All language subtitles for Through.the.Wormhole.S03E04.480p.WEB-DL.x264-mSD.HI

Freeman:
We all spend our lives

on a search
for something so close,

yet always just out of reach.

Some call it the ego.

Others, the soul.

Now modern science
is prying into our thoughts,

our memories, and our dreams,

and asking the profoundly
puzzling question,

"What makes us who we are?"

Space, time, life itself.

The secrets of the cosmos
lie through the wormhole.

♪ Through the Wormhole 03x04 ♪
What makes us who we are?
Original Air Date on June 20, 2012

== sync, corrected by elderman ==

What is it that makes me me?

Or makes you you?

Is it the things we know?

The people and places
we've experienced?

What makes me the same person
now as when I was 40?

Or when I was 10?

What is it
that gives each one of us

our unique identity?

Scientists are beginning to
tackle this profound puzzle.

To do so, they must probe

one of the last great frontiers
of our understanding --

the brain.

Every summer, I used to go
camping with the Boy Scouts.

Each item of clothing
I took with me

had to have my name
sewn onto it.

"Morgan."

It was a name I never really
liked when I was a boy.

I wondered how my life
might be different

if I had been called something
normal like Robert or John.

Well, like it or not,

the name I was given
framed my identity.

It helped make me who I am.

Happy Birthday!

Man:
Look, he's walking!

[ Laughs ]

Show your mom.

Bye!

It's beautiful!

[ Cheering ]

Wish you were here.

Freeman:
Alison Gopnik is on a search

to discover how and when
we first understand who we are.

She's a child psychologist

at the University of California
at Berkeley.

So, the process
of forging an identity,

of figuring out
who it is that we are,

that's a process that really
takes us our whole lifetime.

But some of the most crucial
parts of that

seem to be things
that we're learning

in this very, very early period
of our lives.

Freeman: As adults,

it's easy to take
our identities for granted.

We accept that who we are now

is the same as who we were
a minute ago.

But Alison has discovered

that identity is not so solid
for young children.

They spend much of their time

trying to figure out
just who they are.

So, when kids are just doing the
everyday things that kids do,

when they're playing
and exploring and pretending,

what they're actually doing
is being involved

in this great, existential,
philosophical research program.

What it means to be a person.

Freeman: One of the first
milestones in this program

is called "The mirror stage."

It begins when a child
is first able to recognize

his or her own reflection.

Gopnik: The thing
about a mirror isn't just

that you see a body and a face,
which is fascinating,

but you connect it

to your own kinesthetic feeling
of yourself --

the way your own body feels.

Freeman: Alison uses a clever
experiment on her toddlers

to detect which of them
have developed an awareness

of their reflections.

She places a smudge of blue ink
on their noses

and tells them
to look in the mirror.

Gopnik: There we go.
There he is.

There he is.
Right there. Yeah.

Freeman: 15-month-old John
is hardly fazed

by the blue-nosed child
staring back at him

because he's not able
to recognize

that the child in the mirror
is him.

They're interested in the fact

that that baby in the mirror
has a spot,

but they don't seem to
connect that to the fact

that there's actually a spot
on their own noses.

Freeman: When Alison tries
the same test on Karen,

who is just a few months older
than John,

she does something
quite different.

Gopnik: Look at that!

There we go. Yeah!

What is that?

And now the baby
seemed to realize, "oh, yeah.

"That person in the mirror,

that's the same person
that I am."

Freeman:
It is a big first step

on a long journey
of self-discovery.

But Alison's work has shown
that her subjects have

a lot more philosophical
research ahead of them.

This is 3-year-old Geneva.

Alison tempts her

with what looks like
a box filled with cookies,

but Geneva will soon find out

that she can't judge a box
by its cover.

What do you think
is inside this box?

Hmm.

What do you think
this is?

Good cookies.

Good cookies.
Should we find out?

Let's open the box
and find out what's inside.

Markers.

Markers!
There's markers inside.

Hmm.

[ Laughs ]

When I first showed you this box
all closed up like this,

what did you think
was inside it?

Markers.

Markers!

Freeman:
Geneva cannot reconcile

that she now knows
the box is filled with markers

when she once thought
it was filled with cookies.

The concept that there is a you
who is the same person

even if your thoughts
have changed

is not an understanding
you're born with.

It is something
you come to learn.

Alison tries the cookie box test
with 4-year-old Jim.

I have a question
for you.

What?

When you first saw this box
all closed up like this,

what did you think
was inside it?

Cookies
with chocolate chips.

Uh-huh.
And what's really inside it?

Markers!

Yeah! That's great!

So, a very important part
of my identity

is being able to say,

"Well, when I was 16, I believed
different things than I do now,

but I was me who believed
those different things."

Freeman: When children realize

their identities can survive
any change in their beliefs,

they stop forgetting the things
they don't believe anymore,

and for the first time,

they unlock the astonishing
power of human memory.

Addis: In this very hall,
I used to perform in the choir.

It takes me back.

[ Echoing ] In this very hall,
I used to perform in the choir.

My own memories
are so richly detailed,

and I spent many hours
in this hall,

rehearsing, practicing.

It just takes me back.

[ Choir vocalizing ]

Freeman:
Neuroscientist Donna Addis

is head of the memory lab
at the University of Auckland,

where she investigates
how memories shape us.

She does this by peering in

to a horseshoe-shaped area
in the brain

called the hippocampus.

For the last 50 years,
scientists have known

that the hippocampus is critical
to the storage of memory.

We learned this
thanks to one man,

known as "Patient H.M."

He had severe epilepsy
and, in 1953,

received a radical,
new treatment.

His hippocampus and part
of his inner temporal lobes

were cut out.

After the surgery,

H.M. never suffered
a bout of epilepsy again,

but he had completely lost

the ability to form
new memories.

He said, "Each day is like
waking from a dream."

He had lost his identity.

His sense of who he was
was frozen at age 27.

As days turned into decades,

he could no longer recognize

the man staring back at him
in the mirror.

How much of who we are

is built upon the memories
we make each and every day?

Traditionally, memory research
has really focused on the past,

and in the last few years,
researchers such as myself

have been looking at the ability
to imagine the future

and how memory might actually
play a role in that.

Freeman: Donna and her team
set up an experiment

to determine just how
the hippocampus and our memories

help us perceive
our future selves.

Addis: So, what we do is

we have subjects come
into the lab

and we have them retrieve
around 100 memories.

I remember going to visit
my cousin in Germany.

We walked along the beach,

and at the end,
there was a cave.

And I gave my grandmother
a seashell for Christmas.

Addis: And for each memory,

they identify a person,
a place, and an object

that might be important.

-The Autobahn.
-My mother.

-Two penguins.
-Boston.

-My book bag.
-Auckland waterfront.

-My girlfriend, Sarah.
-The hospital.

-My partner, Wayne.
-Eastern Beach.

-Amsterdam airport.
-A cave.

Freeman: A week later,
Donna brings her subjects back,

places them in an fMRI machine,

and shows them details
from their recalled memories.

But she deliberately jumbles
the details.

An object from one memory

has been grouped with a place
from another memory

and a person from yet another.

Donna then asks them
to make a story

out of these mixed up memories,

to imagine something
that has not happened yet

but potentially could.

We ask them,

for each person, place, object
that they're seeing now,

to imagine a future event
that might happen to them

within the next five years
or so.

Freeman: While the participants
are imagining their futures,

Donna measures
their brain responses.

To her surprise,

the part of the brain
that is vital

to storing memories of the past,
the hippocampus,

is blazing with activity.

The hippocampus is playing
a really important role,

not only in remembering,

but also allowing us to build
these future simulations.

Memory is important
not only for the past,

but also for the future,

for building up that sense
of who we are.

Our memories are crucial
to forming our identities,

but one group of scientists
have discovered

that our memories
can be manipulated

without our even knowing it.

Are we really
who we think we are?

Our ability to remember
is truly remarkable.

In the course of our lives,

the average person will grasp
the meaning of 100,000 words,

get to know around 1,700 people,

and read over 1,000 books.

From these vast mental stores
of experience

we each build our own identity,

a pattern of memories
that is uniquely ours.

But what if those memories
could be rewritten?

Could we change who we are?

[ Indistinct conversations ]

Neuroscientist Tali Sharot

from the University
College London

and Micah Edelson

from the Weizmann Institute
of Science in Israel

love going to dinner parties.

But they're not just having fun.

They're doing it
for the sake of science.

They study how social pressures
alter who we are.

Well, imagine a situation

that you're sitting
in a dinner party.

You have a pretty good memory
of some situation that happened,

and you actually remember it
happening in a certain way,

but all of your friends
are telling you

that you're actually wrong.

They're saying
that something else happened.

And Tali got the umbrella,
and she slid the umbrella

through the letterbox.
Woman: Are you sure it was Tali?

No, no, no.
I'm quite sure it wasn't me.

No, it was definitely you.
You were definitely holding the umbrella.

It was definitely Steve.

I really thought it was Tali,
though.

No, because
we were really impressed

that Steve managed to
hook it around.

Remember?
We had that big fanfare

because we were
out in the rain.

When someone changes
their memory

so that it fits
other people's opinion,

do we actually change
a signal in the brain

that is representative
of the memory,

or is it just that
we try to please other people?

Freeman: Social pressures

can make us change the way
we tell stories.

But can they also make us change
the stories we tell ourselves?

Our actual memories?

Tali and Micah set up
an experiment to find out,

not in a restaurant,
but in a lab.

They bring in
a group of volunteers

to watch a film together.

Afterwards,

the volunteers answer
basic questions about the film

to test what they remember.

A few days later,

the participants
take the same questionnaire

inside a brain scanner,

only this time, Micah and Tali
apply a social pressure.

This time, they were exposed
to fake answers

that were supposedly given
by their fellow group members.

Freeman:
The group is led to believe

that the others
who took the test

remembered the character in
the film was not wearing a hat.

And most people
changed their answers

to go along with the crowd.

Almost 70% of the cases,

the participants conformed
and they gave a wrong answer,

even though they were
initially pretty confident

about the correct answer.

But were they just outwardly
complying with a social norm,

or did their memories
actually change?

So, we test them again
a week after,

once we've removed
the social pressure.

And we assume that if they're
still making an error,

that means that their memory
was actually changed.

Freeman: Tali and Micah found

that most test subjects
stuck with the wrong answer

even without peer pressure.

The falsehood has taken root
in their brains.

It actually causes
a long-lasting memory error,

and using our brain data,

we are able
to actually identify

when such a long-lasting
memory error will occur.

The brains of those people
who changed their memories

showed high activity
not just in the hippocampus,

where memories are stored,

but also in a part of the brain

that is connected with emotional
and social responses,

the amygdala.

Sharot:
A lot of what we know

about the amygdala
and its function

comes from
the animal world.

So our reaction to anything
that's emotional --

if we suddenly hear a noise
which is frightening

or of processing emotional
expressions on one's face --

the amygdala is crucial
for all of these functions.

Edelson: And it probably
helps us increase memory

because, in a fearful
or emotional situation,

the amygdala activation
is heightened

and it also
increases activation

in related structures
like the hippocampus.

[ Growls ]

Freeman: The amygdala is like
a bouncer at a nightclub.

It decides which memories

get to play a part
in shaping our life histories.

The ones that carry emotional
weight are allowed in.

The ones that don't are not.

The participants
who changed their memories

were emotionally affected
by the pressure to conform,

setting their amygdalas ablaze,

and the false memory snuck in.

So, by looking
at amygdala activation,

we can actually predict

which memories are gonna
be changed for a very long time

and which are not.

You have to realize

that memories are not
like a videotape.

'Cause people
can be extremely confident

that things happened
like they think they happened

when they didn't.

Freeman: Our memories
are not just a record

of the events that took place
in our lives.

They are malleable and fallible.

Our identities are created with
constant input from our society.

No man is an island.

But could we go a step further

and deliberately re-engineer
someone's identity?

To do that,

you have to be able to peer into
a person's innermost thoughts,

and believe it or not,

that technology is already here.

[ Beeping ]

We are all actors,
to some extent.

Who we appear to be can change

depending on our mood
or the company we keep.

But there is one time

when who we really are
comes to the fore --

when we dream.

What if we could see our dreams
and study them?

Could we know each other

in a more profound way
than ever before?

During an average life span,

a human being spends
about six years dreaming.

That's more than 52,000 hours
of imagery

buzzing through
our unconscious brains.

[ Alarm buzzing ]

[ Buzzing stops ]

Computational neuroscientist
Yuki Kamitani

believes one day
it will be possible

to watch and record
what people are dreaming.

When that happens,

we will all
get to know ourselves

on a much deeper level.

Kamitani: I believe
that if we can reconstruct

or decode the contents
of a dream,

the identity is revealed.

Freeman:
If we remember our dreams,

it is often as a series
of emotionally charged images.

In fact, scientists have found

that the visual cortex
of a dreaming brain

is highly active.

Patterns of electrical activity
wash over it,

which makes Yuki wonder,

can we learn to read
those patterns

and convert them
into images on a computer?

Brain activity can be seen as
a code or an encrypted message

about what's going on
in the visual world.

Freeman: The patterns of images
we make in our brains

are highly distorted,

in the same way
a pair of shattered glasses

distorts our view of the world.

[ Glass shatters ]

But if we collected data

on hundreds of images seen
through those shattered lenses,

we could find a correspondence

between the distorted images
and the real ones.

It might take a while,

but if we gave that job
to a powerful computer,

it could decode the scrambled
images into recognizable ones.

And this is how Yuki
tries to crack the code

that turns images

into patterns of activity
in the visual cortex.

We measure the brain activity
of human subjects,

and we let the subject
go into the scanner

and scan their brain.

And during that,

we present some images
to the subject.

Typically several hundreds
or thousands of images

in single experiment.

Freeman:
The images Yuki shows people

are simple
black-and-white shapes --

a square, a cross, a line.

Using a powerful computer array,

he records the precise pattern
of activity

in the visual cortex.

After multiple trials
with the same person,

the computer learns
to distinguish

the patterns triggered
by each image.

In other words,

the computer can judge
purely from the brain activity

which of the shapes
the subject is looking at.

And then Yuki does
something remarkable.

He shows the subjects
brand-new images,

images the computer
has never seen,

and lets the computer
try to draw a picture

of what the subjects are seeing.

These are the images

the computer reads
inside people's brains.

And these are the images
they are actually looking at.

This is the first time

anyone has been able to know
what people are seeing

purely by looking at
their brains.

Kamitani:
Looking at the visual cortex,

we have just succeeded
in reconstructing seen images.

We are now trying to reconstruct
imagined images

or images in your dreams.

Freeman:
Yuki's method, as yet,

only works on pixilated
black-and-white images,

but with a few more years
of refinement,

Yuki believes we will be able
to record our dreams

as full-color,
high-definition movies.

And that would truly be
a window into our souls.

Those, you know,
unconscious aspects of our mind

defines what we are
and what the identity is.

So, I think if we can reveal
some dream contents

which someone is not aware of,

then that might reveal some
deep property of that person.

Our true identities

could soon be laid bare
for all to see,

including the parts
we don't want seen,

like our deepest-held secrets
and fantasies.

But you may not have to worry.

Because the power to edit
the contents of our minds

is close at hand.

Our brains
are filled with memories.

Some of them bring us joy.

Others make us wish
we could forget.

Whether we like it or not,

our memories shape
how we think and how we act.

But now one group of researchers
thinks it has found a way

to change memory
and perhaps change who we are.

Can we deliberately change
our sense of identity?

Neuroscientist André Fenton from
the State University of New York

doesn't see why not.

To him, the brain

and its pathways of connections
between neurons

are like the labyrinth
of streets in New York City --

a maze he navigates
on his daily runs.

And just like Manhattan traffic,

conditions for the flow
of electricity around the brain

are not the same on every route.

If you experience something,

there's been
an electrical activation

somewhere in the brain

that spreads through the brain,

and that is your experience.

As in a city,

there are roads that connect one
district to another district,

and those roads
can be very big boulevards

that send a lot of traffic,

or they can be small alleys that
send very specific information,

but nonetheless,
not very rapidly or very easily.

Freeman: For years,

scientists thought
the pathways in our brains

were set in stone after we
matured from babies to adults.

Alleys could not become wider.

Highways
could not become narrower.

But now it has become clear

that the roads
in our adult brains

are under constant construction.

Every time we store
a new memory,

electrical activity propagates
through millions of neurons.

Just as André
is forced to find a new route

if his pathway is blocked,

our neural pathways
adjust themselves

to process and record
new experiences.

Fenton: And so, what
neuroscientists understand is

that there's a sufficient amount
of this plasticity

throughout life,

and that it is affected

and modulated and controlled
by experience.

Freeman: Recently,
scientists have identified

a molecule in the brain

that jumps into action when
we are forming new memories.

It is called PKMzeta.

PKMzeta stands for
"protein kinase mzeta."

It's my favorite molecule.

When PKMzeta gets told
to deploy in a neuron,

it gets told to do that

on the basis
of a recent experience,

and what it does is
it mediates efficient

or increased efficiency
of neural transmission.

Freeman: When a memory
needs to navigate its way

through the traffic
of our brains,

PKMzeta clears the way,

making sure the memory safely
reaches long-term storage.

Fenton:
Those long-term memories,

the ones that you form now
and you will keep forever,

that kind of information storage
seems to be mediated by PKMzeta.

Freeman:
But André knew of a chemical

that could neutralize PKMzeta,

called zeta inhibitory peptide,
or ZIP,

and he wondered if he injected
it into a living brain,

could he prevent it from forming
long-term memories.

Fenton: So, the logic
of the experiment we did

is very straightforward.

What you want to do is
produce a memory.

A rat is in a rotating carousel,

and the key here is that

whenever it enters
that part of the floor,

it becomes electrified.

And so, they very quickly
and rapidly learn

to stay away
from that part of the room.

Freeman: In this computer-generated
read-out of André's experiment,

the rat runs around the carousel

but consistently avoids the
triangular-shaped shock zone.

30 days later, André puts
the rat back in the chamber

and observes that it still
remembers to stay away.

It has stored a new
long-term memory in its brain.

But when André injects
the rat's hippocampus with ZIP,

he sees something extraordinary.

When the rat is put back
in the carousel one more time,

it runs right over
the shock zone

as though it had never
been shocked before.

You could see
that the animal behaved

more or less
like a naive animal,

so it was very exciting.

Freeman: André has erased
a piece of the rat's memory.

The ability to forget
people we have met,

places we have been,
things we have done

is now a pharmaceutical
possibility.

But André can't see
inside his rat's brain,

and so he cannot be sure

how many memories
the ZIP molecule erased.

Fenton:
As we begin to work out

the synaptic organization
of memories,

we'll then be in a position
to understand

whether it's possible

to actually make
selective manipulations

of particular memories.

We are always
going to be confronted

with the possibility
of erasing all memories,

which could never be
a good idea.

Freeman: Using ZIP
to erase a specific memory

is still a ways off.

But in Montreal, one doctor
has found another way.

He is washing away
painful memories

that make his patients prisoners
inside their own identities.

Who we are depends on
where we have been,

who we have loved,
who we have lost.

For some of us, painful memories
can linger like an open wound.

They can hold us back from
becoming who we want to become.

Doctor Alain Brunet
is a psychologist

at McGill University
in Montreal.

He specializes
in treating people

with post-traumatic stress
disorder.

Alain himself has a deep
understanding for the condition.

[ Gunshots ]

In 1989,
at the University of Montreal,

a deranged man carried out
the worst mass shooting

in Canadian history.

Alain was on campus,

studying for his master's degree
in psychology.

He shot --
he went through the corridors.

He shot 12 women,

and eventually
there were 13 deaths.

[ Gunshots, women screaming ]

Brunet:
The crisis intervention

that had been conducted after
this event was very poorly done,

and many of us were left
with a bad taste in our mouth,

and so, it did have
a profound effect on me

and on what I decided to study.

Freeman: This horrific event
started Alain on a path

that he is
still following today.

He helps people
who suffer from PTSD

get back a part of themselves
that seems to be lost.

PTSD can be conceived
as a disorder of memory.

Because in a sense,

it's really about things
that you wish you'd forget.

That memory has been burned
into your brain

and is way too powerful,

and it's making you fearful

in situations
where you shouldn't.

Memory is a little bit
like writing with ink.

So, you can see
that the ink is still wet.

If I use my fingers
and go over my writing,

it will smear what I just wrote.

And this is exactly like
the workings of memory.

Freeman: But when a memory
is emotionally powerful,

proteins in the brain

build connections
between neurons

and the memory is transferred

to a separate
long-term storage area.

There, it leaves
a lasting impression.

Once the ink is dry,
the memory is there for good.

Of course,
it might fade with time,

but that memory
will still be accessible.

Freeman:
Many scientists believe

that once the ink
of a memory is dry,

it is fixed and indelible.

But Alain believes that
every time we recall a memory,

it is like we are creating a
brand-new memory all over again.

Brunet:
When you recall a memory,

it becomes active again,

and it becomes buzzing
with electrical activity.

It's really a little bit like

if you were rewriting the word
"Rouge" again with fresh ink.

Freeman: The moment someone
recalls a painful memory,

Alain believes he has
an opportunity to modify it.

I've had a lot of traumatic
events happen in my life,

which I was able to, you know,
work through and live through,

but then the death
of my daughter --

it was too much.

I couldn't function.
I couldn't work any longer.

I had absolutely lost who I was.

There's no doubt about that.

Freeman: Lois Bouchet,
who has come to Alain for help,

is in for an intense treatment.

As a first step,

he asks her to methodically
recall her painful memory

by reading aloud a personal
account of the traumatic event.

Okay.

"I heard the doorbell
at 5:00 a.m.

"I went to the door
in my nightgown,

"thinking it was
my daughter.

"When I saw
that it was the police,

"I excused myself
to go get my housecoat on.

"As I'm walking down the hallway
to the bedroom,

they ask if anybody is
at home with me."

While Lois reads,

she's under the influence

of a drug Alain administers
called Propranolol,

a simple beta blocker
that reduces high blood pressure

and has a well-known side effect
of slight memory loss.

"I know that something
is terribly wrong.

"I get a knot
in my stomach.

"My heart
starts beating faster,

"and I can feel myself
shaking inside.

"When I come back
to the living room,

"he tells me Nikki has been hit
by a truck on the 401

"and my Nikki is dead.

"All of a sudden,
I crouch down

"and start to sob
uncontrollably.

"The pain is incredible.
My chest hurts.

I think, 'How can I make it
through this?'"

they did that once a week
for six weeks,

and then we tested them with
a battery of tests, interviews,

and psychophysiological
measurement of their responding

while they're listening
to an account of their trauma.

Freeman:
After six weeks of treatment,

70% of Alain's patients

show hardly any signs
of PTSD symptoms.

They could talk about the pain

without being forced
to relive it.

And that really blew our mind,

because they had only received
one small dose of a medication,

and those people had been
suffering from PTSD for decades.

Freeman: Alain's patients

have written over
their traumatic memories.

They have a second chance
to reclaim their lives

and to reclaim a sense of self.

Bouchet: As you carried on,
it got easier.

You never forgot the feelings.

Like, I'm always gonna be upset
about it.

My daughter died.
That's never gonna go away.

But now I can think about
what happened

without feeling like
I'm going to lose my mind.

Brunet: With trauma,

there will always be
a time before and a time after,

but in my opinion,
people gain back their old self.

Freeman: Alain seems to have
found the fine-tuned tool

that can target
specific memories.

But even if
we can envision a time

when our identities
can be transformed or restored,

we still haven't grasped
the most fundamental aspect

about what makes us who we are.

What is it that makes our brains

able to question who we are
in the first place?

One man thinks
he has the answer.

He's trying to re-create

the essence
of what makes us us

in pieces of silicone hardware.

The core of who we are

is something we carry with us
everywhere we go.

It lives somewhere in the web

of billions neurons
in our brains.

Now some scientists
are trying to discover

if this biological network
can be replicated

in silicone hardware,

whether we can build a robot
that will ask itself,

"Who am I?"

Computer engineer Steve Furber

from the University
of Manchester

is on a quest to find out

if a human identity
can be built.

He is attempting to make
the first replica of the brain

that works in real time.

If he succeeds,

he could unlock the secret
of what makes us who we are.

Furber: I think the whole issue
of understanding the brain

is fascinating.

It's so central
to our existence.

We're pretty sure that
our understanding of the brain

is missing
some fundamental ideas,

and one of these is

how information is represented
in the brain.

Freeman: Steve believes

there is a neural code
that runs our brains,

that one code is responsible
for controlling multiple jobs --

seeing, hearing,
learning language.

It's just a matter
of finding out what the code is.

He suspects
the best place to look

is in the part of the brain that
is far more evolved in humans

than in other species --

the thin, wrinkly, outer layer
called the neocortex.

Furber: So, the neocortex is a very
interesting area of the brain

because it's pretty much
the same at the back,

where it's doing
low-level image processing,

and at the front,

where it's doing
high-level functions.

So, if you're born
without sight,

a lot of your visual cortex

will be taken over
processing sound.

And it's quite common that
people who don't have sight

have much more acute hearing.

So there must be something
in common

about the algorithms
that are used there,

if only we could see
what that was.

Freeman: Computer engineers

have been trying replicate
biological brains for decades,

using standard
computer technology.

But Steve believes they've been
going about it all wrong.

In a conventional computer,

data gets moved around
in large chunks.

That would be like a chef

dumping an entire dinner
and dessert into one pot

and serving a pile
to one unfortunate customer.

But the brain is more like
a cocktail party.

Small bits of data
are passed around and shared.

Before you know it,
connections are being made

and a complex situation
is underway.

[ Munching ]

This highly interconnected way
to arrange small packets of data

is what Steve wants to replicate

in a custom-designed
silicone circuit.

He has created a brand-new type
of computer chip

specifically engineered to mimic

the way neurons work
in the brain.

It is called the SpiNNaker chip.

SpiNNaker is a compression

of spiking neural network
architecture.

If you say it quickly enough,
it comes out like "SpiNNaker."

The SpiNNaker chip is
a massively parallel computer

designed to run models
of the brain in real time,

which means that our model runs
at the same speed

as the biology inside your head.

Freeman: Each one
of Steve's SpiNNaker chips

can be programmed to replicate
the behavior of 16,000 neurons.

That's only a tiny fraction

of the 100 billion neurons
we have in our brain,

but it is
a significant step beyond

anything
that has been done before.

Steve and a team from the
Technical University of Munich

are now wiring these
brain-like chips to robots.

This might look like
a remote-controlled toy,

but it is not.

It is controlling itself
by sensing the world around it.

So, the robot is basically
following the line

entirely under neural control.

It has a vision sensor
on the front.

The vision information is being
sent into the SpiNNaker card.

The SpiNNaker card is executing
the real-time neural network,

and then the outputs
from the SpiNNaker card

are being sent back
via the laptop to the robot

and controlling its movement.

The brain is over there,
and the body is over here.

The robot's SpiNNaker chip brain

mimics the way
a real biological brain works.

Just like a child,

it interacts
with its environment

and uses its physical body to
understand the world around it.

The more it experiences,
the smarter it gets.

Our current systems
have four chips on.

They can model
about 50,000, 60,000 neurons.

In a few months' time,

we'll have boards
about 10 times bigger than that,

and they'll be getting up
to the level of complexity

of a honey bee,
which has 850,000 neurons.

And then beyond that,
we'll build systems

and get up to mammalian
brain sizes.

Freeman: The human brain
is a formidably complex system,

and it would take millions more
SpiNNaker chips to build one,

but Steve is confident
it is possible.

If you had a model of the mind
running in a machine,

I don't see why it shouldn't
behave in exactly the same way.

The question of whether
machines modeling the brain

may ultimately be capable
of supporting the imagination,

dreams, and so on

is a very hard question,

but I don't see
any fundamental reason

why we shouldn't expect that.

Freeman: Steve believes

that human brains run
on simple algorithms,

and what works for humans will
also work for his machines.

The journey to forming
an identity begins

when a body,
guided by networks of neurons,

struggles to navigate its way
through the world.

It learns, adapts, remembers,

and eventually
becomes self-aware.

What makes us who we are?

Our identities
are built bit by bit

from our memories, our dreams,
and our imaginations.

No one's sense of self is fixed.

Life is a journey
that makes us all unique,

and discovering who we are

is our greatest
and longest adventure.

== sync, corrected by elderman ==