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Between the turmoil of puberty
and the decline of old age,
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the human body reaches its peak.
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In biological terms, as adults,
we are the finished article.
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Now is the time when we begin to live
our life, rather than prepare for life.
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There's something unique
about the adult body
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which has made us the most
powerful animal species on Earth.
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It has enabled us
to rule the natural world.
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It has given us the flexibility
to escape the confines of our planet,
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to venture out into space.
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We've even managed
to explore inside our own bodies.
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Every day, doctors make repairs
to our internal world.
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So, all the triumphs
of human endeavour stem from one thing.
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It's the most mysterious part
of the human body,
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and yet it dominates the way we live
our adult lives. It is the brain.
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The human brain
is a miracle of evolution.
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It's the most complicated object
in the known universe.
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But to understand how it works,
we really need to know
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how it evolved and where it came from.
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The brain of our ape-like ancestors
was pretty small.
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Its volume was about half a litre.
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That's the size of the engine capacity
of a Fiat 500,
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or a modern-day chimp's brain.
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The human brain is about three times bigger,
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about the size of a sports car engine.
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As our ancient ancestors evolved, they had
to learn ever more complicated skills.
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They needed bigger, better brains,
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brains that would be
more powerful and more adaptable.
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It's difficult to get across
how rapidly the human brain enlarged.
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From our ape-like ancestors
to the bigger-brained humans
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was two and a half million years.
That may seem a long time,
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but in evolutionary terms,
it's remarkably quick.
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The human brain was increasing
by the equivalent of 150,000 nerve cells
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at each generation.
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But in nature, there's no such thing
as a free lunch. Everything has its cost,
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and a bigger brain, like a bigger engine,
is more expensive to run.
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The human brain uses up more energy
to run than any other organ in the body,
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burning a whopping one fifth
of the food that we consume.
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This makes the head hotter
than the rest of the body,
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shown here by a heat-sensitive camera.
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We invest so much in the brain
because of its importance.
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It's what makes
each one of us who we are.
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It's amazing to consider
that I'm holding in my hands
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the place where someone once felt,
thought and loved.
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From just looking at it, there's nothing
to suggest very much ability at all.
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It appears rather gruesome -
wrinkled like a walnut
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and with the consistency of mushroom.
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For centuries, scientists
have been battling to understand
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what this unappealing object
is all about.
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The philosopher Aristotle,
of ancient Greece,
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believed that the brain helped
regulate the body's temperature.
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A runny nose was the cooling fluid
leaking out of the brain.
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He reasoned that since the heart
beat faster when you were excited,
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it must be responsible
for our feelings and thoughts.
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It's easy to laugh at him now,
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but Aristotle was the first person to think
seriously about how the human body worked.
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We've come a long way
since the fourth century BC.
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Now we can actually
see inside a living brain.
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Medical scanners prove the brain
is indeed where we think and feel.
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When a particular area of my brain
is working hard,
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extra blood flows there, through my arteries,
to provide energy for the active nerve cells.
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The scanner
can detect these changes in blood flow,
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giving us a completely new window
into the fascinating world of the mind.
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Using this technique,
we can actually watch the brain at work.
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Here I'm listening to music.
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Not one, but several areas light up.
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This part of the brain
is where we process all sounds,
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and this is where we appreciate music.
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Amazingly,
there are even separate bits for melody...
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for rhythm...
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and for pitch.
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But what's actually happening
deep inside the brain?
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It's a fascinating story,
but it's complicated.
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It all starts with this tree-like structure:
a single brain cell or neurone.
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Here is an actual neurone,
magnified 10,000 times.
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Neurones are
the tiny building blocks of the brain.
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They do something remarkable,
which prompts all our thoughts.
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They fire an electrical impulse.
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Amazingly, we can now see one firing.
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This is the first time
it's been shown on television.
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The electricity is bursting along
the neurone at 400 kilometres an hour.
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Here we're seeing it in slow motion.
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Within a tiny fraction of a second,
it's ready to fire again.
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Your brain has a staggering
100 billion of these neurones.
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Together they could generate enough
electricity to illuminate a light bulb.
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To make things more complicated still,
the branches of each neurone
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are connected
to thousands of other neurones.
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It's hard to grasp
the sheer scale of all these connections.
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Imagine a bustling city
the size of New York.
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Give every person in that city
10,000 pieces of string.
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Tell each person to attach each
piece of string to a different person.
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Now make the city
a thousand times bigger.
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This is the incredible tangle
we call the brain.
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And there's more.
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Go deeper into this tangle,
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travel along a single neurone and take a close
look at the junction with its neighbour.
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0ddly, the neurones are not
physically joined together at all.
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There's a tiny gap.
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To bridge this gap, the neurones
release minute quantities of chemicals
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every time they fire, chemical go-betweens
that influence our thoughts.
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This cocktail of chemicals swirling
about the brain is finely balanced.
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It needs to be
to control the activity of the brain.
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Because it's so much on a knife-edge,
it's very easy to disrupt.
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People do it every day. I like to do it,
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just occasionally, with some Cabernet Sauvignon.
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People have been drinking alcohol
for thousands of years.
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But surprisingly, it's only in the last couple
of years that scientists have discovered
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precisely how it works.
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So, in the interests of science,
I've put myself forward as a guinea pig.
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Before I start,
I need to test my reaction time.
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This little red light will come on,
and I'll press the red button.
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That's fifteen hundredths of a second, just under
one fifth of a second. That's about average.
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Well, I've now had three glasses.
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Unlike what most people think, it isn't actually
the alcohol itself which makes you drunk.
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Rather, as soon as the alcohol enters your body,
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there are a series,
a cascade of chemical reactions.
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It's the by-product of one of these reactions,
the fatty acid compounds,
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which make you drunk.
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Well, I've had well over a bottle of wine now,
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and although I feel pretty good, my ac...
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..reaction time isn't what it should be.
We'll try testing it.
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It's about quarter of a second.
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Slower than before.
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There's a good reason
why my reactions are sluggish.
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The normal chemical balance
in my brain is being disrupted,
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as those fatty acids
clog up the surface of the neurones.
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The fatty acids
attack only parts of my brain,
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including those that control
my speech, my mood and my memory.
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What was I saying?
Well, what was I saying?
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Alcohol just influences behaviour. Some people...
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..just get belliru...belligerent.
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0thers... No, wait a minute.
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Actually, I can't remember terribly
what I'm supposed to say.
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(MAN) Action.
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What was I saying?
Alcohol also influences behaviour.
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Where's the coffee?
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Sorry?
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Well, I... Just say ''action''
and I'll be on the ball.
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Action.
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I'm not sure I can get my head
round this completely now. Actually.
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How can all my thoughts and behaviour come
from chemicals and little neurones?
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Some people
compare the brain to a computer,
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but I think
it's much more like a termite mound.
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It's all to do with the whole thing
being greater than the sum of its parts.
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A termite colony is extraordinary.
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It is as intricate and as complex as a city.
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It can dominate whole areas of the bush
and wage war against other insects.
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Above all, it can build
these stupendous structures,
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with columns and buttresses
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and air-conditioning ducts.
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So where is the knowledge
for this incredible organisation kept?
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Not in an individual worker termite.
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They are supremely dim,
with a brain the size of a pinhead.
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Nor in the enormous,
squirming, egg-producing queen.
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Her brain
is even smaller than a worker's.
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No. The intricate behaviour
of the termite colony
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emerges from the collective effort
of all the termites.
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Here, a group of worker termites
are constructing a new wall.
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Not a single one of them carries a blueprint
for the wall, but working together, it gets built.
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Termites send out chemical signals,
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and between them they pile up
their tiny mouthfuls of mud.
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Clearly the human brain is
totally different from the termite mound.
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Both, though, are composed of numerous
building blocks; either neurones or termites.
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Each, when acting in harmony,
is capable of extraordinary feats.
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It makes no sense
to search for the root of knowledge
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in single neurones in the brain, or,
for that matter, in one termite in a colony.
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The success of both depends on many
millions of simple units working together.
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So it's teams of neurones acting
in unison that give us all our skills.
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Each team, based in a particular region
of the brain, takes on a different responsibility,
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from our most advanced human abilities,
such as language and memory,
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to the more basic ones, like movement.
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Because we walk,
run and reach without thinking,
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we forget how
such incredible precision is possible.
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To see how much brain effort
is required,
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look what happens when we're plunged
into a totally new environment.
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- OK.
- OK, there we go.
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Astronauts have to learn to move from scratch
when they enter a world without gravity.
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The reason why we're able to learn new tasks
and carry them out automatically lies here.
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It's a part of the brain called
the cerebellum, or little brain,
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because it sticks out
right at the base of the brain proper.
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Here are stored the practised movements we
all learn, be it riding a bike, playing the piano,
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or even fixing a satellite.
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The astronauts are in the cargo bay
of the shuttle, but they're not out in space.
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This is the closest they can get to space
back on Earth, an enormous swimming pool -
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a pool so large
that four space shuttles can fit inside it.
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Here astronauts can practise
their tasks over and over again,
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until they can move automatically
without thinking.
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(ASTR0NAUT) I had to jig it a little to lock.
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Yeah, it is finicky about
being directly perpendicular to the rail,
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so try to wriggle it back and forth, from
starboard to port, and from forward to aft.
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OK.
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- We're assuming the latches didn't work.
- So they're manually...
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Marsha Ivens is one such astronaut.
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Talk about seeing the world.
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She's been on four shuttle missions
and orbited the planet 683 times.
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(MARSHA IVENS) Learning to deal with the
absence of gravity takes a little getting used to.
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We are used to walking from place to place,
and you don't walk, you float or fly.
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So when I want to cross the room or the
cabin, I push off with my hand or feet.
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If I push too hard, I smash into the wall.
If I push in the wrong direction, I miss it.
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If I don't push off hard enough, I don't get
to the wall. It takes a bit of getting used to.
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0nce we've practised a skill enough,
the cerebellum can take over automatically.
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A thought starts it off,
and then the cerebellum does the work,
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sending out instructions
to the rest of the body.
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This happens
without us even being aware of it.
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In fact, the unconscious part of the brain
is often more skilful than the conscious part.
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0n the space shuttle is a robot arm.
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The astronauts have to train hard
to operate it, using a joystick.
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But the secret with moving a robot arm smoothly
is not to think too much about it.
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Let the cerebellum take over.
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(MARSHA IVENS) For me it was difficult to
think about moving each joint as I moved it.
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And I just did it, and it got there.
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The more experienced you get, the more
rotations you can make at the same time.
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That's probably true of learning
to use your hand.
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When you reach for something,
you make complex motions with your arm,
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and that's probably as learned a response
as it is learning to control the robot arm.
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The astronauts use the same mental
equipment to control the robot arm
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as we first use as babies
to control our flesh and blood arms.
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People have a fantastic ability to make
almost any tool an extension of their bodies.
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As an infertility doctor, I make full use
of my cerebellum to perform keyhole surgery.
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Here, I'm investigating
why a woman is unable to conceive.
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Surgical tools allow me to examine inside
her, without resorting to major surgery.
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After enough training, it is relatively simple
for me to co-ordinate what I do with my hands
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with what I see on the screen.
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Truth is, that this surgical manipulation,
like all surgical manipulation,
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looks incredibly skilled and very intricate.
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But actually, most of the time
you're doing it totally on autopilot,
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and you can do quite involved procedures
without really thinking about it.
227
00:19:39,200 --> 00:19:42,988
It's only when there's something untoward,
or the surgeon hits an emergency,
228
00:19:43,200 --> 00:19:48,513
that you suddenly need to concentrate much
harder and the conscious brain takes over.
229
00:19:50,320 --> 00:19:54,836
Most mammals have a cerebellum
just as developed as ours.
230
00:19:55,040 --> 00:19:58,430
A rat's primitive brain
is largely cerebellum.
231
00:19:58,640 --> 00:20:02,235
They don't need much more
for their relatively simple lives.
232
00:20:02,440 --> 00:20:06,877
And in humans, the basic design
of this rudimentary part of the brain
233
00:20:07,080 --> 00:20:10,038
has changed little as we've evolved.
234
00:20:10,320 --> 00:20:14,836
It is the rest of our brain
that has enlarged so massively.
235
00:20:17,840 --> 00:20:19,717
Why did it get so big?
236
00:20:19,920 --> 00:20:26,473
Well, surprisingly, a whole quarter
of our oversized brain is devoted to vision,
237
00:20:26,960 --> 00:20:30,430
much more
than for any of our other senses.
238
00:20:31,120 --> 00:20:35,796
What you see when you peer into the back
of the eye is the only part of the brain
239
00:20:36,000 --> 00:20:38,833
which is visible from the outside world.
240
00:20:45,120 --> 00:20:50,274
The optic nerve at the back of the eye
is a direct extension of the brain.
241
00:20:51,600 --> 00:20:56,037
Travelling along the optic nerve,
we pass right through the brain.
242
00:20:57,600 --> 00:21:02,628
Here, at the back of the head,
is where the visual information arrives.
243
00:21:03,000 --> 00:21:07,869
0ur eyes are just a window.
We actually see with our brain.
244
00:21:10,680 --> 00:21:17,233
It's difficult to grasp how complicated vision is,
until you try to programme a computer to see.
245
00:21:17,440 --> 00:21:19,908
It's staggeringly difficult.
246
00:21:20,120 --> 00:21:24,989
What the scientists hadn't realised
was that the eye is merely the first step.
247
00:21:25,200 --> 00:21:28,158
The brain does most of the real work.
248
00:21:33,280 --> 00:21:36,238
These robots
have excellent cameras on board,
249
00:21:36,440 --> 00:21:41,434
but they lack the clout of the brain
to make sense of what they see.
250
00:21:42,280 --> 00:21:44,999
This can be a handicap.
251
00:21:56,480 --> 00:22:01,429
0ur brains are so powerful that we very much
take our visual skills for granted.
252
00:22:01,640 --> 00:22:03,949
To fly this 1940s biplane,
253
00:22:04,160 --> 00:22:09,757
Marsha Ivens relies more on the view
from the cockpit than the instrument panel.
254
00:22:10,320 --> 00:22:13,915
(MARSHA IVENS) In an airplane like this,
vision is your primary means
255
00:22:14,120 --> 00:22:18,511
of knowing where you are,
relative to the world, in the airplane.
256
00:22:19,240 --> 00:22:22,550
My brand of flying doesn't really require
a whole lot of dials.
257
00:22:22,760 --> 00:22:28,949
I can tell what my rate of descent is.
You learn with experience.
258
00:22:29,160 --> 00:22:34,188
I make periodic checks of the altimeter and
the airspeed and the vertical speed indicator
259
00:22:34,400 --> 00:22:38,313
for that information, but mostly I do that
by looking outside.
260
00:22:40,920 --> 00:22:44,754
Whenever we look around us,
we see the world instantly.
261
00:22:44,960 --> 00:22:48,430
The shape of a plane,
its movement, its colour.
262
00:22:48,640 --> 00:22:52,599
But what's surprising
is that all these aspects of the image
263
00:22:52,800 --> 00:22:56,110
have to be processed
by the brain separately.
264
00:22:58,080 --> 00:23:01,072
We know these various elements
of vision are distinct,
265
00:23:01,280 --> 00:23:04,989
because certain people
with brain damage are missing one of them.
266
00:23:05,200 --> 00:23:07,839
Some cannot discriminate colour...
267
00:23:09,040 --> 00:23:13,556
..while, more bizarrely,
others are unable to perceive motion.
268
00:23:15,400 --> 00:23:20,679
It's as if they're seeing a stationary snapshot
of the world every couple of seconds.
269
00:23:22,200 --> 00:23:27,194
But in normal vision, our powerful brain
combines all these disparate elements
270
00:23:27,400 --> 00:23:29,868
into one coherent view of the world.
271
00:23:34,840 --> 00:23:39,994
As the brainpower of our ancestors increased,
they not only observed the world
272
00:23:40,200 --> 00:23:42,760
but also invented ways of shaping it.
273
00:23:42,960 --> 00:23:47,351
We can see this in action
by looking at the tools that chimps make.
274
00:23:50,840 --> 00:23:55,436
The chimps from this group
use an impressive 19 types of tool.
275
00:23:55,960 --> 00:24:01,114
Most of them are to get at food.
Thin sticks help them catch ants and termites.
276
00:24:05,720 --> 00:24:11,829
Chimps even use stone anvils and wooden
hammers to crush the shells of nuts.
277
00:24:20,760 --> 00:24:23,593
It's jolly difficult making a stone tool.
278
00:24:24,680 --> 00:24:27,478
So, here's one that was prepared earlier.
279
00:24:27,680 --> 00:24:30,240
About two million years earlier.
280
00:24:30,440 --> 00:24:34,956
The creature that made it chipped away
slivers of stone to give it a sharp edge,
281
00:24:35,160 --> 00:24:38,436
and it was probably used as a kind of axe.
282
00:24:38,640 --> 00:24:41,996
Archaeologists here
in the Great Rift Valley of Africa
283
00:24:42,200 --> 00:24:45,556
are really excited about this
and the other tools they've found,
284
00:24:45,760 --> 00:24:49,514
because it wasn't apes
that made them, it was people.
285
00:24:52,640 --> 00:24:55,552
Louise, what's so interesting about this area?
286
00:24:55,760 --> 00:25:00,311
All this site is special because there're
such vast concentrations of stone tools here,
287
00:25:00,520 --> 00:25:03,717
and this is because it was a lake basin.
288
00:25:03,920 --> 00:25:08,596
The early humans were coming down
to catch their animals, kill them
289
00:25:08,800 --> 00:25:11,394
and use the stone tools on the carcasses.
290
00:25:11,600 --> 00:25:15,149
I found it quite difficult making a stone tool.
What's the trick?
291
00:25:15,360 --> 00:25:21,959
You need a big brain, and to be quite
well practised to manipulate your hands
292
00:25:22,160 --> 00:25:26,870
to strike a flake off a piece of rock
and come up with a result like this.
293
00:25:27,080 --> 00:25:32,200
I'll forgive the slur on my brain, but how do you
know that these were used to butcher meat?
294
00:25:32,400 --> 00:25:33,913
That seems a bit far-fetched.
295
00:25:34,120 --> 00:25:38,477
We've found stone tools with a carcass,
say of an early elephant,
296
00:25:38,680 --> 00:25:43,196
where you've got stone tools and bones
which show cut marks,
297
00:25:43,400 --> 00:25:48,349
so you're pretty sure those stone tools
were used to butcher that animal.
298
00:25:50,120 --> 00:25:54,989
A chimp cannot make a stone hand axe.
It's not just the lack of brains.
299
00:25:55,200 --> 00:25:58,636
A chimp's thumb is very short
compared to its other fingers,
300
00:25:58,840 --> 00:26:02,628
making it awkward
to use all but the simplest tools.
301
00:26:05,640 --> 00:26:10,475
But over hundreds of thousands of years,
our human thumb lengthened.
302
00:26:10,680 --> 00:26:13,069
This gave us an enormous advantage.
303
00:26:13,280 --> 00:26:17,114
We could make a precise finger pinch
between thumb and forefinger.
304
00:26:17,320 --> 00:26:20,153
It's called ''the opposable thumb,''
305
00:26:21,280 --> 00:26:25,239
and it allowed us to manipulate
objects with great dexterity.
306
00:26:28,800 --> 00:26:34,989
Marsha harnesses this precision control of her
fingers to do safety checks on her plane.
307
00:26:36,040 --> 00:26:41,637
I pluck the wires on the tail
and should hear them ring the same tone.
308
00:26:47,400 --> 00:26:48,753
and the pilot.
309
00:26:48,960 --> 00:26:53,670
As I walk around the airplane, sometimes your
hand will feel something your eye doesn't see.
310
00:26:53,880 --> 00:26:56,348
If I run my fingers along the propeller,
311
00:26:56,560 --> 00:27:00,189
I can feel a nick
that I wouldn't necessarily see.
312
00:27:00,320 --> 00:27:02,470
I don't want nicks,
as that disrupts the airflow.
313
00:27:04,560 --> 00:27:10,157
The sensitivity of our fingers comes
from the ridges and grooves of our fingerprints.
314
00:27:10,360 --> 00:27:15,150
These ridges also give us better grip,
especially in wet conditions,
315
00:27:15,360 --> 00:27:19,990
just like the tread of a car tyre,
cornering in the rain.
316
00:27:21,400 --> 00:27:24,949
But what have fingers
got to do with the brain?
317
00:27:25,160 --> 00:27:29,517
Well, throughout our evolution,
developments of the brain and the body
318
00:27:29,720 --> 00:27:35,989
were constantly bouncing off one another.
As one advanced, it drove the other forward.
319
00:27:36,600 --> 00:27:43,073
This feedback relied on a key turning point,
one that other animals failed to make.
320
00:27:44,760 --> 00:27:50,039
Chimp hands aren't very dextrous, because
they do two contradictory jobs with them.
321
00:27:50,240 --> 00:27:56,475
They hold things, but they also walk on their
hands. So their hands are a compromise.
322
00:27:56,680 --> 00:28:01,629
Not bad for knuckle walking,
but not so good for creating tools.
323
00:28:01,840 --> 00:28:06,914
Human hands excelled at creating tools
and manipulating objects
324
00:28:07,120 --> 00:28:11,272
because they were largely dedicated
to just one activity.
325
00:28:11,800 --> 00:28:14,951
Unlike chimps, we did this.
326
00:28:15,160 --> 00:28:17,879
We stood up on our hind limbs.
327
00:28:18,560 --> 00:28:23,076
This crucial advance happened
over 3.5 million years ago.
328
00:28:23,280 --> 00:28:29,230
Standing up gave our hands enormous freedom
and boosted our brainpower dramatically.
329
00:28:29,440 --> 00:28:31,396
We never looked back.
330
00:28:31,600 --> 00:28:36,515
Standing tall on two legs happened very early
on in the development of the human body,
331
00:28:36,720 --> 00:28:43,398
before we had opposable thumbs, before we
had stone tools, before we had language.
332
00:28:43,600 --> 00:28:46,956
Indeed, standing helped these developments.
333
00:28:47,160 --> 00:28:50,516
Early humans literally had time on their hands -
334
00:28:50,720 --> 00:28:56,511
time to challenge their tiny Fiat 500 brain,
jump-starting it into further evolution.
335
00:28:59,680 --> 00:29:04,037
As our brain got bigger,
so it perfected one rather special trick.
336
00:29:04,240 --> 00:29:08,199
It learned to make order out of chaos,
putting things into categories.
337
00:29:09,760 --> 00:29:14,436
Coffee with caffeine and coffee without?
Kenyan or Colombian?
338
00:29:16,080 --> 00:29:20,631
It's no accident that this is
how we organise our daily life.
339
00:29:20,840 --> 00:29:22,956
I'll take a couple of those. Thank you.
340
00:29:23,280 --> 00:29:28,638
We came to classify things this way so that
we could cope with the complexity of nature.
341
00:29:28,840 --> 00:29:34,233
To survive, we had to learn which plants
were poisonous and which we could eat;
342
00:29:34,560 --> 00:29:40,430
to know which animals would make a good meal
and which were likely to make a meal of us.
343
00:29:40,640 --> 00:29:44,349
Animals do this to some extent,
but the human brain excelled at it.
344
00:29:50,880 --> 00:29:53,235
We still use this skill in city life,
345
00:29:53,440 --> 00:29:59,390
but in the natural world, you can witness it
the way it was originally deployed.
346
00:30:08,400 --> 00:30:12,473
Philip Alderson is a park ranger
in north Australia.
347
00:30:12,720 --> 00:30:18,078
Forest fires sweep the park in the dry season,
and Philip lights small control fires
348
00:30:18,280 --> 00:30:22,990
to burn up dry tinder and stop the spread
of a bigger fire that's approaching.
349
00:30:23,200 --> 00:30:29,878
It's called ''back burning,'' and has been used
by Aboriginal people for thousands of years.
350
00:30:37,560 --> 00:30:42,270
You can see the big cloud of smoke
over there, and it's roaring through.
351
00:30:42,480 --> 00:30:47,076
When the main fire front comes along,
it gets really windy,
352
00:30:47,200 --> 00:30:49,475
with little whirly winds everywhere.
353
00:30:49,600 --> 00:30:53,036
The back burning stops it from coming
any further with the wind.
354
00:30:53,240 --> 00:30:57,711
It would carry it across the other side
of the road, all that debris and sparks.
355
00:30:58,840 --> 00:31:02,799
The ability to understand
and control the natural world
356
00:31:03,000 --> 00:31:06,436
was crucial
to survival throughout our past.
357
00:31:08,720 --> 00:31:11,757
This river is teeming with crocodiles.
358
00:31:11,960 --> 00:31:17,353
The same skills that Philip's ancestors used
to kill them, Philip now uses to count them.
359
00:31:17,560 --> 00:31:19,949
He tracks them down
by knowing their habits.
360
00:31:20,640 --> 00:31:23,677
(PHILIP ALDERS0N) They live underneath
the bank where there's tree roots.
361
00:31:23,880 --> 00:31:26,075
They dig a hole
underneath the tree root.
362
00:31:26,200 --> 00:31:29,954
If you see this hole,
you know it's a breathing hole.
363
00:31:30,200 --> 00:31:32,509
They pick out an area
for their hunting.
364
00:31:32,640 --> 00:31:36,030
If another crocodile goes in there,
they soon have a go at him,
365
00:31:36,240 --> 00:31:38,435
because they get very territorial.
366
00:31:38,640 --> 00:31:42,076
To outwit nature,
we needed our brains above all.
367
00:31:42,280 --> 00:31:44,714
Most important was powerful memory.
368
00:31:44,920 --> 00:31:49,789
Working memory, usually lasting only a few
minutes, is like a mental blackboard,
369
00:31:50,000 --> 00:31:52,719
storing just seven items or so.
370
00:31:56,240 --> 00:32:01,030
Working memory is remembering if that's
the same crocodile you saw before
371
00:32:01,240 --> 00:32:03,800
or where you just put your notebook down.
372
00:32:04,000 --> 00:32:06,912
The vast majority of these memories
quickly disappear.
373
00:32:09,200 --> 00:32:14,149
But there's a part of the brain that ensures
memories can be stored for much longer.
374
00:32:14,360 --> 00:32:20,037
As certain thoughts are remembered,
over and over, they are passed to the cortex,
375
00:32:20,240 --> 00:32:23,232
the folded part enveloping
the front of the brain.
376
00:32:23,440 --> 00:32:26,671
This is where
our long-term memory resides.
377
00:32:28,040 --> 00:32:32,511
How these memories persist
is not yet fully understood,
378
00:32:32,720 --> 00:32:38,078
but the best explanation is that memories
are shared across many different neurones.
379
00:32:38,280 --> 00:32:43,195
0ver time, the branching connections
between these neurones are strengthened.
380
00:32:44,000 --> 00:32:49,791
This is how we remember our family and friends,
the important events of our life.
381
00:32:50,000 --> 00:32:55,996
0ne estimate is that an average person
store in their brain a million different items.
382
00:32:59,280 --> 00:33:06,277
This powerful memory originally evolved to help
us navigate our way around our environment.
383
00:33:06,480 --> 00:33:12,749
(PHILIP ALDERS0N) If you come back at night,
you can pick out certain points or channels.
384
00:33:12,960 --> 00:33:15,554
You know where you are then, you know.
385
00:33:16,120 --> 00:33:19,078
- It is quiet, isn't it?
- Yeah, it's quiet.
386
00:33:19,280 --> 00:33:23,990
- You'd reckon we'd pick one up by now.
- Yeah... Look straight up there, mate.
387
00:33:24,640 --> 00:33:27,473
The crocodiles prefer
to come out at night.
388
00:33:27,680 --> 00:33:33,152
In the dark, Philip can still spot them.
Their eyes reflect the torchlight.
389
00:33:34,280 --> 00:33:37,590
(PHILIP ALDERS0N) There's one
there, straight up, near the bank.
390
00:33:37,800 --> 00:33:39,995
Every time Philip revisits the river,
391
00:33:40,200 --> 00:33:45,115
he gets to know it that little bit better,
as it's etched on his mind.
392
00:33:45,320 --> 00:33:46,594
Turn to the left.
393
00:33:51,120 --> 00:33:52,838
Guess what?
394
00:33:53,040 --> 00:33:54,359
Got a fish.
395
00:34:04,240 --> 00:34:08,631
A few people have memory skills
well beyond the ordinary,
396
00:34:08,840 --> 00:34:13,277
and most of the best are collected here,
at the 13th Mind 0lympiad in London.
397
00:34:13,480 --> 00:34:16,790
They've come
to flex their powers of recall.
398
00:34:21,400 --> 00:34:25,678
so you get 15 minutes
to commit to memory,
399
00:34:25,880 --> 00:34:27,950
starting now.
400
00:34:28,160 --> 00:34:31,709
The contenders come
from a surprising range of backgrounds.
401
00:34:31,920 --> 00:34:37,916
There's a DJ, a fireman, a naval officer,
and the usual contingent of students.
402
00:34:38,120 --> 00:34:44,878
They all share the staggering ability to
memorise thousands of numbers off by heart.
403
00:34:45,080 --> 00:34:47,878
Andy Bell has been coming here
for three years.
404
00:34:48,080 --> 00:34:52,437
I'm here is to try and win.
It's very competitive.
405
00:34:52,640 --> 00:34:56,349
I've broken some records, but the main
thing is to try to win the championship.
406
00:35:00,360 --> 00:35:02,669
There's little chance of that today.
407
00:35:02,880 --> 00:35:06,031
(ADJUDICAT0R) Ready, steady, go.
408
00:35:07,080 --> 00:35:11,073
This man has won
the memory championships four times.
409
00:35:11,280 --> 00:35:15,353
This man has learnt the answer
to every single Trivial Pursuit question.
410
00:35:15,560 --> 00:35:19,519
The only thing that stands between him
and victory today is a full deck of cards,
411
00:35:19,720 --> 00:35:24,953
he has to view in under 40 seconds
and memorise in just three minutes.
412
00:35:28,880 --> 00:35:31,189
He is Dominic 0'Brien.
413
00:35:32,480 --> 00:35:34,072
How do they do it?
414
00:35:34,280 --> 00:35:37,829
(ADJUDICAT0R)
Stop memorisation, start recall.
415
00:35:38,520 --> 00:35:42,672
The National Institutes of Health
in America has spent three years
416
00:35:42,880 --> 00:35:48,477
and a quarter of a million dollars to find out
what was different about these people's brains.
417
00:35:48,680 --> 00:35:51,911
Six of spades, eight of spades.
418
00:35:52,120 --> 00:35:55,271
Their conclusion:
these people are completely normal.
419
00:35:55,480 --> 00:35:56,754
Three of spades.
420
00:35:56,960 --> 00:36:01,033
They don't have photographic memory,
which most scientists believe is a myth.
421
00:36:01,240 --> 00:36:04,391
In fact, the only difference
between them and you
422
00:36:04,600 --> 00:36:08,559
is that they have
trained the memory that we all share.
423
00:36:10,360 --> 00:36:12,635
Queen of diamonds. Is that right?
424
00:36:12,840 --> 00:36:14,512
(ADJUDICAT0R) One minute.
425
00:36:14,720 --> 00:36:16,472
That's the one I got wrong.
426
00:36:19,560 --> 00:36:22,233
Another victory for Dominic 0'Brien.
427
00:36:22,840 --> 00:36:25,798
So what's Dominic's secret?
428
00:36:26,280 --> 00:36:30,239
(D0MINIC 0'BRIEN) If I'm presented with a
hundred-digit number, it doesn't mean anything
429
00:36:30,440 --> 00:36:35,195
unless I break it up. So I break up a
long number, sequence it into pairs of digits,
430
00:36:35,400 --> 00:36:37,994
and give each pair of digits a character.
431
00:36:38,200 --> 00:36:43,149
For instance, the number 10 is Dudley Moore
and the number 07 is Roger Moore.
432
00:36:43,360 --> 00:36:45,635
99 would be Mr Whippy.
433
00:36:45,840 --> 00:36:51,233
Then I have something I can work with.
To remember those numbers in sequence,
434
00:36:51,440 --> 00:36:56,639
I imagine them on a journey. It's a bit like
making up a story involving those characters.
435
00:36:56,840 --> 00:37:02,153
That means the story
for the number 1-0-0-7-9-9 would be
436
00:37:02,360 --> 00:37:06,069
Dudley Moore meets Roger Moore
437
00:37:06,280 --> 00:37:08,635
for an ice cream. Easy.
438
00:37:08,840 --> 00:37:11,593
(D0MINIC 0'BRIEN)
We're born to hunt and gather,
439
00:37:11,800 --> 00:37:13,836
so that's why I use journeys.
440
00:37:13,960 --> 00:37:17,396
I have to translate the abstract
thousands of meaningless numbers
441
00:37:17,520 --> 00:37:22,275
to something my primitive - if you like,
caveman-like brain - can understand.
442
00:37:23,080 --> 00:37:25,548
You look very serious.
A little bit happier.
443
00:37:25,680 --> 00:37:28,672
Dominic turns
random information into stories
444
00:37:28,880 --> 00:37:33,431
because his brain
has evolved to absorb stories easily.
445
00:37:35,720 --> 00:37:41,397
Stories have played a key role
in retaining other much longer memories.
446
00:37:41,840 --> 00:37:47,597
The Aboriginal animals and gods on this
wall tell their own tales from long ago.
447
00:37:48,320 --> 00:37:51,835
Rock art
is really just an extension of memory,
448
00:37:52,040 --> 00:37:55,999
a more lasting way
of storing traditions.
449
00:38:06,600 --> 00:38:10,878
The big red kangaroo on the top there.
There's some barramundi.
450
00:38:11,080 --> 00:38:12,877
Perch, another one.
451
00:38:13,080 --> 00:38:17,631
If you'd hunted your first fish,
they'd paint it up on the wall,
452
00:38:17,840 --> 00:38:21,389
so everyone can have a look
at what type of fish it was.
453
00:38:21,600 --> 00:38:26,355
A lot of these paintings are
20,000- to 40,000-year-old paintings,
454
00:38:26,560 --> 00:38:30,155
and you can see it was
almost like painted yesterday.
455
00:38:31,680 --> 00:38:34,911
You find them
down there sinking the hole.
456
00:38:35,120 --> 00:38:40,831
Parents teaching their children
is another way of passing on information.
457
00:38:41,040 --> 00:38:45,636
Philip shows his son how to find
the turtles that live in the mud.
458
00:38:47,080 --> 00:38:51,471
They're in the hollow, Sam.
Hollow one, like rock.
459
00:38:55,240 --> 00:38:59,199
That's the one. Big one. Dig him up.
460
00:39:01,120 --> 00:39:03,076
They're learning a lot.
461
00:39:03,280 --> 00:39:08,070
Teaching a kid from a young age is important,
because it helps you keep your culture,
462
00:39:08,280 --> 00:39:12,068
and understand the grassroots
of where you come from.
463
00:39:14,960 --> 00:39:19,954
Through our parents, through art, through
education, we learn about the world.
464
00:39:20,160 --> 00:39:23,755
All this knowledge is absorbed
by the powerful human brain.
465
00:39:23,960 --> 00:39:30,832
I mean, in many parts of Islam, if a woman
can't reproduce, she is very badly damaged.
466
00:39:31,040 --> 00:39:35,830
Sometimes we look at Islam and think
''How bizarre,'' but it's the same in all religions.
467
00:39:36,040 --> 00:39:39,715
I'm a Jew. It's the same,
to some extent, in Judaism.
468
00:39:39,920 --> 00:39:43,390
It's the same in Christian society.
469
00:39:43,600 --> 00:39:46,956
The brain's hardest task
is how to deal with human society.
470
00:39:50,920 --> 00:39:54,879
Perhaps the ability to cope
with other people and get on in society
471
00:39:55,080 --> 00:39:59,551
has been the main force
behind the growth of the human brain.
472
00:39:59,760 --> 00:40:02,832
If you think about it,
the most complicated thing
473
00:40:03,040 --> 00:40:07,192
that an ancient human would
meet in their lives would not be food,
474
00:40:07,400 --> 00:40:12,190
nor a tool. Not a predator,
but another person.
475
00:40:13,480 --> 00:40:19,919
It's other people, not the world itself,
that's difficult to deal with.
476
00:40:20,120 --> 00:40:26,195
To work out the motives of others, to persuade,
to charm, to make friends and not enemies,
477
00:40:26,400 --> 00:40:28,960
all this takes brains.
478
00:40:29,480 --> 00:40:32,278
We can see it in action
with our closest relatives.
479
00:40:35,440 --> 00:40:39,877
Chimps are constantly vying with one another
to be leader of the troop.
480
00:40:41,320 --> 00:40:45,996
Here, a young male chimp
is attempting to usurp the older male.
481
00:40:47,200 --> 00:40:52,593
And while fights are certainly dramatic,
often more important than just brute strength
482
00:40:52,800 --> 00:40:58,397
is the ability to forge alliances
with other chimps. Brain over brawn.
483
00:41:00,560 --> 00:41:04,712
Chimps spend hours picking
through the hair of their colleagues.
484
00:41:04,920 --> 00:41:08,879
It's called grooming,
and it's the key to social climbing.
485
00:41:09,080 --> 00:41:11,719
The better chimps are
at these social niceties,
486
00:41:11,920 --> 00:41:15,879
the more likely they are
to rise through the ranks.
487
00:41:17,080 --> 00:41:19,036
Scientists have discovered
488
00:41:19,240 --> 00:41:25,475
that the more complex the social group
an animal belongs to, the bigger its brain.
489
00:41:28,200 --> 00:41:33,115
An ability to deceive,
to make allies, to win others over,
490
00:41:33,320 --> 00:41:37,233
must have been vital
in the development of the chimp mind.
491
00:41:37,440 --> 00:41:39,396
Sound familiar?
492
00:41:41,040 --> 00:41:44,999
Human societies are the most complicated
of all animal societies.
493
00:41:45,200 --> 00:41:47,919
There's continual pressure to be number one.
494
00:41:48,120 --> 00:41:52,511
And where better to look for it
but in the corridors of power?
495
00:42:03,040 --> 00:42:06,271
While the ceremony of parliamentary life
looks rather splendid,
496
00:42:06,480 --> 00:42:11,793
it's the jostling that goes on behind
the scenes that is often more important.
497
00:42:14,600 --> 00:42:18,559
Politicians huddle together
in conspiratorial whispers.
498
00:42:18,760 --> 00:42:21,194
Deals are made and broken.
499
00:42:21,400 --> 00:42:24,039
The MPs, the lords and ladies,
500
00:42:24,240 --> 00:42:28,870
are demonstrating skills that
haven't changed for millions of years.
501
00:42:29,080 --> 00:42:32,117
I should know, I work in the place.
502
00:42:32,320 --> 00:42:35,278
We're not chimps,
but it's a jungle out there.
503
00:42:36,160 --> 00:42:40,711
And you don't have to go to the
Houses of Parliament to come across politics.
504
00:42:40,920 --> 00:42:45,630
All the time our brains are dealing
with politics with a small ''p''.
505
00:42:45,840 --> 00:42:48,479
Gossip, flattery, backbiting.
506
00:42:48,680 --> 00:42:53,629
At home or in the office, it's really just
our way of getting along with people.
507
00:42:55,600 --> 00:42:57,556
0ver millions of years,
508
00:42:57,760 --> 00:43:02,914
the human brain and body have evolved
to meet ever more complicated challenges.
509
00:43:03,120 --> 00:43:08,274
We learned to manipulate tools,
we made full use of our visual sense,
510
00:43:08,480 --> 00:43:11,597
and we developed a powerful memory.
511
00:43:13,200 --> 00:43:19,150
More recently, we mastered language,
a highly efficient form of social grooming.
512
00:43:21,480 --> 00:43:25,519
We can now build up a detailed picture
of the brain we've evolved:
513
00:43:25,720 --> 00:43:29,633
the cerebellum,
responsible for automatic movements;
514
00:43:30,680 --> 00:43:33,353
the back of the brain for vision;
515
00:43:34,200 --> 00:43:37,397
the frontal cortex for memory.
516
00:43:38,240 --> 00:43:41,516
There's even
a particular site for language.
517
00:43:46,200 --> 00:43:49,556
But there's still something missing
from this map.
518
00:43:50,400 --> 00:43:56,509
It's the mysterious thing that makes
you who you are and me who I am.
519
00:43:56,800 --> 00:43:59,917
Scientists call it consciousness.
520
00:44:02,000 --> 00:44:06,198
Consciousness is the greatest
of the brain's qualities.
521
00:44:06,720 --> 00:44:09,439
It's actually very difficult to define,
522
00:44:09,640 --> 00:44:14,236
but essentially it's our ability to be aware
of our own thoughts and feelings,
523
00:44:14,440 --> 00:44:17,512
for each of us to have our own personality.
524
00:44:18,520 --> 00:44:22,798
Without consciousness,
we'd be little more than robots,
525
00:44:23,000 --> 00:44:25,958
trundling through the motions of life.
526
00:44:29,040 --> 00:44:33,113
Consciousness allows us to appreciate
the greater things in life:
527
00:44:33,320 --> 00:44:37,108
love, art, science, and religion.
528
00:44:37,960 --> 00:44:44,308
Consciousness makes our brain more than just
a collection of little grey cells and electricity.
529
00:44:44,520 --> 00:44:47,478
It's what makes us truly human.
530
00:44:49,640 --> 00:44:54,156
As a subject, consciousness is
extremely difficult to study.
531
00:44:54,360 --> 00:45:00,435
But a series of extraordinary surgical operations
have revealed some startling new facts.
532
00:45:00,640 --> 00:45:04,872
This rather sad story
began in the 1960s.
533
00:45:05,600 --> 00:45:09,832
Brain surgeons, desperate to treat
their severely epileptic patients,
534
00:45:10,040 --> 00:45:14,591
pioneered an operation
to try and control epileptic fits.
535
00:45:14,800 --> 00:45:19,237
OK, Dave, I'm going to start
to divide the corpus callosum.
536
00:45:19,800 --> 00:45:25,193
This dramatic surgery involved
slicing the brain right down the middle.
537
00:45:25,480 --> 00:45:29,314
They hoped to restrict future fits
to one side of the brain only.
538
00:45:29,520 --> 00:45:31,670
It was a radical approach.
539
00:45:31,880 --> 00:45:36,510
But the patients had such severe epilepsy
that this was their last hope.
540
00:45:38,040 --> 00:45:43,068
The operation usually worked, but it had
unfortunate side-effects in a few patients.
541
00:45:43,280 --> 00:45:46,989
Vicky is one such patient.
542
00:45:48,120 --> 00:45:53,797
Afterwards, scientists discovered
the surgery gave her two independent minds,
543
00:45:54,000 --> 00:45:57,436
each controlling one half of her body.
544
00:45:58,760 --> 00:46:02,435
It became apparent
even when Vicky got dressed.
545
00:46:02,640 --> 00:46:05,074
(VICKY) I knew what I wanted to wear,
546
00:46:05,280 --> 00:46:12,072
and I would open up my closet, and one hand
would get ready to take it out,
547
00:46:12,280 --> 00:46:16,717
but my other hand would just take control.
548
00:46:16,920 --> 00:46:20,196
A couple of times
I had a pair of shorts on,
549
00:46:20,320 --> 00:46:22,754
and I found myself
putting another pair on,
550
00:46:22,960 --> 00:46:27,511
on top of the pair I had on,
which I knew was wrong.
551
00:46:27,640 --> 00:46:29,949
I wouldn't go out the house that way.
552
00:46:30,160 --> 00:46:34,153
Each of her hands
is obeying one half of her brain.
553
00:46:34,360 --> 00:46:37,796
It's as if her consciousness
has been split in half,
554
00:46:38,000 --> 00:46:40,719
two minds in her one brain.
555
00:46:41,760 --> 00:46:43,751
This is extraordinary.
556
00:46:43,960 --> 00:46:47,555
If our consciousness is located
in just one side of the brain,
557
00:46:47,760 --> 00:46:51,833
it can never be separated into two,
in the way that it is for Vicky.
558
00:46:52,040 --> 00:46:56,989
So I cannot point at one part of my brain
and say that is where ''I'' reside.
559
00:46:57,200 --> 00:47:01,637
Put simply, consciousness
is part of the whole brain.
560
00:47:03,680 --> 00:47:09,437
Perhaps, in the same mysterious way that
the termites work together in the colony,
561
00:47:09,640 --> 00:47:14,668
so the many elements which make up
our consciousness work in harmony.
562
00:47:15,720 --> 00:47:18,712
It looks like
the higher abilities of the brain -
563
00:47:18,920 --> 00:47:22,356
memory, perception and emotions -
564
00:47:22,560 --> 00:47:26,394
are seamlessly bound
into one wonderful whole.
565
00:47:26,840 --> 00:47:29,877
But is there more to it than this?
566
00:47:33,280 --> 00:47:36,955
As a scientist, I believe
that science is the most powerful way
567
00:47:37,160 --> 00:47:39,833
of finding out about the human body.
568
00:47:40,040 --> 00:47:45,478
Even so, there will always be some questions
that it just cannot answer.
569
00:47:50,000 --> 00:47:54,073
As a religious person, I believe
that much of what makes us human
570
00:47:54,280 --> 00:47:58,319
will forever remain mysterious,
even spiritual.
571
00:47:58,840 --> 00:48:00,796
I call it the soul.