Brain Story (2000) s01e02 Episode Script

Dennis Sines is a Vietnam veteran.
Every day is a battle with his emotions My concentration is lousy.
My emotions are, I try not to get too close to people including my wife and family.
Because to open up to them is, I find destructive.
The hopelessness, the death, if I you know today I died so what, you know.
How can the terror he experienced in Vietnam have had such long lasting effects on his brain? Emotions are what make life worth living.
They are indescribable experiences.
Thoughts come and go inside our heads, but moments of intense emotion take us over completely.
They seem to involve far more than just thinking.
We experience emotions with our whole bodies, the clenching of the muscles with excitement, the beating of the heart with joy.
And above all the utter sensuality of relaxation, the sand between your toes, the sun on your face and the wind in your hair.
The search for things that feel good motivates everything we do, from playing with the children to going on holiday.
But unlike most animals we humans can take our time, getting our emotional rewards.
The interesting thing about us is that we don't live from moment to moment, we don't expect instant pleasure.
Instead we plan complex long term strategies that defer gratification.
We're prepared to work hard for most of the year to save money for two weeks of bliss in the sun.
Unravelling how our brains create emotions is anawesome challenge.
Why do they feel the way they do, and how are they interwoven with our thought processes? As brain science unlocks the secrets of emotions, we're beginning to understand the intriguing and surprising ways in which feelings underpin every single moment of our lives.
For centuries emotions have been the domain of artists and writers.
At London's Globe Theatre, crowds come to watch plays performed just as they were in Shakespeare's day.
Emotions are so variable, and so personal, they seem out of the reach of science.
But looking at these faces you know what they're feeling, even if you can't explain why.
Something about the facial expression conveys so much.
It takes a poet to be able to express in words what a moment, an expression can convey.
The face tells you that's what's happening right at the moment, this person is about to fight, or this person is finding things very distasteful or offensive.
Or right at the moment we're having a great time, and you know that instantly and you know that without words and when you the perceiver see it you don't necessarily translate it into words, you just know it, you feel it.
Paul Ekman realised that our facial expressions are actually a powerful way to let others see what we are feeling.
A theatre like this wouldn't work if you couldn't at the back of the Globe be able to distinguish each of the emotions, and that's just what our research found.
But the most long distance transmitter of all is the smile, you can recognise the smile at 70, 80 metres away.
Just about the distance that you could throw a rock or a spear.
Thirty years ago Paul Ekman travelled to Papua New Guinea.
The work he did there was to become a landmark study of facial expressions.
The young psychologist went to live with the last remaining stone age culture on earth.
In 1967 and 68 I lived in the Highlands of New Guinea which at that time had had no contact, really virtually no contact with the outside world.
Most of the people I studied I was the first or second outsider they had seen, they had never seen a photograph or magazine, a mirror, television, film nothing.
Paul Ekman wanted to know whether the facial expressions used by people in the industrialised world were different from the expressions of these tribes.
In other words do facial expressions change as societies develop, or are they fixed and universal? I did two kinds of studies with them.
I showed them photographs and asked them to point to the one that fit a particular story, point to the one where the person is angry about to fight, or to the one where he's just learned his child has died.
Then I asked them to be actors, to show me their expressions - if your child had died show me what your face would look like, if you were about to fight show me what your face And I found exactly the same thing I'd found elsewhere.
Muscle for muscle, the facial expressions this ancient, isolated culture used were the same as our own.
Ekman went on to suggest that these universal expressions revealed a simple set of core universal human emotions.
The basic ingredients of our entire emotional repertoire.
The six basic facial expressions he identified were those of - happiness, - sadness, - disgust, - surprise, - anger and fear.
The question for neuroscientists is how might these core universal emotions each be generated by the brain? A Tuesday night in London's East End.
We all know what it feels like to lose control, those moments when we're totally uninhibited.
It's as though we're letting primitive urges which are normally suppressed, take over.
One of the first attempts at a complete theory of how emotions operate in the brain was based on exactly this idea.
Our brains contain structures which we have inherited from more primitive ancestors - the brain stem, which controls sleeping and breathing, dates back to reptiles.
Around that is the limbic system which is present even in the earliest mammals, and on top of that, most recently evolved of all is the cortex, Iinked to humans higher thought processes, logic and reason.
The big idea was that these three parts worked together in a rigid hierarchy with reason at the top.
Moments of extreme emotion, Iike naked aggression were seen as powerful drives coming from the reptilian parts of our brain and temporarily overriding the rational higher structures.
In this early theory, emotion was completely separate from thought.
But now we know that the brain doesn't work in such a simple way.
Thoughts and emotions are totally intertwined.
Emotions must be more than just reptilian urges slipping free from rational control.
Imagine if I told you now that the boxer we had just been watching had suddenly collapsed and gone into a coma.
I bet you'd feel something.
Please rest assured that he is actually fine, but the point I'm trying to make is this - that a mere thought can trigger an emotion.
In this house is a strange laboratory.
It's home to an unusual scientist who has become a world authority on one particularly powerful emotion.
The scientist's name is Paul Rozin and he calls himself Doctor Disgust.
-Hello.
-Hello.
We have a curiosity about it.
If I say to you there's something in this little bottle that smells disgusting, and offer it to say can I smell it and you smell it and say "ooh, it's disgusting" I mean why did you even want to smell it? Paul Rozin has spent twenty years disgusting people.
He's been investigating how thoughts and emotions become linked as we grow up.
Disgust seems to be about food and it's about the mouth, the disgust face is around the mouth.
I realised pretty early that most of the examples of disgust that we ran into were not about food.
There's the disgust at touching things that are dead, the disgust at seeing blood or gore.
People would say certain kinds of unnatural sex is disgusting.
People would say that certain people were disgusting.
So the question is what was the relation between the original food core of disgust and all these other things.
It's been a dirty busy, involving a range of unsuspecting victims and lots of messy foods.
Put some ketchup on it.
Now how would you like to have that? No! I hate the banana.
Anyone with children knows how quickly they learn what they do and don't like to eat.
I don't want to eat that.
Would you like to eat that? By three or four they've learned there is a basic distinction between food and things that shouldn't be eaten.
A crayon? No that's for drawing.
Would you like to lick it? How about touching it? No.
Do you know what that is? A poopy.
That's right, that's a doggy poopy would you like to eat it? No.
You don't want to eat it? It's yucky.
Oh yuck.
Would you touch it? No.
Would you eat it? No Little Cleo at 14 months will try anything once.
She will only reject things if they taste bad, and since this is chocolate fudge she's not going to learn that lesson today.
So for a one year old child who will eat virtually anything in it's way Food is just something that's a lump out there that you can taste and either reject or accept depending on whether it tastes good.
For a three year old already there's some things that just are not to be eaten, not because of their taste only they seem just inappropriate and offensive.
So within a few years, disgust is felt, not just because something tastes bad but because of more sophisticated ideas we've acquired.
For Rozin, one key landmark is the emergence of the concept of contamination.
Do you know what that is? A bug and I don't want it.
No bugs.
It's a cockroach.
And I'm going to put it on this spoon and drop it in your juice over there, maybe stir it around a little I'm going to stir it around a little.
I'm not going to eat that.
Are you going to eat that? No.
Why not? Because it's gross.
Would you drink some of that apple juice? I can't drink the bug You don't want to drink that juice? But I don't want to drink the bug.
OK now suppose I take the cockroach out of the juice.
It's pretty easy to identify with the idea that the juice has been contaminated.
But we're not born with ideas like that, so when does this association develop? No thanks.
By seven years of age as we saw with Richard the juice is still bad after the cockroach has gone.
He has a much higher cognitive level of perceiving the situation, he is seeing this as the history of the juice.
Something was left in the juice even though it's invisible.
The thought of the cockroach seems to confuse slightly younger children.
Has it got legs in it? At four, Zac is not keen and he takes a bit of persuading.
I'll taste it.
Sure you will.
Hm Though they would not eat a cockroach, they found it offensive, they were happy to drink the juice after the cockroach was removed.
So they still don't have the sense of contamination.
Put it on the plate.
Now would you How about drinking the apple juice now? Yeah.
OK.
To an adult, what Ely is doing is disgusting.
Now this is a Nazi hat from World War ll, it's got a swastika on it as you can see.
Rozin believes that the sophisticated adult reactions to abstract ideas all somehow develop from the basic response to something that tastes disgusting OK, thank you that's fine.
It sort of seems to start as a get it out of my mouth emotion.
in respect to bad tasting foods, or offensive foods.
And it ends up an emotion that is very broad, that seems to be about anything offensive.
It's sort of get it out of my mind or even get it out of my soul, I want to be a better person by not having to interact with this thing.
I sometimes think of it as the emotion of civilisation.
If you imagine somebody who doesn't have disgust, you would think they were uncivilised.
You know what this is right? That's a bedpan right.
It's a brand new bedpan, never been used for its' proper purpose.
I'm going to take some apple juice now and I'm going to pour it into the bedpan, now would you be willing to pick up the bedpan and drink some apple juice from the bedpan? It's a brand new bedpan.
No, I can't do it.
OK that's fine.
If all disgust involves the same basic emotion, might there be a disgust centre in the brain? It would be active whenever we find anything disgusting? An obvious way to search for the physical source of an emotion is to scan someone while they're actually experiencing it.
I think I'm about to be totally disgusted.
Inside the scanner I'm shown various images designed to evoke the emotion of disgust.
There's activityall over my brain.
But one structure seems to be particularly active when I'm feeling disgusted - The anterior insular.
What's interesting about this region is that it is also very active when we feel something unpleasant or painful in the gut.
The insular seems to be important in helping us to detect that something unpleasant is in our gut, whether that be literally physically or more metaphorically as in being disgusted in normal sort of social circumstances.
So even if you haven't literally got something unpleasant in your mouth, your brain is acting Acting as if there were.
So the insular is specifically involved in disgust.
But is this tiny bit of brain responsible for the whole feeling of being disgusted? I don't think so.
When people are shown the face of someone else being disgusted the insular is just as active, even though the person being scanned isn't themself feeling the emotion.
The insular seems to be involved not only in helping usdevelop this feeling of disgust per se, and feeling that something unpleasant is inside us, but it also helps us recognise disgust in other people.
So if we see disgust in someone else's face it's like a warning to us that yes there's disgust around, but we don't have to actually go through the process of being disgusted, vomiting etc ourselves.
So there seems to be a brain area specialising in disgust, but it doesn't on its own produce the actual feeling of being disgusted.
And do the other emotions have their own distinct areas? No one has yet found specialist structures for anger, sadness, happiness or surprise.
Only one other emotion seems to involve a specialised brain region - fear Fear is the most powerful and primal emotion of all.
There's nothing like being in a fire fight that you know gets everything moving.
Every emotion you ever sustain, you've got that within two minutes of a fire fight.
It was a very frightening thing.
You lay there, you're helpless cos you don't know where they are.
They're throwing grenades at you.
Shooting machine guns at you.
You don't know if you can get up, run.
There's no hiding cos they'll find you.
I mean where can you go? Nam was hell.
Nam took our souls, took my soul and took it away from me.
Whatever goodness, real goodness I had, or happiness, it's still over there somewhere.
Psychiatrist Doug Bremner has been working for ten years with patients like Dennis who have been permanently traumatised by the terror they experienced in Vietnam.
Dennis has symptoms of post traumatic stress disorder including intrusive memories of the war that come back to him at any time of the day, and which he has little control over, and they replay in a repetitive manner.
He has nightmares of the war.
He's jumpy and easily startled, he's hyper vigilant and on guard all the time.
Nearly a fifth of Vietnam vets returned, like Dennis, traumatised.
I feel trapped in my life.
I feel like I'm trapped in some kind of shell, something that's never going to go away.
I'm suicidal at times, and hopelessness you know and the dreams, I think because of, thinking about Vietnam so much and how hopeless that situation is I just kind of carry it into my life today.
I don't like busy streets all that much.
I try to stay away from walking the streets of New York or somewhere, I'm a little more watchful.
You know, of the ambush.
Someone like Dennis knows that anyone could pop out of the bushes at any time with a gun and shoot you and there's nothing that you can do about that and he walks around with that knowledge all the time.
But that makes it more difficult for him to work and to be close to his family and to do all those other things that we all take for granted.
Dennis is on a hair trigger to fear.
Cars backfiring or just the smell of diesel take him back to Vietnam.
So what has changed in Dennis's brain to leave him so fearful? Doug Bremner exposes Dennis to vivid reminders of the Vietnam War.
Pictures and sounds designed to frighten in order to study the brain circuits involved in the fear response.
One current theory is that fear involves two separate pathways in the brain.
Any potential threat activates a specialised fear structure called the imigdala, which automatically sends out signals triggering responses like sweaty palms or increased heart rate.
But a slower, second circuit routes right through the cortex This is how we weigh up the threat, and if it's a false alarm the imigdala is shut down.
So it's a delicate balance.
You need the primitive part of the brain to survive to turn on the fear response.
But you don't want the fear response to become so incapacitating that you can't think.
Could this balance have been upset in Dennis's brain? Doug Bremner has looked at the brain activity in traumatised veterans compared with those who have come through unscathed.
He's found there's far less activity in one particular area of Dennis's cortex than there should be.
This area is part of the pathway which normally shuts down the automatic fear responses when they're not needed.
So in Dennis's brain, even the slightest threat unleashes the full terror.
So why can't Dennis control his fear responses? Doug Bremner thinks that the best clue comes from the way patients Iike Dennis seem to dwell on their memories of the war.
One of the things that I found most interesting when I first began working with Vietnam veterans was that many of my patients they could remember what happened in Vietnam as if it were yesterday, and they'd show me picture books of their friends from the war and talk about them as if they'd just seen them the day before.
But they couldn't remember what they had for breakfast that morning.
They had sort of a vague idea about maybe how long they'd been in the hospital and these more recent things they had a lot of problems with.
Bremner believes that Dennis's faulty fear response also involves a brain structure called the hippocampus, known to play a vital role in memory.
We did an MRl scan on Dennis and this is his hippocampus here, this grey area there and it's visibly, I can just look at the scan and tell you that it's smaller in volume, compared to a normal individual where the hippocampus is much larger.
This change to Dennis's hippocampus is very exciting.
Constant terror has changed the structure of his brain.
This is from the land we left so much at, it's incredible.
It's as if his experiences in Vietnam have worn such a deep groove that he's trapped in the past.
Even a handful of soil from the Ho Chi tunnels is enough to reduce him to tears.
Emotions have long lasting effects on all of us.
Emotions are what make those landmark moments from childhood so memorable.
.
Everyone remembers their first day at school.
For me it was here in this daunting assembly hall, almost forty years ago.
All the new girls had to assemble on these steps and wait to be allocated their class.
I remember vividly wearing a red baggy uniform with the expectation that I'd grow into it, clutching my brand new satchel on my knee feeling very lonely and very small.
Emotional experiences make us who we are.
Our own personal histories are woven into the fabric of our brains.
But it 's not just moments of extreme emotion that leave their mark.
Every day the after shocks of past emotional upheavals are influencing our actions.
As we go through life these after shocks are silently nudging us towards decisions.
We are oblivious to this process, but every moment of our lives we are influenced by the foot prints of our past.
Emotion is about value emotion is about what's good, what's evil, what's pleasant, what's unpleasant, what's painful, what's pleasurable.
If you take away that, you do not have a value system to operate effectively.
Here in Chicago neurologist Antonio Damasio has done some insightful studies into the role of emotions in everyday life.
We're going to play this interesting gambling task.
He's interested in how emotions influence us at those times when we feel at our most logical, when we're trying to make difficult decisions.
And he's invented a gambling game to prove his point.
I turn over cards and either win or lose money, but he doesn't tell me why.
The payouts vary wildly, they're deliberately designed to confuse.
So there's some rule operating here that I can't work out.
OK.
Another black.
And you're going to get $50 as well.
I'm baffled, but determined to work out which packs are paying out more.
It's very tempting to just do it randomly, but that's completely non logical to do that.
I can't see any relationship between what I'm doing and what's happening to me.
A bit like life I suppose, OK, so A.
That is going to be, I'm afraid to say, 1,250 to me But I will give you a hundred.
Well that's just being kind or No no, that's just the rules.
I'm trying my best to unravel the rules of the game, but the pattern of pay outs is so complicated I can't work it out logically.
So I'm forced to use something else - my emotions.
Although they give the highest rewards, I get the feeling that packs A and B also seem to inflict more damage.
And that steers me way from them.
I'm being guided by emotionally loaded but covert signals, what Damasio calls sematic markers.
Eventually I adopt a more conservative policy, winning back my losses by sticking to packs C and D.
That's going to be another 50 and that's the end.
So how do you know it's the end? Oh because I decide.
So what is odd is that I was trying to use all the logic within my abilities and trying different logical strategies but none of them seemed to work, none of them seemed adequate.
There seems more to it than logic.
Logic alone really does not help you solve problems in which there is as much uncertainty as you had here.
So what we do most of the time is that we use of course logic and we use knowledge, no question about it.
But we also use something very smart, which is the experience that we've had in the past of certain situations and of the outcomes of certain actions that we have taken and the attached emotion.
So when I'm deciding which pack to choose, I'm guided by the emotional consequences of my earlier decisions.
These good or bad feelings, which Damasio calls sematic markers, guide our choices.
But I wasn't always aware of feeling anything when I was deciding which pack to choose.
When you confronted a very large penalty and you actually had to pay er quite a lot of money, that's an example of a sematic marker at a gut feeling level that's a very old idea, very traditional.
But throughout most of the task you were actually not having that kind of signal, you were having something that was far more subtle, that was happening without you knowing below the level of consciousness.
It's possible to measure these unconscious sematic markers.
After a card turn, electrical sensors can pick up a tiny increase in sweat, indicating an emotional response to the result.
But these changes are also detected just before the card turnas the actual decision is being made.
So unconsciously emotions are guiding our every move.
Emotions guide our behaviour.
They make us want to do things.
They are the driving force that becomes action that indescribable brain kick that makes what we do worth doing.
Feelings motivate us to try, to care, to win.
That rush, that thrill that makes certain moments so special.
For scientists, the nature of subjective experience has always been slippery.
How can you measure what you can barely describe? But now at last we're able to tackle the really big question - where does the actual feel of feelings come from? Here in San Francisco Doctor Rebecca Turner has chosen to study that most longed for feeling of all - love.
It's very difficult for a scientist to use a term like love, which has typically been the domain of poets and artists.
She's trying to pin down what it is about being in love that creates such powerful emotions So we want to know about relationships, intimacy and emotions.
Why do we have our strongest emotions in relationships in ways that seem completely beyond our control.
And why do we suffer so much when someone goes away? I remember when my husband asked me to marry him and er, I remember exactly we were in my apartment, we were sitting on the floor in the sun in the morning and I remember he asked me you know if I'd share my life with him.
And it was wonderful, I was, I felt so loved, and I loved him so much and I was so ready to really commit myself to someone, to be with him.
And As Shoshana remembers happy times with her husband to be, a nurse takes a blood sample.
Turner and her team are interested in a hormone called oxytocin.
We'd only been together actually two weeks.
We've known about oxytocin for a long time.
It plays an important role in many reproductive behaviours - breast feeding, child birth and orgasm.
And recently it's emerged that oxytocin must also have a role in brain function.
What's interesting is that there are oxytocin receptors throughout the human brain in the limbic system and in the brain stem, so they're in areas that are associated with emotion, and the autonomic control of emotion.
If oxytocin is released into the blood during reproductive behaviours, and it's active in the brain, could it be the basis of the emotional feelings of love? We found that when experiencing positive emotion particularly about relationships some women experience surges of oxytocin.
When they were talking about sad feelings, having lost someone that they love, their oxytocin levels decreased.
I think about the fact that since my mother passed away several years ago she will never meet my child and she would have been a great grandmother, and that's really sad.
It's hard.
So, oxytocin levels do seem to rise and fall in relation to the level of loving attachment the volunteers felt.
With neuro scientific techniques, and what we're starting to learn aboutthe brain and emotion and behaviour, it's reasonable to think of oxytocin as something that can influence loving, and certainly patterns of loving and behaviours that we associate with loving.
But does that mean that a surge in brain oxytocin is what produces the feeling of love? I don't think it's that simple.
In theory, some totally different brain process could be producing that loving feeling and the changes in oxytocin might just be a side effect.
But overall it's now clear that there is some kind of relationship between the ebb and flow of our feelings and the many chemicals in our brains.
We know that we can influence the way we feel by deliberately changing our brain chemistry.
We do it all the time, with drugs such as coffee, nicotine and alcohol.
But here in Chicago one scientist has been experimenting with drugs.
Drugs serve a very useful function in the study of emotion because they stimulate the very system that's activated in a natural situation when people go through an emotional situation.
So we can use them as a tool to stimulate the limbic system.
Harriet de Wit has devised a cunning experiment to test the effects of one drug, a stimulant, amphetamine.
Two of the volunteers are told they've been given an inactive placebo pill.
The other two that they've been given a stimulant.
In fact all four have taken a dose of amphetamine.
Drugs like amphetamine work by mimicking natural biochemicals in the brain.
So if changes in bio-chemistry are all there is to experiencing an emotion, all the subjects should feel the same, whether they know they've taken a drug or not.
Half an hour into the experiment and the amphetamine begins to take effect.
All the subjects will be experiencing an overall increase in arousal.
They become restless.
Tim and Ryan know they've taken a stimulant and are out of their seats already.
But how will the unsuspecting Brook and Mike react? We saw quite clearly that the people who were expecting to receive a placebo interpreted the sensations that they experienced quite differently, and they experienced them in a more negative way.
They felt jittery, they felt anxious, they didn't enjoy the experience.
And in contrast the people who knew that they were going to get a stimulant drug recognised and identified the sensations that they experienced as being due to the drug, and they actually enjoyed the drug effect.
They felt energised, they felt focused, they talked more, they were amusing.
So their behaviour was really quite different and their, each of their experiences of the effects of the drug were quite different, just simply depending on what they were expecting to receive.
I am single I found a pebble on the floor which has caught my interest.
Their different responses reveal a great deal about the way subjective feeling is processed in the brain.
I want to kick it I think it tells us that the basic physiological responses that are involved in emotion are really only a part of the emotion, and what makes the experience that we describe as an anxious emotion or a positive emotion is very strongly influenced by the person's understanding of the situation, and the person's interpretation of the situation.
So even though they've all taken exactly the same drug, their experiences are quite different.
The feeling of an emotion must be generated by something more than merely the presence of drug molecules in the brain.
We've come a long way from the old idea of primitive brain regions unleashing an emotion and now we know that emotions aren't simply some biochemical change flooding the system wholesale.
Perhaps the mistake has been to think of emotions as some kind of an occasional event that can be switched on or off.
Surely any explanation of how we feel should deal with the fact that emotions are with us all the time.
Whatever generates feelings must be somewhere in the brain's endlessly shifting patterns of activity.
So far science has only been able to show what emotions are not, but over the last few years I've been trying to work out what really might be going on.
Although I think emotion is always with us, it's easiest to deal with moments of extreme emotion.
Whether it's the thrill of the fairground ride or a blind rage, extreme emotions are all about living in the here and now.
In the heat of the moment our whole brain is caught up in a rush of sensory processing.
A deafening roar that drowns out our rational measured minds.
It's all about losing yourself and just experiencing.
Perhaps it is this extreme passive central state that is all there is for an emotional high.
But how does that translate into the feel of feelings? If there is no special area, or single chemical change, what is the source of the visceral nature of emotions? In my view, the first hand feel of different emotional states, must actually emerge directly from the ever changing patterns of neural circuits firing in the brain.
At the moment this is just a theory, the ultimate test would be to find a way to monitor these swiftly changing configurations of neurones in the brain while someone was experiencing different emotions.
I'm convinced that in this new century we'll be able to do just that.
Only then, when we have a way to measure feelings flashing through the brain will scientists really have the tools to unlock the secrets of emotion.
In the next programme, how the brain is constantly distorting our view of the world.
It feels as though we just open our eyes and see what's there, but nothing could be further from the truth.