All language subtitles for brain2

Why do we do the things we do?

What really makes us tick?

How do our minds work?

For centuries, these questions were largely left

to philosophers and theologians.

Around 100 years ago, a new science

began to shine a bright light on the inner workings of the mind.

It was called experimental psychology.

But doing scientific experiments

posed some terrible ethical and moral dilemmas.

Do you think the research was justified? Would you have stopped him if you could?

In this series, I will explore how psychologists have probed inside

our minds, by way of experiments, which sometimes were frankly barbaric.

- The experiment requires that we continue...
- But he might be dead in there.

Ever since I was a medical student, I have been fascinated by psychology,

by its brutal history and by how far some researchers have been prepared

to go in the search for answers.

This time, I'm exploring how scientists have struggled

to understand that seemingly irrational

and yet deeply complex part of our minds, our emotions.

Oh, dear.

I'm playing my own small part in this quest.

You're going to be experiencing some...

moderate pain.

How are you going to create the pain?

Emotions are a huge part of our lives,

but where do they come from?

Can they be controlled?

What are they there for?

The answers they came up with were rich, complex

and also profoundly uncomfortable.

They have made me re-evaluate the role of emotions in my own life.

It's a load-bearing belt, it's got to be done up securely, because your life may depend on it.

Safety helmet.

'A problem faced by anyone who wants to study emotions is how to reproduce them.

'Some emotions are harder to generate that others.

'The one we're hoping to generate today is fear.'

A pair of gloves - if you do get stuck, it'll stop you ripping your fingernails off.

Do you ever get people who freak out when they're down there?

- Frequently.
- Right.

'I have never done this, because I have always been aware that

'when I go into small, dark spaces and I even think about doing so,

'I become really, really uncomfortable.

'I think I probably have a mild degree of claustrophobia,'

but I've never challenged it, and that's kind of why I want to do it now,

I want to see what it's going to actually be like.

There's your cave.

God, wow! That's small, isn't it?

I was imagining something large.

Ha...! OK.

- First of all, there's just...
- Ooh, that's nasty.

'Now, one of the questions that scientists have grappled with

'down the years is the relationship between reason and emotion.

'I see myself as a rational creature

'and yet I can be overwhelmed by my feelings,

'as I think I'm about to find out.'

There's a part of which is absolutely convinced I'm a rational creature -

whatever emotion is engendered by the cave,

I can control it.

But I don't know until I do it.

- Ooh, cor blimey, it's a long way down.
- Going down.

Aha! Yep, I'm fine.

- Lay right down.
- Yep.

And get your legs in first, insert your legs.

Oh, jeez.

- Twist your hips.
- Oh, God, this is horrible.

- Yeah, just relax.
- I realise...

that actually it's not

the dark and the small - it's the fear of getting stuck.

HE SIGHS

Right... Do people panic at this point?

Well, the secret is, your mind and your body both have to be relaxed.

Ah, Jesus.

Ah, I can feel panic.

Calm down, objectify it -

out of a score of ten, how bad is it?

Probably about nine at the moment.

And could I...? No. It's really, really horrible.

Ssh, ssh, ssh. Just stop, relax.

- You come to what they call the grip self moment.
- Right.

When you've got to grip self, but you absolutely have to take control.

All right?

Just don't think about it, just keep breathing. Jesus Christ!

My arm has got stuck,

- I have my left arm underneath me.
- Just adjust yourself a little bit - don't panic.

Do I put my hands in front of me or what?

- Yeah, whatever's most comfortable. Take your time.
- But I'm not going to get stuck?
- No.

Oh, jeez, that was horrible. Oh, God.

Ah, it's unbelievable, man.

My arm was trapped underneath me. I really thought...

..I was going to be stuck.

Now, that was just...

absolutely bloody awful. Oh, God!

'It is clearly possible to produce a powerful emotion,

'but to really understand them is a very different challenge.'

HE SIGHS DEEPLY

In the early days, psychology largely relied

on speculative, unproven theories.

Then, at the start of the 20th century, psychologists

finally began to apply the scientific method to their discipline.

One of the first to do so was young, ambitious JB Watson.

The place, John Hopkins University, Baltimore.

The question he was asking was deceptively simple -

where do emotions come from?

Are we born with them? Do we learn them?

He already had a pet theory.

Now, Watson believed that we're all born with three basic emotions -

love, fear and rage - and that by mixing those together,

you get all the emotional range that we enjoy as adults.

But where he broke with other people was,

he believed that every experience you had, all the emotions

you felt later in life, were the product of some childhood experience,

that what you experienced as a child would determine who you fell in love with,

what you hated and what you got angry with.

Watson's own childhood was not happy.

His father was drunk and often absent.

Perhaps because of this, Watson was immensely driven

and, in 1920, began planning something that would make him famous.

Now, Watson was about to do what will turn out to be

one of the most controversial and also important experiments

of the early 20th century.

He must have been...

nervous, and so must the people taking part in this experiment.

Watson wanted to study fear,

and to do that, he was going to have

to find someone and utterly terrify them.

These are his props -

a clown mask...

..some newspaper and matches,

a steel bar and a hammer.

So, who was he going to terrify?

Watson chose, as his subject, a nine-month-old infant

he called Albert.

Albert's mother was a wet nurse at the local hospital, who probably

needed the dollar a day usually paid to experimental subjects.

A corridor conveniently linked Albert's hospital home

to Watson's lab.

Now, Watson must have hoped this was going to be something memorable,

because he filmed it, which was something extremely unusual for the time.

Watson wanted to prove that though babies are born

with an instinctive capacity for fear,

initially, there is not much they're actually frightened of.

They learn what to fear.

Watson started by testing

Albert's reaction to a series of potentially dangerous things.

This is a burning pile of paper.

Will Little Albert be frightened of it?

And the answer is no -

Little Albert was trying to reach out and grab the flames.

He's obviously not frightened. He doesn't know that fire burns,

he hasn't had that experience.

Then animals were pushed in front of him.

Albert was curious, but showed no signs of actually being frightened.

But Watson knew

he COULD terrify Albert with loud, unexpected noises.

So far what he'd done was pretty innocuous. The next bit wasn't.

Imagine this doll is Little Albert,

and this bit of cotton wool is a mouse. Well, the mouse comes

to play with Little Albert, and they have some fun together.

And then, on one occasion, the experimenter comes up behind Little Albert

and, completely unexpectedly,

terrifies the kid by banging a loud noise.

They do this again and again.

What they wanted to see was, had they induced fear in Little Albert,

towards the rat that he had previously really liked?

Watson was deliberately trying to condition Albert to associate

all these objects with fear.

The test would be...would Albert be scared of them without needing to startle him with the bang?

So Watson and his colleagues pushed the objects in front of Albert once more.

Ooh.

Albert is obviously very uncomfortable.

He's trying to run away, and they're almost torturing him.

You can see it, he's crying.

He's screaming...

he doesn't want anything to do with it. He's trying to run away,

and they're just bringing it back to him - it really is quite disturbing.

Watson noted that when the rat alone was presented,

Little Albert puckered his face and withdrew his body sharply to the left.

Oh, and this is nasty - they've got the mask out now.

Oh, this is horrid. The experimenter's got the mask on

and he's deliberately setting out to try and terrify the child.

Watson had proved that you can learn fear of almost anything.

Extreme fear.

You can make a person phobic.

So I've read about the case of Little Albert before,

but I've never seen the footage, and it's really quite upsetting,

particularly when you think of him as an innocent young child of eight months,

having these horrible things done to you by adults.

There's a sort of coldness about this experiment,

which is really, really uncomfortable.

Watson's work was a landmark.

By frightening Little Albert, he had shown that, whilst our capacity

for emotions is innate, how they develop depends on what we experience.

The experiment ended after five months,

when his mother got a new job and moved away.

She took with her a child filled with fears.

For nearly a century, one of psychology's most iconic figures vanished.

Recently, however, a relentless researcher

did manage to track him down.

But there was to be no happy ending.

Little Albert died from an infectious disease

when he was a child.

'Even the name Watson gave him isn't really his.

'His mother called him Douglas.'

He is this sort of big event in the history of psychology

and yet he's also utterly anonymous...

..which is quite sort of sad in its own way.

And also because his mother...

took his secrets with her to the grave, we have no idea what happened

to Little Albert after he left.

We have no idea whether the fear that was conditioned into him

by Watson persisted.

All we know

is he lies here, he died aged six, probably of encephalitis,

and that...

his mother loved him.

Fast-forward to the 21st century, and it's clear that the influence

of the Little Albert experiment has been profound.

Watson had shown that we learn fear by association.

It wasn't long before others began using the same technique

to reverse the effect,

to use the power of association to unlearn fear.

His legacy is behavioural therapy,

one of the most effective treatments today for helping people with phobias.

Ten years ago, I made a TV series about phobias.

I particularly remember Daniel.

He was so frightened of dogs, he could barely walk down the road.

Oh, my God! Mum! Mum!

It's all right, it's OK.

It's OK, it's OK.

But, look, he's coming up that way - please can we cross over?

It's all right, it's all right.

OK? Just keep walking - it's all right.

- No, I don't...
- OK?

'Daniel had a few sessions with a behavioural psychologist,

'which seemed to help.

'But has it lasted?'

'Daniel is now 20, and I've come to meet him with my own dog, Guy.'

- Hello, there!
- Hiya.

Hi, there. Michael.

- Hiya. Daniel.
- Hello, very nice to see you.
- Hi, nice to meet you.

You've changed a lot since I last saw you! Are you OK with Guy?

Ah, yeah, fine. Yeah, it's no problem.

Very good, very good, I'm impressed.

Do you mind, I'm just going to bring Guy next to you?

I just want to see, are you happy patting Guy?

I don't mind.

- There you go.
- See that's not... that's fine NOW.
- Yep.

- But years ago, that would never have happened.
- Yep.

It's a lot, it's a lot easier to rationalise and weigh up now.

Before it would have just been anything to get away from the situation.

'Behavioural therapy does not claim to cure but to make fear manageable.

'I wanted to see if Daniel would be able to handle

'a bigger challenge than Guy.'

- So what do you think about the one over there?
- It's fine when it's over there.

Would you be happy going over there and having a chat,

or me bringing her back over here?

I'd rather you didn't, to be honest, but I could probably walk past.

Shall we go and see how close we can get before you feel uncomfortable?

- Yeah, I think I can walk past, yeah.
- Let's go and see. Come on, Guy!

'Behavioural therapy involves gradually increasing the exposure

'to whatever it is you fear.'

So, out of ten at the moment?

I'm anxious.

Six or seven.

- So it's going up?
- It is, yeah.

OK, tell me kind of when you want to stop, then.

'If Daniel runs away now, his fear of dogs will be reinforced.'

- See, this is OK. I mean, I wouldn't want to get much closer, to be honest.
- OK.

'But staying while his brain shrieks, "Run!" is hard to do.'

You all right?

I am, but...

- Is your pulse running...?
- Yeah, probably a bit faster.

Mind if I just have a go at your pulse?

- About 125, 130.
- Which is...?

- Which is about, I'd imagine, twice what it normally is.
- Really?

Yes. So I think you're feeling a trifle anxious.

'If Daniel can tough it out, his anxiety will fade,

'and he will start to break the association between dogs and fear.'

You're now running at about 90.

- Which is a little bit above.
- It's a little bit, but it's come down...

- In the last minute or so, it's come down from about 120 to 90.
- Yep.

'I don't think Daniel will ever love dogs, but nor will he allow

'a fear of them to rule his life.'

Well done. Really, really impressive.

By the 1950s, psychologists felt they had a grasp of how fears develop

and how they can be controlled.

But what about a more positive emotion?

What about love?

I don't actually bring out these photographs very often,

and they are incredibly evocative.

This is me and Claire on our honeymoon,

sort of looking at each other.

And it brings a very sort of warm glow.

And then these are pictures of...

me and the kids growing up.

That must be Jack, probably about two years old,

very sweet.

So what is love and what is it for?

In the 1950s, the answers were unclear.

There were just a series of assumptions going back half a century.

They knew babies are born with basic instincts,

and the most basic is to eat.

The dominant idea was that affection and love develop

towards whoever is feeding us.

Love is just there to reinforce this bond with the feeder.

But no-one had put this idea to the test.

People didn't understand how you could study it, let alone...

be willing to study it.

It was something which was seen as almost unstudyable,

certainly in the laboratory,

and that anyone who attempted to do so was probably a fool.

One man who thought that, as far as love was concerned,

psychology had been a complete failure, was Harry Harlow.

In 1958, Harlow set about challenging this by doing a strange

and compelling experiment.

What Harlow wanted to do was explore love.

Now, how do you actually do something like that?

Well, he had an idea -

it's rather extraordinary and certainly bizarre.

What Harlow needed for his experiments were baby monkeys

and very basic building materials.

What Harlow wanted to investigate was the nature

of love between a mother and a child.

What is it a child really wants?

This was going to help him answer that.

'There were lots of theories about love and the relationship

'between a mother and child but virtually no experimental data.'

Ah!

HE LAUGHS Right.

So what Harlow was attempting to do

was build...

something which was a sort of surrogate mummy monkey.

'The baby monkeys were to be separated from their mothers

'and then offered DIY alternatives, built out of bits of scrap.'

Now, the interesting thing is that Harlow was doing this fascia,

not really for the benefit

of the baby monkeys,

but because he wanted parents to identify with this...

funny little creature he was creating.

Harlow wanted this to be about people, not just monkeys.

And finally what I need is...

yes, one of these - basically, a source of food.

A mother,

pared down to her absolutely bare essentials - basically one...

breast, if you like, one nipple to feed, one face to smile

and a frame to sort of cuddle onto.

Right, so that was monkey number one.

Now he needed to build monkey number two.

'The purpose of the experiment was to offer baby monkeys

'two types of surrogate mother and see which they preferred.

'One would offer food, the other something less obvious.'

At this point, these two monkeys look really quite similar,

but I'm just going to add Harlow's final touch.

'To the second surrogate mother, Harlow added just one thing -

'a soft cover.'

And the question was, if he took a baby monkey and he introduced

the baby monkey to these two parents, who would it prefer to go to?

Conventional theory said that you get love, or love is generated,

by fulfilling something of your basic wants.

So, in theory, and that's certainly what everyone believed at the time,

the baby monkeys would become attached and bonded to this monkey,

because this monkey is providing milk, it is satisfying a need,

satisfying hunger.

So what happened?

Harry Harlow is no longer alive,

but I'm going to meet someone who worked very closely with him.

- Hello?
- Hi, come on in, come on in!

Hello, thank you.

Wooh! Well, hello.

- What happened?
- Hi.

Ah, as I heard somebody once say,

I put my foot down, and it broke itself.

'Len Rosenbaum is an eminent psychologist.'

We're going, I think, into this front room.

Fabulous.

Did people really think it was enough just to feed and to clothe?

I think, at that time, people thought those primary drives,

the survival needs,

were enough to carry infants - monkeys or others -

from immaturity to maturity.

No-one, at that point, thought that something like what Harlow

called the affectional drives, these bonding tendencies, were in a sense

as primary as the need for food, the need for water and so on.

Thus the experiment.

OK.

'The baby monkeys were offered their choice.

'Harlow recorded exactly what happened.'

Watch!

He's going to the wire mother.

The baby readily fed from the wire object, but rather rapidly left the wire mother

and then spent its time clinging, 15, 16, 18 hours a day...

Each of these had a clock attached, so you could time

how much time was the baby spending clinging to one or the other.

The attachment was developed towards the cloth surrogate,

regardless of the source of the food.

So it was not food in the end - it was touch which was important to the baby monkey?

That was what these experiments purported to show, yes.

'Having shown that the babies preferred the cloth mother,

'they wanted to investigate what this really meant.

'What was the baby feeling for the cloth mother?'

The whole idea was to ask the question...

well, fine, the kid prefers the cloth, even though the wire feeds.

But what... how far does that preference go?

What's its ultimate meaning?

'They used fear to test the strength of the baby's bond.

'Faced with a scary object, which mother would they run to?'

And now Dr Harlow is, ah, moving to the front

of the cage one of these very scary objects.

- He raises the door, scares it...
- The monkey goes, "Ah!"
- ..and the baby rushes away.

- Immediate, isn't it?
- Where does it rush?

Not to the feeder but to the cloth surrogate.

So Mummy really is providing everything they need - protection...?

- Exactly. The thing is to be in her presence.
- So this is love?

- This is what Harlow would call love in a way?
- This is what Harlow would call love.

And I'm inclined to agree.

'Next, Len and Harlow tested

'the strength of a baby's love for its mother.

'Just how unpleasant would the cloth mother have to be

'before the baby monkey ceased to want it?'

What I did was to try and provide a mother, a cloth mother,

that the infant would become attached to

but which would provide a kind of rejection,

which meant that what I did was used compressed air

to blow a blast of air at the kid, at some periodic interval.

The baby then steps off, gets away, and then what happens?

That's the question. Does the kid say, "Well, I don't want any more of this.

"I don't... This is not for me"?

No, just the opposite. The theory is this...what if,

every time you're emotionally upset, you do the thing that you always do

when you're emotionally upset, you rush to your mother?

But now when you're on your mother, I make you even more emotionally upset, what do you do?

Well, you want to be on your mother even more!

There's a linkage between the infant's emotional state

and its desire to be on the mother, even if the mother is the source

of that emotional distress.

I mean, it kind of makes sense,

but when I was working with delinquent children, it always...

I was young, I was sort of 20, but I was surprised

by the extent to which these children, who frankly

had abusive mothers... It didn't matter HOW badly their mothers had

behaved to them - they would get really, really angry if you ever,

EVER accused their mothers of being in any way inadequate.

Absolutely the case.

And it was exactly those kinds of observations, at the human level,

that was a natural bridge for us to study.

These experiments threw a powerful light on a baby's need

for its parents' touch.

But Harlow was about to go further.

He now asked...what would happen if we had no love, no contact -

nobody at all?

Would this lead to depression and despair?

And if so, would this help our understanding

of this terrible affliction?

Harlow himself had suffered from depression.

He put baby monkeys in total isolation, for up to a year.

Some were not only isolated, but confined in a restricted space

known as the Well of Despair.

All the monkeys came out

severely disturbed - those placed in the well were particularly damaged.

'Len did not work with Harlow on these experiments.'

Do you think the research was justified?

Would you have stopped him if you'd had the choice then?

The isolation experiments, I probably would not have.

The Well of Despair studies, I probably would have.

But, what was the goal?

If we could create a meaningful, valid

monkey model of depression,

would that be worthwhile?

Without question in my mind,

I would say it would be ABSOLUTELY worthwhile.

- Whatever you had to do to the monkeys to achieve that?
- Well...that's your phrase,

I don't know... I can't answer the "whatever I had to do".

But, would I have said, if I were on a grant committee, reviewing

research that said, "Our goal is to create a monkey model of depression

"that would allow us to understand ultimately brain mechanisms" -

I would say - having worked in a psychiatry department for 47 years -

you're damn right I would have been supportive of it.

To be able to solve that problem - to be able to knock

a piece of that problem out of the way - is OVERWHELMINGLY worth it.

'Harlow's work is deeply controversial.

'But what he gave the world

'is something that I think is of profound importance.

'He proved just how much we all need affection

'and close physical contact.'

OK...

"When we were walking home from school,

"Betty told me she had this idea..."

- "Tells."
- "Tells", yeah. Thank you...

'After Harlow, hospital-born babies were no longer

'separated from their mothers, but placed physically close to them.

'What had seemed natural to so many mothers

'was now confirmed by science.

'This particular experiment utterly altered the way that people dealt

'with the subject of love, and the way they brought up children.

'From then on you begin to see that'

the important thing is that children should feel touched, cuddled, held.

And for that, I am profoundly, profoundly grateful to Harlow.

Watson had shown that emotions are learnt,

and Harlow, that we are intensely social creatures.

So it was natural to put these two ideas together, and ask,

how much of what we do and feel is learnt from other people?

In 1961, American psychologist Albert Bandura set out to see

how far just watching other people influences our behaviour.

Bandura chose to study aggression.

At the time, the widespread view

was that watching violence reduces aggression - it purges us.

But was this true?

To find out, Bandura experimented on small children

aged three to five.

So what Bandura did, is he put an adult in a room with a child

and a bunch of toys, including

something he called the "Bobo doll", which is a giant inflatable doll.

Then, what happened after about a minute is the adult unexpectedly

started beating up the doll in really quite a vicious manner -

shouting, screaming, kicking,

hitting with a hammer - and went on like this for about ten minutes.

What would the child do, if after watching the adult

they were left in a room on their own, with the same toys?

Ooh! She really is going for it.

She's doing exactly the same as she saw the adult do, she's lifted

the doll up and now she's really hammering it.

She's got a little hammer out, and she's having a go at its toes now.

Which shows innovation if nothing else...

'Every child who'd watched the adult being violent

'copied much of what they'd seen.

'The closest imitation

'was when a child observed an adult of the same sex.'

Now he's got the gun out, and he's using

a combination of the gun and the hammer to just whack the doll.

He's got a very aggressive expression on his face.

'Importantly, another group who had watched an adult play gently

'played calmly, showing no signs of aggression.

'Basically, what the children saw, the children did.

'This was an utterly unexpected finding.'

Before Bandura did this experiment, psychologists thought that

seeing somebody else acting out

a violent scene would be cathartic, it would sort of purge you.

But what this clearly demonstrated,

and really shocked people at the time,

is that actually what happens when

you see something doing violent actions - you tend to imitate them.

Bandura's findings were given added impact by his timing.

His experiment took place just as television was moving into the home.

Two years later,

Bandura re-ran his experiment with one important difference.

This time, he wanted to compare how children react

to watching an aggressive adult not in real life - but on film.

Children watched two versions.

One was a straightforward recording

of the adult beating up the Bobo doll.

The second, a fantasy version,

with the attacking adult dressed as a cat.

In almost every case, Bandura got the same results -

children imitated what they'd seen.

The results were dynamite.

This was one of the first experiments

to look at the impact of television violence.

The complicated relationship between

TV and behaviour is still being debated.

But it was Bandura who opened the floodgates,

and launched an entirely new area of research.

Right. OK - oven on...

'Bandura had shown that we CAN be strongly influenced

'by other people's behaviour.

'This is the basis of so-called social learning theory.'

We don't have a bowl.

- OK, so we measure out about...
- How much?
- Four ounces, I think.

Which one's ounces? The quarter one?

'But it's also clear that how we learn changes as we mature.

'As we grow up, something else happens to temper our behaviour.

'We develop a capacity to reflect on what we see.

'We identify with other people.

'We develop empathy.'

- Mmm... Tastes good.
- It's good, isn't it?

'So how exactly do we DO this?'

Well, for decades nobody really knew, and then researchers developed

new ways of looking inside the brain for answers.

I'm on my way to Holland, to experience experimentation

21st-century style.

We've left the world of abuse and exploitation behind -

though what I'm about to do WILL involve pain.

Christian Keysers is researching empathy,

by trying to watch it at work in our brains.

So we think the big question is a bit, how we understand other people.

And I think you've all experienced that sometimes you'd

see your partner, for instance, accidentally hurting herself.

And when you see that, the funny thing is you don't just realise

that the other person IS in pain,

but you almost have to hold your own finger, because you kind of embody

to a certain extent the pain of the other.

And so what our lab is all about

is trying to understand, at the level of the brain,

what happens while we get these very strong insights

into what somebody else is feeling.

Christian is investigating the extent to which our own feelings of pain

are important in understanding the pain of others.

So basically there's going to be two phases to the experiment...

There's a first phase in which you're going to be watching movies,

and then there's going to be a part

where you're going to be actually experiencing some moderate pain...

How are you going to create the pain?

Well, I think you're going to find out a little bit later on

in the experiment.

'Christian is going to collect two sets of data.

'First, he records what happens in MY brain

'when I see someone else in pain.'

OK, ready to go?

- Yep.
- OK, here we go...

- OK, Michael? How was that?
- Fine...

'Then, he measures what happens in my brain, when I am repeatedly

'and enthusiastically whacked by one of his colleagues.'

Three, two, one... Go.

Three, two, one... Stop.

'The two brain scans can then be compared.

'What they're finding suggests that empathy is actually measurable.

'Many of the same brain areas light up, whether we are experiencing pain

'or watching someone else in pain.'

What's really special about this area we're in,

is that by seeing that the same brain area is active in two cases

you don't just see WHERE in the brain it's being done,

but you see that it's done by this recall of your own experience.

When tested this way, people show very different responses.

I'm a bit nervous.

Will the machine reveal that I am warm and empathic -

or perhaps a secret psychopath?

"I often have tender, concerned feelings

"for people less fortunate than me"...

Yeah, I... Mmm, yeah.

'This questionnaire will help them compare how empathetic I think I am

'with how empathetic the MACHINE thinks I am.'

"When I see someone get hurt, I tend to remain calm"...

No, that probably doesn't describe me very well.

'First, Christian shows me what happened when I was slapped.'

This created very reasonable results. So you...

you did activate your S1,

- your S2, your insula and your ACC, just like your average Joe.
- OK...

'So far, I was normal. I'd activated areas involved in

'sensation and emotion, like most people do.'

Now, this is the part where you probably want to distract your wife.

While we were showing you the movies the first thing we saw was this.

None of the red areas get reactivated while you observed it.

And now you can call her again, because what we then did was

we lowered the threshold a bit, kind of looking for weaker activity,

and when we did that, we actually saw that you do have activity

that is typical - but there was lower than what we find on average.

So I'm not a psychopath,

but I'm not, erm...wholly in touch with the feelings of others?

- Exactly. You're not the most soft-hearted person, maybe.
- OK.

Where you reacted yesterday...

'What made it more embarrassing, was the brain images

'did not match the answers I had given on the questionnaire.'

OK - maybe I lack insight, then.

That could actually be, because one of the funny things is

when we scanned a psychopath,

the brain images really suggested that they weren't all that empathic,

but the questionnaires made it look like they were model citizens!

Oh, God, so I AM a psychopath?! There you go.

Well, maybe that's pushing it a little bit, but...

I think what tends to happen is we tend to, erm,

exaggerate our best characters, don't we? We have vain brains.

- Yes.
- Yes, quite.

So what the brain scans are doing, in a funny way,

is they are answering one of the more fundamental questions -

which is who are we, as opposed to who we THINK we are.

Yes!

Our understanding of empathy is developing,

because today's technology allows us to see inside the brain.

It's revealing that empathy seems to be deeply embedded

in the networks of our minds.

While I'm witnessing you go through some experiences,

my brain does exactly that -

it doesn't just make me SEE what is going on in you,

it makes me share all the different senses.

I will feel the pain you go through,

I will empathise with the actions you do to get away from it.

It really reminds us of the fact

that we are kind of incredibly social by nature -

that kind of everybody around us

is not just around us, but kind of IN us.

Cutting-edge technology, and sometimes brutal experiments,

have each opened a window onto human emotions.

But there is another way we have come to learn about

the role of emotions in our lives, and that's an accidental by-product

of terrible personal misfortune.

In the 1990s, a neuroscientist called Antonio Damasio started researching

patients who had damaged a part of the brain key for normal emotions.

He was struck by the differences in the way they were making decisions.

His research would reveal the

surprisingly pervasive role emotions have in every corner of our lives.

Dave is a patient, like those in Damasio's original study.

Until eight years ago, life was good.

We, um, had a really good relationship I think.

Very affectionate, yeah. Very loving.

He could put himself in my shoes and think about,

what could he do to make me feel

more at ease? And so he would do those kinds of nice things.

In 2002, Dave was diagnosed

with a brain tumour, and had surgery to remove it.

What neither he nor his wife realised,

was that the operation would involve

removing a part of his brain crucial for processing emotion.

When he woke up, he just was...

really um...cold.

He told me he didn't want me to touch him, or talk to him...

The doctor came, the surgeon, and I said, you know,

"That's not Dave. What happened?"

Dave's IQ was unaffected, and he has returned to his job

as an animal psychologist.

But he is very conscious of being changed.

'A lot has gone, from that aspect. Emotionally flat.'

It's... that's the toughest thing, is uh...

you don't realise how important emotions are

until you don't feel 'em, and you can only remember 'em.

- Hi...
- Hi.

Dave had not fallen out of love with Lisa...

but he was no longer capable of feeling it.

They divorced - but she remains devoted to him,

and takes him to all his medical appointments.

Do you want any more coffee before we go?

No, I've just filled up.

Well, shall we...?

All right.

Dave's case is so rare,

he is being studied by a doctor who trained under Antonio Damasio.

At Wisconsin University, Dr Koenig is continuing

the investigations started by his teacher, into the impact of emotions

on our capacity to reason.

So is it fair to say that

you're maybe not operating with the same intuition in terms of emotion,

but you're relying more on the sort of cognitive or rule-based

strategy to try to...you know, put together what this person might be

thinking, and, you know, "What is MY responsibility in this situation?"

Right. It's...

I have to... think about what it would feel like

rather than feel it.

Mm-hm...

I was...thinking the other day...

And I don't want this to sound strange, but I imagined,

"Well, maybe serial killers don't have emotions"...

Not that I would ever be a serial killer, but I think

I have that sense of...

- ..it doesn't bother me.
- Mm-hm.
- You know what I mean?

But the thing that prevents me from BEING a serial killer

is that I... can remember that I'm not.

Hello...

'What Dave is experiencing is intensely personal,

'but it is also scientifically revealing.

'I wanted to meet Dave's doctor, to find out what had happened

'to his brain to produce these profound changes.'

So what are we looking at?

So here we're looking at Dave's brain

in a number of different views.

As we move forward in his brain

you can see, here are his eyes...

Ooh, dear...

Yeah, so...so right above his eyes you can see...

- That's tragic.
- ..very obviously a loss of tissue there on the right.

Can he still... READ emotions - say, in Lisa...

If he saw someone crying, I mean, he would know that,

you know, tears mean this person is sad.

Now, if that would MEAN anything to him, if that would impact him

emotionally, is a different question.

So he can probably recognise these social and emotional cues

that are emitted by other people, but...

you know, can he use those to influence

HIS decision-making, is a different process.

Patients like Dave are making it increasingly clear

that our power to reason is NOT independent of our emotions.

They are supporting the evidence first gathered by Antonio Damasio.

Through most of the 20th century there was this

really predominant view that our decision-making is dominated by some

cold, logical processing, some reasoning.

So I think Antonio Damasio's work

was seminal from the standpoint of highlighting the importance of

emotion for decision-making. And patients like Dave were really

the key piece of evidence like that.

Damasio undermined the widely held belief that most of our decisions are

logical ones, by devising an ingenious test.

He took his inspiration from gambling.

He devised a gambling test, that would try to mimic the uncertain mix

of risk and benefits that we juggle with in everyday life.

Damasio was convinced that, even when we THINK we are making a decision

based on reasoning, we are actually following an emotional hunch.

'Damasio tested this by a carefully designed gambling task.'

OK, so I've got 2,000...

and I will pick this one here.

Reward, penalty... Good, I'm 2,100.

Let's keep going on that one.

'I'm playing a computer version of the game.

'The player is offered four rows of cards.

'They sample each one, and find out that two of them

'will give them small but consistent rewards.'

I like this one...

'The other two give them big rewards, but also big losses.'

Aaagh...!

Damn!

'Normal people respond before they are even aware of this.

'They just instinctively feel wary of the risky cards.'

Oh... That's a bad one. That is a bad one.

'They are not necessarily conscious of this.

'They have an emotional cue -

'what we often call a gut instinct.'

"You earned a total of 2,900." Whoa!

"You may now leave. Please alert the experimenter that you are done.

"Press the X to exit."

So, yes... OK, that was fun!

'What struck me, was I had no idea I was getting an emotional cue.'

That feels like a sort of simple, logical decision,

it doesn't feel like an emotional decision.

Right - well, in the end, after enough experience,

you do sort of process it at this sort of

explicit level, where you say "This is just a logical choice."

But as you're going through the test, what we've found is that

neurologically healthy individuals

will start to move towards the safer decks before they can explicitly

articulate that these decks are safer than the other ones.

So they seem to be operating more on an emotional hunch.

So actually, what I think of as a logical decision is actually

a rationalisation after the event - my gut has already decided which is

the safe bet, and then my... intelligence catches up with it!

Yeah, that's one way to put it, that your emotional system

is really the instrument of learning here, which precedes

your sort of conscious awareness.

- DAVE:
- 50 bucks...

Dave has never done the gambling test before.

With his damaged emotions, how will he do?

Right, I lose money there.

Penalties...

- You owe us some money, Dave!
- I do.
- You owe us some money.

- 1,500... 1,450.
- Get your chequebook out.

- I'd rather owe it to you.
- DR KOENIG LAUGHS

Yeah, I didn't learn anything on that, did I?

- You win some, you lose some. That's what gambling's all about.
- Yep.

So as you were doing it, did you have any feeling that

"This is sort of a risky decision", or "This is a safe play", or...?

Um...no.

We go through life thinking decisions we make - big or small -

are the result of our uniquely human ability to think rationally.

But as Dave and other

unfortunate individuals show us, reason without emotion is nothing.

On a more personal level,

Dave also shows us how vital emotion is to feeling alive,

and how crucial empathy is to even knowing who you are.

I'm going through life missing some of these important pieces that

we don't have to think about, that just happen.

The longer I go basing what I should feel on memory,

I'm kind of nervous that eventually the memory will fade,

and then trying to remember what the actual emotion felt like will be...

..more mysterious.

At least now I have the memory -

so I can at least go through life with that understanding.

If I didn't have that memory...

..I guess it would be a lonely, lonely existence.

BAT CHIRRUPS

CHILD SHRIEKS AND GIGGLES

Whoa...!

You want to try that, Clare?

'Nearly a century since Watson set out to terrify Little Albert,

'and in the process triggered an extraordinary

'and sometimes disturbing quest to try and understand human emotions...

'..we now realise that, far from being something you have to curb,

'suppress, restrain,'

emotions are actually central to becoming a rational, complex,

fully functioning human being.

Snap!

'But the price of applying the scientific method

'to the study of the mind has been high -

'terribly high in some cases.

'And this leaves me with conflicting feelings.'

Some of the experiments, particularly the later work with monkeys carried

out by Harlow, and the experiments done on Little Albert, you just

couldn't justify, you couldn't get away with, in the modern age.

I certainly would obviously

never allow any of MY children to be terrified as part of an experiment.

But do I think it was worthwhile in the end?

Yes, I do. I'm glad it was done.

I do believe that the knowledge that was gained

was worth the price that was paid.

Subtitles by Red Bee Media Ltd

E-mail subtitling@bbc.co.uk