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17 September 2014
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Heather Birt's numbers are coloured, and she sees them arranged in space
Derek Tastes of Earwax

Perhaps one in every hundred people experiences a blending of the senses.

Programme summary

Questions and answers about synaesthesia

NARRATOR (DILLY BARLOW): When someone talks to James he doesn't just hear the words, he also tastes them.

JAMES WANNERTON: I have a problem with the name Derek for instance which... it's like urgh it's horrible, its earwax.

NARRATOR: John sees colours when he hears numbers.

JOHN FULLWOOD: They're just like flashing colours, for example one would be a whitish colour and two would be an orangey colour.

NARRATOR: And Heather is able to make quick calculations because she literally sees her numbers around her.

HEATHER BIRT: I've got nought in front of me here and I have nought to ten and then ten to twenty in an L shape, then twenty to thirty and that's all on a plane.

NARRATOR: They all have a bizarre condition called synaesthesia, in which their senses are joined up. For a long time no-one took people like them seriously, but now it turns out they're not so different from the rest of us. And their condition may even help explain how we made that great evolutionary leap to develop language.

NARRATOR: Dorothy Latham has an extraordinarily colourful way of seeing the world... a world in which colours just jump out at her. They're triggered when she sees letters and numbers.

DOROTHY LATHAM: Manningtree is quite a mid green because of the big M at the beginning and my M is mid green. Norwich is a bright yellow word because my N's are bright yellow. The reality of it is white on blue but the images of the riot of colour are in my mind.

NARRATOR: And it's not just written words that produce this experience... spoken words have an even more curious effect.

TRAIN ANNOUNCER: Platform 12 is the delayed 12.03 train from Braintree. The delayed 12.03 arriving from Braintree is now approaching platform 12.

DOROTHY LATHAM: I see the words spelt out letter by letter, on a sort of ticker tape in front of my forehead here and I do see the letters in colour, in my colours.

NARRATOR: Of course, Dorothy knows the colours aren't really there. These colours are triggered by the intermingling of her senses of vision and hearing. It's a condition called synaesthesia.

DOROTHY LATHAM: I imagined everybody would be exactly the same until I spoke to school friends about it when it was about ten and they said you're imagining it and you're a weirdo and so I shut up about it and kept quiet.

NARRATOR: Adding colours to other senses is the most common form of synaesthesia... but it can get a lot stranger.

NARRATOR: Running this pub can get very confusing for James Wannerton. He has an unusual form of the condition, which means that he doesn't just hear words, he also tastes them.

JAMES WANNERTON: I see a customer, if I know his name I instantly get the taste of his name. There's somebody that comes in here that tastes of wet nappies... but it isn't that strong, I mean it's not nice and it doesn't sound very nice but it's not that strong a flavour, therefore it doesn't affect me as bad as much as say Derek would. I mean Derek, I don't find Derek offensive because it's earwax but because it's very very strong.

NARRATOR: James has no control over which taste is linked with which word.

JAMES WANNERTON: The problems I have are but I mean somebody will come in, they then order say a pint of that, I get the bacon rind taste, they then order a packet of roasted nuts and I don't get roasted nuts, I get some sort of peculiar burnt meat taste. They then pay me the fiver from which I get a taste of strawberry jam sandwiches, very very specific, I then have to give them their change, change invariably tastes of processed cheese, a cheesy taste.

NARRATOR: In everyday conversation he is bombarded with flavours.

NARRATOR: His synaesthesia can even set off a battle between real flavours and the ones that are triggered by words.

JAMES WANNERTON: If somebody says something to me, they're talking to me I can be doing this but whatever they've said I'll get the flavour, the flavour will come and I'm sitting here listening to him before tasting flavours while looking at this, smelling this.

JAMES WANNERTON: It's the conflicts, if somebody is saying do you like this and then I get a strong taste of yoghurt. I find it very difficult to sit there preparing sausages and bacon and eggs when I'm getting yoghurt and chocolate tastes and everything over the top of it, it makes me feel horrible.

INTERVIEWER: So what would work well for you if you had to spend more time in a kitchen?

JAMES WANNERTON: I'm getting confused, all these smells...

INTERVIEWER: Do you want to go and get a breath of fresh air?

JAMES WANNERTON: Would that be all right?

INTERVIEWER: Yeah of course it's all right.

JAMES WANNERTON: You know it's just all the smells.

INTERVIEWER: No that's fine yeah, just go and take a walk.

JAMES WANNERTON: I can't get these out my head. Sorry.

INTERVIEWER: That's all right.

NARRATOR: For decades synaesthesia baffled the scientific community and no-one could quite believe it was real.

NARRATOR: For a while hallucinogenic drugs were blamed, especially in the 1960s. Some put it down to an overactive imaginationo... thers thought it was caused by associations from childhood that had survived into later life. In the end no-one could find out what was causing it, so synaesthesia was placed in the same scientific category as séances and spoon bending.

NARRATOR: But Professor Ramachandran thought it should be taken more seriously. He's one of the world's leading brain researchers and at the University of California, San Diego he devised an experiment to test whether synaesthesia was real or not.

PROFESSOR VS RAMACHANDRAN: We decided to invent what you might loosely call a clinical test for synaesthesia. A way of finding out whether somebody's genuinely experiencing the colour, literally seeing the colours when confronted with certain numbers or whether they're just making it up or just crazy maybe.

PROFESSOR VS RAMACHANDRAN: Take a seat. A simple experiment, just look at this display and what do you see there?

NARRATOR: The volunteers were shown displays, in which on letter of the alphabet was arranged in a simple shape and then two other letters were added at random to make a confusing picture. They only had a short time to see if they could spot the hidden shape.

PROFESSOR VS RAMACHANDRAN: Do you see any shape?






JEFF COLEMAN: I saw a square.

JEFF COLEMAN: It looked like a triangle.

PROFESSOR VS RAMACHANDRAN: When you were viewing this what was your internal subjective experience?

JEFF COLEMAN: Well I'd see a field of letters, different colours and a red triangle would pop out or a red rectangle or something and I would just see it.

NARRATOR: According to PROFESSOR VS RAMACHANDRAN, Jeff had to be synaesthete. The only way he could see the hidden shapes so quickly was if the letters appeared to him as coloured.

PROFESSOR VS RAMACHANDRAN: This suggests that in fact he's not crazy, he's literally seeing those numbers tinged with colour. This was the first clear cut evidence that synaesthesia is an authentic early sensory process and it's probably caused somewhere in the sensory pathways in the brain, evoking the actual perception of the colour.

NARRATOR: So synaesthesia was real, not a trick of the memory or imagination. It sparked a new search for what could be causing it.

NARRATOR: One of the clues lies with people like Dorothy Latham. Seeing colours runs in the family.

DOROTHY LATHAM: This rather darkish blue is the colour B in my own particular coloured alphabet.

PETER LATHAM: A is a slightly paler yellow... also August would be around this colour as well.

DOROTHY LATHAM: The pink is like my P and also number seven is this shade of pink.

NARRATOR: Not only does her brother Peter have colour synaesthesia but so does Peter's son.

DOROTHY LATHAM: Oh there's some strong colours up there shall we go back up to where the colours are stronger?

PROFESSOR COLIN BLAKEMORE: I think it's pretty clear that it is genetically influenced, it certainly runs in families very consistently. It's probably as much influenced by genetic disposition as conditions like schizophrenia and autism and dyslexia for instance.

DOROTHY LATHAM: Neither of these colours are represented in my alphabet.

PETER LATHAM: The mauve would stand for V which would be a dark purple and also lighter but not as light as this Thursday.

NARRATOR: But Dorothy and Peter don't always see the same letters as the same colours.

PETER LATHAM: There's a strong red down here...

DOROTHY LATHAM: Oh yes, well that's my O colour, strong red.

PETER LATHAM: Oh that's interesting, that's more my R colour and Z.

NARRATOR: The fact that even in families, each synaesthete is affected differently, suggests that synaesthesia is not caused by a simple genetic mechanism.

PROFESSOR COLIN BLAKEMORE: It's probably only about seventy per cent influenced by genes, so there must be environmental influences that determine whether you're actually going to become synaesthetic or not.

DOROTHY LATHAM: I didn't think we did have any similarities but suddenly we've discovered a couple already but we've also hit on loads that are different.

NARRATOR: Having established a genetic link, scientists have now set out to discover what environmental influences might be shaping each person's Synaesthesia.

NARRATOR: Clues to those environmental influences might come from the mind of James Wannerton and from his ability to taste words.

JAMES WANNERTON: Covent Garden is chocolate, crinkly chocolate. Edgware Road is a sausage flavour, a very slight sausage flavour. Russell Square its celery with toffee.

NARRATOR: Today he's on his way to take part in a research project, which will look for any experiences in his life that might have shaped these bizarre associations.

JAMES WANNERTON: It's quite nice that, a melted fruit gum.

NARRATOR: Dr Jamie Ward is a neuro-psychologist who has been studying James for the past two years. He's found that James consistently links the same words with the same tastes. Now he wants to discover if there's a pattern to those links which may explain how they were first formed.

DR JAMIE WARD: Thanks for coming in today James. What I'd like to go through with you is the particular tastes that you get in response to some words so I'm just going to read aloud some words and if you just describe to me the best you can, any taste that you might get from them okay?


DR JAMIE WARD: Er lets start with the word might.

JAMES WANNERTON: I get a strong marmite flavour.

DR JAMIE WARD: What about the word wipe?

JAMES WANNERTON: That's marmite again.


JAMES WANNERTON: It's very weak so it is different from the other marmite taste but it's still marmite.

DR JAMIE WARD: Right, so what you're saying is both the word might and wipe have the taste of marmite.

JAMES WANNERTON: They do, yes.

DR JAMIE WARD: Okay, well that's interesting, because both of these words obviously have particular sounds in common. So let's try another word that sounds similar, what about the word light.

JAMES WANNERTON: Yeah, that's marmite again... and with lots of butter this time.

DR JAMIE WARD: What's really interesting about this is that it suggests that there's a structure to his synaesthesia and it's not just arbitrary associations between words and tastes but there is in fact a structure and a shape to this which might tell us a little bit about how it's come about and about how it's actually wired in.

NARRATOR: But Dr Ward has also noticed another pattern, which may explain how James's connections between words and tastes might have begun.

DR JAMIE WARD: Okay, let's try another word, what about seven?

JAMES WANNERTON: Seven's nice that, it tastes like... well the only way I can articulate it it tastes like Spangles, which are sweets, Spangles sweets but I mean I haven't had one of those in years but it's a sweet I used to have as a child.

DR JAMIE WARD: That's interesting because it suggests that some of your taste experiences are not for things that you're currently eating in your diet, they're for things that you used to eat before.


NARRATOR: Dr Ward has found that James's synaesthetic tastes are from his childhood. There are no associations with foods from later in his life like olives or curry.

JAMES WANNERTON: But a lot of those flavours I've noticed are sort of things like tinned carrots and processed peas, I must have had a pretty awful diet, mustn't I?

DR JAMIE WARD: So what's perhaps happened in James is that in his childhood during the process of vocabulary acquisition there's kind of been a chaining between the sounds of words with the sounds of the names of food, going back down to the actual concrete experience of tasting that food.

NARRATOR: What James shows is that childhood experience must be a vital environmental influence in shaping his synaesthesia. Having established this, scientists wanted to go a step further, to find out what was happening inside a synaesthete's brain.

NARRATOR: Important insights have come from studying John Fullwood. He sees colours that are triggered by spoken words.

JOHN FULLWOOD: They're just like flashing colours, for example one would be a whitish colour... two would be an orangey colour... four and five are sort of reddish colours...

NARRATOR: But for John, not all words produce colours. From childhood, his only coloured words have been ones that fit into sequences, like numbers or days of the week or months of the year.

JOHN FULLWOOD: I think as soon as I started to be aware of things that needed to be ordered I started to attach colours and spatial attributes to them.

NARRATOR: What is remarkable is that John is able to see these colours at all, because for all his adult life he's been blind.

JOHN FULLWOOD: It's a nice thing to have because it enables you to be able to distinguish things, one from another. You can distinguish something from something because they've got different colours.

NARRATOR: Because he is blind, John's synaesthesia cannot possibly be influenced by any signal from his eyes so he's an ideal person to study. His very real sense of seeing colours can only be triggered by something inside his brain.

NARRATOR: Megan Steven of Oxford University is conducting an experiment to discover what is happening inside John's brain, when he sees his synaesthetic colours. A scanner will show which parts of his brain are activated when he hears words.

MEGAN STEVEN: Okay, John we're gonna do the first experiment now, what I'd like you to do is...

NARRATOR: First she studies his brain activity when he listens to words that don't give him colours.

MEGAN STEVEN: Master... like... exquisite... society... more... okay John, how did that go?


NARRATOR: Neuroscientists have discovered that our different senses seem to be processed in separate areas of our brains, so the vision areas are usually only triggered by signals from the eye, the hearing areas only by signals from the ears and it's the same with other senses like touch.

PROFESSOR COLIN BLAKEMORE: If you look at the brain, the anatomy of the brain and how it's organised, look at where the obvious nerve bundles go to, it all looks as though the senses are completely separate from each other. You have the eyes connecting through to particular parts of the brain and the ears and then the tongue and so on, they're all very very separate from each other.

NARRATOR: As expected John's brain scan shows activity in his sound processing areas when he listens to these ordinary words.

MEGAN STEVEN: Okay, here we go.

NARRATOR: But Megan Steven then reads John a list of words that do trigger his colours.

MEGAN STEVEN: February, April, Saturday. Okay John, well done, now we're just gonna come and see what happens on the screen here.

NARRATOR: The scan now reveals what it is that is causing his synaesthesia. Not only is the sound area of the brain active, but parts of the visual area have been triggered as well. Areas, which should only be activated by a signal from the eye.

MEGAN STEVEN: When John hears words like Monday or January he sees a specific colour and you can see here the area of his brain that lights up when he sees that colour, an area of the brain we call V4, it's a visual area and it's an area that processes information about colour. And we also have another area that's lit up at the same time and that's an area we call V1, another visual area. If a sighted person were to look at red you would see the same areas of the brain activated but John, of course, is blind so we know that the only way he could be activating these areas of the brain that process vision and colour is through the synaesthesia.

NARRATOR: So Synaesthesia is caused by the creation of special working connections between areas of the brain which are normally quite separate.

PROFESSOR COLIN BLAKEMORE: That I think must mean that particular groups of nerve cells are becoming connected functionally somehow, connected together with each other so when one group of nerve cells fires off then another bunch somewhere else, maybe a long way away in the brain, very specifically fires off together with it and you get these conjunctions of sensation.

MEGAN STEVEN: Well done John, this is really interesting.

JOHN FULLWOOD: It makes me confident that I'm not actually making this up.

MEGAN STEVEN: We've got hard proof now, you can tell your wife that you weren't kidding all along.

NARRATOR: So it is these extra connections within the brains of synaesthetes which create for them the sense of a strange world that doesn't really exist. However, recent discoveries suggest that synaesthesia may not be so unusual after all... it may be something we all have.

NARRATOR: All summer long a secret experiment was underway at the Science Museum in London.

DR JAMIE WARD: Well, it's a very exciting project because we've come here to test over a thousand members of the general population so we've kind of taken the science out of the lab and what we're trying to find out is just how common is synaesthesia.

DR JAMIE WARD: So basically you're going to see a letter or number on the screen here. And we want you to choose the best colour that goes with them. So how you do that is up to you, there's no right or wrong answer. So just go with your instincts.

NARRATOR: The public didn't know they were being tested for synaesthesia. They also didn't know that after they'd done the test once they would be asked to repeat it. Synaesthetes should consistently link the same colours to the same letters and numbers in both parts of the experiment. Non-synaesthetes should be less consistent, as they are using guesswork.

DR JAMIE WARD: What we find is that the scores of people who don't have synaesthesia normally lie between 0 and 50 per cent consistent, whereas people with synaesthesia, when they're asked to choose the best colour, are normally between 80 and a 100 per cent consistent.

NARRATOR: The results show that nearly one in a 100 of us have this form of synaesthesia. So there could be as many as half a million people in Britain who see coloured letters and numbers.

DR JAMIE WARD: It suggests that if you start asking your friends and your relatives that it's not beyond the realms of possibility that you will soon find somebody who is a synaesthete. It might be somebody who you've gone to the pub with every week and all of a sudden you say you know do you think about A as being coloured, do you think about 5s being coloured and they'll say yes of course I do, you know everybody does. Well not everybody does but it is still quite common and you haven't got to look too far in order to find it.

NARRATOR: Jamie Ward's experiment has revealed a massive hidden population of synaesthetes... but he's gone on to make an even more startling discovery. Synaesthesia might be a condition that affects all of us.

NARRATOR: The discovery came when he began a study involving Dorothy Latham. Dorothy doesn't just see colours when she hears spoken words, she also sees colours when she listens to music.

DOROTHY LATHAM: As I play the notes from low notes through middle to high, the colours change for each note in slight gradations and they go from the purples and blacks and dark browns through greens and mid browns to bright colours like yellow and white.

DOROTHY LATHAM: So as I play these colours will be changing in my mind.

DR JAMIE WARD: What we were keen to find out with Dorothy was whether or not it was just a simple random association of colours with notes or whether there was an underlying logic. What we did with Dorothy is we presented her with a whole series of notes over three octaves in a random order. For each of the notes we presented her with a colour palette of a wide range of colours and asked her to choose the best colour that goes with that particular note and we got some amazing results. So what you can see here is that for the low pitched notes we've got these darker purple and brown colours and as we move further up we get oranges and yellows and right at the top end it's more white. So we've got this amazing pattern going from dark to light. What this suggests is that there is some organising principle which dictates how particular musical notes become associated with particular colours.

NARRATOR: But the big surprise came when he repeated the experiment with a control group of non-synaesthetes.

DR JAMIE WARD: This is what we found for a typical control subject. So differently from Dorothy you haven't got a gradual transition from one colour to the other, but nevertheless you can discern some kind of trend where there are darker colours for the low pitched notes and much lighter colours for the high pitched notes. What our results suggest is that beneath the surface we all have mechanisms that link together sound and vision and the mechanisms seem to be pretty much the same in both synaesthetes and other members of the population.

NARRATOR: So we're all in a way synaesthetes, even if we don't realise it. Our senses of vision and hearing are linked together within our brains. It's just that some people experience a more exaggerated version.

PROFESSOR COLIN BLAKEMORE: What's really extraordinary about synaesthetes is that they have the experiences, they have the experiences as strongly and vividly and genuinely as your experience of looking at me, so it touches on the whole issue of what it is about certain kinds of brain activity that lead to awareness.

NARRATOR: But if synaesthesia is so widespread, it begs the question why? Can there be some strange evolutionary benefit to human beings in having senses that intermingle and if so, what could it be?

NARRATOR: An important clue has come from Heather Birt.

NARRATOR: Heather sees coloured numbers which are arranged in three dimensional space around her. She has what is known as a number line.

HEATHER BIRT: I've got 0 in front of me here, and I have 0 to 10 and then 10 to 20 in an L shape, then 20 to 30 and that's all on a plane, then 30 to 40 which is above, 40 to 50, 50 to 60 and so on in tens all the way up to a 100 and then the block repeats itself exactly up to 200 and so on in blocks all the way up to a 1000 here... and then it carries on forever.

NARRATOR: Heather's number line suggests that her synaesthesia has an extra dimension. The mechanism that links numbers to colours also seems to connect to the part of her brain that produces a sense of space.

NARRATOR: It's an aspect of her synaesthesia with a real practical benefit. It helps with her maths. By moving around her number line she's able to calculate her change.

HEATHER BIRT: Thank you very much, cheers. It is difficult for me to imagine anyone else doing maths in another way as it probably is for you to work out how I do it with my visual thing because it's the only way that I know.

NARRATOR: And she's not alone in having a number line. John Fullwood also sees numbers in space. He sees days of the week, months of the year and years themselves around him, including the year of his birth.

JOHN FULLWOOD: From where I'm sitting, it's back there.

INTERVIEWER: Is 1949 back there?


INTERVIEWER: And where's 2004?

JOHN FULLWOOD: Well 2004 is where I am now.

INTERVIEWER: And what about 2020?

JOHN FULLWOOD: Oh that's over there.

NARRATOR: Jamie Ward decided to find out just how common this ability to work with numbers by arranging them in space was among synaesthetes. He found it was widespread.

DR JAMIE WARD: Lots of synaesthetes said that they have number lines in which numbers were arranged out in space. And this was very exciting because it was as many as 60 per cent of people who have coloured numbers also see numbers being arranged in space, which is a huge percentage of the synaesthetic population.

NARRATOR: But the true revelation came when he ran an experiment with a group of non-synaesthetes.

DR JAMIE WARD: One experiment involves showing numbers on a computer screen and what people have to do is make a decision about those numbers with their left and their right hand. So for example they might judge whether a number is odd or even. And what we find is that people are faster at responding to small numbers such as one or two with their left hand and faster at responding to larger numbers such as eight and nine with their right hand. So it appears as if we all have a number line that runs from one on the left through to nine and so on on the right hand side.

NARRATOR: So it seems we all have a sense of numbers arranged in space.

NARRATOR: These number lines suggest to Dr Ward a reason why synaesthesia might exist in the human population.

DR JAMIE WARD: One clue for why synaesthesia might survive is that it enables us to deal with abstract concepts such as numbers and other sequences in a very concrete way using our senses.

DR JAMIE WARD: What we do is we actually put these sequences into a special arrangement and this seems to be common to each and every one of us but its something that Synaesthetes are very aware of but most of us are not aware of.

MAN IN PARK:Yeah hi mate, yeah hi.

NARRATOR: So synaesthesia may be a more extreme form of something we've all had to develop.

MAN IN PARK: You've booked a table yeah? What six people, no you need to make it more, about eight.

HEATHER BIRT: Thirty to forty.

NARRATOR: Synaesthesia could be a manifestation of how we have learned to work with abstract concepts... to manipulate numbers and ideas. Something that has defined our species and helped shape our civilisation and some scientists go even further. They think synaesthesia may help explain another critical skill that defines us as human... our creativity.

NARRATOR: This idea was developed when one scientist began to wonder about the genetics of synaesthesia. What purpose did these genes actually serve?

PROFESSOR VS RAMACHANDRAN: Very often in biology when you find a gene that doesn't have an apparent function, a non-functional gene, there's usually hidden agenda. So what might the hidden agenda be in the case of synaesthesia, why is it so widely prevalent?

NARRATOR: When he looked for answers, one thing in particular struck him.

PROFESSOR VS RAMACHANDRAN: The clue comes from the fact that synaesthesia is eight times more common among artists, poets and novelists than the general population.

NARRATOR: He began to develop a daring theory. Could synaesthesia help explain creativity? He started to look at artists and their influences.

NARRATOR: Aldeburgh, on the Suffolk coast. The light and landscape here have long attracted artists. Jane Mackay is a painter and the inspiration for her work starts with her synaesthesia.

JANE MACKAY: The sea is quite complex, it has a velvety beige bit to it, it also there, just how that... that oom boom of the wave coming down is quite grey and expanding. There's also the sound of the pebbles being pulled back by the sea. It's some sort of bluey grey sort of sound. It is absolute bliss because all I have to do is just listen to some music and I have got so much I want to paint, I can hardly breathe.

NARRATOR: She's exhibiting paintings that are inspired by an opera by Benjamin Britten who lived and worked here.

NARRATOR: The opera is based on a disturbing ghost story, the Turn of the Screw.

JANE MACKAY: The purple just appeared... almost subconsciously here because with the colour of the two main instruments here, which is the alto flute and the bass clarinet, and to me they were absolutely purple velvet, they couldn't have been anything else.

JANE MACKAY: This one is variation one of the opera and I saw it as this incredibly sharp shaft of coloured light, rising out of the centre on a blue background.

JANE MACKAY: It gets more and more dissonant and more and more spooky really, that's why all these sort of jangley shapes came in, almost like cut glass.

NARRATOR: Many famous artists have been synaesthetes, including the jazz legend Miles Davies... and the painter Kandinsky.

NARRATOR: No-one believes that synaesthesia directly causes creativity, but experiencing one sense in terms of another can be a source of artistic insight.

PROFESSOR VS RAMACHANDRAN: The basis of creativity is seeing unexpected links, sometimes even making seemingly random links and picking the ones which make sense but which are beautiful, whatever that means. This is the basis of all creativity, whether in poetry or in visual art or in literature.

NARRATOR: Professor Ramachandran was particularly interested in one type of creativity used in everyday speech - metaphors. Ways of speaking which connect different concepts. He's noticed that these often involve links to the senses.

PROFESSOR VS RAMACHANDRAN: Our language is replete with what we might call synaesthetic metaphors, where you are sort of linking different sensory systems in metaphorical usage. As, for example, you say loud shirt. My shirt's not making any noise, why do you call it loud shirt, you instantly understand what I'm talking about. It heightens your appreciation of its vivid colour. Or when you say cheddar cheese is sharp. Obviously, cheese isn't sharp, if you rub it on your skin it's soft but then you say well no no no, I mean it tastes sharp but there's a circularity and we're using a tactile adjective to describe a taste.

NARRATOR: Ramachandran believes that this ability to see and express one thing in terms of another is central to the artistic process.

NARRATOR: Take for example Shakespeare. The Globe Theatre in South London. Director Tim Carroll has seen how powerfully Shakespeare's metaphors work on audiences today.

TIM CARROLL: Take something like my heart has turned to stone, we know that somehow it isn't really your heart that's doing the feeling and your heart hasn't really turned to stone but it's so much more immediate and so much more real to us to hear that your heart has turned to stone than if you simply said my feelings have become rather cold or hardened.

NARRATOR: Many of Shakespeare's metaphors are synaesthetic, involving a link to the senses.

TIM CARROLL: When Shakespeare uses the expression bitter cold he's connecting the feeling of coldness, the taste of bitterness and putting them together. Now logically that may not make any sense but for all of us it works, we feel it's right.

NARRATOR: But Tim Carroll believes the genius of Shakespeare comes when he goes beyond sense metaphors to ones which involve links to more abstract ideas.

TIM CARROL: One of my favourites is from the Tempest, this music crept by me upon the waters, which brings together an abstract music with something so real as to creep. What kind of animal it is that might creep by Ferdinand upon the waters we don't know but it creates an image in our minds which is exciting.

PROFESSOR VS RAMACHANDRAN: I think that use of metaphor may rely on mechanisms similar to those used in synaesthesia. One highly speculative idea is that maybe the same genes which give rise to synaesthesia, when expressed more diffusely, may be more prone to make these links across different conceptual realms, therefore make you more creative, more imaginative, make you more prone to metaphor in other words.

NARRATOR: He believes that synaesthesia and creativity may share a similar genetic basis, an ability to open links within our brains, not only between senses but also between concepts. If this is so, it's an extraordinary insight. But he thinks synaesthesia may explain even more. It may also cast light on one of the most fundamental scientific puzzles of them all... how this started.

NEIL ARMSTONG: It's one small step for man... one giant leap for mankind.

PROFESSOR VS RAMACHANDRAN: The emergence of language has always been an extremely controversial topic.

MARGARET THATCHER: The lady's not for turning.

BILL CLINTON: I did not have sexual relations with that woman.

PROFESSOR VS RAMACHANDRAN: How do you start with the grunts and groans and howls, of our ape like ancestors and then evolve all the sophistication of a Shakespeare or a George Bush? This is one of the big puzzles of language. How do you evolve an arbitrary set of symbols to denote objects and events and relationships in the world. Did our ancestors all sit next to the fireplace and say 'axe', everybody say 'axe' after me, 'axe'? Obviously not, that's not how it got started. But if that didn't happen, how did it get started?

NARRATOR: He's come to Pacific Beach in California to test his theory on how language might have started. He believes that our common synaesthetic ability to link sounds and objects may have been the springboard to language.

PROFESSOR VS RAMACHANDRAN: I'm gonna do a simple experiment right here on the beach. To test this, we're gonna take two shapes, one of which is kind of round and the other is sort of jagged and we're gonna give them to people and ask them to tell us which one is a booba, which one is a kiki. These are just nonsense words and we're gonna see if there is any non-random correspondence between one shape and one sound. One of them is booba, the other is kiki, which is which?

PERSON AT BEACH: Booba and kiki.

PROFESSOR VS RAMACHANDRAN: This is kiki, this is booba?

PERSON AT BEACH: I think that's booba and that's kiki


PERSON AT BEACH: Well that's a kiki and that's a booba.


PERSON AT BEACH: Pretty sure.

PERSON AT BEACH: I'd say this is booba, this one is kiki.


PERSON AT BEACH: It just looks like a booba, thank you.

PERSON AT BEACH: Booba and kiki.

PROFESSOR VS RAMACHANDRAN: Well, when we showed people these shapes and said one of them is booba the other is kiki, tell me which is which, the majority of them, 99 per cent of them of them spontaneously said that's a booba and that's a kiki without even thinking about it.

PERSON AT BEACH: Kiki, booba.

PERSON AT BEACH: Kiki, booba.

PERSON AT BEACH: This one's booba and this one's kiki

PROFESSOR VS RAMACHANDRAN: Excellent, very good. This means there is a non-arbitrary correspondence, a spontaneous tendency in all of us to pick the bulbous amoeboid shape as the booba, so the gentle undulation of the sound contour represented in the hearing centre in your brain mimics the gentle undulation of the visual contour, similarly kiki has a sharp edge to it, sharp sound and that's mimicking the sharp inflection of the visual contour of the kiki and this is what you need, this initial bias is what you need to get the first words going.

NARRATOR: Ramachandran believes this synaesthetic connection between our senses of hearing and vision was an important initial step towards the creation of words. Our earliest ancestors first started to talk by using sounds that actually evoked the object that they wished to describe. But that was only part of the process. He found that there was a cascade of other links in our brains which reinforce this tendency.

PROFESSOR VS RAMACHANDRAN: Just as you have synaesthesia within sensory areas you also have the propensity to mimic hand movements with lip and tongue movements. Now this is probably because the hand and the mouth area are right next to each other in the brain and there is some cross activation of the kind you see in synaesthesia. What I am claiming is that there is a non-arbitrary mapping between the hand gestures and unconscious lip and tongue movements. For example un peux, diminutive, teeny weeny, tuna in Indian language versus enormous, large where the lips actually mimic what the fingers are doing and I don't think that's a coincidence.

NARRATOR: If he's right then language emerged from the multitude of synaesthetic connections within our brains.

PROFESSOR VS RAMACHANDRAN: We've got several types of interaction in place but we can see how in evolution all of these acting in conjunction start boot strapping each other and enhancing each other resulting in the whole avalanche that we call language.

WINSTON CURCHILL: Ah this is not the end, this is not even the beginning of the end, though but it is perhaps the end of the beginning.

NARRATOR: Synaesthesia is a truly strange phenomenon, but most synaesthetes enjoy having their senses intermingled. They wouldn't want to be without it.

JOHN FULLWOOD: It's so important to me. It would be like losing a finger or something, you would feel physically bereft that it had gone.

NARRATOR: James Wannerton is more ambivalent. His form of synaesthesia is often unsettling.

JAMES WANNERTON: Normally there's a lot of information on one of these signs here and I'm reading through, I'm getting the flavours which means I can't comprehend the exact town names or whatever and then I get totally confused. It's like where am I going, I don't know where I'm going, right, straight ahead, left?

NARRATOR: But given a choice he wouldn't want to be without it either.

JAMES WANNERTON: I enjoy probably about ten or fifteen per cent of this, the rest of it's bad.

INTERVIEWER: Given the choice, if they would say, look it's only gonna be the synaesthesia we take away, you will no longer taste words. What would you say?

JAMES WANNERTON: No, no though about it, no, I wouldn't want them to. No I couldn't. I'm just terrified of what it would take with it.

NARRATOR: Today, synaesthesia is no longer regarded simply as a bizarre or rare condition. It may now be opening a window into our greatest mysteries and some of our greatest achievements.

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