0:00:02 > 0:00:07We live in a world made of a kaleidoscope of colours.
0:00:07 > 0:00:12They are part of your everyday life and influence everything you do.
0:00:15 > 0:00:17From what you wear
0:00:17 > 0:00:21to what you eat, to how you live.
0:00:21 > 0:00:24They delight us.
0:00:24 > 0:00:26They guide us.
0:00:26 > 0:00:30But are these colours quite what they seem?
0:00:30 > 0:00:33Probably most people, when they open their eyes,
0:00:33 > 0:00:37very naturally, think they're seeing the world as it really is.
0:00:37 > 0:00:39Is the sky really blue?
0:00:41 > 0:00:43Are the leaves actually green?
0:00:44 > 0:00:47Is this definitely red?
0:00:47 > 0:00:49That's what people think they are seeing
0:00:49 > 0:00:54and it's useful to think that. But, in fact, none of that exists.
0:00:54 > 0:00:59It's an unsettling idea that colours may not really exist.
0:01:01 > 0:01:06And that's led researchers to ask a disarmingly simple question.
0:01:10 > 0:01:13Do you see red in the same way that I do?
0:01:13 > 0:01:16Is your green the same as mine?
0:01:16 > 0:01:20Do people across the world even see the same colours?
0:01:20 > 0:01:24Do we all see colour in the same way? Broadly speaking, that's true.
0:01:24 > 0:01:27Absolutely not. No-one sees the same colours.
0:01:28 > 0:01:32Now researchers may have a surprising answer to this age-old question.
0:01:34 > 0:01:38When it comes to colour, do you really see what I see?
0:01:46 > 0:01:50Dr Beau Lotto is fascinated by illusions.
0:01:51 > 0:01:55He believes they hold clues to how our senses work.
0:01:56 > 0:01:58To how we build the pictures of the world around us.
0:02:02 > 0:02:07But the illusion he's most interested in is one of nature's greatest tricks - colour.
0:02:09 > 0:02:12Colour is effectively an illusion, right?
0:02:12 > 0:02:14It's an illusion that helps us to see the world
0:02:14 > 0:02:16in a way that's useful to see.
0:02:18 > 0:02:21To try and explain how it works, he's designed an array
0:02:21 > 0:02:26of experiments, which will help explain how we each see colours,
0:02:26 > 0:02:29and if we even see the same ones.
0:02:29 > 0:02:33Do old people see colour in the same way as young people?
0:02:33 > 0:02:37Do men and women, or people from different cultures see colour in the same way?
0:02:39 > 0:02:43He's invited 150 members of the public, of different ages, gender
0:02:43 > 0:02:47and nationality, to take part in his world-first experiment.
0:02:50 > 0:02:53So my name is Beau and this is Rich here.
0:02:53 > 0:02:57We work together, and today we're going to study the perception
0:02:57 > 0:02:59of your colour vision, all right?
0:02:59 > 0:03:03So, you're actually going to be subjects in real experiments,
0:03:03 > 0:03:06so all the stuff we're doing today, we've never done before, literally.
0:03:06 > 0:03:08We have no idea what's going to happen.
0:03:14 > 0:03:19Over the course of the next few weeks, he'll put visitors to London's Science Museum
0:03:19 > 0:03:24through experiments which will test if colours can change your perception of time,
0:03:24 > 0:03:29which will look at how we feel about different colours,
0:03:29 > 0:03:33and ultimately whether any of us see the same colours at all.
0:03:34 > 0:03:39If we understand how the brain sees colour, we can understand how it does nearly everything else.
0:03:41 > 0:03:46And the search to understand why colour is an illusion, and how it works,
0:03:46 > 0:03:48begins with the colour red.
0:03:51 > 0:03:54Red is deeply rooted in the human psyche.
0:03:54 > 0:03:59It conjures up conflicting emotions, from passionate love
0:03:59 > 0:04:01to danger and even violence.
0:04:03 > 0:04:05But six years ago, a group of scientists
0:04:05 > 0:04:10wanted to investigate what effect wearing red might have on us.
0:04:10 > 0:04:13We started speculating about the role that it might play in humans,
0:04:13 > 0:04:15and whether the clothes that we wear
0:04:15 > 0:04:19could in some way manipulate our dominance in competitive situations.
0:04:21 > 0:04:26Russell wanted to find solid evidence about what effect red
0:04:26 > 0:04:30might be having, and it came from an unlikely source.
0:04:30 > 0:04:34From the Olympic sport tae kwon do.
0:04:34 > 0:04:37The Olympics offered a perfect situation for this.
0:04:37 > 0:04:41In the Olympics, in combat sports such as boxing and tae kwon do,
0:04:41 > 0:04:45and in the two forms of wrestling, individuals are randomly assigned
0:04:45 > 0:04:49either red or blue to wear depending on their position in the draw.
0:04:49 > 0:04:53And of course, if red has no effect, or colour has no effect
0:04:53 > 0:04:55on the outcome of sporting contests,
0:04:55 > 0:04:59then we'd expect to find an equal number of red and blue winners.
0:04:59 > 0:05:05When he studied the results of the bouts, he found that red and blue didn't win equally.
0:05:08 > 0:05:12We found, looking at the 2004 Olympics,
0:05:12 > 0:05:14there were many more red winners than blue.
0:05:14 > 0:05:19In these close contests, red individuals won nearly two thirds
0:05:19 > 0:05:23of the bouts that we were looking at in that particular study.
0:05:23 > 0:05:29So wearing red seemed to help people win in a competitive situation.
0:05:29 > 0:05:34But this on its own wasn't enough to convince him, so he dug more deeply.
0:05:39 > 0:05:43He came across an experiment by another group of scientists.
0:05:43 > 0:05:48It too was looking at whether colour affected the outcome of a tae kwon do match.
0:05:49 > 0:05:52They took the video of the tae kwon do and, in the original video,
0:05:52 > 0:05:58you had a fighter in blue and another in red. They manipulated that so the original red fighter
0:05:58 > 0:06:02was fighting in blue and the original blue fighter was fighting in red.
0:06:02 > 0:06:05And when they showed this footage to tae kwon do referees,
0:06:05 > 0:06:08in the original untouched footage,
0:06:08 > 0:06:11the red fighter was perceived to have scored more points.
0:06:11 > 0:06:12But in the manipulated film,
0:06:12 > 0:06:15it was again the red fighter who was judged to have more points,
0:06:15 > 0:06:19even though in the original footage they had been fighting in blue.
0:06:21 > 0:06:24Again the judges tended to favour the player in red,
0:06:24 > 0:06:27whether or not they deserved it.
0:06:27 > 0:06:30So the colour the athletes were wearing was enough to override
0:06:30 > 0:06:34the fundamental ability of the judges to give points.
0:06:35 > 0:06:39Clearly, the colour signal there is manipulating the way
0:06:39 > 0:06:43in which these contestants are being perceived by the referees.
0:06:45 > 0:06:48Russell published a scientific paper with his findings.
0:06:52 > 0:06:57Here was the first evidence that the colour you wear is more than just a fashion choice.
0:06:57 > 0:07:01If you wear red, it could make you a winner.
0:07:03 > 0:07:06But that raises a more fundamental question.
0:07:09 > 0:07:11If red has an impact on sporting encounters,
0:07:11 > 0:07:15a key question is to work out whether it's actually having an effect
0:07:15 > 0:07:18on the wearer of the red or it's something perceived by the opponent.
0:07:18 > 0:07:22The question was WHY wearing red might make you a winner.
0:07:25 > 0:07:30To try and answer this question, he's assembled a group of footballers.
0:07:31 > 0:07:35He's chosen football because there's a long-held belief,
0:07:35 > 0:07:39among fans anyway, that wearing red helps teams to victory.
0:07:41 > 0:07:46A lot of the top football teams that that have played over the last 30 or 40 years in England have worn red -
0:07:46 > 0:07:53Liverpool, Manchester United, Arsenal - and so there was a suggestion that there might be something there.
0:07:53 > 0:07:57His experiment is going to be a lot more scientific.
0:07:57 > 0:08:02It starts with a red, blue and white penalty shoot-out.
0:08:03 > 0:08:07This sort of experiment hadn't been tested in this way before.
0:08:07 > 0:08:14We know from looking at actual sporting data that wearing red does seem to influence
0:08:14 > 0:08:17the outcomes of sporting events, but what we don't really know
0:08:17 > 0:08:19is the mechanisms by how that comes about.
0:08:21 > 0:08:26What they'll be looking at is the effect of red on the physiology of the players.
0:08:26 > 0:08:33He's teamed up with someone who was initially sceptical about his research, Dr Iain Greenlees.
0:08:33 > 0:08:35I was really keen to do my own work,
0:08:35 > 0:08:40to look at it within a more experimental context, to test
0:08:40 > 0:08:44Russell's archival data within an experimental setting.
0:08:44 > 0:08:49So, together they've devised today's experiment.
0:08:49 > 0:08:54They've assembled 32 penalty-takers and 14 goalkeepers.
0:08:54 > 0:08:56OK, lads, thanks for coming down.
0:08:56 > 0:09:00Hopefully this will be an interesting and fun afternoon,
0:09:00 > 0:09:03lots of penalties scored, lots of penalties saved.
0:09:03 > 0:09:05Today, you'll be taking part in...
0:09:05 > 0:09:08For the experiment to work, the players cannot know
0:09:08 > 0:09:11that it's the colour red which is being scrutinised.
0:09:11 > 0:09:15..In each of those, you'll face five penalties from three
0:09:15 > 0:09:17or four different players.
0:09:20 > 0:09:24Before they start, saliva samples need collecting,
0:09:24 > 0:09:28heart rate monitors put on, and correct colour kit allocated.
0:09:31 > 0:09:35What they're hoping to find out is whether wearing red
0:09:35 > 0:09:37makes you feel stronger,
0:09:37 > 0:09:41or if seeing red makes you feel threatened.
0:09:43 > 0:09:46They're not expecting to see an obvious difference
0:09:46 > 0:09:49in number of penalties scored.
0:09:49 > 0:09:52They will be measuring two hormones in the footballers -
0:09:52 > 0:09:54testosterone and cortisol.
0:09:54 > 0:09:57If either of these changes in the men,
0:09:57 > 0:10:00it could explain why wearing red makes you a winner.
0:10:00 > 0:10:05Testosterone is a hormone that's related to dominance and status.
0:10:05 > 0:10:13We'd be arguing that those wearing red might see elevated levels of testosterone.
0:10:13 > 0:10:17If we go on the assumption that cortisol is a measure of stress,
0:10:17 > 0:10:22then what we might find is that penalty-takers
0:10:22 > 0:10:25wearing red would have lower levels of cortisol than penalty-takers
0:10:25 > 0:10:28wearing blue and white.
0:10:37 > 0:10:41We're hopeful. We expect the effects to be there but they are subtle.
0:10:41 > 0:10:44Simply wearing red doesn't mean you'll be a winner.
0:10:44 > 0:10:48There's no point me putting on red and hoping to play professional football,
0:10:48 > 0:10:51so we're hopeful but you never know in these experiments.
0:10:52 > 0:10:55Russell is about to reveal the true nature of the experiment
0:10:55 > 0:10:57to the unsuspecting footballers.
0:10:57 > 0:11:00It's been fantastic to have your involvement.
0:11:00 > 0:11:05As with many psychology experiments, we didn't give you the full story
0:11:05 > 0:11:08of what we were interested in looking at at the outset.
0:11:08 > 0:11:14The players are a bit surprised that colour might be having an effect on their performance.
0:11:14 > 0:11:17Being a Chelsea supporter, and they play in blue,
0:11:17 > 0:11:19I don't know how I feel about that.
0:11:19 > 0:11:24I paid no attention to what colour I had on. I don't like red. I support Tottenham.
0:11:24 > 0:11:27I play in dark blue and we win all the time so...
0:11:31 > 0:11:37It would be another four weeks before the hormone results came back.
0:11:37 > 0:11:41The first results were the testosterone analyses.
0:11:41 > 0:11:46If that was rising, it would suggest red was making the wearer more aggressive.
0:11:46 > 0:11:50We didn't really detect any evidence that there were differences based
0:11:50 > 0:11:54on the colour that the individual penalty-takers were wearing.
0:11:56 > 0:11:59Then they analysed the cortisol.
0:11:59 > 0:12:03The more modest its increase, the more confident the players were feeling.
0:12:05 > 0:12:08We found that there were subtle differences in what the colour
0:12:08 > 0:12:11was having on these cortisol responses.
0:12:13 > 0:12:18Even though all competitors seemed to show an increase in cortisol levels in advance of the penalties,
0:12:18 > 0:12:22this seemed to be suppressed by those individuals that put on the red shirts.
0:12:22 > 0:12:25If we can substantiate this with further analysis,
0:12:25 > 0:12:30it suggests that these individuals, by putting on the red shirt, may be going through an elevation
0:12:30 > 0:12:34in confidence, and as a consequence this suppresses their cortisol levels
0:12:34 > 0:12:38with cortisone being a marker of stress.
0:12:38 > 0:12:43If red is leading to an enhance in confidence, then any individual
0:12:43 > 0:12:45wearing red may experience that enhancement.
0:12:48 > 0:12:55Russell and Iain's study is just one part of a growing picture of the effect colour can have on all of us.
0:13:03 > 0:13:06At the Science Museum, neuroscientist Beau Lotto
0:13:06 > 0:13:11has devised his own experiment to test another aspect of how powerful red can be.
0:13:12 > 0:13:16Red in our society is an incredibly strong signal
0:13:16 > 0:13:18for warning, for making mistakes.
0:13:18 > 0:13:21People perform less well with an IQ test if they see red
0:13:21 > 0:13:24just before taking the IQ test. It's amazing.
0:13:27 > 0:13:29What Beau wants to find out is something which might seem
0:13:29 > 0:13:34rather bizarre - whether colours can change our sense of time.
0:13:35 > 0:13:40In order to do this, he's set up three colour pods.
0:13:40 > 0:13:43One white, one red,
0:13:43 > 0:13:45and one blue.
0:13:47 > 0:13:51The white pod is used as a control to compare to the red and the blue.
0:13:51 > 0:13:53OK, are you ready?
0:13:53 > 0:13:59What we're going to do is we want to get a sense of how long you think a minute lasts.
0:14:00 > 0:14:04Each of the 150 people taking part today are asked to stand in a pod
0:14:04 > 0:14:09bathed in colour and give a sign when they think a minute has passed.
0:14:09 > 0:14:12I'm going to turn you around, I want you to face the wall,
0:14:12 > 0:14:16and I want you to turn back around as soon as you think
0:14:16 > 0:14:17a minute's gone past.
0:14:22 > 0:14:26Here we're looking to see, if someone is bathed in red,
0:14:26 > 0:14:28it might increase their sense of anxiety
0:14:28 > 0:14:31and whenever we're in a sense of anxiety,
0:14:31 > 0:14:33we perform less well on pretty much anything.
0:14:33 > 0:14:38In contrast to blue, where people get a sense of calmness,
0:14:38 > 0:14:41we'll find out if that's true because, if it's true,
0:14:41 > 0:14:44people will be better able to judge time.
0:14:44 > 0:14:47In fact, they might even think a minute lasts two minutes. Who knows?
0:14:47 > 0:14:50150 people,
0:14:50 > 0:14:52young and old,
0:14:52 > 0:14:55men and women...
0:14:58 > 0:15:02All asked to estimate how long a minute took under different lights.
0:15:04 > 0:15:09After analysis, the colour-pod experiment showed some interesting results.
0:15:09 > 0:15:13So, this result, for me, was a bit of a surprise.
0:15:13 > 0:15:16In fact, I had a bet on it and I've lost.
0:15:16 > 0:15:18I thought red would do the opposite.
0:15:18 > 0:15:20I thought I'd feel in a state of arousal
0:15:20 > 0:15:22and time would go very quickly.
0:15:22 > 0:15:24In fact, it does it just the opposite.
0:15:25 > 0:15:29It turns out that colour can speed up time.
0:15:31 > 0:15:34But it's not the colour red that does it.
0:15:34 > 0:15:39If they are in a blue pod, a minute lasts 11 seconds shorter
0:15:39 > 0:15:41than if they are in a red pod.
0:15:41 > 0:15:4511 seconds is a phenomenally long time.
0:15:45 > 0:15:49Yet, all they were doing is surrounded by blueness
0:15:49 > 0:15:52and their perception of time sped up.
0:15:52 > 0:15:57So, colour does significantly affect your perception of the passage of time.
0:15:58 > 0:16:02One possibility is that red is altering our state of arousal.
0:16:02 > 0:16:05It's making us highly aware of our environment.
0:16:05 > 0:16:09So that would be very advantageous in a fight-or-flight response,
0:16:09 > 0:16:13where you want to be really noticing that things are happening around you.
0:16:13 > 0:16:15In a sense, you want time to slow down.
0:16:15 > 0:16:19So, maybe that is one possibility for why, if you embed yourself in red,
0:16:19 > 0:16:23time actually slows down in your mind.
0:16:25 > 0:16:30For scientists, colour is more than just an expression of personal taste.
0:16:30 > 0:16:32Red could be having an impact on your hormones,
0:16:32 > 0:16:34making you more confident,
0:16:34 > 0:16:37and blue seems to be able to speed up time.
0:16:40 > 0:16:44The clues about the deeper meaning of colour have emerged from people
0:16:44 > 0:16:48who we know don't see colour in the same way as most.
0:16:56 > 0:17:01Meghan Sims is a photographer and artist from Ontario.
0:17:03 > 0:17:06But she doesn't see colours the way you do.
0:17:08 > 0:17:11In fact, she has never seen a colour in her life.
0:17:19 > 0:17:23We live in a visual world and, more so, we live in a colour-coded world.
0:17:23 > 0:17:29So, for instance, asking directions in a strange city,
0:17:29 > 0:17:37people will use landmarks, such as "that red-coloured building".
0:17:37 > 0:17:42And then, you know, I'll sort of look confused and say, "Which one?"
0:17:42 > 0:17:49What makes Meghan unusual is that she lacks colour receptor cells called "cones" in her eyes.
0:17:49 > 0:17:54Cells that react to red, green and blue wavelengths of light.
0:17:57 > 0:18:01Favourite time of day is definitely dusk,
0:18:01 > 0:18:06when the sun has gone down, there is just a glow of the sun in the sky.
0:18:07 > 0:18:09It's just the perfect amount of light.
0:18:13 > 0:18:18She does have the separate cells, "rods", that help all of us to see in low light.
0:18:20 > 0:18:25When night rolls around, everything just comes alive
0:18:25 > 0:18:29and, um, I could lead you through the forest, at night.
0:18:32 > 0:18:34She sees the world in black and white.
0:18:39 > 0:18:42But she has, in a way, learnt to see colours...
0:18:45 > 0:18:48..by matching them to shades of grey.
0:18:52 > 0:18:58I learnt about colours by comparison and memorisation.
0:18:58 > 0:19:04So, I will learn a certain shade of grey.
0:19:06 > 0:19:08Of a Granny Smith apple.
0:19:08 > 0:19:15And, from that point on, that will be, to the best of my ability,
0:19:15 > 0:19:18that green, that apple green.
0:19:19 > 0:19:23Even though she can't see colour, it's an important part of her life.
0:19:26 > 0:19:30Putting on clothes in the morning, putting on make-up,
0:19:30 > 0:19:34erm, colouring my hair, you know, everyday things.
0:19:34 > 0:19:36Painting my house.
0:19:38 > 0:19:42You know, there's a billion different shades of green
0:19:42 > 0:19:45and I tend to like the ones that are really bright
0:19:45 > 0:19:48and make people want to be sick!
0:19:49 > 0:19:52As a clue to the fundamental power of colour,
0:19:52 > 0:19:56she experiences colours as linked to deep emotions.
0:19:59 > 0:20:04Red I will attribute things like danger.
0:20:04 > 0:20:11Blue brings out a sadness, or expresses a sadness,
0:20:11 > 0:20:13erm, or loneliness.
0:20:13 > 0:20:15Yellow...
0:20:17 > 0:20:18..I'm not sure about.
0:20:18 > 0:20:21I don't really understand yellow.
0:20:22 > 0:20:26It seems all of us, whether we can see colour or not,
0:20:26 > 0:20:29have a natural ability to link colour with emotion.
0:20:30 > 0:20:33Colour is deeply embedded with how we make sense of the world.
0:20:42 > 0:20:46It is the surprising power of the colour blue in our lives that is starting to be uncovered.
0:20:49 > 0:20:52It's an investigation that has brought a leading neuroscientist
0:20:52 > 0:20:55to a different sort of lab.
0:20:55 > 0:20:58A rather well turned-out restaurant in London.
0:20:58 > 0:21:01I think, increasingly, with so many hours of science,
0:21:01 > 0:21:02information has been siloed.
0:21:02 > 0:21:04What's happening, increasingly,
0:21:04 > 0:21:06is different groups are talking to each other.
0:21:06 > 0:21:11Neuroscientists are interacting with lighting designers, or architects.
0:21:13 > 0:21:15Reds and browns are often used by restaurant designers
0:21:15 > 0:21:19because they are colours that are believed to make you hungry.
0:21:23 > 0:21:24The lighting is often set up
0:21:24 > 0:21:28to give a warm and relaxing atmosphere to your eating experience.
0:21:32 > 0:21:35But one lighting designer decided to try a new concept.
0:21:35 > 0:21:38Instead of reds and browns, he chose blue.
0:21:41 > 0:21:45Why would you put blue light into a space to make it feel warm?
0:21:45 > 0:21:47It was a difficult concept to get across.
0:21:47 > 0:21:49It's counter-intuitive.
0:21:49 > 0:21:52You know, "We want to make your restaurant feel warm,
0:21:52 > 0:21:54"so we want to put blue light in it."
0:21:54 > 0:21:57It's very difficult to understand,
0:21:57 > 0:22:01but it does come right back to the pure science of how we see.
0:22:03 > 0:22:08It makes everything seem warmer, so your skin tones are warmer.
0:22:08 > 0:22:11The phrase I used to the client was that it is about
0:22:11 > 0:22:14making the beautiful people look more beautiful.
0:22:15 > 0:22:20But what Mark hadn't predicted was an unexpected effect the blue light had on diners.
0:22:23 > 0:22:26It seemed that night after night, at around ten o'clock,
0:22:26 > 0:22:29their behaviour started to change.
0:22:31 > 0:22:34Just at a time when you think people would start winding down,
0:22:34 > 0:22:36people started to perk up.
0:22:36 > 0:22:40There was a vibrancy to it, there was a texture to it
0:22:40 > 0:22:42and we didn't understand why that was.
0:22:44 > 0:22:49In trying to make the beautiful people look more beautiful, we also created
0:22:49 > 0:22:54this second effect of creating a vibrant, enhancing space
0:22:54 > 0:22:57that got better and better through the evening
0:22:57 > 0:23:01as this blue light component that we had in the presentation increased.
0:23:03 > 0:23:08To find out what was causing this behaviour, Mark turned to a scientist.
0:23:10 > 0:23:14Professor Russell Foster studies how the changing cycle of night and day
0:23:14 > 0:23:16creates a natural body clock within us.
0:23:18 > 0:23:23He wanted to discover exactly how these circadian rhythms are created in our bodies.
0:23:24 > 0:23:26We were fascinated, a few years ago,
0:23:26 > 0:23:28in trying to understand the mechanisms
0:23:28 > 0:23:30whereby the light-dark cycle
0:23:30 > 0:23:33is detected by the eye and regulates internal time.
0:23:33 > 0:23:37Scientists have long understood that the body clock exists,
0:23:37 > 0:23:41but how exactly light regulates it has been a mystery.
0:23:41 > 0:23:45We asked what we thought was a fairly naive question.
0:23:45 > 0:23:48How does the eye grab light to regulate internal time?
0:23:48 > 0:23:53He knew that clues lay somewhere in the biology of the human eye.
0:23:53 > 0:23:56But he could find no links between the rod and cone cells
0:23:56 > 0:23:57to the body clock.
0:23:57 > 0:24:01The rods and cones are fantastic for grabbing an instant image
0:24:01 > 0:24:02of the world,
0:24:02 > 0:24:07but they're not so good at getting an overall appreciation of the amount of light in the environment,
0:24:07 > 0:24:10hence time of day and hence for setting the clock.
0:24:10 > 0:24:14We couldn't understand how the rods and cones could do this.
0:24:14 > 0:24:17We wondered if we may have missed something.
0:24:17 > 0:24:21Maybe there's something else in the eye regulating this part of our fundamental biology.
0:24:24 > 0:24:26His team made a breakthrough.
0:24:29 > 0:24:32They discovered a completely new cell in the human eye.
0:24:35 > 0:24:38It's a cell called a photosensitive ganglion.
0:24:40 > 0:24:42It plays no part in seeing the world,
0:24:42 > 0:24:47but this elusive cell does seem to play a vital role in regulating the body clock.
0:24:48 > 0:24:51This is more than a receptor regulating the clock.
0:24:51 > 0:24:56These photo-receptors are plugged into a variety of structures in the brain.
0:24:56 > 0:24:58The sleep structures, the arousal structures,
0:24:58 > 0:25:03so what these photosensitive cells do is regulate broad areas of physiology.
0:25:03 > 0:25:08Not only our body clock, but our levels of arousal, our levels of alertness and awake,
0:25:08 > 0:25:12and, indeed, our propensity to go to sleep or wake up.
0:25:15 > 0:25:19Crucially, this cell that sends a signal to your brain to wake you up
0:25:19 > 0:25:23was sensitive to only one wavelength of light - blue.
0:25:28 > 0:25:31This is why the people having dinner were waking up at ten o'clock.
0:25:35 > 0:25:40For Russell, this new scientific understanding is set to change how we use colours.
0:25:42 > 0:25:44- Hello, good to see you. - Nice to see you again.
0:25:45 > 0:25:49Together, they are using this new understanding of colour
0:25:49 > 0:25:53to design lighting for where we work and where we live.
0:25:53 > 0:25:57- OK, so what do you think? - Well, it's blue.- It's blue.
0:25:59 > 0:26:04Scientists are now starting to understand that colours do more than show us how the world is.
0:26:04 > 0:26:07They powerfully shape how we feel as well.
0:26:09 > 0:26:12But to really understand the fundamental power colour has over our lives,
0:26:12 > 0:26:16you have to look to clues from the very beginning.
0:26:16 > 0:26:21To how and why we learnt to see colour in the first place.
0:26:21 > 0:26:25I think you deserve a toast. Cheers!
0:26:32 > 0:26:37In Washington state, Professor Jay Neitz has been trying to answer
0:26:37 > 0:26:40the big questions about colour for the last 30 years.
0:26:40 > 0:26:44There are so many different emotional reactions that people have to colour
0:26:44 > 0:26:49and I would really like to understand why.
0:26:51 > 0:26:56Probably my favourite scene in any movie is the scene in the Wizard Of Oz,
0:26:56 > 0:26:58where the whole film is black and white
0:26:58 > 0:27:00and then there is that scene
0:27:00 > 0:27:02when suddenly it goes to Technicolor.
0:27:02 > 0:27:08And just the impact it has on the audience is fascinating to me.
0:27:11 > 0:27:14He believes the clues to the power colour exerts in our lives today,
0:27:14 > 0:27:17lie deep in our evolutionary past...
0:27:19 > 0:27:24..beginning at a time when our earliest ancestors were a humble, single-celled organism,
0:27:24 > 0:27:26living in the murky depths of the oceans.
0:27:28 > 0:27:33When the Earth was covered with water and all organisms had just one cell,
0:27:33 > 0:27:36the only thing to see was the sky overhead.
0:27:38 > 0:27:41Life on Earth is dependent on energy from the sun.
0:27:43 > 0:27:46But these one-celled organisms had a problem,
0:27:46 > 0:27:50and that is that they had to be able to harvest the energy
0:27:50 > 0:27:52from the longer wavelengths -
0:27:52 > 0:27:54the oranges, the yellows and the reds -
0:27:54 > 0:28:00but they had to be able to avoid the damaging, lethal, ultraviolet rays.
0:28:00 > 0:28:04It is the earliest signs of why colour mattered.
0:28:04 > 0:28:09These single cells moved up and down in the oceans to avoid certain wavelengths of damaging light.
0:28:11 > 0:28:16In the middle of the day, they used to send it away from the surface of the water,
0:28:16 > 0:28:21down low enough where the UV was not intense.
0:28:21 > 0:28:26Then, at dawn and dusk, they would come up to the surface
0:28:26 > 0:28:31to capture those longer wavelength lights and that is how they got energy.
0:28:33 > 0:28:38Our earliest sensitivities to colour were a simple two-colour system -
0:28:38 > 0:28:39blue, yellow.
0:28:43 > 0:28:45But as life on Earth evolved and changed,
0:28:45 > 0:28:49the way our early ancestors processed colour changed, as well.
0:28:52 > 0:28:58It was around 40 million years ago that primates developed
0:28:58 > 0:29:00another set of structures in the eye.
0:29:00 > 0:29:04These ones sensitive to red and green.
0:29:04 > 0:29:11The main advantage of adding an extra dimension of colour vision is
0:29:11 > 0:29:13colour is like a language.
0:29:13 > 0:29:16It would be like adding to your vocabulary.
0:29:16 > 0:29:18Hello.
0:29:18 > 0:29:23There is an entire communication throughout the entire biological world
0:29:23 > 0:29:27that's dependent on this very elaborate colour-vision system.
0:29:31 > 0:29:35It was when it was useful to recognise the colours of fruits for food
0:29:35 > 0:29:41and the warning signs of nature, that we gained the red-green colour cones.
0:29:41 > 0:29:45One thing we can imagine, then, it was this that gave them
0:29:45 > 0:29:49the huge advantage and was responsible for the explosion
0:29:49 > 0:29:52of all the different kinds of primates we see now
0:29:52 > 0:29:56that have exactly the same beautiful colour vision like humans do.
0:29:57 > 0:30:01For us as a species, the way we learnt to see colours has a history.
0:30:04 > 0:30:09To blue-yellow colour sensitivity, we added red and green,
0:30:09 > 0:30:12expanding our very own language of colour.
0:30:19 > 0:30:23It's that history that Jay believes plays out today.
0:30:29 > 0:30:33And helps explain why we have such different reactions to colours.
0:30:35 > 0:30:38Meet Dalton.
0:30:38 > 0:30:40Meet Sam.
0:30:42 > 0:30:49They are squirrel monkeys that Jay has been working with for the last four years.
0:30:50 > 0:30:54Like all squirrel monkeys, when they arrived at Jay's lab,
0:30:54 > 0:30:58they were colour-blind, and couldn't see reds or greens.
0:30:58 > 0:31:02The squirrel monkeys have red-green colour-blindness.
0:31:02 > 0:31:04So the thing that red-green colour-blindness means
0:31:04 > 0:31:08is that these animals that have that, and humans too,
0:31:08 > 0:31:12they completely lack the sensations of either red or green.
0:31:16 > 0:31:20The big question was, does this change the way that the brain
0:31:20 > 0:31:25interprets the signals from the eye, so they would have an experience of colour vision
0:31:25 > 0:31:27that would be like what a human would?
0:31:27 > 0:31:31His team did something remarkable to these monkeys.
0:31:31 > 0:31:34They gave them the missing receptors in their eyes,
0:31:34 > 0:31:38and allowed them to see the reds and greens which had been invisible.
0:31:38 > 0:31:42He wanted to find out whether having these new cones in their eyes
0:31:42 > 0:31:46would allow them to see new colours.
0:31:48 > 0:31:53All of a sudden, they were able to pick out those red dots and green dots against the grey background.
0:31:53 > 0:31:59Probably a thing that amazed us the most, besides the fact that it worked at all,
0:31:59 > 0:32:03is that it seemed they were able to get this new colour sensation
0:32:03 > 0:32:06immediately, as soon as the new thing turned on.
0:32:06 > 0:32:12So somehow, the brain was able to make some kind of sense out of this immediately.
0:32:13 > 0:32:16This was the moment when Jay could study in a lab
0:32:16 > 0:32:20something that happened nearly 40 million years ago.
0:32:20 > 0:32:24With their new sense of red-green colour vision, Sam and Dalton could,
0:32:24 > 0:32:30for the first time, point to the green and red dots on the screen.
0:32:30 > 0:32:33And crucially, when it came to feeding time,
0:32:33 > 0:32:38they were able to associate colours with different coloured food.
0:32:38 > 0:32:41And so over time, they learnt to associate different colours
0:32:41 > 0:32:44with different objects, and now they take on lives for themselves,
0:32:44 > 0:32:48they say, "Oh, this is a food I like, so I like red."
0:32:51 > 0:32:54But this is the key to how colours became connected to emotions.
0:32:54 > 0:32:58If the monkeys like red fruit,
0:32:58 > 0:33:03then they learnt to associate the colour red more generally with pleasure.
0:33:05 > 0:33:11And what that means for our sense of colour is that the earliest colours we learnt - blue and yellow -
0:33:11 > 0:33:13have hard-wired emotional connections.
0:33:16 > 0:33:20Our associations with red and green, we've had to learn.
0:33:22 > 0:33:25So I think that maybe red-green colour vision
0:33:25 > 0:33:30is very different than blue-yellow colour vision, that's so deep inside of us.
0:33:30 > 0:33:35That those emotions are driven by something that we were born with.
0:33:35 > 0:33:37The fact that the blues are kind of calming.
0:33:37 > 0:33:44That's why people make such a strong distinction between cool colours and warm colours,
0:33:44 > 0:33:46as opposed to red and green,
0:33:46 > 0:33:50because those are very deep feelings that we're all born with.
0:33:50 > 0:33:53Whereas red-green is a modern thing
0:33:53 > 0:33:56that's completely a function of our cerebral cortex,
0:33:56 > 0:34:01and it's a learning process, just a little different buzz inside your head,
0:34:01 > 0:34:07but it takes a lifetime to be able to associate different colours with their real meaning.
0:34:08 > 0:34:12This shows that all colours are not equal.
0:34:12 > 0:34:17Blue digs in to our earliest evolutionary responses.
0:34:18 > 0:34:22Red and green are colours which we have had to learn.
0:34:22 > 0:34:26I think for all of us, the reason that we see red as the same
0:34:26 > 0:34:29is because we have shared experiences.
0:34:29 > 0:34:32Red is the colour of lipstick, red is the colour of blood,
0:34:32 > 0:34:35the colour of stop signs and flashing lights.
0:34:35 > 0:34:37And green is the colour of pastures.
0:34:39 > 0:34:42Essentially, our earliest experience of these colours
0:34:42 > 0:34:46was inextricably linked to pleasure and pain.
0:34:52 > 0:34:56To see these colours meant we could function more successfully in the world.
0:34:59 > 0:35:01This has stayed with us to the present day.
0:35:03 > 0:35:09But this new understanding of why different colours have such powerful effects on our lives
0:35:09 > 0:35:12raises another, more fundamental, question.
0:35:15 > 0:35:19How do we create colour in the first place?
0:35:25 > 0:35:31For Beau Lotto, colour is one of the most powerful illusions that nature plays on us.
0:35:31 > 0:35:36While for physicists, colour may be simply wavelengths of light,
0:35:36 > 0:35:39for Beau, his long fascination with illusions
0:35:39 > 0:35:43has been powerful proof that colour is more than that.
0:35:43 > 0:35:47I want to show you how quickly your brain can redefine normality.
0:35:47 > 0:35:51See the world in a completely new way, based on its experience,
0:35:51 > 0:35:55except in this case, it'll be an experience for one minute,
0:35:55 > 0:35:59and you're going to see something completely different as a consequence.
0:36:00 > 0:36:02Through this illusion,
0:36:02 > 0:36:07Beau wants to show how easily the colours you see can change.
0:36:07 > 0:36:11For now, the sky in both pictures is blue, and the sand is yellow.
0:36:13 > 0:36:15Now, look up here.
0:36:15 > 0:36:19Do you see a green square on your left and a red square on your right?
0:36:19 > 0:36:24OK. What I want you to do is to stare at that dot
0:36:24 > 0:36:27between the red and the green squares.
0:36:27 > 0:36:29The illusion should work
0:36:29 > 0:36:33if you carry on staring at the dot between the two top squares.
0:36:33 > 0:36:34While you're looking at it,
0:36:34 > 0:36:37I'll tell you what's happening inside your head.
0:36:37 > 0:36:41Your brain is learning that the left side of its visual field
0:36:41 > 0:36:44is under green light.
0:36:44 > 0:36:47It's also learning that the right side of its visual field
0:36:47 > 0:36:50is under red light. That's becoming its new reality.
0:36:50 > 0:36:54For this to work, you must keep your eyes on the dot.
0:36:54 > 0:36:56When I tell you, you're going to look at the dot
0:36:56 > 0:37:00between the two desert scenes. Don't do it now, when I tell you.
0:37:00 > 0:37:045, 4, 3, 2, 1.
0:37:06 > 0:37:11SURPRISED LAUGHTER
0:37:13 > 0:37:14That's amazing.
0:37:16 > 0:37:19For most people, this is how they see the colours change.
0:37:19 > 0:37:22The sky that was blue is now pink on the left
0:37:22 > 0:37:25and more green on the right.
0:37:27 > 0:37:32In just one minute, the colours have changed.
0:37:36 > 0:37:39Colour doesn't exist. Colour is a construct of your brain.
0:37:39 > 0:37:43There is nothing literal about colour in the world.
0:37:44 > 0:37:49And this understanding of how the signal from your eye becomes an experience of colour in your brain
0:37:49 > 0:37:54is one of the most exciting and challenging questions in modern science.
0:38:02 > 0:38:05Take a look at this trick of the brain.
0:38:05 > 0:38:11It's one that happens every time you walk from an artificially lit room to daylight.
0:38:13 > 0:38:17It's so good, you don't even know what's happening.
0:38:17 > 0:38:21But the light outside is a range of different wavelengths.
0:38:21 > 0:38:25The light may look the same, but it isn't.
0:38:25 > 0:38:28This is closer to what it really looks like.
0:38:28 > 0:38:32But your brain fixes the picture so the colour stays constant.
0:38:38 > 0:38:40It's called colour constancy.
0:38:40 > 0:38:45And it's something that has intrigued and baffled scientists for centuries.
0:38:48 > 0:38:52Neuroscientist Anya Hurlbert studies colour constancy
0:38:52 > 0:38:56because it may offer insight into how the brain processes colour.
0:38:56 > 0:38:59Colour constancy is so fundamental to the way we see colours
0:38:59 > 0:39:04that we don't think about it in everyday life, we don't know how we do it.
0:39:04 > 0:39:07And in order to understand how the human visual system
0:39:07 > 0:39:10achieves colour constancy,
0:39:10 > 0:39:13we need laboratory measurements of just how good colour constancy is.
0:39:18 > 0:39:23To do this, she set up an experiment involving a well-known set of objects.
0:39:23 > 0:39:24Fruit.
0:39:24 > 0:39:27And she's going to be asking people to try and estimate
0:39:27 > 0:39:31the colour of the banana as the light changes.
0:39:37 > 0:39:41Your task here is to match the colour of the banana.
0:39:46 > 0:39:50I'd like you to make another practice match, this time to the banana.
0:39:52 > 0:39:54There are in fact two yellows in the picture.
0:39:54 > 0:40:00The banana, and a simple patch of the same yellow in the background.
0:40:00 > 0:40:02As the light changes,
0:40:02 > 0:40:08how will someone's perception of the colour of the banana and the patch change?
0:40:08 > 0:40:11Is the match that a person makes to the yellow banana
0:40:11 > 0:40:15different from the match the person makes to a yellow patch?
0:40:15 > 0:40:20If the matches are different, that means the object is influencing colour perception.
0:40:22 > 0:40:25Experiments show they are different.
0:40:25 > 0:40:30People perceive the yellow patch as changing as the light changes.
0:40:32 > 0:40:34But the yellow of the banana stays more constant.
0:40:37 > 0:40:41And the reason this colour constancy works, Anya believes,
0:40:41 > 0:40:44is because we should know what a banana looks like.
0:40:46 > 0:40:49One of the factors that might contribute to colour constancy
0:40:49 > 0:40:52in the human visual system is object knowledge.
0:40:52 > 0:40:55So for example, the fact that we know that bananas are yellow,
0:40:55 > 0:40:59and we've seen bananas under many different illuminations,
0:40:59 > 0:41:05may enable us to perceive the yellow of a banana as more constant under changing illumination
0:41:05 > 0:41:08because we know what colour it should be.
0:41:09 > 0:41:14Colour constancy shows once again that your eye doesn't simply SEE colour.
0:41:17 > 0:41:19Your brain creates it...
0:41:23 > 0:41:28..by drawing on knowledge of what things should look like.
0:41:32 > 0:41:34That raises the intriguing possibility
0:41:34 > 0:41:39that many different aspects of what make you individual go into making colour.
0:41:42 > 0:41:46Not just memories, but other complex operations that happen in your brain.
0:41:46 > 0:41:51Even, it now seems, the language you speak.
0:42:03 > 0:42:09It may seem a strange idea that language might affect the colours you see.
0:42:09 > 0:42:12And some of the clues might lie in understanding
0:42:12 > 0:42:16what happens inside your brain as you begin to learn words.
0:42:17 > 0:42:19This is a subject that Dr Anna Franklin,
0:42:19 > 0:42:23from the Surrey Baby Lab, has been looking at.
0:42:30 > 0:42:36Colour vision is not something that you are automatically born with.
0:42:36 > 0:42:40So newborns have got really, really limited colour vision.
0:42:40 > 0:42:44And their colour vision develops over the first three months of life.
0:42:44 > 0:42:49As the colour cells in their eyes develop over these three months,
0:42:49 > 0:42:50they begin to see colour.
0:42:52 > 0:42:57But what Anna has found is that something as simple as the words you learn
0:42:57 > 0:43:02might be having an impact on how your brain processes colour.
0:43:02 > 0:43:09Potentially, language could actually structure how the brain is structuring the visual world.
0:43:09 > 0:43:14The first clues arose when Anna started looking at what happens to children's brains
0:43:14 > 0:43:16when they learn to speak.
0:43:18 > 0:43:21It was comparing the brains of children pre- and post-language
0:43:21 > 0:43:25that they discovered something rather fascinating.
0:43:25 > 0:43:29So, Claudia, thanks very much for bringing Max and Noah to the lab today.
0:43:29 > 0:43:33What we're looking at today is how babies and toddlers categorise colour.
0:43:35 > 0:43:42In the English-speaking world, we have 11 colour categories.
0:43:42 > 0:43:47What Anna is looking for is how the brain processes these categories pre- and post-language.
0:43:50 > 0:43:53First in the chair is Max, who has no concept of language.
0:43:53 > 0:43:56Colour categories appear to be present in infants,
0:43:56 > 0:44:01even before they have learnt the words for colour, so somehow,
0:44:01 > 0:44:05infants are also dividing up the spectrum of colour into categories,
0:44:05 > 0:44:10even though they don't have language to tell them how to do that.
0:44:11 > 0:44:14By tracking Max's eye movement,
0:44:14 > 0:44:17Anna is able to tell that it's the right side of the brain
0:44:17 > 0:44:20which is processing the colour categories.
0:44:20 > 0:44:24What's fascinating is what happens when three-year-old Noah,
0:44:24 > 0:44:27who HAS learnt his categories, does the same experiment.
0:44:27 > 0:44:31Their category effect is stronger in the right visual field,
0:44:31 > 0:44:35and the right visual field initially projects over to the left hemisphere,
0:44:35 > 0:44:37which is the hemisphere that's dominant for language.
0:44:39 > 0:44:42So inextricably linked is colour to language
0:44:42 > 0:44:47that it jumps across your brain as soon as you start acquiring words.
0:44:47 > 0:44:50We're really excited about these findings, because it suggests,
0:44:50 > 0:44:54potentially, that learning language or learning colour terms
0:44:54 > 0:44:58can actually change the way in which your brain
0:44:58 > 0:45:01is actually categorising the visual world,
0:45:01 > 0:45:05the way in which your brain is deriving structure
0:45:05 > 0:45:09from the world which it's seeing.
0:45:11 > 0:45:14This suggests the way you process colour
0:45:14 > 0:45:17and how you learn language are connected.
0:45:17 > 0:45:20But to really understand how language might help shape colour,
0:45:20 > 0:45:23scientists began looking at a group of people
0:45:23 > 0:45:27with a colour vocabulary as different from most of ours as possible.
0:45:33 > 0:45:36Northern Namibia.
0:45:36 > 0:45:39A remote and barren landscape.
0:45:40 > 0:45:44Home to a remarkable tribe, the Himba.
0:45:48 > 0:45:52The Himba women are famous for covering themselves with ochre,
0:45:52 > 0:45:55which symbolises the Earth's rich red colour,
0:45:55 > 0:45:58and blood, which symbolises life.
0:46:03 > 0:46:07But that's not what has brought Serge Caparros here.
0:46:07 > 0:46:11He's here because there's something rather special
0:46:11 > 0:46:14about how the Himba describe the colours they see.
0:46:14 > 0:46:16What is the colour of water? >
0:46:16 > 0:46:18HE SPEAKS IN NATIVE LANGUAGE
0:46:18 > 0:46:20White. >
0:46:20 > 0:46:22OK. And milk?
0:46:22 > 0:46:24HE SPEAKS IN NATIVE LANGUAGE
0:46:24 > 0:46:26Also white. >
0:46:26 > 0:46:30For me, you see, where I come from, we say the water is blue,
0:46:30 > 0:46:34and the sky is blue, and you say the sky is black, water is white.
0:46:34 > 0:46:37So we have different words to talk about the same thing.
0:46:39 > 0:46:42While we have 11 words to describe colour,
0:46:42 > 0:46:44the Himba have half the amount.
0:46:50 > 0:46:53They include "Zoozu", which is most dark colours,
0:46:53 > 0:46:56and includes reds, blues, greens and purples.
0:46:59 > 0:47:05"Vapa", which is mainly white, but includes some yellow.
0:47:06 > 0:47:09"Borou", which includes some greens and blues.
0:47:10 > 0:47:15And "Dumbu", which includes different greens, but also reds and browns.
0:47:20 > 0:47:25They clearly describe colour differently, but do they see the same way?
0:47:31 > 0:47:34Serge has been running experiments to find out.
0:47:36 > 0:47:41OK, now you look at these squares, one of them has a different colour, which one?
0:47:41 > 0:47:43He's testing how long it takes them
0:47:43 > 0:47:47to spot a colour which is different from the others.
0:47:49 > 0:47:51Can you do the same thing again?
0:47:51 > 0:47:53This is what they're looking at.
0:47:53 > 0:47:57For us, it's quite hard to spot the odd one out.
0:47:57 > 0:48:01OK, can you point one more time towards the different colour?
0:48:06 > 0:48:07Very good.
0:48:09 > 0:48:13But for the Himba, it's easy to see the green which is different.
0:48:18 > 0:48:21So you see, in this particular trial,
0:48:21 > 0:48:24this green patch looks very much like the other ones,
0:48:24 > 0:48:28at least to me, and I think to most other Westerners.
0:48:28 > 0:48:31Whereas for the Himba, this is a different colour,
0:48:31 > 0:48:35they have a different word for this type of green
0:48:35 > 0:48:37compared to the other types of green,
0:48:37 > 0:48:42and that allows them to more easily distinguish between these two colours
0:48:42 > 0:48:45when they're next to each other, whereas for us it's very hard.
0:48:45 > 0:48:49When Westerners do this exact same trial, they will spend much longer
0:48:49 > 0:48:53and be much more likely to make a mistake than the Himba.
0:48:55 > 0:48:57The next experiment is trickier for the Himba.
0:48:57 > 0:49:01In this one, they're shown a circle of green squares,
0:49:01 > 0:49:04which includes one blue square.
0:49:04 > 0:49:06So again, 12 colours,
0:49:06 > 0:49:10and you point towards the one that is different from the other 11 colours.
0:49:12 > 0:49:16For us, we have separate words for green and blue.
0:49:16 > 0:49:18But as the Himba have the same word for both,
0:49:18 > 0:49:22it takes them longer to spot the blue.
0:49:27 > 0:49:29It's not there. She can't see it.
0:49:30 > 0:49:32OK, that was a difficult one for him.
0:49:32 > 0:49:36The difference between the two categories of colour
0:49:36 > 0:49:40are very close to each other - for us it's clear the one that is different,
0:49:40 > 0:49:43but for them, they have to look very hard.
0:49:43 > 0:49:48We measure the time they take to give a response, as well as errors.
0:49:48 > 0:49:52And what we find is that the Himba will take much longer
0:49:52 > 0:49:57to find the different colour in this version of the experiment with blue and green.
0:50:09 > 0:50:11The Himba, with their five words,
0:50:11 > 0:50:16do, in some ways, see the world slightly differently from us.
0:50:26 > 0:50:29At Goldsmiths College, at the University of London,
0:50:29 > 0:50:35Serge's professor, Jules Davidoff, is trying to get to the bottom of this difference.
0:50:35 > 0:50:37I'm going to show you this.
0:50:37 > 0:50:41Look at it carefully. Don't say anything.
0:50:42 > 0:50:45He's been doing similar experiments with children.
0:50:45 > 0:50:49Look at it carefully. Ready?
0:50:49 > 0:50:56It seems that the number of terms a culture has for colours is all down to how much we need them.
0:50:56 > 0:50:59There are many languages in Europe
0:50:59 > 0:51:02that only had five or six colour terms until quite recently.
0:51:02 > 0:51:06Welsh is one example, where there was no word for pink or brown.
0:51:06 > 0:51:08But now these words are important,
0:51:08 > 0:51:12and so the words have become imported into their language.
0:51:12 > 0:51:16Language does have a subtle effect on how you see colour.
0:51:19 > 0:51:22It really shows up, not with individual colours,
0:51:22 > 0:51:24but when you compare two colours side by side.
0:51:26 > 0:51:28For individual colours,
0:51:28 > 0:51:31everybody sees the same sensation.
0:51:31 > 0:51:34But when we have two colours,
0:51:34 > 0:51:36we have to make a similarity judgment.
0:51:36 > 0:51:41And making a similarity judgment, we believe,
0:51:41 > 0:51:46differs according to whether you have different words for colours.
0:51:50 > 0:51:52All this suggests that seeing colour
0:51:52 > 0:51:56is about lot more than just opening your eyes.
0:51:56 > 0:51:58Colour is created in your brain.
0:52:00 > 0:52:05It's made from the language you speak.
0:52:05 > 0:52:08The memories you carry.
0:52:08 > 0:52:12Even the moods you feel.
0:52:12 > 0:52:15It is one of nature's great illusions.
0:52:18 > 0:52:24That's why Beau Lotto wants to test how each of us creates colours.
0:52:24 > 0:52:27Because maybe we all do it differently.
0:52:28 > 0:52:31Do we all see the same colours?
0:52:31 > 0:52:34People have been asking this question for centuries, really.
0:52:34 > 0:52:39And it's a fascinating question. Is one person's perception of red the same as someone else's,
0:52:39 > 0:52:43or could your perception of red be my perception of green?
0:52:45 > 0:52:50The first experiment was looking at how people arrange colours together.
0:52:50 > 0:52:52They were given 49 different tiles,
0:52:52 > 0:52:56and asked to place them in any pattern they liked on the board.
0:52:57 > 0:52:59And the question is, what do they do?
0:52:59 > 0:53:02They're going to create a pattern, but which pattern,
0:53:02 > 0:53:04and why that one, as opposed to another?
0:53:06 > 0:53:11There are hundreds of billions of different ways these colours could be arranged.
0:53:11 > 0:53:13Rather a lot.
0:53:13 > 0:53:16But he found that people didn't arrange them at random,
0:53:16 > 0:53:19but in patterns that were so predictable
0:53:19 > 0:53:25that Beau could generally work out how people were going to place them together.
0:53:25 > 0:53:28So if you gave me a colour, I could predict the colours
0:53:28 > 0:53:32that people would put around it, almost perfectly.
0:53:32 > 0:53:35And yet each person there had no instruction,
0:53:35 > 0:53:39just to take these colours, put them on this board,
0:53:39 > 0:53:43and they all created something that was highly predictable.
0:53:44 > 0:53:50The clue to predicting the patterns people were creating lay in nature.
0:53:50 > 0:53:56People were creating structures that were similar to the natural images they saw every day.
0:54:01 > 0:54:06So what that tells us is that when it comes to seeing colour,
0:54:06 > 0:54:08we can't escape from our ecological history.
0:54:08 > 0:54:12We can't but help impose that structure onto the world.
0:54:14 > 0:54:20We all have, hard-wired into our brains, a natural sense of how colours should fit together.
0:54:23 > 0:54:27A second experiment looked at how the way you feel
0:54:27 > 0:54:29might affect what you see.
0:54:29 > 0:54:33Beau used two different states often used in psychological experiments.
0:54:33 > 0:54:37Feeling powerful and in control, or powerless.
0:54:37 > 0:54:42Because of some of the manipulations we're doing to people during these experiments,
0:54:42 > 0:54:45we're giving them a sense of power, by them remembering
0:54:45 > 0:54:48a time in their life where they had a sense of control.
0:54:56 > 0:55:01The experiment he gave them was to look at a coloured dot on grey,
0:55:01 > 0:55:05and to say if they noticed the colours changing.
0:55:05 > 0:55:08We then sat them down, and we altered the light,
0:55:08 > 0:55:11and we asked them, how different does it have to be before you see it?
0:55:11 > 0:55:17The question was whether the people placed in the powerful state could spot the difference in colour,
0:55:17 > 0:55:20in the same way as people in a powerless state.
0:55:22 > 0:55:25Now, you would have thought something as simple as that
0:55:25 > 0:55:29could not be affected by how I feel. But in fact, it is.
0:55:29 > 0:55:32He found that people feeling more powerful
0:55:32 > 0:55:37were able to spot changes in colour more effectively than the powerless.
0:55:38 > 0:55:44The more powerful, the more control they had, the more sensitive they were.
0:55:47 > 0:55:51There's even a difference between men and women.
0:55:51 > 0:55:57What was remarkable is that not only were women more sensitive
0:55:57 > 0:56:03than men, but then, women who had a stronger sense of control
0:56:03 > 0:56:05were even more sensitive than women who were not.
0:56:05 > 0:56:10How these women felt about themselves actually caused them
0:56:10 > 0:56:14to see the world more accurately, or less accurately.
0:56:16 > 0:56:20The experiments looked at different aspects of colour perception.
0:56:20 > 0:56:22Just push on forward.
0:56:23 > 0:56:28Looking at how young and old people connected colour and emotion.
0:56:30 > 0:56:35Looking at how they perceived patterns of light and dark.
0:56:35 > 0:56:39And of course, at how colour affects the perception of the passing of time.
0:56:39 > 0:56:44For those of you see the shades of grey different over here than over here,
0:56:44 > 0:56:46you're going to be a bit surprised.
0:56:47 > 0:56:50When he examined the results in detail,
0:56:50 > 0:56:55he found consistent patterns in how groups of people perceived colour.
0:56:55 > 0:56:59We discovered that in fact, people of different sex, different age,
0:56:59 > 0:57:04different levels of status, actually perceive colour differently.
0:57:04 > 0:57:08And that seems really quite remarkable, when we remember
0:57:08 > 0:57:11that all we're dealing with is the light that falls on to your eye.
0:57:13 > 0:57:16It's a remarkable finding. It suggests that in everyday life,
0:57:16 > 0:57:21we could be experiencing colours differently from those around us...
0:57:24 > 0:57:28..even experiencing colours differently from day to day.
0:57:28 > 0:57:32So in thinking about whether, do you see what I see?
0:57:32 > 0:57:37The answer really depends on what it is we're looking at.
0:57:37 > 0:57:42So if what we're looking at is something that's been shaped by evolution itself, then yes,
0:57:42 > 0:57:44we probably see something very similar.
0:57:44 > 0:57:47But if it's something shaped by our own individual experiences,
0:57:47 > 0:57:50then no, we can see the world very differently.
0:57:50 > 0:57:55What's surprising for us is that our individual experiences,
0:57:55 > 0:57:58the differences in our individual experiences,
0:57:58 > 0:58:00in the way I feel at this moment,
0:58:00 > 0:58:03can alter something as simple as colour.
0:58:04 > 0:58:07So we can see colours differently, based on how I feel.
0:58:07 > 0:58:11What that means is that the colours that are hard-wired
0:58:11 > 0:58:17into our evolutionary history, we probably see these the same.
0:58:24 > 0:58:29But for the others, like the colour you see in someone's eyes when you're in love,
0:58:29 > 0:58:34or the colours you choose when you're feeling sad,
0:58:34 > 0:58:40when it comes to these, you're probably not seeing what I see.
0:58:40 > 0:58:45# Somewhere over the rainbow
0:58:45 > 0:58:51# Way up high
0:58:51 > 0:58:56# And the dreams that you dreamed of
0:58:56 > 0:59:02# Once in a lullaby... #