29x03 - Secrets of the Mind

[bunniefuu]

[ machine beeping]

MAN:
Up.

NARRATOR:
Graham Young is blind.

YOUNG:
You're moving it up and down.

Up.

NARRATOR:
Yet he can see.

YOUNG:
Down.

NARRATOR:
Derek Steen feels pain
in an arm that no longer exists.

John Sharon sometimes believes
he is God.

SHARON:
My attitude was that I was God

and that I had heaven and hell
in my eyes.

I was the... the grand guy
who created heaven and hell.

NARRATOR:
David Silvera is convinced
his parents are impostors.

SILVERA:
It can look like my father.

It can look identical to him,
exactly like him

but it's not him.

NARRATOR:
These people are not crazy.

They have all suffered damage
in tiny sections of their brains

that has profoundly distorted

the way they perceive themselves
and the world around them.

In the past, these bizarre cases

would have been dismissed
by science

but today one neuroscientist
tracks them down

with the dogged persistence
of a detective.

MAN:
What excites me

is I can go in there

and pretend I'm Sherlock Holmes
and try and figure out

what has gone wrong
in this patient's brain...

What's changed that accounts
for the strange symptoms.

And this, of course,
is a lot of fun to do

because you're learning a lot
about the brain;

learning a lot about
what causes the symptoms

in that particular patient.

But more importantly,
it's telling you

about how
the normal human brain works

and how the activity of neurons
in the normal brain

gives rise
to conscious experience

and gives rise to the whole
spectrum of abilities

that we call human nature.

NARRATOR:
Can the misfortune
of brain injury

shed light on the workings
of the normal brain

perhaps even help solve

some of the eternal riddles
of human nature?

Understanding the human brain

is one of the ultimate
challenges in science.

Watch my two fingers.

Do you see my two fingers?

NARRATOR:
Dr. Vilayanur Ramachandran
is revolutionizing

our understanding
of how the brain works.

His efforts to solve

some of the most baffling
neurological mysteries

take him from the hospital bed

to the outer limits
of brain science.

RAMACHANDRAN:
The human brain is,
without any doubt

the most complexly organized
form of matter in the universe.

The brain is made up of 100
billion nerve cells, or neurons.

Someone has calculated

that the number of possible
permutations and combinations

of brain activity

exceeds the number of elementary
particles in the universe.

And this gives you some idea
of the staggering complexity

one is faced with
in trying to understand

the functions
of this mysterious organ.

So, the question is
how do you even begin?

NARRATOR:
Ramachandran began
his investigations

with a strange phenomenon
called "phantom limb syndrome."

It's not uncommon for amputees
to feel the vivid presence

of a missing limb
long after it has gone.

One of Ramachandran's first
patients was Derek Steen.

STEEN:
in a motorcycle accident

and I pulled the nerves out
of my spinal cord up in my neck.

They told my parents directly

that I would never
use my arm again

About seven years ago I was
reading through the classifieds

and I saw an ad in there...
"Amputees Wanted."

I thought it was a joke.

STEEN:
It's just basically

connecting the club to the ball.

STEEN:
So I called the number
and it was Dr. Ramachandran.

NARRATOR:
Today, Derek is teaching
Ramachandran how to play golf.

But several years ago, Derek
made a crucial contribution

to Ramachandran's pioneering
work in brain science.

Yes, that was amazing.

STEEN:
After my surgery,
I sat up in the bed

and still felt the arm there,
still felt everything there

and I'm looking down
and I'm seeing nothing.

[ chuckling]:
It was pretty bizarre.

The more I thought about it,
the more it hurt.

The more it hurt,
the more I thought about it.

So it was... it was, like...
it was never-ending.

I mean, I'd break out
in a cold sweat
and turn pale

just standing here
talking to you

because the pain
would hit so bad.

If there is any one thing

about our existence
that we take for granted

it's the fact
that we have a body...

Each of us has a body and,
you know, you give it a name

it has a bank account,
and so on and so forth.

But it turns out even your body

is something that you
construct in your mind

and this is what we call
your body image.

Now, of course, in my case,
it's substantiated by the fact

that I... there really is a body
with bone and tissue

but the sense I have,
the internal sense I have

of... of the presence of a body
and arms and all of that

is, of course, constructed
in my brain and it's in my mind.

And the most striking evidence
for this

comes from these patients
who have had an amputation

and continue to feel the
presence of the missing hand.

STEEN:
Yay!

NARRATOR:
It was the beginning
of an important relationship...

Important for Derek

because not only would
he finally understand

his phantom pain;
he would also get to the bottom

of a mysterious sensation
he felt while shaving.

STEEN:
When I first started shaving

after my surgery

I would feel my absent hand
start to hurt and tingle

whenever I shaved
this left side of my face.

NARRATOR:
Meeting Derek was important
for Ramachandran

because the explanation
he came up with

would rock the world
of neuroscience.

RAMACHANDRAN:
How about that?

STEEN:
That's just my arm.

NARRATOR:
The first thing Ramachandran did

was to invite Derek to his lab
for a simple test.

Derek, I'm going to touch

different parts of your body

and I just want you
to tell me what you feel

and where you experience
the sensation. Okay?

Okay.

Close your eyes.

Could feel that on my forehead.

Anything anywhere else?

No.

Okay.

On my nose.

Okay.

My chest.

Your chest, okay.

I can feel that on my cheek

and I can feel rubbing
on the phantom left hand.

On the phantom left
hand in addition
to your cheek?

I'm going to run the Q-tip
across your jaw

and see what happens.

I can feel the Q-tip on my cheek

and I can feel
a stroking sensation

across the phantom hand.

You actually feel it
stroking across your
phantom hand?

Across the palm?

RAMACHANDRAN:
So, here is a medical mystery
of sorts.

Why does this happen?

Why would a person,
when you touch his face

claim that it's also touching
his missing phantom fingers?

That's fine.

Palm.

Thumb and palm.

NARRATOR:
This was just
the kind of mystery

that Ramachandran
was drawn to...

although it would take
some time to solve.

One day, while Derek
was making one-armed repairs

on his favorite Chevy

Ramachandran turned up
with his solution.

It was a groundbreaking theory.

RAMACHANDRAN:
The reason we think it happens

is that in the brain,
there is a complete map

of the surface of the body.

The entire left
side of my body,
the skin surface

is mapped on to the
right side of my brain

along a vertical strip of cortex

which we call
the somatosensory cortex.

Similarly, the right side
of my body is represented

on the left side of my brain.

So every point
on your body surface

has a corresponding point
on this body map.

Now, it turns out

that the representation
of the face on this map

is right next to
the representation of the hand.

Now, that's a bit surprising

as you'd expect the map
to be continuous

and faithfully represent
the left side of my body.

But it doesn't.

Now, imagine what would happen

if the left arm were amputated.

The part of the brain
corresponding to the hand

no longer gets any input

and it's hungry for new
sensory input, so to speak.

The sensory signals
from the face

normally activate
only the face area

that's right next
to the hand area.

But they now invade
the vacated territory

corresponding
to the missing hand

and start activating
the hand region in the brain.

And so whatever is reading
those signals higher up

misinterprets those signals.

It says those signals
are coming from
the missing hand

so you experience the sensations

as coming from
the missing fingers

even though I'm
touching your face.

This is showing
there's been a massive
reorganization

of the sensory pathways
in your brain after
the amputation.

And it's as though there's
been a cross-wiring
in your brain.

Exactly, exactly.

NARRATOR:
At first

some members of
the neuroscience community

scoffed at Ramachandran's
new theory

that neural pathways
in the brain can change.

One of the dogmas in neurology
has always been

that connections are laid down

in the fetus
and in early infancy

and once these connections
are laid down

there's nothing you can do
to change them.

NARRATOR:
As a scientist

Ramachandran knew that
such a radical proposal

needed scientific proof.

It was time to give Derek
a brain scan.

Hopefully, this would show

what was actually going on
in his brain.

But would it prove

that Ramachandran's hunch
was correct?

When various parts
of Derek's body were wired up

the corresponding activity
in his brain

revealed the layout
of his body map.

This is a scan of Derek's brain.

The green spot shows
the brain's response

to the stimulation of
Derek's existing right hand.

Next to it, the red spot shows

that the right side of Derek's
face is also being stimulated.

So far, everything is normal.

But in the right hemisphere,
the green spot has disappeared

because Derek's missing left arm

can no longer send signals
to his brain.

Remarkably, the red area, which
corresponds to his left cheek

has now taken over
the whole space.

These results vindicated
Ramachandran's detective work.

RAMACHANDRAN:
It's as though now

the sensory input from the face
is innervating

a completely new part
of the brain

and this means new pathways
have been opened up.

Whether this is because
there's been an actual sprouting

of new nerve fibers

or there have been
preexisting silent pathways

which are now suddenly active

we are still working on.

We suggested that maybe the
connections are already there

like reserve troops
ready to be called into action

and when you amputate the hand

these latent connections
suddenly become active.

NARRATOR:
Phantom sensations do not only
occur in the limbs.

RAMACHANDRAN:
But in fact,
you can get a phantom

with almost any part
of the body.

You can get phantom menstrual
cramps after a hysterectomy.

You can get phantom
appendix pain

even after the appendix
has been removed.

Theoretically,
you could have a phantom

of almost any part
of the body...

except, of course, the brain.

You can't have a phantom brain
by definition

because that's where we think
it's all happening.

NARRATOR:
Luckily for Derek,
his phantom pain has subsided.

But that's not always the case.

James Peacock has suffered
excruciating pain

since he lost his hand
six years ago.

A few days after I woke up,
you know...

It might have been under a week

to eight or nine days,
something like that...

Before the pain really started
getting bad, you know

to where it was, like

your hand is just crinched up
real tight and stuff

or balled up, you know,
and you can't move it.

To unclench it,
it's just... you can't.

You can try in your mind...

NARRATOR:
This raises a perplexing
clinical problem:

How do you treat pain
in a body part that's missing?

James tried everything
from painkillers to hypnotism

but nothing worked.

Until I found out
about the mirror box.

NARRATOR:
It was then that he came
to see Ramachandran.

One answer might be

that the brain is sending
signals to the arm

and trying to clench it.

But in you and me there's
messages going back

from the muscles of the hand

telling you you're clenching
too much or too fast

and this damps
the command signals

so you can slow down.

But the patient has no feedback

because he doesn't have an arm

so the brain says, "Send
even more signals," okay?

And this goes on

and you get into a
positive feedback loop.

So I said, "Well,
if you give him

"some other source of feedback

"such as visual feedback

"maybe that'll trick
the brain into thinking

"that the hand is
clenching or unclenching

and maybe you can
interrupt this loop."

So I said, "Well, why don't
we put a mirror there

and, James, look
inside the mirror?"

So it's as though you
have visually resurrected

the phantom limb.

And, of course, the patient
knows it's an illusion

but it's very, very compelling.

PEACOCK:
Right now as you look in there
and you move your hand

and your phantom does
the same thing

as your left hand is doing.

The first time I got in here
and I've done this

it was just like
it relieved the phantom pain

and unclenched it.

You know, it was just
so intriguing, you know.

Sometimes it's just hard to
explain how you felt, you know.

NARRATOR:
Ramachandran believes
the mirror box

needs to be evaluated
with many patients

before he can be sure
that it really works.

But its undeniable success in
uncramping James's phantom hand

suggests that even pain
can be a construct of the mind.

The phenomenon
of phantom limbs reveals

how our brains can delude us

into being conscious of
something that isn't there.

But Ramachandran has come across
an even stranger condition...

A remarkable ability of
the brain that allows you to see

even though you are
totally blind.

This rare condition
is called "blindsight."

Ramachandran found Graham Young
in Oxford, England.

He is one of the world's
few known blindsight patients.

This paradoxical condition
shows just how much

our brains run our lives
without our being aware of it.

When I was eight,
when I had the accident...

It was a road accident
that caused the brain damage...

I literally used to walk
into lampposts.

I ran into...

you know those huge great
pillars you get in stations?

I ran into one of those one day.

NARRATOR:
The main visual centers
in humans

occupy nearly half the brain

in a large region
towards the back of the head.

Graham's vision was devastated
by the accident.

Today, he can see to the left

but is blind to everything
on the right, in both eyes.

If you put an object
in that part of the field

and ask him, "What is it?"
he has no idea.

He cannot perceive it
consciously.

[ machine beeping]

YOUNG:
Up.

RAMACHANDRAN:
And yet the remarkable thing is

if you move this object

he will tell you
which direction it's moving

even though he cannot
see the object.

Down... up.

You can see things over here?

YOUNG:
Oh, yes.

I'm going to move
my hand across.

You tell me when it appears...

When it comes into view.

Now.

Very precisely, as it enters

the seeing part of your field.

If I just hold it over here

and you look there

you can't see anything?

No.

How about now?

You're moving it up and down.

MAN:
But you're seeing it?

It's very easy for me
to say to you

"Oh, I saw that
move up, Colin."

And as soon as I say that

you're going to say,
"Ah, he can see!"

No, I can't.

NARRATOR:
Colin Blakemore is
an Oxford scientist

for whom Graham's
mysterious abilities

raise intriguing questions
about consciousness.

I think blindsight is
extraordinary when you see it.

It's shocking.

I think it's shocking

because it brings home the fact

that we can actually manage our
brains without consciousness...

To some extent...
And that leads to...

"Why not
everything?"

"Why not
everything?"

And why do we need consciousness

for certain things?

What is the extra gloss
that consciousness gives...

If anything... to our actions?

[ machine beeping]

YOUNG:
Right.

I'm aware of individual
functions of sight.

Sometimes I'm aware of a motion

but that motion has no shape,
no color, no depth

no form, no contrast.

Sometimes I can tell you
what orientation it's at

but then we lose
everything else.

BLAKEMORE:
So what you lack is

the ability
to put it all together

and to recognize
an object, a thing?

Yeah.

Something with meaning?

Mmm.

BLAKEMORE:
Well, "blindsight" is this term
introduced by Larry Weiskrantz

to describe the ability

of people like Graham

to detect things but not
to be aware of them;

so very, very different

from what we would
normally call vision.

YOUNG:
Right.

BLAKEMORE:
If there's one thing

that this phenomenon
of blindsight teaches us

it is that vision is
not entirely seeing...

That there can be
a disconnection

from the capacity to respond
to visual information

and the actual act of being
visually aware of something.

Those two things
can be separated

and probably are
in our everyday lives

but the problem is
that, obviously

we're not aware of the things
that we're not aware of.

We just don't know the extent
to which they play a part.

RAMACHANDRAN:
It's almost as if
the patient is using ESP.

He can see and yet cannot see.

So it's a paradox, it's
almost like science fiction.

How is this possible?

Well, if you look at the anatomy

you can begin to explain
this curious syndrome.

It turns out from the eyeball to
the higher centers in the brain

where you interpret
the visual image

there's not just one pathway;
there are two separate pathways

which subserve
different aspects of vision.

One of these pathways is
the evolutionarily new pathway...

The more sophisticated pathway,
if you like...

That goes from the eyeball
through the thalamus

to the visual cortex
of the brain.

Now, you need the visual cortex

for consciously
seeing something.

[ train warning bells ringing]

The other pathway,
which is older evolutionarily

and is more prominent

in animals like rodents, lower
mammals, birds and reptiles

goes to the brain stem, the
stalk on which the brain sits...

and from the brain stem
gets relayed eventually

to the higher centers
of the brain.

Specifically, the older pathway
going through the brain stem

is concerned with
reflexive behavior...

Orienting to something important
in the visual field...

Making eye movements,
directing your gaze

directing your head
toward something important.

In these patients, one of these
pathways alone is damaged...

The visual cortex is damaged.

Because that's gone

the patient doesn't
see anything consciously.

But the other pathway
is still intact

and he can use that pathway
to guess correctly

the direction of movement
of an object that he cannot see.

NARRATOR:
Graham's vision is similar
to that of reptiles

who depend on unconscious
blindsight for their survival.

A lizard, if it wants
to catch a fly

doesn't actually
have to see a fly

doesn't have to recognize a fly;

it just has to be aware
of something moving.

So I suppose me and the lizard
are distant cousins.

RAMACHANDRAN:
One of the goals of neuroscience

is to understand

which parts of the brain
are dedicated to what function...

How different mental capacities
map onto different pathways

and different neurocircuits
in the brain.

And surely this
fascinating syndrome

is going to help us understand
not only the nature of seeing

not only the division of labor
between these different pathways

but the question of
"What is consciousness?"

What does it mean to be
consciously aware of something?

Why is one pathway alone
conscious

but as the other pathway
behaves like a zombie

that's trapped inside him,
that's unconscious?

The syndrome is so strange that
when it was initially reported

people didn't believe it

and there are some people
who still don't believe it.

But in a sense it's not that
strange, if you think about it

because in a sense we experience
blindsight all the time

in our daily lives.

For example, as
I am driving this car

and having this conversation

all my attention is
on the conversation

on the person next to me.

And, in fact, I'm not conscious
of what's going on around me

even though I'm negotiating
all this traffic

avoiding obstacles,
avoiding that car on my right

avoiding the car on my left.

That's all being done
in parallel

by another part of my brain

and it never emerges
into conscious awareness

unless something
very strange happens

like a big truck passes by
and I might notice it.

NARRATOR:
Blindsight enables us
to steer our way successfully

through the world
as if on autopilot.

How are we on the right side...

NARRATOR:
Without this zombie
in our brains

we'd be swamped
by visual information

unable to focus
on what really matters.

Unlike Graham, Peggy Palmer
has normal vision.

She should be able
to copy this star easily.

PALMER:
I'll never get
this star.

I'm hopeless at this.

NARRATOR:
But something odd is happening.

One whole side of the star
is missing.

Peggy has a condition
called "visual neglect."

Although her eyesight is fine

half of her visual world
no longer seems to matter.

Ten years ago,
Peggy suffered a stroke

in the parietal lobes
of her brain.

The parietal lobes
are concerned mainly

with creating a three-
dimensional representation

of the spatial layout
of the world

allowing a person
to walk around, to navigate

to avoid bumping into things.

When the right parietal
is damaged

the patient is unable to deal
with the left side of the world.

NARRATOR:
This condition has
fascinated neurologists

for more than a century

because it reveals not only
how the brain shapes

the way we perceive space
in the present;

it even determines the
spatial look of our memories.

This became apparent
when Peggy was asked

to draw a daisy from memory.

All right.

A daisy it shall be.

NARRATOR:
For neuropsychologist
Peter Halligan

Peggy's drawings reveal
exactly what's gone wrong.

HALLIGAN:
It's like a radar system

whereby the actual radar system
on the left-hand side

is no longer working well.

If someone comes in

on my left-hand side now,
or I'll hear a sound

my eyes will immediately move
to the left-hand side.

That makes me,
for evolutionary purposes

very aware of my environment

because if I wasn't aware
of those things

I'd have accidents:
I'd get hurt

or I might get eaten
by wild animals and whatever.

Now, in Peggy's case,
she will not attend

to those things that
we would normally be aware of.

NARRATOR:
Peggy thinks she's drawn
her daisies right

until it's pointed out to her.

HALLIGAN:
You've noticed
that, have you?

PALMER:
Oh, dear.

So, what Peggy's drawn for us

is several nice daisies

with the left side missing.

The same with this one,
and this one and this one

and look at this one...

This is a very good example.

I've done it on all of them.

[ laughing]:
Sorry.

RAMACHANDRAN:
Which means that she's not only
neglecting events in the world

but when she conjures up
a mental image

she's ignoring the left side
of that mental image.

PALMER:
I thought I was going
all the way around, you see?

And this shows you that is
not simply a sensory problem

but a problem of consciousness.

PALMER:
I don't know.

It's because I was
so concentrating
on that side.

It takes everything
away, you see?

Guess it's attention, really.

It's taken away.

There must be two attentions
somewhere in your body

that one side's taking
the other one away.

I can't make it out at all.

Very odd.

NARRATOR:
Peggy's one-sided daisies
graphically reveal

how damage to the visual centers

can warp our consciousness
of the world

and how complex the human
visual system actually is.

RAMACHANDRAN:
When I was a medical student,
I was taught

there's an area in the back of
the brain called "visual cortex"

and that's where
seeing takes place.

But since then we've learned
in fact there's not just one

there are 30 areas in the brain
concerned just with seeing.

NARRATOR:
For Ramachandran, a walk through
this Southern California mall

shows exactly what these
visual areas have evolved for.

RAMACHANDRAN:
And maybe these different areas
are specialized

for different aspects of vision.

One area for seeing colors

another area for seeing movement
or form and shape

relative distance and depth.

Now, despite
the staggering complexity

of all these different areas

there seems to be a simple
overall pattern of organization.

In fact, the visual input
as it comes in

seems to divide into two
parallel streams of processing.

There is one pathway,
which we call the "how" pathway

to which
some of these areas belong

and that "how" pathway
seems to be concerned

mainly with navigation...

With being able to walk around,
avoid bumping into obstacles

be... avoiding uneven terrain

reaching out
and grabbing something.

NARRATOR:
The "how" pathway leads
from the main visual areas

to the parietal lobes
at the top of the brain

where Peggy suffered her stroke.

The other pathway,
the "what" pathway

leads from the main visual areas
to the temporal lobes

located just behind our temples.

RAMACHANDRAN:
The "what" pathway

is concerned with
recognizing the object:

"What am I looking at?

"What does it mean for me?

"Is this an edible object?

"Is it a flower?

"Is it a person's face?

What is it that I'm looking at,
and what does it mean for me?"

That's what the "what" pathway
is concerned with

and it's that pathway that seems
to be damaged in David.

NARRATOR:
David presented Ramachandran
with one of the strangest cases

he has ever encountered.

Two years ago David was involved
in a terrible car accident

while driving back
to California from Mexico.

SILVERA:
There was a problem with the car

and I landed in the highway
with my head first.

RAMACHANDRAN:
Okay.

Like this truck
that is coming by...

NARRATOR:
For five weeks
David lay in a coma.

Serious injuries led
to the loss of his right arm

but to everyone's relief,
when he regained consciousness

his mental capacities
seemed to be intact.

RAMACHANDRAN:
He was articulate

he was intelligent

not obviously psychotic
or emotionally disturbed.

He could read a newspaper,
everything seemed fine

except he had
one profound delusion:

He would look at his mother
and he would say

"This woman, doctor, she looks
exactly like my mother

"but in fact she's not my
mother, she's an impostor.

She's some other woman
pretending to be my mother."

NARRATOR:
The injury to David's brain had
brought on a very rare condition

called the Capgras delusion.

MOTHER:
I was cooking dinner

and he probably didn't like the
food that night, and he said

"You know, the lady
who comes in the morning...

She cooks much better than you."

It's that... "That lady...
I like that lady very much."

But the lady was me,
of course, all the time.

NARRATOR:
David was also convinced
that his father was an impostor.

MOTHER:
He would say to his dad

"You know, I'm sure you
would like to meet this guy.

"He's so much like you

but he drives better,
he doesn't go so fast."

SILVERA:
It can look identical to him

exactly like him,
but it's not him.

NARRATOR:
After two months
of this disturbing behavior

David's parents decided
to seek help from Ramachandran.

But when you looked at your...

the person who looked
like your father

what was your feeling?

Did it look
like there's
some other person

who resembles your father

who's not really you father,
something like that?

Exactly.

It's the difference in the fact

that I know that that person
happens not to be my father.

It is not my father
or my mother, right?

I don't expect things
from that person

as I would expect
from my parents.

[ chatting quietly]

NARRATOR:
David not only had
delusions about people;

he also believed
the house that he lived in

was just an imitation
of his home.

MOTHER:
One day he started

getting really angry:
"I want to go to my house!

I want to go to David's house!
I want to go to David's house!"

And we were in the apartment

and I'm just going,
"What am I going to do?"

So I decided, I said,
"Okay, David, let's go."

So I took him down the stairs...

and I went around
through the back

came back through the elevator,
took him to the same apartment

and I said,
"This is your house."

And I opened the door
and I said, "Okay, ciao."

And just left him there alone,
it was the same apartment.

And he looked at it and said,
"Oh, yes, this is my apartment."

Things like that would happen

and then maybe a few days after,
he would start saying

"I want to go to my house,
David's house.

This is not David's house."

NARRATOR:
Amazingly, David
sometimes referred to himself

as the other David, as if
his own self were an impostor.

RAMACHANDRAN:
The Capgras delusion
has been known

since the turn of the century

but has been treated
as a curiosity, an anomaly.

The standard explanation

which you find in most
psychiatry textbooks

is a Freudian one, and the idea
is something like this:

This young man, like most young
people, when he was an infant

growing up, he had strong
sexual attraction to his mother

the so-called Freudian
Oedipus complex.

No, I went...
I talked to him.

I said he cannot evaluate me

because I'm not playing.

Hmm...

He said, "Wait, you're
not... Evaluating..."

But then along comes
a blow to the head

and suddenly... and inexplicably

these sexual urges come
flaming to the surface

and he finds himself sexually
attracted to his mother

and he says, "My God,
if this is my mother

"how come I'm attracted to her,
how come I'm aroused?

This must be
some other strange woman."

Now, this is
an ingenious explanation

but it doesn't quite work

because I've seen a patient
who has the same delusion

about his pet dog.

He'll look
at his pet dog and say

"Doctor, this is not Fifi.

"It looks just like Fifi

but in fact it's been replaced
by another identical dog."

So how does a Freudian
explanation account for this

unless you start talking

about the inherent bestiality
in all human beings

or something like that?

So, what really causes
the Capgras delusion?

Well, it turns out
that when you look at an object

the message goes
to the temporal lobes

to the visual centers
in the temporal lobes.

But seeing is
a multilevel process;

after you've recognized it

you also need to respond
to the object emotionally.

This is obvious when you look
at a Picasso or a Rembrandt

or any beautiful picture.

Even when you look at,
say, your mother's face

the appropriate emotional warmth
has to be evoked

or when you look at a lion,
you have to be afraid

and all of this is part
of the visual process

but happening in a different
part of the brain.

NARRATOR:
Whenever we look
at an object or a face

the message reaches the temporal
lobes, where it's identified

but then it gets relayed to
a structure called the amygdala

which is the gateway
to the limbic system

that contains the emotional
centers of the brain

and it's here that we generate

the appropriate
emotional response

to whatever it is
we're looking at.

RAMACHANDRAN:
Now, what I've suggested is

that what's going on
in this patient

is the message gets
to the temporal-lobe cortex

so the patient recognizes
his mother as being his mother

and evokes
the appropriate memories

but the message doesn't get
to the amygdala

because the fibers going
from the temporal cortex

to the amygdala and to
the emotional centers are cut

as a result of the accident.

Therefore, there is no emotion,
there is no warmth

and he says,
"If this is really my mother

"why is it I'm not
experiencing any emotions?

"There's something
not quite right here.

"Maybe she is
some other strange woman

pretending to be my mother."

NARRATOR:
Ramachandran's hunch
that David's delusions

were being caused by the rupture
of specific brain circuits

was lent unexpected weight

when David's mother recalled
a breakthrough with the phone.

David, ¿cómo estás?

Tu papi.

MOTHER:
We got so tired of him saying

"You're not my dad,
you're my dad

"you're not my mother,
you're my mother," we decided

"Okay, you go downstairs,
call on the phone"

and said, "David, hi!"

and on the phone he would know
he was his dad.

On the phone he never ever...

RAMACHANDRAN:
Had this problem.

MOTHER:
Had this problem.

RAMACHANDRAN:
So, on the phone
he'd always recognize...

MOTHER:
On the phone...

No problem.

But when he saw him,
he would say

"You look
like my father..."

MOTHER:
"But you're not my father, no."

RAMACHANDRAN:
This shows the patient
is not crazy.

Why would he be crazy in person
but not on the phone?

The answer is,
there's a separate pathway

that goes
from the auditory cortex...

The hearing part of the
temporal lobe... to the amygdala

and that pathway was not damaged
in David by the car accident.

Therefore when he listens
to his father on the phone

there is no delusion.

Good, great.

RAMACHANDRAN:
This is a lovely example

of how you can take a completely
bizarre neurological syndrome...

Maybe from the "X-Files"
of neurology...

Which no one really understood...

A person claiming
that his mother is an impostor...

And then come up with
a very detailed explanation

in terms of the known anatomy
of the brain

saying, "Here is
where the flaw is"

and then doing an experiment
that takes just an hour to do...

So, this first one's...

RAMACHANDRAN:
And showing that this is what's
gone wrong in this patient.

TECHNICIAN:
Okay, you comfortable?

NARRATOR:
To test his theory
about the Capgras delusion

Ramachandran arranges to measure
David's galvanic skin response

which is the basis
of the lie detector test.

If David's brain were normal

he would react emotionally
to this picture of his father.

This in turn would stimulate

an almost indiscernible increase
of sweat on his skin

and a heightening
of electrical resistance

that can be measured.

The prediction is that when
people with normal brains

look at photographs of people
they don't know

they will not respond
emotionally

so there will be no change
in skin resistance.

But a familiar face will prompt
an emotional response

and invariably,
there is a change.

Now the question is,
what happens with David?

If Ramachandran's theory
is correct

pictures of his parents will not
evoke an emotional response

so the line should remain flat.

RAMACHANDRAN:
Now, this is also telling you
about how all of us

how normal people, respond
to faces and to objects

because what happens in this
patient is truly extraordinary.

The lack of emotional response
actually leads him

to this very profound delusion

that this person is
not really his mother.

In other words the lack
of the autonomic, gut reaction

this emotional response, leads
him to an absurd conclusion

overriding what his intellect
is telling him

and this tells you
how closely linked

your intellectual view
of the world is

to your basic emotional
reactions to the world.

NARRATOR:
Luckily for Capgras patients

the condition seems
to heal itself.

David no longer thinks
his mother is an impostor.

And the man who looks
like his father is his father

and triggers the flow of all
the old familiar feelings.

David's lack
of emotional response

showed just how crucial
emotions are

to the recognition process
of the normal brain.

But what would happen

if the emotions were
to run out of control?

What effect might
an excess of emotion have

on the way
we interpret the world?

John Sharon has
temporal-lobe epilepsy.

SHARON:
The seizures involve

my person and my soul
and my spirit, all of it.

When I get one of those feelings
my whole body just tingles

and just, oh, I'm, like,
"That's that."

NARRATOR:
John's epileptic seizures

are essentially an electrical
storm in his temporal lobes

when a group of neurons
starts firing at random

out of sync
with the rest of his brain.

Recently, John experienced one
of his worst episodes to date.

He'd gone out to the desert
with a girlfriend

and they'd both got very drunk,
with disastrous results.

John was suddenly hit
by a volley of seizures.

Each one lasted
about five minutes

and involved violent convulsions
that left him unconscious.

Eventually, John managed

to get a call through
to his father

who drove out to the desert
to bring him home.

SHARON:
On the way home, him and I just
got into some philosophical...

you know, questions
about everything

and I just would not
shut up once I...

on the way home
I was going and going.

It was like I was wired.

It's basically an earthquake
within the body

and like any earthquake,
there are aftershocks.

And like any earthquake
that does damage

things have to be rebuilt,
things have to subside.

Mainly what I deal with
is the aftermath

particularly
with this last episode.

It was very much

like stepping into a
Salvador Dalí painting, okay?

Instantly everything
was surreal.

And that's, in essence,
what his seizures are all about:

the aftermath...

Where it puts his brain,
where it puts his memory

where it puts his mind,
his thinking ability

everything else.

NARRATOR:
When John's seizures
came to an end

he was exhausted,
but he felt omnipotent.

SHARON:
I went running down the streets
screaming that I was God

and then this guy came out

and I just, like, pelvic-thrust
at him and his wife

and I was, like, "You want
to 'f'-ing bet I ain't God?"

And I said literally,
"You as*h*le, get back in here!

"What do you think you're doing?

"You know, you're disturbing
the neighbors.

"They're going to call the cops.

What is this all about?"

SHARON:
I kind of just looked at him,
cool and calm

and apologized to him

and I'm, like, "No one's going
to call the police."

Like, I didn't say this last
part, but I'm thinking to myself

"No one's going to call
the police on God."

NARRATOR:
John had never been religious

yet the onset of his seizures

triggered overwhelming
spiritual feelings.

RAMACHANDRAN:
It had been known for a long
time that some patients

with seizures originating
in the temporal lobes

have intense religious auras...

Intense experience
of God visiting them.

Sometimes it's a personal god;

sometimes it's
a more diffuse feeling

of being at one
with the cosmos...

Everything seems suffused
with meaning.

The patient will say

"Finally, I see what
it's really about, doctor.

"I really understand God.

I understand my place in the
universe, in the cosmic scheme."

Why does this happen,
and why does it happen so often

in patients
with temporal-lobe seizures?

NARRATOR:
Ramachandran met John shortly
after the episode in the desert.

He was still feeling

the extreme highs and lows
that follow his seizures.

Ramachandran was
about to witness

the emotional intensity
that John endures.

I have been in so much pain

that I'd rather
be shot to death, dude

or just whipped to death...
whipped to death.

RAMACHANDRAN:
Also joy?

I've been in so much joy that I
would rather be left alone, man.

Get... take everything away
and just let me sit there

and have that much joy.

I feel like I can
float and stuff
sometimes, you know.

Okay.

It's just... it's, like...
it's, like, the best.

There were times
where he would have

seven or eight grand mal
seizures in a day.

Mm-hmm.

He would never come back

to this reality
during that time.

I have looked in his eyes
in those times

and I have seen,
seen a cry for help.

No, I mean, you guys...
that's the thing, though...

A lot of other people
can just walk around

and see the beauty of the world.

I can...

[ sighs]

Sorry, it's not
as beautiful, man.

SHARON, SR.:
He has a seizure,
he'll want to talk philosophy.

He'll want to discuss all the
things that are floating around

in this stew he's got up here

that he's trying to reconstruct.

Thoughts that he may have had

just floating through his mind

while he was in
a seizure mode,
may come surfacing.

I see, okay.

Okay, it's a...

Also you said he's
become more emotional

because of the seizures,
so that's helpful, too.

Much more sensitive

but oddly enough, not
in regards to himself.

Okay.

But in regards to atrocities

disasters, things like that...

Anywhere and everywhere.

Wrongs done to other people.

Oh, my God.

And you know what?

I am so right in my own head

I know I could go out there
and get people to follow me.

Not like these wackos
with sheets on their heads

not like those idiots.

But now it's just... the new
generation of the prophets.

And were all the prophets

people that were flopping
around on the ground?

Is that what
this whole message was...

The gift from the gods,
this whole time?

RAMACHANDRAN:
That's possible,
isn't it? Yeah.

I've never been religious ever.

People say, you know,
you can't see into the future.

Uh-uh, that's what that gift is

but... you got to pay for it
by getting slammed around.

RAMACHANDRAN:
Now, why do these patients have
intense religious experiences

when they have these seizures?

And why do they
become preoccupied

with theological
and religious matters

even in between seizures?

One possibility is

that the seizure activity
in the temporal lobes

somehow creates all kinds
of odd, strange emotions

in the person's mind,
in the person's brain.

And this welling up
of bizarre emotions

may be interpreted
by the patient

as visits from another world,
or as "God is visiting me."

Maybe that's the only way
he can make sense

of this welter of strange
emotions going on in his brain.

Another possibility is that
this has something to do

with the way in which
the temporal lobes are wired up

to deal with the world
emotionally.

As we walk around
and interact with the world

you need some way of determining

what's important,
what's emotionally salient

and what's relevant to you

versus something trivial
and unimportant.

How does this come about?

We think what's critical
is the connections

between the sensory areas
in... in the temporal lobes

and the amygdala,
which is the gateway

to the emotional centers
in the brain.

The strength of these
connections is what determines

how emotionally salient
something is.

And therefore you could speak

of a sort of emotional
salience landscape

with hills and valleys

corresponding
to what's important

and what's not important.

And each of us has

a slightly different
emotional salience landscape.

Now, consider what happens
in temporal-lobe epilepsy.

When you have repeated seizures

what might be going on is an
indiscriminate strengthening

of all these pathways.

It's a bit like water
flowing down rivulets

along the cliff surface.

When it rains repeatedly,
there's an increasing tendency

for the water to make furrows
along one pathway

and this progressive deepening
of the furrows

artificially raises
the emotional significance

of some categories of inputs.

So instead of just finding lions

and tigers and mothers
emotionally salient

he finds everything
deeply salient.

For example, a grain of sand,
a piece of driftwood, seaweed...

All of this becomes imbued
with deep significance.

Now, this tendency
to ascribe cosmic significance

to everything around you

might be akin to what we call
a mystical experience

or a religious experience.

NARRATOR:
For Ramachandran,
John's story is the basis

of one of his most intriguing,
and controversial, theories.

Could there be a specialized
area of the brain

that drives human beings
to seek religion?

RAMACHANDRAN:
A few years ago,
the popular press

inaccurately quoted me
as having claimed

that there is a "God center"

or a "G-spot"
in the temporal lobes.

Now, this is complete nonsense.

There is no specific area in the
temporal lobe concerned with God

but it's possible there are
parts of the temporal lobes

whose activity is somehow
conducive to religious belief.

Now, this seems unlikely,
but it might be true.

Now, why might we have neural
machinery in the temporal lobes

for belief in religion?

Well, belief in religion
is widespread...

Every tribe, every society has
some form of religious worship.

And maybe the reason it evolved,
if it did evolve

is that it is conducive
to the stability of society.

And this may be easiest

if you believe in some sort
of supreme being.

And that may be one reason

why religious sentiments evolved
in the brain.

SHARON:
The only reason

I probably would get rid
of the seizures and epilepsy

because I've never even seen
them, is because of my family...

Because of him.

I would keep them

for those visions

because of the way I see
the world falling into place

and things like that.

It's a wild little place
to be stuck in there.

It also seems like a key

and right now I haven't learned
how to get to the key without...

use the key
without those seizures.

If I was told that
I would never have a chance

to have that key again...

Sorry, I'm going to hold on
to that thing.

RAMACHANDRAN:
Just because some patients
with temporal-lobe seizures

have intense
religious experiences...

This does not in any way
invalidate that experience

for that patient.

In fact, it can
very often enrich

the patient's life enormously

and it poses a dilemma
very often for the physician

because what right do we have

to treat the patient with
medication or with surgery

thereby, in some instances

depriving him of
these valuable experiences?

To me, the exciting thing

is that subjects
like God and religion

can now be actually addressed
by us scientists.

We can begin to ask questions
about religion and God

and begin to approach
these questions

by listening to these patients

by talking with them
and by studying them.

NARRATOR:
It's a tragic irony
that today's breakthroughs

in our understanding
of the human brain

are made possible by
the misfortune of brain injury.

For centuries

philosophers have labored to
understand God, consciousness

and the mysteries
of human nature.

Now perhaps science
will have its chance.

On NOVA's Web site

investigate the remarkable
complexity of the mind

through other
unusual case studies

collected by Dr. Ramachandran

on pbs.org or AOL keyword: PBS.

Next time on NOVA...

WOMAN:
The doctor said that
there had been an accident.

MAN:
We can impose a gender identity
on a newborn.

WOMAN:
He did not say
it was an experiment.

MAN 2:
I was never happy
as Brenda, never.

"Sex: Unknown."

NOVA is a production
of WGBH Boston.