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00:00It controls all our actions.
00:09It's who we are.
00:14It's the source of our emotions.
00:19It contains a lifetime of memories and a world of inner thought.
00:28This series will take you inside the living human brain.
00:36I'm going to get you counting and talking when I touch your brain with an electrode.
00:421, 2, 3, 4.
00:456, 7, 8, 9, 10.
00:49That's correct.
00:51I'm Susan Greenfield and my goal as a scientist is to discover how the brain works.
00:57This is a unique form of scanning in that it enables us to actually see a thought.
01:05We'll meet people whose extraordinary brains help us understand ourselves.
01:12Joe's split brain allows him to draw two different objects simultaneously.
01:19Brain damage has left this woman unable to see anything that's moving.
01:27We'll explore the surprising ways our brains play havoc with reality.
01:37We'll delve into our darkest fears.
01:43How can the terror of the battlefield physically change a soldier's brain?
01:51How can the web of living cells inside our heads give rise to the stunning range of sensations we experience?
02:00Could love simply be a hormone surging through our veins?
02:07From birth to death, we'll see the amazing ways our brains are constantly changing.
02:13We'll search for the roots of fabulous creativity unleashed in this man's diseased brain.
02:20Even the most spiritual aspects of our lives will be dissected.
02:26I don't feel alone.
02:37The Walls of Ancient Jerusalem
02:53The walls of ancient Jerusalem have witnessed the ebb and flow of cultures for thousands of years.
03:06And yet in all this time, the essential nature of what it is to be an individual human being has remained the same.
03:27Every generation that's ever walked these streets must have come up against the same basic questions.
03:33Why do we think and feel the way we do? What makes us who we are?
03:37And yet despite thousands of years puzzling over these fundamental aspects of human nature, we still seem to understand so little about ourselves.
03:47People have always believed that there is more to the human spirit than mere flesh and blood.
03:56But as a neuroscientist, my view is that we can explain everything about ourselves by looking inside.
04:05I'm sure it has to be the brain that makes us who we are.
04:08Our hopes, our fears, our thoughts, our dreams are all somehow hidden away inside our heads.
04:14I'm convinced there isn't a single aspect of our lives that doesn't reside in the sludgy mass of our brain cells.
04:22I'm convinced that one day we will be able to interpret even our most intense spiritual feelings in terms of the workings of the brain.
04:33Research is finally bringing us closer.
04:41We've already learnt an enormous amount about the basic physical processes going on in the brain.
04:46But now I feel we're on the verge of being able to apply what we know.
04:49To take that knowledge and transform it into a true understanding of ourselves.
04:53I think that science might be about to lead us into a place we've never been before, inside the human mind.
05:05This is the challenge. To uncover what's going on inside a kilo and a half of pulsating brain with its network of a hundred billion nerve cells.
05:20I've known neurosurgeon Henry Marsh for over 25 years.
05:25But this is the first time I've seen him at work.
05:28The first time I've been face to face with a living human brain.
05:37Standing next to Henry, peering down at the surface of the brain, it is incredible to think that these nerve cells somehow create the human mind.
05:50We all think of mind and matter as being separate things.
05:54But it is very extraordinary when you actually see the brain, particularly if you operate upon it.
06:00And if you think, I'm actually operating upon thinking, I'm operating upon feeling.
06:07Today, Henry is going to remove a tumour from Sarah Kitchen's brain.
06:12It's a delicate operation, because the tumour is near a region of the brain that is involved in language.
06:19Damage a vital area, and Sarah might never speak again.
06:24To avoid this happening, Henry has to do something extraordinary.
06:28They've been going now for about an hour, and the critical phase is coming where they're going to have to remove the tumour.
06:33In order to do that, Sarah has to be awake.
06:40If you have a general anaesthetic and go into an operating theatre and have somebody operating upon your brain,
06:46it's jumping into the deep end with a blindfold on, and you hope you're going to come out the other end in one piece.
06:53But if you're actually awake while it's going on, there's a much greater sense of control, and in a way you're part of a team.
07:00What we're going to do now is we're going to get you counting and talking when I touch your brain with an electrode,
07:05so we can just work out where the speech area is.
07:08OK?
07:09Sarah, can you squeeze my hand?
07:13Once Sarah's awake, Henry begins to pinpoint the crucial speech areas.
07:19By using tiny pulses of electric current, he can jam temporarily the mental activity going on at a particular site in her brain.
07:27I want you to do some counting for me. I want you to count up to ten and then back down again.
07:32One, two, three, four, five.
07:43Six, seven, eight, nine, ten.
07:45That's great. That's great.
07:48It wasn't that she knew the number five, but couldn't actually say it.
07:53She could think the number five, but couldn't think of it as a number, so to speak.
07:57I mean, it's different. One's not paralysing the vocal cords.
08:00One is actually paralysing the mental processes that turn a concept, a thought, whatever you want to call it, into a word.
08:09Carry on.
08:10One, two, three, four, five, six, seven, eight, nine, ten.
08:23Go on counting.
08:32Twelve, thirteen, fourteen, fifteen.
08:34OK. Wash please.
08:36Well done.
08:37Sarah, thank you very much. Sorry to play games with you like that.
08:40It's such a bizarre experience, talking to Sarah about her favourite recipes,
08:45while Henry is prodding around in the very thing that makes her who she is.
08:51I have one the other day that I absolutely love, like the ricotta cheese and spinach and a nice light pastry.
09:03Do you feel slightly drunk?
09:04A little bit.
09:06I like that feeling.
09:07No, you sound fine. It's nice to see you smiling.
09:12Everything's going really well.
09:14It is actual living proof of the fact that thought is a physical phenomenon.
09:21And we're all so brought up, not just by our parents, but by thousands of years of culture,
09:30to feel that thought is somehow as free as the air, it's mind as opposed to matter.
09:36But I actually see somebody talking on one side of the screen,
09:40and on the other side you see this blob of brain which is doing it.
09:44It is a very profound, thought-provoking experience.
09:49I've spent 30 years of my life studying the human brain.
09:54And I'm still fascinated by the idea that this messy-looking lump contains all our secrets, our thoughts and our feelings.
10:03But the brain is doing much more than we're ever aware of.
10:07We take so much for granted.
10:10So, how does the brain generate all the different aspects of our mental lives?
10:15Can we say where thoughts and feelings actually take place inside our heads?
10:21Well, there is one mental function which does seem to be related to specific areas of the brain.
10:27And that is to say, it's a function of thoughts and feelings.
10:33Our arms and legs are continually feeding back information to the brain,
10:38which then somehow creates the sensation of what our body is doing.
10:46The brain constructs a body image.
10:49It generates it in such a way that we attribute some of our thoughts and feelings to it.
10:55The brain constructs a body image.
10:58It generates it in such a way that we attribute sensations, when we feel objects, to the part of the limb that's being contacted.
11:07And that's very important.
11:09MUSIC
11:25Peter Halligan studies people with an intriguing disorder.
11:29Five years ago, Angela Button had a blood clot in her right arm that meant it had to be amputated.
11:35But Angela feels as though her lost hand is still there.
11:39She has what is known as a phantom limb.
11:42The phantom hand, just to illustrate where it is.
11:45My fingers feel probably, I would say, about there,
11:48because my whole of my hand feels as if it is joined on to my stump.
11:55Patients with phantom limbs feel the experience to be of such reality
12:01that they often, in the early stages at least, will attempt to make use of them.
12:05And this is not surprising.
12:07People with phantom legs will get out of bed and assume the leg is there and fall over.
12:12Patients, for instance, who have maybe an itch on their nose will attempt to use their phantom limb to actually scratch it.
12:19Angela, can I have just a look at the actual stump at the moment?
12:23And just test the extent to which you actually have sensations there.
12:29And just tell me what you feel, as it were.
12:32So if I'm touching there, what do you feel?
12:36Movement in my thumb and my little finger.
12:39You're actually feeling it in your...?
12:41Feeling it in my fingers.
12:43OK, that's interesting. Over to here.
12:46How's that?
12:48My two, these two fingers are going.
12:50Movement. You feel movement, OK.
12:53For Angela, the phantom is very real.
12:56Any physical contact with the end of her arm generates sensation in the missing hand.
13:01But it's not her arm that is generating the phantom.
13:04It's her brain.
13:06Angela has not suffered any explicit demonstrable brain damage.
13:10So the brain area that represents the hand is still intact.
13:14And therefore the idea would be that it would be capable of still representing an experience of that,
13:20despite the fact that the hand isn't there.
13:23The brain contains a map of your body.
13:26And it is here that nerve signals from the legs, the arms, the face, are translated into sensations.
13:34Even though there are no signals from Angela's amputated limb,
13:37her brain continues to generate the sensation of having an arm.
13:41And in her case, something else has happened to the brain's body map.
13:46Let's try here. Just tell me...
13:49What do you feel?
13:51My little finger is moving.
13:54That?
13:57Tingling on my little finger.
13:59Let's see down here now. Do you experience any sensations?
14:03That's my thumb going.
14:05OK. Now if I combine those two...
14:09Touching Angela's face seems to create a vivid sensation in her phantom hand.
14:14As a result of the loss of the limb, the brain appears to restructure itself,
14:21such that information that now comes from the face is actually related or linked to the hand area.
14:30With no incoming signals from a hand to keep her hand area working,
14:35the activity in the neighbouring face area spills over into this vacant territory.
14:41Touching Angela's face now triggers the hand area in her brain as well.
14:50Phantom limb seems to be suggesting that sensations in different parts of the body
14:56correspond to activity in particular areas of the brain.
15:05It's intuitively appealing to think of the brain as having different specialised regions,
15:10and for certain basic functions, this seems to be the case.
15:13But what about the less physical aspects of our lives, our individual way of thinking?
15:19Is it possible that every nook and cranny of our characters
15:23can be traced back to an individual part of the brain?
15:33200 years ago, scientists thought they had succeeded in doing just this.
15:38The phrenologists believed that every single mental skill
15:41was controlled by its own particular brain area.
15:49Now we know the truth is far more complex.
15:52But to a certain extent, the brain does seem to break down
15:57into areas specialised for different functions.
16:09After an accident ten years ago,
16:12Isabelle Rye has lost the ability to recognise music.
16:39ORCHESTRAL MUSIC PLAYS
16:42COUGHS
17:04Isabelle has a condition known as amusia, a subtle form of brain damage.
17:11It allows us to explore whether even something as sophisticated as music
17:15has its own specialised area in the brain.
17:19She does hear that it is music and not language or some noise,
17:25but I don't have the slightest idea how music sounds in her brain.
17:30I'd love to know.
17:33No matter how many times Isabelle hears a piece of music,
17:37it sounds like she's hearing it for the first time.
17:42But there's nothing wrong with her hearing.
17:44It's inside her brain that her recognition of music breaks down.
17:57What is spectacular about Isabelle is that her musical functions,
18:04most of them, seem to be so severely impaired while her language is intact.
18:12Here in Montreal, Professor Peretz has begun to explore
18:16exactly what happens in Isabelle's brain when she listens to a piece of music.
18:21ORCHESTRAL MUSIC PLAYS
18:35She puts it...
18:37ORCHESTRAL MUSIC CONTINUES
18:46Isabelle has brain damage in areas known to be involved
18:49with processing the raw nerve signals coming from the ears.
18:54But does her condition really prove that these areas are the brain's music centre?
18:59As Peretz has delved deeper into Isabelle's mind,
19:02it seems that the answer is not that simple.
19:11ORCHESTRAL MUSIC CONTINUES
19:13ORCHESTRAL MUSIC CONTINUES
19:33Strangely, Isabelle's ability to grasp the mood of a piece of music is intact.
19:43ORCHESTRAL MUSIC CONTINUES
19:49Isabelle is living proof that even something as abstract
19:52as the appreciation of music can be traced to a physical activity in the brain.
20:06But she hasn't completely lost the ability to respond to music,
20:10so the brain processes involved in dealing with music
20:13must be much more complicated than just a single specialist area.
20:18For complex experiences like this, we rely on many parts of the brain,
20:23and only when all of these parts are intact and working together
20:27is the experience complete.
20:29ORCHESTRAL MUSIC CONTINUES
20:39Every time scientists have tried to pin down a complete aspect of behaviour
20:44to a single brain area, they have failed.
20:49Although there are undoubtedly areas specialised for different functions,
20:54we will never be able to say exactly what happens where in the brain.
21:05My own research in Oxford is into degenerative brain disorders
21:09like Parkinson's and Alzheimer's diseases.
21:13Studying these devastating conditions involves getting to grips
21:16with another aspect of how the brain works.
21:19I've spent almost 30 years trying to understand what goes wrong
21:22in the brain in Parkinson's disease.
21:25We've known for a long time that the heart of the problem
21:27lies in a small brain region in the base of the brain
21:30called the substantia nigra.
21:32But why is it that when the cells there are damaged,
21:35we can no longer translate a thought into a movement?
21:41These patients illustrate the classic symptoms
21:44associated with damaged brain cells.
21:47The symptoms associated with damage to the substantia nigra.
21:51They are fully lucid, and yet the effects of the disease
21:54prevent their brain cells sending out the correct nerve signals to the muscles.
22:00It turns out that this mental paralysis can be overcome
22:04by replenishing the brain with a chemical called dopamine.
22:11Unfortunately, this dramatic effect doesn't last,
22:15but it does reveal the powerful role chemicals play in the brain.
22:20Dopamine works by allowing individual brain cells, called neurons,
22:24to communicate with each other.
22:27And there are dozens of other chemicals, each like dopamine,
22:30with their own role in the brain.
22:37Between each neuron is a gap called a synapse.
22:41When an electrical signal reaches the end of a neuron,
22:44it releases a particular chemical.
22:47This neurotransmitter then travels across the synapse
22:51and triggers a new electrical signal in the next cell.
22:56All brain activity boils down to this.
23:06So everything we do involves a frenzied web
23:10of chemical and electrical activity.
23:15If we're ever going to explain how we work,
23:18we'll need to keep track of all these microscopic interactions
23:22throughout the whole brain.
23:28We know all the answers have to be in there,
23:31but how will we ever see inside?
23:37I'm about to be scanned in a machine called a magnetoencephalogram,
23:41or MEG for short.
23:43This device will come down over part of my head
23:46and actually pick up minute magnetic fields,
23:49and these fields are generated as a result of the electrical activity
23:52in my brain cells.
23:54This is a unique form of scanning
23:56in that it enables us to actually see a thought.
24:07It can't measure chemical changes in the brain,
24:10but MEG is currently the most precise tool
24:13that exists for monitoring fast changes in electrical activity.
24:17In this way, it reveals how different areas of the brain work together.
24:24At the moment, scientists can only use MEG
24:27to explore what's going on during very simple tasks,
24:30because anything more difficult throws up patterns of activity
24:33that are far too complex to decipher.
24:37In this experiment, I have to count the number of times
24:41the small squares change to large ones.
24:44It seems like a simple task,
24:47and yet MEG reveals something intriguing.
24:50Massively slowed down, coloured patterns of electrical activity
24:54show what happens in my brain.
24:57In the course of half a second,
25:00different areas across my entire brain are pressed into service.
25:07MEG is showing us how the brain functions as a whole.
25:11It seems that for even the simplest of tasks,
25:14many regions must work together.
25:16But the big question is how does the brain do it?
25:19How does it integrate all this different activity
25:22into the seamless experience that we call life?
25:30For me, the challenge is not just to understand
25:33how the brain works in general,
25:35but also to explain exactly how each one of us
25:39comes to be the unique individual we are.
25:42What is the basis of our own specific memories,
25:46emotions and thoughts?
25:49What is the basis of our personality?
26:06Dick Blingham is not the man he once was.
26:10Eight years ago, his wife Lynne began noticing changes in Dick
26:14that she could not explain.
26:19His personality has changed in that he is less aware
26:24of the effect his behaviour has on people.
26:28There's no... There's much less empathy than there used to be.
26:32He can get very agitated if things aren't going his own way,
26:37which he wouldn't have done before.
26:39He would have just sorted it.
26:43I live with the husband I love dearly,
26:46but we can't even watch a film together on television
26:49because he can't follow the plot.
26:53Dick's been diagnosed as having a degenerative brain disease.
26:57It's slowly destroying him.
26:59My wife was given to understand that it might well just be
27:04two years before I was in a mental...
27:08Well, I suppose some sort of home, anyway,
27:11and that she would not be able to look after me.
27:14But in point of fact, we've had seven years and it's gone pretty well.
27:18I must drive her to distraction, but I'm unaware of it.
27:22One of the strange parts of it is that I'm not aware of it.
27:26But I'm unaware of it.
27:28One of the strange by-products of my illness is that you don't really mind.
27:32So...
27:34..from that point of view, it's pretty good.
27:40What's remarkable about this disease
27:43is that as cells are gradually dying off in the front of Dick's brain,
27:47his entire personality is undergoing a dramatic change.
27:52The frontal lobes are the most sophisticated part of the brain,
27:56the part that makes us individually different from each other.
28:00They're very important for our temperament,
28:04our social interaction, our personal style.
28:08It all depends very much on the frontal lobes.
28:13Damage to his brain is turning the person Dick was
28:17into a very different individual.
28:19Who is behaving in very different ways.
28:26He's always been very good at telling jokes and stories.
28:30But now he does upset people sometimes in some situations
28:34because the jokes are inappropriate.
28:39Although he was told some of the things he'd been doing,
28:43it didn't matter to him.
28:45He didn't see the significance of them.
28:48And nor do I wish him to know some of the time.
28:51If he doesn't feel it in himself,
28:53then what's the point of just always pointing out to him
28:57what he's doing, what he's saying?
29:02As Dick's condition has worsened, something incredible has happened.
29:06The brain damage has released abilities that Dick never knew he had.
29:11He has become overwhelmed with the urge to paint.
29:19I've put diluted ink onto the paper.
29:24The idea really is to just build up a pattern,
29:28which later I will try to interpret into...
29:35..some reasonable picture.
29:38As his brain continues to degenerate,
29:41this new skill, sadly, will fade.
29:45And this new personality will disappear.
29:59I never reckoned I could...
30:01I never reckoned I could do this.
30:05I never reckoned I could paint anything in particular.
30:09I was never wonderful about that.
30:13I've... I enjoyed doing art at school,
30:16but that was 40-odd years ago,
30:19and I haven't done any... any art since then.
30:23I think the interesting thing is not whether the pictures are any good,
30:28that's almost an irrelevance,
30:30but the fact that you're doing it for the first time in all that time.
30:35I quite like that image,
30:37although I'm a little unsure as to what's happening here.
30:44We don't know why Dick's brain damage has changed him so dramatically.
30:49But for me, this tragic condition is proof that one day
30:54we'll be able to explain individual personality and creativity
30:59in terms of physical processes within the brain.
31:12I think one has to think of the brain as a number of interactive modules
31:18and that some perhaps inhibit or suppress the function of other modules.
31:24And so if you knocked out a module that was...
31:27that's main role was inhibitory,
31:30then you could have a gain of function of other parts of the brain.
31:36Maybe the disease has caused some widespread reorganisation
31:40in the basic circuitry of Dick's brain.
31:43We can't yet say.
31:45The neural roots of creativity must be complex.
31:51Many other types of brain disease
31:54can also have striking effects on people's artistic imaginations.
32:03In May 1889, a young artist was admitted to this mental asylum
32:08in the small French town of Saint-Rémy.
32:11He was suffering from severe mental delusions
32:15and was quickly diagnosed as having epilepsy.
32:19His name was Vincent van Gogh.
32:24Sitting among the very scenes that van Gogh captured on canvas
32:28poses intriguing questions as to how he saw the world.
32:31Is it possible that the physical upheaval in his brain
32:34somehow transformed his perceptions?
32:36Could it be that the epilepsy led not only to his crippling mental problems
32:41but at the same time to his awesome creativity?
32:49MUSIC PLAYS
33:01I believe van Gogh saw the world differently
33:04and we are so lucky that he was able to put it on the canvas
33:07and let us see it through his eyes.
33:11For the last 30 years, Shahram Kashbin has attempted to piece together
33:16the effect that van Gogh's epilepsy had on his life and his art.
33:20In the case of Vincent van Gogh, it was a type of seizure
33:24that had more to do with his ideas and rush of ideas and his behaviour
33:29than had to do with the traditional aspect of epilepsy
33:33where patients fall to the ground, jerk all over and foam at the mouth
33:36and lose consciousness.
33:39Kashbin believes that in van Gogh's case,
33:42the epilepsy affected the area of his brain just behind his temples,
33:46known as the temporal lobe.
33:51Sensory integration takes place there, vision and hearing,
33:55because it comes in there and gets processed there.
33:58So it's easy to see how a disturbance in this area
34:04could create a different sensory experience.
34:08The epilepsy that van Gogh probably suffered is not uncommon.
34:12But in a small number of cases,
34:14the resulting uncontrolled brain activity
34:17can permanently change the way a person perceives the world.
34:29I see colours very vividly.
34:32I love rainy days because it brings out the colour in the buildings around here
34:38and I can enjoy them even more.
34:45Like van Gogh, Rin Carter has had temporal lobe epilepsy all her life.
34:50Dr Kashbin has been working with patients like Rin
34:53to find out exactly how the epilepsy distorts their perceptions.
34:57Colours are brighter.
34:59Shades are not grey, that they're distinct.
35:04She describes that.
35:06That experiences, other than visual, also have the same connotation.
35:12Things tend to stand out, become more separated, become more vivid,
35:17become more outlined, if you wish.
35:20And I hear this over and over again from my patients and I hear it from her.
35:24When I was a student, I'd go to visit the library.
35:29I never checked out books, but I would go to visit the elevator.
35:35It was a red and a green arrow.
35:41I'm sure to everybody else, very ordinary colours,
35:44even maybe a little bit muted.
35:46But when the elevator was going,
35:49it just would make me feel so good to look at it.
35:52It was almost rapturous.
35:55One day, I made three hours of going up and down,
36:01just looking at those arrows and watching it change colour.
36:06I was like, oh, this is so beautiful.
36:09If epileptic seizures happen regularly in the temporal lobe,
36:13a sufferer's thoughts, emotions and actions can be altered permanently.
36:18Malfunctions here may sometimes even be the trigger
36:23for our most intense spiritual feelings.
36:32During his time at San Remy,
36:34Van Gogh began to display some extreme physical symptoms.
36:39During his time at San Remy,
36:41Van Gogh began to display some extreme character traits.
36:45Among his obsessive habits,
36:47his religious beliefs suddenly became far more intense.
36:53He studied to be an evangelist
36:56and then he was hired as a priest for a while.
36:59And the reason why they discharged him
37:01was because they said his zeal was scandalous.
37:04Imagine how religious he must have been.
37:07He must have been too religious for the church.
37:16On Sundays, Van Gogh would often visit three or four churches.
37:21Religion was beginning to consume his whole life.
37:28He was writing religious remarks on the walls,
37:31at one point writing, I am the Holy Spirit.
37:34These are above and beyond the religious experiences
37:37one would have expected.
37:41We'll never know for certain whether Van Gogh's religious beliefs
37:44were triggered by his epilepsy.
37:46But the very idea is fascinating.
37:48It raises the possibility that even our most spiritual experiences
37:52can somehow be boiled down to the firing of neurons inside our heads.
37:57Starting from a very early age,
38:01I would have these sensations
38:03that would make me want to talk about things
38:07that the other children didn't want to talk about.
38:11I just felt like I had a destiny to do something.
38:16For most of her life,
38:18Rin Carter has experienced vivid religious hallucinations.
38:28Her temporal lobe epilepsy
38:30seems to have been a key factor in her religious beliefs.
38:34One day, I had a dream
38:38where I was sitting in a chair,
38:41and I was looking up.
38:43His crown of thorns was not like the kind you always see.
38:50It wasn't all dried up and brown,
38:54and it was very alive.
38:57It was green and had a lot of light.
39:01And I had a vision of Jesus on the cross.
39:06It was very alive.
39:09It was green and had some leaves on it, even.
39:13That was a very big thing to me,
39:16to prove that this must be real.
39:20I thought God was helping me to have this experience.
39:31I don't think that I can for sure say
39:34that her entire belief system is based on this condition,
39:39but I can for sure say that this condition has affected it.
39:54When I look back at the vision of Jesus on the cross,
40:00I believe that I had a seizure.
40:11My religion is more now in the practical sense,
40:15but I keep hoping that something will come back to me.
40:21Cases of temporal lobe epilepsy give us an intriguing insight
40:25into the changes that can occur when the brain is disrupted.
40:29But is it really likely that all religious experiences
40:33can be boiled down to the firing of neurons?
40:39For thousands of years, we've looked to the heavens
40:43for answers to our questions.
40:46For thousands of years, we've looked to the heavens
40:49for answers that we couldn't find on Earth.
40:52In Jerusalem, the importance of religion to Christians,
40:57Muslims and Jews is powerfully evident.
41:02For millions of people, it remains a central pillar of life.
41:08There are many questions about religion
41:11that aren't easily tackled by science.
41:14What is the soul? Is there an afterlife?
41:17Does God exist?
41:19But surely that shouldn't stop us trying to explore
41:22what might be going on in the brain of someone
41:25who's having an intensely personal, spiritual experience.
41:29It may well be a very sensitive area of scientific investigation,
41:33but if we're going to try and understand every aspect of our lives
41:36in terms of brain function,
41:38then surely it's something that we can't simply ignore.
41:47Whatever is going on in the brain is not beyond science.
41:51Now, that doesn't remove its fascination or its mystery or its significance.
41:55It just tells us that the brain is generating it.
41:58What we have to do as scientists is to understand
42:01the pattern and what it means.
42:12In Canada, a series of controversial experiments are taking place
42:16that explore how the brain might generate spiritual experiences.
42:20The experiments are actually quite simple.
42:23Individuals are randomly selected, usually volunteers.
42:27OK.
42:30The subject is brought into the laboratory.
42:33They sit in an acoustic chamber.
42:37We blindfold them so that those neurons,
42:40which would typically be engaged in surveillance of your environment,
42:43can be recruited into the experience to amplify it
42:47so that the individual can experience it very vividly.
43:00How do you want to talk?
43:02The volunteers have no idea what the experiment is about.
43:06They are simply told to relax and describe what they experience.
43:10Is it like a forest fire?
43:13But it's really far away.
43:15Persinger has designed a method for stimulating the temporal lobe.
43:20It's a big hill or something.
43:23Like a fire.
43:25Coils in the helmet generate a magnetic field
43:28that amplifies the activity in this part of the brain
43:31and stimulates the thoughts and sensations produced there.
43:37Yeah, there it is.
43:39It's way over there.
43:41It's like an eye.
43:44It's moving.
43:46I'm getting closer.
43:50The experience is generated by the brain.
43:53The experiences generated certainly seem out of this world.
43:58It's black and there's a big eye.
44:00Ooh, bright light, nice purple.
44:03Yeah, that's not an eye anymore.
44:06It's gone.
44:08The kinds of experiences, they're always related to temporal lobe themes.
44:12Vibrations, movements,
44:15experiences of being out of their body,
44:19of moving through tunnels or shapes or orifices of some type,
44:23seeing bright lights.
44:25Tunnel.
44:28Tunnel. I'm in a tunnel again.
44:30Tunnel with a bright light.
44:33Like things are moving too fast.
44:36And I'm coming up the tunnel. This is me.
44:42Now the tunnel's going up.
44:45But Persinger can manufacture far more disturbing sensations
44:49than just visual hallucinations.
44:52If we apply the fields in a specific sequence,
44:56we can induce the experience of a sensed presence,
44:59that there are some entities standing beside the person,
45:03the idea of someone standing nearby.
45:05I don't feel alone.
45:08And I'm going really fast over bumps and bumps of water.
45:15His stimulation experiments
45:17have never yet produced a clear-cut spiritual experience.
45:21But Persinger's convinced that he has recreated
45:24many of the basic sensations that accompany religious belief.
45:28In our laboratory, it's context.
45:30You know you're safe, you know it's a laboratory, you know we're doing it,
45:34you know the experimenter's doing it,
45:36or something is involved with the experimenter.
45:38Black. I see a face.
45:41Well, suppose that same experience,
45:43the same richness and vividness and feeling of a presence,
45:46something taking over your body,
45:48occurred at 3 o'clock in the morning
45:50when you were by yourself in your bedroom.
45:52Somebody just shut the lid.
45:54Then, of course, there would be a different explanation.
45:57You wouldn't have the easy, pat explanation,
45:59well, the experimenter's are doing it.
46:01Instead, you'd have to have an explanation given to you by culture,
46:05and most explanations for an unusual phenomenon
46:08are attributed to gods.
46:11Cindy? What?
46:12We're coming in. Just relax, OK? Yeah.
46:17One thing we do know is that the experiences
46:20that we call god and mystical experiences are from the brain.
46:23And now we know we can experimentally duplicate them,
46:26at least fragments of them, in the laboratory.
46:28That means we can understand them more,
46:30and they're no longer just the privileged experiences of a few,
46:34or individuals who have been anointed to interpret these experiences.
46:39All people have them. It's a part of our brain.
46:41And like any talent,
46:42some people will have more of these experiences than others.
46:45The critical thing is that now science has the technology
46:48to find out how these experiences actually work.
46:56Although experiments like this
46:58only begin to throw light on the physical basis of mystical sensations,
47:02they are part of a growing attempt to understand personal experiences
47:06that, until recently, have been beyond the reach of science.
47:17In the course of this series,
47:19we will try to reveal the basic brain processes
47:23that lie behind every aspect of our mental lives.
47:28Not just spirituality, but memories,
47:32intelligence, and the very nature of conscious experience.
47:40We'll be seeking a scientific explanation for who we are.
47:46I don't think we should find this idea too upsetting,
47:49the idea that we might be reduced to a mere pile of neurons.
47:53We shouldn't be any the less awestruck by life.
47:56Maybe the real wonder is that 100 billion brain cells,
48:00working together, can produce so much.
48:20In the next programme, we'll find out what makes life worth living.
48:25How does the brain create the intense feelings
48:28of love, fear, anger and joy?
48:33We're going to explore our emotions.
48:55Transcription by ESO. Translation by —