...about Brains James May's Things You Need to Know

Inside each and every one of us is the most marvellous

and complicated object in the known universe - the human brain.

This great big blancmange of hardware is responsible for

everything from our personality to our potential,

but have you ever used to your brain to wonder

why don't men ask for directions?

Why are zombies scary?

And can I trust my brain?

Join me as we venture deep inside the landscape of your mind

to discover the things you need to know about the human brain.

Starting with...

Well, according to Aristotle, you don't really use it at all.

He thought it was just a radiator for keeping us cool.

But modern science now knows that even though it looks like a wobbly walnut,

you use all of your brain all of the time.

In fact, even though it's only 2% of your body mass,

this machine devours nearly a quarter of your energy.

To only use 10% of its capability

would be like buying a Sherman tank for the school run.

This idea that we only use 10% has been perpetuated

by some psychics and self-help gurus for many years.

They claim that the untapped 90% is where

we will find our superhuman powers.

However...

..it simply isn't true.

It would be madness if we only used 10% of our brains.

Our brains have evolved for some reason to be the size that they are.

Our brains are huge and they're extremely complex.

And in fact, it's dangerous that they're the size that they are.

We're a species where childbirth can be very, very dangerous

and that is because of the size of the baby's head.

I did a first aid course about 15 years ago

and it was taught on the course that head injuries aren't serious

because we only use 10% of our brains.

And I was thinking, "What?!" I mean, this is incredible.

This was being said by somebody who was standing up and talking,

knowing his name, breathing,

all of that being made possible by his brain working extremely hard.

Right now, your brain is powering 100 billion neurons.

There's over 100,000 miles of this electric spaghetti at work

in your brain, enough to go around the world four times.

Even the simple act of drinking tea

creates a lightning storm of activity.

But first, you need to know what tea is.

So your hippocampus calls up old memories of drinking tea.

Then your visual cortex cleverly picks out the cup from the saucer,

before your motor cortex lifts the cup to your mouth.

Mmm!

And while these bits of your brain are enjoying a tea break,

the rest of your brain is hard at work supporting these neurons.

We tend to think that the brain is made up of neurons,

which are the brain cells that do all the work in your brain.

But actually the vast majority of cells in your brain are glial cells

and they are there to support the neurones.

It's like the neurones are thoroughbreds

and they need a whole team of people to look after them.

So, there's an underlying army of cells that provide insulation,

food and protection, and sweep up dead neurons.

All in, you have about one trillion brain cells.

In fact, there are more cells in your head,

than there are stars in the entire galaxy.

So, we're already using the entire brain,

but what if we fancy a bit of an upgrade?

How can we get more out of what we've got?

How can I boost my brain?

You can train your body, but is there a workout for your brain?

Before you invest in the latest

brain-training games by Dr Do-Very-Little,

you might want to consider this recent research

from the University of Cambridge.

They took eight scientists, 12 brain-training games

and over 11,000 volunteers through a six-week mental workout,

and found no improvement to intelligence whatsoever.

Another myth is the so-called Mozart effect.

This is the idea that by listening to the musical genius you will

somehow boost your own brilliance,

and you do, but only by a very tiny amount

and it only lasts for about 15 minutes.

So you'd probably get the same effect by having a nice cup of tea.

It's been shown that this can work with all sorts of music,

it hasn't got to be Mozart.

Basically, you can boost your brainpower with certain sorts of tasks

for about 15 minutes with the U2 effect, the Blur effect, whatever you like.

You can do it with music cos music just basically energises you a bit.

There's nothing special about Mozart.

But there is one way to get maximum brain gain.

Playing any musical instrument,

even the drums.

You see, your brain is a bit like plasticine.

It's shaped and moulded by the things you do.

Musicians have more connections between the two sides.

They've got bigger cerebellums and up to 130% more grey matter.

And that's because intense concentration and co-ordination

physically improves the brain.

Learning to play a musical instrument basically involves

activity throughout the entire brain,

getting all different brain areas talking to each other.

Playing music can change your brain because there's this neuroplasticity,

we form new brain connections when you do something like, say, learn to play piano.

It's essentially the perfect work-out for the brain.

But before you dust off that saxophone, there's something you should know.

It takes about 10,000 hours to become an expert in something.

And your plasticine brain starts to stiffen as you get older.

But there is another way to boost your brain,

and you don't have to start young.

London cabbies are required to learn 25,000 streets

within a six-mile radius of Charing Cross.

Some scientists got under their bonnets with a brain scanner,

and they found their memory centre was actually bigger.

The hippocampus had grown to accommodate all that extra knowledge.

But they still have trouble working out the correct change.

So, those London cabbies have a natural advantage when it comes to navigation.

But what about the rest of us? How do we get from A to B?

And more importantly...

Navigation doesn't come easily to human brains,

or indeed jellyfish, who haven't got any.

No, nature's great navigator is the Arctic Tern.

They clock up an incredible 44,000 air miles every year.

Their tiny brains contain biomagnetite,

which can sense the earth's magnetic field.

A bit like having a compass in your own head.

Humans don't have that luxury.

But we're not all slaves to sat nav just yet.

Some trends suggest that men and women have developed different ways of getting about

and it might be down to the way we use our brains.

Now, if you've ever been in a car with a member of the opposite sex,

I'm sure you'll agree we have

very different opinions about which way to go.

So, you're off on a trip, in a race to the airport.

It's thought that women tend to use each brain hemisphere equally,

making them better at language.

They like to navigate using landmarks that can be described.

Go past the big clock and turn left at the shoe shop.

However, research suggests that men tend to use their right brains more.

It's slightly bigger than the left

and isn't really interested in talking,

preferring instead to create a 3D model of the surroundings.

Men tend to be much better than women on visuospatial

and navigation tasks, such as rotating 3D objects in your head,

wayfinding on maze tasks and also other mental rotation tasks.

Men think about places as points on a compass.

They just want to head south.

So, who's right?

The female method would be more efficient.

Using landmarks, you might get to your destination quicker,

and with fewer wrong turns.

That is until the sun goes down.

Unable to see the landmarks, you've had it,

although there is some doubt about this theory.

It's pretty controversial.

You can see these differences, but they tend to be trends

and sometimes we read more into these trends,

maybe because we want there to be interesting differences.

If you get a load of people to do some visuospatial tasks,

then 75% of the people who do really, really well on them will be male.

But that doesn't mean that there aren't some women who are really, really good at it, as well.

So, why don't men ask for directions?

Because we're not lost.

Even when we are.

Hiya!

We humans really are clever, aren't we?

We're able to represent three-dimensional space in our mind's eye,

manipulate it and then use it to travel over really long distances,

which sort of leads to an interesting question...

Your brain will do practically anything to keep your body alive.

However, for a lot of life's problems,

it's only got one answer.

Food poisoning - vomit.

You're pregnant - vomit.

Even a bumpy road - you guessed it, puke city.

Vomiting is your body's answer to quite a lot of problems.

Bangs on the head, ingested poisons, vomiting is the answer.

It's your body trying to get rid of things it thinks could be causing the problem,

things that might be poisoning you.

The trouble is your brain is sometimes wrong, and here's why.

Buried deep inside your inner ear, you've got a motion detector.

It's called the vestibular system and it's basically

three fluid-filled chambers full of microscopic hairs.

When you move, the fluid sloshes about.

It bends the hairs to let your brain know which way you're going.

So, as you bounce along in the back of a car,

the fluid in your inner ear is splashing about,

but your eyes tell a different story.

Seeing the inside of a car,

they think your body is completely stationary.

Your brain can't agree on what you feel and what you see,

so it jumps to the only logical conclusion - you've been poisoned.

Your brain heroically steps in to save the day.

It tells your stomach to contract, forcing its contents back out.

Try explaining that to the owner of the car.

Something that really seems to help with travel sickness

is to be able to look at some fixed point like the horizon

or something far in front of you.

This seems to be why drivers don't get sick,

because that's what they're doing when they drive.

It's not just car travel that affects your vestibular system.

A similar thing happens when you drink too much.

Alcohol is a bit of a sly one.

Its tiny molecules sneak into your inner ear.

It's much lighter than water, thinning the fluid,

causing it to become massively over-sensitive.

The result is the dreaded spin,

and more vomit.

That's the annoying thing about alcohol - once you've had a few,

you're too drunk to remember that you've already had enough.

But what if your memory's already a bit random even without the booze?

Or to put it another way...

So, you're at the office party and you've just met your dream girl.

But there's a problem - you've already forgotten her name,

and everyone else's.

Don't worry, you're not losing your marbles,

just your chance of a date.

When you meet someone for the first time, there is so much activity

going on in the brain to do with governing that social interaction.

It's all about "What am I going to say next?

"What are they going to think of me?"

The last thing you're thinking about is the person's name,

so of course you forget it.

Making memories is tricky.

Your neurons have to forge new connections.

If you remembered everything you heard,

you'd soon run out of brain space.

So your mind deliberately makes it hard.

First, you have to get through your working memory,

which is constantly being rewritten

because it can only hold about seven things.

That's why it's hard to remember anything longer than a phone number.

But, if important,

it gets stored in your long-term memory by your hippocampus.

Usually, though, there's no logic to names,

which makes them hard to keep hold of.

Names can be difficult because they can be so arbitrary,

because there's not necessarily meaning to help you.

So here's a John. Well, there's not necessarily anything Johnish about John.

There could be lots of Johns,

they won't necessarily have anything in common with each other.

So all you've got to go on is to remember the link itself.

There's nothing else to help you.

Now, if this new girl's name was King Kong,

and she looked like a massive gorilla,

then she'd be almost impossible to forget.

Luckily, she's not.

But you get the idea.

So to help, you need hold on tight to new names by repeating them to yourself, over and over.

But remembering Anne is only half the battle.

You then you need to find her name again,

and your brain is like a messy bedroom,

with memories scattered all over the place.

However, there is a trick.

You can create a "memory palace".

To do this, you link new names with the memories you've already got,

like objects around your home.

So, to remember Anne, give her a spray tan,

and mentally put her in the back of your van.

By creating this rich visual imagery,

your neurons make more connections

and you might stand a chance of getting that date after all.

As well as being good for remembering names and places,

your brain has a dark side,

because it controls one of our most automatic responses...

..fear.

So, why are zombies scary?

If you didn't fear things, you wouldn't live for very long.

You'd forever be walking into oncoming traffic

or picking fights with tigers.

And evolution prefers the activities that keep you alive

by staying well away from the brain-hungry reanimated undead.

But how does fear work?

If there's a sudden bang, even newborn babies will jump,

and this is the startle reflex that they're born with.

Fear is something that's so crucial to all of us.

So, if you hear an almighty crash,

you'll jump.

The sound goes straight to your amygdala,

the emotional part of your brain.

It's a bit trigger-happy,

and initiates your fear response without really knowing the score.

This sends your brain into overdrive,

releasing up to 30 different hormones

that cause a physiological response,

so your pupils dilate to let in more light.

Your digestions shuts down and saliva production grinds to a halt.

Your mouth goes dry.

Rapid breathing sends more oxygen into your bloodstream.

Your heart beats faster and veins constrict,

forcing blood and more energy to your arms and legs.

And all this happens in just one fifth of a second,

before you're even consciously aware of what's going on.

Meanwhile, as the shuffling silhouette comes into focus,

the pictures get beamed to your visual cortex.

Your hippocampus flicks through your memory bank

and finds all those old horror films.

You correctly recognise the unidentified intruder as "zombie".

The really scary thing about zombies

is that they're a little bit too like us.

But we know deep down that they're fundamentally different.

They're revolting, but they are very human at the same time.

They're not really there.

There's some absence of humanity behind the eyes.

There's something missing.

So, your amygdala was right.

Finally, you're ready to fight for your life or to run like hell.

But there's no rush.

All this happened in just a fifth of a second,

and zombies are slow.

Fortune may favour the brave,

but evolution definitely favours those who keep out of trouble.

And to help you with this,

your brain has another trick up its sleeve - pain.

But have you ever wondered...

Sphenopalatine ganglioneuralgia to give its scientific name,

characterised by a sharp pain to the forehead

while having an ice cream or very cold drink.

But first things first. What is pain?

Your average Egyptian thought

it was caused by spirits getting in through his nostrils.

So he sported a nose ring, not for fashion,

but to ward off the evil apparitions.

Science didn't catch up until 1906,

when the first pain receptor was discovered.

And it turns out there's an army of up to 80,000 of them beneath your skin.

When disturbed, they send word to your cortex,

which registers the source of the attack.

It's your body's way of telling your brain that you're in danger.

Believe it or not, pain is actually a good thing

because it alerts you to potential sources of harm.

So, what's so dangerous about tucking into a rum and fudge sundae?

Well, when the cold stuff hits the roof of your mouth,

the tiny blood vessels contract so rapidly,

a small pain message is sent to your brain.

But the message intersects with an eight-lane mega-highway,

running from your forehead.

By the time it's arrived at your cortex,

your brain thinks it's come from all over your head,

and that's where you feel the crippling pain.

Pain is a really interesting sensation

because it's highly subjective.

So, you could be either picking up a kettle and it's really, really hot.

If it's empty you'll drop it.

If you're picking up a kettle that's full of boiling water,

and it's really, really hot,

you'll place it back down rather than drop it,

because hurling boiling water all over yourself would be worse.

So, how best to deal with pain?

Scientists think swearing might be the answer.

When given permission to shout a four-letter word of your choice,

you can withstand pain for up twice as long.

But the people around you

might prefer it if you just took a couple of aspirin instead.

You don't need to go far to find a painkiller.

Inside your brain is a private pharmacy making its own.

They're called endorphins.

But there's one human activity that generates even more brain chemicals than this -

love.

Plato thought he knew a thing or two about love.

He reckoned that men and women were originally joined together.

A super-being with four arms and two heads,

we tried to overthrow the gods.

But they didn't take kindly to that sort of thing,

so Zeus split us in two

and we've been trying to get back together ever since.

A nice story perhaps, but the truth is far more powerful.

When it comes to love,

we are completely at the mercy of our brain's biochemistry.

Wait till you get a load of these guys.

Cupid's arrow comes dipped in a heady cocktail of brain chemicals.

They are literally addictive, like cocaine,

and they work in three different stages throughout the course of your life.

Amongst the first is dopamine and testosterone.

They give you the racing heart, sleeplessness,

and the butterflies in your stomach when you meet someone you fancy.

But that's just the warm-up act, lust.

If you look at the brain chemically in the early stages of love,

the absolute head-over-heels area of it,

it's interesting that the levels of serotonin,

which makes people feel happy, are actually low,

which is surprising and is what you would see in somebody

with an obsessive compulsive disorder.

The second stage of love pushes you head over heels into romantic love,

and enter the real star of the love parade - oxytocin.

This is released when you have sex,

and creates that special bond.

It's the superglue that holds you together.

But around three years after your first date,

dopamine production slows down and the romantic gestures die off.

The third and final stage of your relationship

depends on endorphins to keep you together.

These are your natural painkillers

and give you that sense of well-being and security,

potentially for the rest of your life.

Actually, the frenzied brain activity we see in the lovestruck

has similarities with mental illness.

Your brain is driving you mad,

which leads me to ask...

Do you see strange things in the corner of your eye,

or mistake one thing for another?

Do not adjust your brain!

There is a problem with reality.

There's just too much information out there,

and your brain can't take it all in.

If it did, your head would be so big,

your neck couldn't support your expanding cranium.

So, to make sense of the world, your brain takes a few shortcuts,

and sometimes it gets it wrong.

For starters, only 1% of what you see is actually in focus.

Everything else is a blur.

Hold your hand out like this.

Look at the end of your thumb.

That little bit there represents everything that you can see clearly.

Everything else is just a blur.

You can't necessarily trust your brain

because although the things that you can see and hear can feel real,

actually the majority of that is your brain filling in all kinds of details all the time,

because you don't see that much and you don't hear that much.

In fact, your eyes are constantly on the move,

so your brain takes snapshots, three per second,

to build a composite picture, piece by piece.

It can't capture everything

so it fills the blanks with memories and guesswork.

Test it out.

Take a look at this flashing image.

Your brain is only taking in the important bits of this scene,

so things get missed.

Did you notice the change?

It's called "change blindness",

and it proves that you can't take in everything all of the time.

So, if your eyes are constantly on the move,

how come the world isn't one big blur?

Well, your brain cleverly turns your eyes off every time they move,

leaving you in the dark for 200 milliseconds at a time,

which adds up.

For about two hours a day, you are blind.

One of the reasons we know so much about things such as

time perception, and memory and fear is because we've been able to study

those unfortunate people who,

for one reason or another, have bits of their brains missing,

and that brings me to my final question...

There's a very simple way to figure out how important

certain brain bits are.

Take a piece out and see what happens.

You'll quickly discover which sections make you happy...

..or remember where you live,

and the bits that know the difference between your dad

and a daisy.

But removing perfectly good brain parts to see what happens isn't cool.

However, that sometimes happened by accident.

Nowadays, we use brain scanners to understand how the human brain works,

but up until 20 years ago,

the only real way we could find out more about what the human brain did

was by working with patients who had some sort of damage to their brain,

nature's accidents if you like.

In 1953, one of those accidents

left a man unable to make any new memories.

But, on the upside, this allowed us

to identify the hippocampus as the bookkeeper to our memory banks.

But perhaps the strangest story is that of Phineas Gage.

In 1848, in the USA,

demolition man Phineas was blasting his way through solid rock,

making way for a new railroad,

ramming gunpowder into a hole with an iron bar.

Health and safety hadn't really taken off yet.

Unsurprisingly, the gunpowder went off,

sending the bar straight through his face.

It landed around 100 feet away, having removed his frontal lobe

and his inhibitions.

Talk about a bad day at work.

According to the records, he sprang back to his feet and vomited,

which caused even more of his brain to fall out onto the ground.

Amazingly, he survived, but with dramatic consequences.

He went from being a nice guy to short-tempered and rude.

He even lost his job.

If it wasn't for him,

we wouldn't have known what this prefrontal cortex does.

The man goes from being incredibly disciplined,

reliable individual, to totally socially inept,

having a conversation, starting to urinate in front of people.

He was absolutely unable to control his impulsive behavior.

So, Phineas' personality switch proved, for the first time ever,

that your grey matter defines who you are.

In spite of all the wondrous and surprising things

the human brain can do,

I think it's fair to say that

most of us wander around blissfully unaware that we even have one.

You don't need to know you have a brain.

It's just there.

But if you stop and think about it for a second,

you realise that it's your brain that makes you truly human.

It makes you you

and not me,

and you should be happy about that

because I appear to have had my head cut off.

Goodbye.

Subtitles by Red Bee Media Ltd