Vision allows us to see color, motion, form, and shadow. Our brain interprets images so that we understand what we see. In this episode, series host and naturalist Diane Ackerman considers both the biology of vision and the mental processes and perceptions that govern vision. She seeks answers to how the brain makes sense of optical illusions, what the importance of eye placement is in predatory animals, how artists use light and color, and why the sky is blue.
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00:01Mystery of the Senses
00:04A NOVA miniseries with Diane Ackerman.
00:32Tonight, the sense of vision.
00:38The light of the morning star pierces the night sky.
00:46Navajo artist Jobin Jr. greets the dawn, praying for beauty.
00:53Beauty before, behind, and on either side of him.
00:57Beauty all around him.
01:02The sun rises, rinsing the world with color.
01:08Jobin begins a new day.
01:14The sun rises, rinsing the world with color.
01:26Jobin begins a new day.
01:28A painting like this takes months to create.
01:34It's a mosaic of sand, laid down grain by grain.
01:40Sand painting comes from a Navajo ritual centuries old.
01:46Traditionally, it's part of a healing ceremony.
01:56The vibrant colors come from crushed minerals and rocks.
02:00It's only light and matter.
02:02And yet a work of art sparkles in the mind of an artist.
02:06We call that interplay of sight and insight the artist's vision.
02:16We all see the world in many ways.
02:26We record the sheer spectacle of life, and we create private images in the imagination.
02:38Some mornings I walk by a river near my home in upstate New York.
02:42Light and water fill my eyes in such delicious ways as I explore the mystery of vision.
02:48But how does the rich tapestry we see come from light, our eyes, and the secret workings of the brain?
03:16We're in the heart of Navajo land, Arizona's Canyon de Shea.
03:36This morning, Joe Ben is searching for colors for a new painting.
03:42He spent years training his eyes to read the cliffs.
03:50He's looking for veins of richly colored rock so finely layered that he needs a telescope to help him pinpoint the right hue.
04:00What I'm looking for is trying to locate some blue.
04:12And I located one here, which is quite near the ochre color, right above the lavender.
04:22So the lavender is the main vein, and the ochre above it, which will be great too.
04:28So that's what I'll do is just head out there to where the canyon thins out and see if we can locate this.
04:34Where Joe Benzai focuses on subtle detail, we see a vast landscape, the cliffs, the sky, the dark shadows.
04:48He sees a minute cavalcade of colors, picking out a vein of honey ochre above one of green sage.
05:00But despite such different visions, we all see in the same way.
05:06Light is what allows us to see.
05:08And the biggest source of light is our local star, the sun.
05:12No wonder we love bright days.
05:16We depend on the sun for warmth, energy, and the gift of vision.
05:22It's light bouncing off these rocks and this running water that travels straight to my eyes.
05:28But how does the light become what my eyes are actually seeing?
05:32Light is a very queer business.
05:34Frankly, nobody really understands it properly.
05:37And the reason is, it's not like anything else.
05:40It's unique.
05:42It looks as if it's made of waves.
05:43It also looks as if it's made of particles, like little bullets.
05:46It's both particles and waves.
05:49Nothing else is like that.
05:52The second thing about light is this.
05:54Although it makes us see, it activates the eye.
05:57The seeing behind the eye is completely different from the light that reaches the eye.
06:03We call the light that reaches my eye from the sun white light.
06:09But actually, it contains the whole palette of colors.
06:14A prism sets them free.
06:16Red through orange to yellow, green, blue, indigo, and violet.
06:24At the exploratory in Bristol, England, young scientists examine how light and lenses help our eyes capture an image.
06:39It's fascinating to experiment with light.
06:46Its founder is Professor Richard Gregory.
07:00As a matter of fact, in any optical system, light always goes, so to speak, as fast as it can.
07:10In other words, it takes the path which enables it to travel faster.
07:14So is that what happens in the eye?
07:16Yeah, exactly the same in the eye.
07:17The eye's got a thing like that in it.
07:19It's got the lens in it.
07:20And also the front of the eye.
07:22That's the lens as well.
07:24The bit in the middle actually changes shape.
07:26So what's happening in the eye is exactly like what is happening here.
07:29And the bulging lens, which is thicker in the middle, bends the light.
07:33And that makes the light come together to form a focus.
07:37Rays of light reflect off this bird as it flies into view.
07:46The light forms an image on the back of the eye.
07:51Here on the retina, it's upside down.
07:56But the eye itself is only sensitive to three colors, red, green, and blue.
08:02And these are signal to the brain.
08:04And it's a mixture of the red and the green and the blue signal to the brain,
08:08which gives you all the colors that you can see.
08:19It's hard to believe that the sumptuous colors of this landscape begin in the retina with just red, green, and blue.
08:32But it's in the retina where light waves are transformed into electrical signals.
08:44Instantly these signals rush into the brain along the optic nerve.
08:48Other signals carry cues about form, depth, and motion.
08:53Color occurs as much in the mind as in the world.
09:02Joe Ben sees more than the blue sky, the green leaves, the red cliffs.
09:08To him, these canyon walls resound with stories from the past.
09:13One wall is a field of stars and an ancient sky.
09:18An elder, Annie Kahn, teaches him to see where the past and the present meet.
09:24In the universe, we have different stars that forces our eyes so that we can see beyond the normal vision of what we see every day.
09:37Ceremonial sand painting requires a lifetime apprenticeship.
09:46Joe Ben has studied since he was 13.
09:49It's a spiritual quest. He's transformed into an art.
09:53He begins by searching for just the right morsels of color.
10:08His eyes patrol the landscape where he searches through shadows, prospects among the rocks,
10:26and is rewarded by vast amounts of information, all channeled to the back of the brain.
10:39Back of your eye has nerve cells that are sensitive to light.
10:42When they get struck by the light, they convert the light to nerve impulses.
10:45Those travel back into your brain until they finally get to the cortex.
10:50The cortex then travels forward.
10:53So the first place the light is processed is in the back of your brain.
10:57So if you get hit in the back of the head, you may see stars.
11:00Then travels forward and is separated into several different pathways which do different kinds of things.
11:05So vision is not one thing.
11:07In fact, vision consists of at least four distinct elements.
11:12Color, motion, form, and depth.
11:15From the reversed image in the retina, the eyes' light-sensitive cells separate these components
11:25and send them rushing back into the brain.
11:31Billions of these signals meet at the back of the brain in a place called the primary visual cortex.
11:38Motion and depth are processed here.
11:42Color and form in these areas.
11:48One third of the brain is devoted to processing what we see.
11:58In the end, the brain somehow creates a single perception.
12:02But it is a mystery how.
12:07As Jobin continues his search for pigments, we can see other elements of vision at work.
12:24We detect motion first, and the brain is quick to pick it up in black and white.
12:30We may see the world in color, but our brain actually processes motion in black and white.
12:36If danger is stalking you, there is no time for the luxury of color.
12:41Another pathway in the brain handles shape or form.
12:57Behind Jobin, the form of Shiprock Mountain cuts across the sky.
13:02Its jagged outline seizes our attention.
13:09Despite all the pageantry of light, shade, and color, form rules this scene.
13:19You can see the interplay of form and color when you look at this lovely watercolor by Picasso.
13:26The color seems to cling to the contour Picasso has drawn.
13:31But when you take the outline away, it's hard to make sense of the picture at all.
13:36Here form is easier to interpret than color.
13:40Another aspect of vision is the perception of depth.
13:52Did you ever wonder why we have two eyes?
13:55Jobin is digging a hole in the ground to gather the fine desert sand he needs for his painting.
14:01His brain brings together two different images, one from each eye,
14:06blending them so that he perceives the world in three-dimensional space.
14:11But there are other ways of judging death.
14:31As Jobin moves away, his eyes adjust to distance.
14:35Here a plant seems huge because it's close.
14:39The mountain's small because it's far away.
14:42This is what's called perspective.
14:44And artists use it to convey a feeling of distance.
14:54In this drawing, the back line, the line in the distance, seems much larger.
15:05But as we move them, we see the two lines are exactly the same size.
15:14We can be fooled by perspective, so we need additional evidence to make our way in the world.
15:20Shading is another clue that gives us information about depth or distance.
15:25It's the shading on these rocks that gives them depth.
15:28Here, in the shadow of the sacred mountain of Shiprock,
15:34Jobin returns from his day's expedition.
15:37His truck is filled with colored rocks that he has collected throughout Navajo land.
15:42He spreads a canvas of earth tones, finely textured sand typical of this region.
16:03.
16:33The collection of my material is where I've traveled,
16:38but the majority of my material is from this area in the southwest.
16:42These materials came to be this color or this texture or hardness or softness
16:50by natural phenomena, natural happenings as far as heating, pressure, cooling.
16:58And through these natural processes, they store these energies.
17:03And through these stored energies, we are able to perceive color in them.
17:07We are able to feel texture in them.
17:10And a lot of times you are able even to taste, and some material have odor to it.
17:21As an artist, Joe Ben uses all his five senses to sift through his materials
17:26and begin to create.
17:33Eyes are the great monopolists of the senses,
17:36but they do far more than just witness and record.
17:39We see everything in a halo of meaning.
17:45Forming an image does you no biological good.
17:48That's not perception.
17:50Perception is extracting meaning from the image.
17:56Although it feels like you've just got a picture,
17:58you're really doing much more than that.
18:00That's what fooled computer vision people for so long.
18:03They thought it would be trivial to make a machine that could see it.
18:06It turned out to be almost impossible.
18:08It's taken them decades to get a machine that can drive along a road
18:11and not drive off of it.
18:13Because it turns out that seeing is much more than we thought it was.
18:18It isn't just a high-quality image.
18:22As you're moving about the world, you're not just seeing patches of color and texture.
18:26You're seeing objects. The world's meaningful.
18:28When we talk about meaningfulness,
18:30what we're really talking about is your ability to enter memory
18:34from previous encounters with objects
18:36and identify that something you're seeing now
18:39that's red and a certain shape and a certain size
18:43in fact corresponds to something you saw before,
18:45that you've got stored in memory.
18:47As soon as you do that,
18:48it's no longer just a red, round thing of a certain size.
18:51It's an apple.
18:53And you know it's got seeds inside even though you can't see them.
18:56The reason that you know it's got seeds inside,
18:58even though you can't see them right now,
19:00is because in memory you've got stored information about things like that
19:04that you learned at previous times you encounter them.
19:08So if you think about, say, recognizing my face,
19:14if you just take a picture of my face
19:16and then you've got a memory of my face somewhere in your memory bank
19:21and what you want to do is know if what you're looking at
19:24is the same as what you remember,
19:26what are the important parts of this image that you're looking at.
19:30Few sights mean more to us than the face of a loved one.
19:34But what happens when that meaning is lost?
19:37Four years ago, Robert Brodston of Montezuma, Iowa, had a stroke.
19:42His eyes are fine, but his brain is damaged.
19:45He can see faces, but he can't recognize them.
19:48Faces to me, of my grandchildren, all look very similar.
19:56And I have a hard time telling them apart.
20:00I tell them by their hair and also, if they talk just a little bit,
20:06why I know them by their voice.
20:08That's what I go by, his voice more than anything.
20:11Okay, Bob, we're going to look at some pictures here.
20:15These are pictures of people's faces.
20:17Some of them you know, some of them you may not.
20:27Looks familiar, but I don't know who it is.
20:29So you think it's somebody you might know?
20:31Yes, I think it might be.
20:33But you can't identify?
20:35I can't, no.
20:36Do you have a guess?
20:37Um, it kind of looks like, uh, my wife in earlier days.
20:46As this examination reveals, he can barely recognize the face of his wife,
20:51his partner for 48 years.
20:53Yes, I think it could be.
20:55Okay, let's try another one.
20:58And we're going to give you an idea of what kind of process...
21:03Doctors Antonio and Hanna Damasio are trying to understand the problems
21:08of patients like Robert Brodston.
21:11Now that we have seen that this patient has difficulty
21:14in the recognition of faces,
21:17uh, it's very important to see how the brain is
21:21in this particular patient.
21:23And we're looking here at a series of reconstructions
21:26of the patient's brain that are performed with a new technology
21:31that allows us to look at the human brain,
21:34the living human brain, in three dimensions.
21:39Now when you look at the external views,
21:41the outside view of the, of the brain,
21:44you don't actually see any sign of damage.
21:46It's perfectly intact.
21:48However, when you now split the brain
21:51the brain and look at the internal view
21:54of both the right and the left hemispheres,
21:57we see two areas that are the areas of damage.
22:01Those are the areas that were impaired by the strokes
22:04that this patient had.
22:06And it is because of these areas
22:09that the patient has a problem with the recognition of faces.
22:13These damaged areas make it hard to remember certain information.
22:17Do you recognize this one?
22:20I have seen that picture, that face,
22:24but I don't know who, I can't put a name with it.
22:26A few deeply embedded facial memories survive.
22:29But faces newly encountered are much more difficult to recall.
22:33Do you recognize this person?
22:35Yes, that is a picture of my mother.
22:38That face looks familiar, but I can't tell you who it is.
22:55His grandchildren are very hard to identify.
23:01It about halfway looks like one of my grandson.
23:04What could be more important
23:05than recognizing the people we love and are loved by?
23:08I'm not sure who it is.
23:10Well, doggone, you know, you'd feel bad if you couldn't,
23:15you can't recognize your grandson.
23:19Anybody would feel bad about it.
23:24Faces are usually the first thing we notice about people,
23:32and faces change.
23:34Oh, here's my first face.
23:37I was less than a year old,
23:39and I look so excited and so tentative.
23:42My brother seems to be having a good time, though.
23:45I love this picture of me with the little chipmunk cheeks,
23:52and I have such a worried expression on my face.
24:06Seeing these faces brings back so many memories.
24:09There's a picture of me in junior high school,
24:12when it was in fashion to wear headbands.
24:18And with my mom in Spain,
24:20I was wearing a miniskirt.
24:22She had her hair teased up in a beehive.
24:31I don't remember when this picture was taken,
24:33but I seem to have such a soulful look on my face.
24:36I just know it was in college.
24:42I think of this as my Loretta Young look.
24:49Here I am with some women friends,
24:50down at the farmer's market.
24:52Images like these stop the rush of life for a moment,
24:56so we can glimpse ourselves and all the people we cherish.
25:00But sometimes vision can be fooled.
25:05Do you see a vase or two faces?
25:13Our brain switches between the two.
25:19Here our eyes struggle to focus,
25:21and so we experience a pulsing sensation.
25:23Look at this figure.
25:32Do you see a box?
25:38What about now?
25:46There's a visual trick at work here,
25:48an optical illusion.
25:50It's quite difficult to define an illusion.
25:54Basically, it's an error.
25:56It's some kind of discrepancy from the truth.
25:59But the difficulty is,
26:00we don't always know exactly what the truth is.
26:03And when you call it an illusion,
26:04it really means that it's disturbing,
26:06it's upsetting,
26:07it makes your behavior go wrong.
26:10But if you're an artist having a lot of fun with illusions,
26:12then they're just great.
26:13You use them, you know, usefully.
26:14So the definition is really not simple.
26:16In this etching, which way is up and which way is down?
26:24We experience up and down all at once.
26:28Escher's art both puzzles and delights us.
26:32And that's what makes illusions fun.
26:35They enchant and confound at the same time.
26:38Sometimes art plays with our sense of reality.
26:48Artist Roy Lichtenstein,
26:50founding member of the pop art movement,
26:53celebrates everyday items.
26:58Blowing them up so that you can see the dots of the printing press.
27:01I was leafing through a book full of Roy Lichtenstein prints.
27:16And I came across this one.
27:18And it was in the middle of a series called Monet's Cathedral.
27:22Here's how the French impressionist painter Monet portrayed the cathedral at Rouen.
27:27Here's Lichtenstein's version of Monet's painting.
27:32If you look at this, it doesn't look much like Monet's Cathedral until you introduce, using a filter,
27:38a luminance contrast between the red and the blue.
27:41And then suddenly it jumps out at you.
27:43So you don't see the shape until you introduce a luminance contrast.
27:47Monet captures a world of sensations where colors seep together like separate moments.
27:52Marge Livingston views art through the eyes of a scientist.
27:57But how does Roy Lichtenstein see his own work?
28:03As a young man, he fell in love with Monet's art.
28:07The Monet things, of course, were seen through French eyes, European eyes,
28:13however you want to put it, the School of Paris,
28:16that had certain paint qualities.
28:18He learned to paint like the French masters, but in time he radically changed his style.
28:24He took his love of comic book images, images coming from the printing press made with dots,
28:32and the dots became his signature.
28:35I did recognize that putting dots next to flat areas was somewhat akin to putting thick and thin paint on.
28:43It was that I really thought you could use these elements that was in the tradition of painting,
28:53the kind of painting everyone was used to and was elegant and beautiful,
28:58but it just became less and less important that everyone could do this now.
29:04It wasn't discovering anything, it was simply repeating a kind of beauty that we were taught.
29:10Lichtenstein sees the world as a field of dots.
29:15For him, beauty balances somewhere between the visible whole and its nearly invisible parts.
29:21Joe Benn also draws upon his culture in powerful ways.
29:34He creates two kinds of sand paintings.
29:37Public ones for exhibition, and traditional sand paintings that are secret.
29:41As if emptying an hourglass, he pours the sands of time, nature, all creation.
29:57Adopting the techniques of his Navajo ancestors, he blends the past with the present.
30:03When you create a sand painting, you recreate your natural surroundings, your landmarks.
30:12You also create, through your mythology, how you came to existence, how you came to be.
30:19You also create time, place, and you also create the universe in this.
30:31Artists share their unique vision of the world by making the ordinary seem newly discovered,
30:47and the extraordinary familiar and inviting.
30:50Joe Benn's artistry is rooted in a sense of color.
30:53For him, colors have great meaning that can be traced to the history and tradition of his people.
31:02The color that I'm working with now, I collected it a couple days ago.
31:06And what I tried to do is reconstruct your surroundings in this painting.
31:14And this particular color is from the West.
31:17To me, it was important to utilize material from this area.
31:25The color I collected from the West.
31:28And also in the area of Canyon de Chez,
31:32which is a place with a lot of pectoral glass and pectoral grass.
31:35This is the same material that a lot of Navajos used in their work years ago.
31:57Realizing the source should be quite near, I scanned the sides of the canyons.
32:03And when I did this, I saw some veins.
32:08And studying the veins, I was lucky enough to find it.
32:13The color that we see here, there's four colors.
32:17White, blue, the yellow, and the black.
32:19They symbolize or represent several things.
32:20The most important is the cycle of the day, and also the direction.
32:22The white representing dawn, the east.
32:25The colors that we see here, there's four colors, white, blue, the yellow, and the black.
32:39They symbolize or represent several things.
32:43The most important is the cycle of the day and also direction.
32:48The white representing dawn, the east, the blue representing day, the south, yellow representing
32:57evening, the west, and black representing night, the north.
33:07For Joe Benn, color is a way to convey a sense of place and time.
33:12Like him, we all see through the many lenses of our culture, personality, and upbringing.
33:33This is a dance contest at the annual Shiprock Navajo Nation's Fair.
33:48There are over 210,000 Diné or Navajo people, proudly rooted in land, clans, and traditions.
33:55The Navajo culture dances in Joe Benn's art.
34:10The Navajo culture dances in Joe Benn's art.
34:14Its Equi-e.
34:16THE ANNE COMING
34:49When I see the pictographs and petroglyphs of Navajo, what was this person expressing
35:03here as a culture, as a society, as a human being?
35:09Questions that artists raised hundreds and thousands of years ago, we asked those same
35:15questions but in a different form, a different language.
35:21To me, the strength of art is to express and to explore yourself for your self-understanding.
35:29Explore the cosmos and look at that.
35:32Joe Benn is on a pilgrimage of discovery, asking questions, questions about himself
35:37and his world, in a private language of sand and color.
35:45But there is something more, imagination.
35:48Aren't these beautiful flowers?
35:50They remind me of being 16, one summer that I spent in the Poconos.
35:56Every visual image is a tripwire for the emotions.
35:59Just look at a carpet of green grass.
36:01I bet you can remember exactly what cut grass smells like, how it leaves stains on your blue
36:06jeans, how cool and damp and smooth it feels to walk across grass, and what it's like to
36:12roll in tall grass on a hot, breezy summer day.
36:17That's imagination, the ability to present to the senses what's not really there.
36:26You can think of the back of the brain as if it's sort of like a TV screen.
36:30In perception, you've got a camera.
36:33So the camera's aimed at something that's outside, comes in, it's registered, the screen.
36:38Imagery is like there's a videotape recorder, so the camera's not working, it's not picking
36:42up what's outside, rather something you've seen previously, it's sort of getting replayed.
36:47But once it's replayed, you sort of see it again, and you can notice things you've never
36:50seen before, you didn't pay attention to before.
36:52Of course, there's no screen in the head or cameras recording images.
36:57So how do perception and imagery, or as we say, seeing and imagining, operate in the brain?
37:02Okay, we're going to be putting a mask on your face.
37:06All right.
37:07It's going to be rather tight, and it's very important that you try and not move while
37:11we're taking the images.
37:13Now I know what an armadillo feels like.
37:15Dr. Steve Koslin designed a PET scan experiment to find out what happens in the brain when
37:21our eyes actually record an object, and what happens when we simply imagine the same object.
37:27That's good.
37:29I'm just going to install the monitor.
37:32I'm at the Massachusetts General Hospital in Boston to participate in Steve Koslin's
37:37experiment and to view my brain at work.
37:44Positron emission tomography, a PET scan, measures the blood flow during mental activity.
37:50It's a good way to find out what the different areas of the brain are doing.
37:55Okay, I'm just going to put on a set of nasal cannula.
38:00This is what you'll breathe in the radioactivity with.
38:03And during this test, I'd like you to breathe in through your nose, and if these come off,
38:09I want you to let me know.
38:10Okay.
38:11And this sort of looks like an oxygen mask, but it's actually a vacuum that pulls the
38:18radioactivity...
38:19Radioactive gas is used in tiny amounts to trace the flow of blood in the brain.
38:23It's not dangerous, and it helps scientists understand what's going on.
38:27How does that feel?
38:29Interesting.
38:31Is it comfortable enough for you?
38:33Yes, it's just fine.
38:34Okay.
38:35Okay, so during this experiment, you're going to be hearing names of common objects that
38:40are going to be called out by the computer.
38:42I want you to keep your eyes closed and visualize these objects in your mind's eye.
38:48Okay?
38:49Mm-hmm.
38:50In the second part of the experiment, you'll actually be presented with these objects on the screen.
38:55So I want you to open your eyes and look at the screen, and you'll also hear names of objects
39:00called out, and these objects will be presented to you.
39:04You'll actually see them.
39:06Okay.
39:09In the first part of the experiment, I'm told to close my eyes and imagine certain objects.
39:16Once I visualize an object, I press a foot pedal to let the computer know.
39:28Teddy bear.
39:33Knife.
39:36Cake.
39:40Cushion.
39:43Car.
39:45Cushion.
39:46Bean bag.
39:47Dog.
39:48In the second part of the experiment, the computer tells me the name of an object and
40:00shows me a picture.
40:01As soon as I see it, I press the foot pedal.
40:04Apple.
40:05Dog.
40:06Knife.
40:07Cake.
40:08This experiment is making me very curious.
40:16Can my brain tell the difference between a real object and an imagined one?
40:23Car.
40:25The next day, Nate Alpert and Steve Koslin went over their findings with me.
40:29I see it.
40:30Steve, what does this mean?
40:32Okay.
40:33Up here, we've got the slice through a brain.
40:36It's showing the activity in the brains when people are doing different things.
40:40And the top one is the activity that you see during mental imagery, when you're actually
40:44not seeing something.
40:45You're supplying it in your own mind.
40:47And the bottom is what you see when you're seeing it.
40:50Red indicates the greatest blood flow or brain activity, and yellow is next.
40:54Blue means inactivity.
40:56So the first thing that I think you should get out of these images is how similar these
41:07look.
41:08The same kinds of activities are occurring in your brain when you're visualizing something.
41:12It's not really there.
41:13You're visualizing it as when you're actually seeing it.
41:16The second thing that I think is important to get out of these images is you'll notice
41:19it's not just one place that's lit up.
41:21There's a whole configuration of activity in both cases, in both imagery and perception.
41:26That is, each of these mental activities is not just a single undifferentiated entity.
41:31There are actually a lot of separate things that are going on and working together in your
41:34brain when you're either perceiving or visualizing.
41:41So we've been talking about vision as if it's a camera that projects onto a screen, and mental
41:46imagery as if it's a tape that gets played, videotaped forming an image.
41:50But that's really too simple.
41:51It turns out that even during vision, you're getting information from memory, imagery-like
41:55information coming backwards and filling in what you're not actually seeing, fleshing out
42:00what you've glanced at.
42:03See the hand and imagine the apple.
42:08See the apple and imagine the hand.
42:13Imagination, or imagery as Steve Costlin calls it, fills in what we cannot see but know must be there.
42:22So the line between imagining and seeing isn't so sharp.
42:26The brain is very active. We're very much active viewers.
42:30We're not just passively sitting and registering what's coming in our eyes.
42:34We're actively anticipating and filling out what we expect to see and what we know about
42:39the world and using that to fill in what we're actually seeing.
42:45Each of us has a unique way of seeing the world.
42:49a special blend of vision and imagination, our own private museum of curiosities.
42:58In 1989, the French government decided on an innovative use of a 16th century chateau in the Loire Valley.
43:17They turned this ancient castle into an art museum, placing art from Africa, the Americas, Asia and Europe beside the castle's original collection of Renaissance art.
43:36For the global civilization that we are here, I am in the Alec, Asia and Europe, and the American town of Guinea.
43:45And the German town of Paris was a, the German town of Paris.
43:48Today, the German town of Paris was inspired by the American town of Paris.
43:51Even though it was a worldview with a university town in the nation, and in July the Quebec city are golden times,
43:54It was an international beast and the French town of Paris.
43:56It was an international town of Paris.
43:57It was an international arts, and the British town of Paris.
43:59This town of Paris was such an international day.
44:01Today, classical art hangs alongside the latest in contemporary art.
44:23Here is a ceremonial dance mask from Nigeria.
44:29The history and spirits of the Igbo traditions highlight both the dance and the dancer.
44:44Every room is a celebration of the ways that artists stimulate our senses.
44:57An early owner of the chateau was in charge of the horses that Louis XIV used to fight
45:03his many wars.
45:07This is his war council room.
45:11In 1993, an Italian artist added a modern twist by creating sculptures using artifacts from
45:18past wars.
45:25This is the artistic imagination at work.
45:28It may not be your private vision or mine, but what would happen if we let our imaginations
45:34run wild?
45:37You can replace something you've seen, an apple or whatever.
45:42Or you can modify them, not just by rotating them, but you can put them together in combinations
45:46you've never seen before.
45:47So you can imagine your mother on a surfboard, for example.
45:51How do you do that?
45:52Well, you know what a surfboard looks like, so you can visualize that.
45:55You know what your mother looks like, so you can visualize her.
45:59You also know what on corresponds to.
46:01So there's a very active process that involves an enormous amount of the brain, where you synthesize
46:06two different memories, creatively putting them together, and then seeing what things look
46:10like.
46:11So once you've got your mother on the surfboard, you can answer questions like, if she stuck
46:14her arms out, would they extend over the front of the surfboard, putting the two together.
46:19So imagery involves a creative process of amalgamating things that you've seen before in new ways,
46:25not just a simple playback.
46:27Here artists combine familiar objects in fresh new ways.
46:34An artist from Bosnia brings to life a mythical French war, which he called the Pitchfork War,
46:41where farmers rebel against the aristocracy.
46:45The farmers become pitchforks thrust into the walls, and the wealthy landowners are reduced
46:50to arrogant, disdainful portraits.
47:18An English artist doesn't use paint at all.
47:20He uses wine, a light bulb, and antique glass.
47:40He places real objects on a real table, in a way that highlights the beauty of simple
47:45things.
47:47These paper mache monsters come from Mexico.
47:54When an artist imagines something, to the artist it is as real a fact as the sun.
48:01These papier-mâché monsters come from Mexico.
48:06When an artist imagines something, to the artist it is as real a fact as the sun.
48:13Then we look at the artwork, and on some level we understand that what we're seeing isn't real.
48:18But our brains process the information as if it were real.
48:22And so we're transported to the world the artist lives in.
48:26We feel the emotion. We enter that creation.
48:31The 20th century artist René Magritte wanted to shock us into seeing the world in a whole new way.
48:38Visible things can be invisible, he said.
48:41The rider hides the trees and the trees hide her.
48:44The invisible is that which light cannot throw light on.
48:49Artists help us unlock doors to unseen worlds.
48:53Worlds within and beyond ourselves, sometimes worlds of long ago.
48:58I saw pictographs and petroglyphs that was done hundreds and some thousands of years ago.
49:05One particular petroglyph was very simple.
49:09It was five concentric circles with a path to the center.
49:13Join the brush.
49:14One person will show us how the sky.
49:15The blue is blue.
49:16The blue is blue.
49:17The pale green.
49:18The blue is blue.
49:19The blue is blue.
49:20The blue.
49:21The color white.
49:22The blue is blue.
49:23The blue is blue.
49:25The blue is blue.
49:28It's blue.
49:30Blue stands for day, the middle years of our life.
49:42Then yellow, the color of autumn and maturity.
49:50Finally we head north into the black of night, old age and death.
49:59So that is what it is here.
50:05The path again from the center developed in one's consciousness
50:10and the path through developed consciousness there
50:14to the south, to the west and to the north.
50:20In the Navajo language there is no word for artist.
50:33There are people who play this role, but they are not called artists.
50:38They are medicine men or spiritual people who will be able to venture and to vision,
50:45to look at their culture, to look at other cultures,
50:49interpret and reflect that back to the people.
50:52That is the role of an artist.
50:55Traditionally, sand paintings are done for healing.
51:06A sand painter creates stylized symbols to address a patient's imbalance with nature.
51:13During the healing ceremony, the patient sits on the sand painting to restore that balance.
51:30Joe Ben turns these symbols into art, ever mindful of their spiritual origins.
51:40Okay, it is completed.
51:45The work is completed.
51:49I will put it away now.
51:53And the order to be putting it away will be from the east to the south, the west and the north.
52:04What Western culture considers destruction, the Navajo culture sees as regeneration.
52:32All the energies from this sand painting go back into the earth to be reclaimed.
52:39Our world becomes its richest when we take it in through our eyes.
52:44But we savor the world's beauty with all our senses.
52:53However much we may understand, the senses stay cloaked in mystery.
52:59They began in mystery, and they will end in mystery.
53:02But what a wild and beautiful country lies in between.
53:06The End
53:15The End
54:19A production of WGBH Boston and WETA Washington.
54:31This is PBS.