was he doing?
He was doing a program called Posit Science that I described in the book.
Now, this is a company, an actual company.
Yeah. Tell me more about because you have been claiming like 80-year-olds to be like 50-year-olds.
Well, they've shown it.
Posit Science was set up by perhaps
the world's leading neuroplastician and
neuroplasticity researcher, Michael Merzenich.
And,
he's already a man of great accomplishment. He was one of
the inventors of the cochlear implant that allows the deaf to hear.
He's
helped kids with learning disabilities,
with reading disabilities,
moved from problems to basically normal or above normal levels.
And they set up a program that rebuilds
the auditory cortex,
the part of the brain that processes language from scratch in older people.
What happens is that we age. One of the reasons that we cannot remember things
is
our brain maps for sounds
are just kind of getting dulled.
They need to be tuned up at the very basic level of distinguishing sounds like "ba
and da
and pa."
The reason is we haven't really used them intensively
often. Once, we hit middle age, we are usually replaying, mastered skills.
But to maintain a brain in good shape,
you've got to work as hard as you worked when
you were learning a French vocabulary in high school,
maybe you didn't work at it, but as hard as you should have worked at.
And so people go for decades without
putting themselves for that intensive kind of training
and
the cortex just kind of gets
dull and you develop what are called fuzzy engrams.
You don't hear the sound of the person's name at the party crisply,
so they rebuild it from the ground up. How would our viewers get this program?
Posit Science.
Just go to put that in the internet and you'll come to the website for that.
What do you think the next big breakthrough is in brain research?
What's the next big thing we should be watching for?
It's the translation of the fundamental laws
of brain plasticity into applications for everything
in therapeutics, in all kinds of training, you know, that means sports,
the military education, anything you want to do and develop
Right
now
basically
many of these disciplines have an intuitive grasp of some of the laws of plasticity,
but the neuroplasticians can help sharpen and speed up learning.
So
that's where I imagine it would come.
I know that people will want to get
very highfalutin and try to facilitate neuroplastic change
with chemicals and some of that might be doable.
But that's also very problematic for the reason I
said that chemicals are still a very blunt instrument.
At a personal level,
I mean that this book is full of very,
not just amazing but inspirational and uplifting stories.
I mean,
over the course of doing the research,
did it kind of change your sense of what
human potential and perhaps even human nature is?
Yes, it did.
One of the most important insights I think I had
while doing the book was what I call the "plastic paradox,"
and that is this.
The plasticity,
the brain is always plastic,
but it can give rise to both flexible or rigid behaviors.
It can give rise to rigid behaviors because once those networks are established,
they
tend to out compete the other one in a
war of nerves that's going on inside our head.
You know, the human brain is a habit-forming thing.
So,
the way to understand plasticity is think of it as like a hill,
snow on a hill in winter, and we want to ski down that hill,
so we get to the top of it. Because the snow is plastic or pliable,
we can take many paths down that hill,
but it being a hill,
it has rocks and trees and we be inclined towards certain favorite paths.
As we
keep using those paths
again precisely because the snow is pliable and plastic,
we'll develop tracks and ruts.
And what we do in our lives
and what we tend to think that because we're stuck in a rut
and repeating something
that not only is the behavior rigid, but the underlying brain is rigid.
So when I'm working with patients,
I try not to get fooled by the plastic paradox and
they're often fooled by the plastic paradox and I would submit
that
all of humanity to a large degree has been fooled by the plastic paradox.
I think we've underestimated
how plastic our brains really are.
Doctor Norman Doidge, I want to thank you very much for joining me.
It's been fascinating and a real pleasure. Thank you.