Incredible Human Machine Page #8

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- There you go.

Oh, my gosh.

(Air hisses)

(Cries)

- lt's a big girl.

- lt's a big girl.

ln the nine months it takes her to go from

fertilised egg to fully formed human baby

she will have grown

more than 5,000 times bigger.

As women around the globe can attest,

getting to this point is no easy task.

And yet some 260 humans

are born this way every minute.

That's 37 4,000 every day

and more than 1 36 million every year.

(Laughter)

Why evolve such a painful and risky way

to keep a species going?

lt's the price we pay for our giant brains.

Hi.

Billions of neurons

are buzzing around in that head of hers,

virtually all the nerve cells

her brain will ever need.

Throughout her childhood

they'll be reaching out to other neurons,

making more connections

with each new experience.

With each connection mind and body fuse

to form the thing that is us.

And at the helm, the most remarkable

command centre in the world.

Every system in the body is complex, but there

is only one presiding over everything we do.

Every second since our day began,

our brains have been guiding,

guarding and giving orders.

Defining nothing less than what we are.

Through an information superhighway of nerves

fanning throughout our bodies

our brains keep tabs on every part of us -

eyes and ears, skin and bones,

heart and muscles.

Through a hundred billion specialised cells

called neurons

zapping millions of electrical and chemical

signals at up to 200 miles per hour

these three-pound blobs of fat and water

let us think, feel, want, remember and react.

lt really is what makes us human,

because it encapsulates everything

from our ability to paint a beautiful picture

to construct a building,

to render violence on somebody else.

lf l transplant your heart, for example,

you're still you.

But if we do something that damages your brain,

the very character,

your very personality may change.

And so the brain is you.

And when this unremarkable-looking organ

is under assault,

everything that defines you is at risk.

Hi, Brandon. This is Dr Liau.

They're gonna be putting you to sleep now, OK?

- OK.

- l'll see you when you wake up.

Everyone in this UCLA operating room

is acutely aware of the brain's vulnerability.

23-year-old Brandon Carson

has a large cancerous tumour

near a region of his brain critical for language.

His tumour is very close to Broca's area.

(Whirring)

lt's probably one of the closer ones l've seen.

The challenge to Dr Linda Liau

and the team of doctors

is to remove the tumour

whilst keeping Brandon's speech intact.

Brandon, wake up.

Which is why once they've opened his skull

and revealed his brain

the doctors do their best

to keep Brandon awake.

Brandon, open your eyes.

The brain doesn't have pain receptors,

so Brandon doesn't feel anything,

even when they do wake him up.

- Give it a try.

- Brandon.

(Low conversation)

- No, no.

- No, you can't.

Don't sit up.

Can we do this test real quick?

DR LlAU:
Language is a function

we can't map when a patient is asleep.

We can measure muscle and things like that,

but we can't really with a 1 00% certainty

know where his language areas are

unless we wake him up

and stimulate those particular areas.

OK. What's this?

Good. And this one?

Using easily-identifiable flash cards, a

psychologist tests Brandon's language capacity.

Simultaneously, Liau disrupts tiny areas of

his language centre with a mild electric shock.

Let's try that same area again.

lf Brandon has trouble recognising these

images while the shock is being delivered,

the team then knows this is a critical area

and makes sure to work around it.

Jessica, there's an area that l think is safe.

l'm going to start there

and you just keep talking to him.

By imaging the brain before and during surgery,

something she couldn't do just ten years ago,

Liau can cut out the tumour with confidence.

And with a living, functioning,

awake brain exposed,

neuroscientists get a rare opportunity

to peer inside down to individual blood vessels

and glimpse the mysterious organ in action.

Mapping the human brain is a Holy Grail -

we all want to do it.

We want to create a map

where we know what structures are where

and what the function is in those structures.

But unlike the map of the Earth where there's

latitude and longitude and so forth,

the human brain is individualised.

Each is different from the other;

it's what makes us unique.

At UCLA's Laboratory of Neuro lmaging,

Dr Arthur Toga isjust beginning to understand

these differences

with what is called the Brain Atlas.

lt's a collection of thousands and thousands

of scans of human subjects.

Various ages, various groups, various genders.

With it, we can watch a brain develop

from five years old to 90

and see it start to degrade during middle age.

Comparing a man and a woman's brain.

His may have more volume

but hers has added surface area.

Here's the brain activity of someone who speaks

one language, and someone who speaks two.

A right-hander and a left.

The Brain Atlas looks at our master organ

from a variety of perspectives,

right down to individual neurons.

Through functional magnetic

resonance imaging, or FMRl,

we can see the exact spots where conscious

thoughts originate as they form.

Navigating a map, listening to music,

experiencing fear and laughter.

This is remarkable.

You can watch the human brain function

in a normal, living individual.

FMRl also allows us to watch the brain

as it malfunctions.

Two years ago a severe car crash

left 22-year-old Kimberlee Lizarraga

crippled by pain in her neck and shoulders,

and she feels it to this day.

Just picking up groceries or driving a car

can be excruciating.

The pain that l felt was so unexplainable.

l can't even explain the pain that l felt.

lt affects my job,

it affects my whole life tremendously.

Kimberlee suffered no brain trauma in the

accident and her injuries are completely healed.

Her pain lives only in her brain.

And with the help of Stanford's Dr Sean Mackey

and an FMRl, Kimberlee is learning to control it.

Pain doesn't live in one region.

We believe it is ultimately a flow of information,

a flow of neural activity

between a multitude of regions within the brain.

What we're working on now is actually

trying to control the volume on... the faucet,

so to speak,

on information flowing back and forth.

Mackey doesn't want to stop

that flow completely.

Pain does have its place.

What's wonderful about pain

is that it's so terrible.

My son only had to touch a hot stove once

to learn not to do it.

The problem is when pain becomes chronic.

When it lasts beyond the time you would expect

for the tissue to have healed after an injury.

lt's persistent.

lt robs our soul, it robs of who we are.

All right, Kimberlee, we're going to take

anatomical images of your brain.

This is gonna take about two minutes.

Which explains why Kimberlee submits to

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