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Optical illusions show how we see | Beau Lotto

Optical illusions show how we see | Beau Lotto


I want to start with a game. Okay? And to win this game, all you have to do is see
the reality that’s in front of you as it really is, all right? So we have two panels here,
of colored dots. And one of those dots
is the same in the two panels. And you have to tell me which one. Now, I narrowed it down to the gray one, the green one,
and, say, the orange one. So by a show of hands,
we’ll start with the easiest one. Show of hands: how many people
think it’s the gray one? Really? Okay. How many people think it’s the green one? And how many people
think it’s the orange one? Pretty even split. Let’s find out what the reality is. Here is the orange one. (Laughter) Here is the green one. And here is the gray one. (Laughter) So for all of you who saw that,
you’re complete realists. All right? (Laughter) So this is pretty amazing, isn’t it? Because nearly every living system has evolved the ability
to detect light in one way or another. So for us, seeing color is one of the simplest things
the brain does. And yet, even at this
most fundamental level, context is everything. What I’m going to talk about
is not that context is everything, but why context is everything. Because it’s answering that question that tells us not only
why we see what we do, but who we are as individuals, and who we are as a society. But first, we have to ask
another question, which is, “What is color for?” And instead of telling you,
I’ll just show you. What you see here is a jungle scene, and you see the surfaces
according to the amount of light that those surfaces reflect. Now, can any of you see the predator
that’s about to jump out at you? And if you haven’t seen it yet,
you’re dead, right? (Laughter) Can anyone see it? Anyone? No? Now let’s see the surfaces according to the quality of light
that they reflect. And now you see it. So, color enables us to see the similarities and differences
between surfaces, according to the full spectrum
of light that they reflect. But what you’ve just done is in many respects
mathematically impossible. Why? Because, as Berkeley tells us, we have no direct access
to our physical world, other than through our senses. And the light that falls onto our eyes is determined by multiple
things in the world, not only the color of objects, but also the color of their illumination, and the color of the space
between us and those objects. You vary any one of those parameters, and you’ll change the color
of the light that falls onto your eye. This is a huge problem, because it means that the same image could have an infinite number
of possible real-world sources. Let me show you what I mean. Imagine that this
is the back of your eye, okay? And these are two projections
from the world. They’re identical in every single way. Identical in shape,
size, spectral content. They are the same,
as far as your eye is concerned. And yet they come
from completely different sources. The one on the right
comes from a yellow surface, in shadow, oriented facing the left, viewed through a pinkish medium. The one on the left comes
from an orange surface, under direct light, facing to the right, viewed through sort of a bluish medium. Completely different meanings, giving rise to the exact same
retinal information. And yet it’s only the retinal
information that we get. So how on Earth do we even see? So if you remember anything
in this next 18 minutes, remember this: that the light that falls onto your eye, sensory information, is meaningless, because it could mean literally anything. And what’s true for sensory information
is true for information generally. There’s no inherent
meaning in information. It’s what we do with that
information that matters. So, how do we see?
Well, we see by learning to see. The brain evolved the mechanisms
for finding patterns, finding relationships in information, and associating those relationships
with a behavioral meaning, a significance, by interacting
with the world. We’re very aware of this in the form of more cognitive
attributes, like language. I’m going to give you some letter strings, and I want you to read them
out for me, if you can. Audience: “Can you read this?” “You are not reading this.” “What are you reading?” Beau Lotto: “What are you reading?”
Half the letters are missing, right? There’s no a priori reason why an “H” has to go
between that “W” and “A.” But you put one there. Why? Because in the statistics
of your past experience, it would have been useful to do so. So you do so again. And yet you don’t put a letter
after that first “T.” Why? Because it wouldn’t have been
useful in the past. So you don’t do it again. So, let me show you how quickly
our brains can redefine normality, even at the simplest thing
the brain does, which is color. So if I could have
the lights down up here. I want you to first notice that those
two desert scenes are physically the same. One is simply the flipping of the other. Now I want you to look at that dot between the green and the red. And I want you to stare at that dot.
Don’t look anywhere else. We’re going to look
at it for about 30 seconds, which is a bit of a killer
in an 18-minute talk. (Laughter) But I really want you to learn. And I’ll tell you — don’t look
anywhere else — I’ll tell you what’s
happening in your head. Your brain is learning, and it’s learning
that the right side of its visual field is under red illumination; the left side of its visual field
is under green illumination. That’s what it’s learning. Okay? Now, when I tell you, I want you to look
at the dot between the two desert scenes. So why don’t you do that now? (Laughter) Can I have the lights up again? I take it from your response
they don’t look the same anymore, right? (Applause) Why? Because your brain
is seeing that same information as if the right one is still
under red light, and the left one is still
under green light. That’s your new normal. Okay? So, what does this mean for context? It means I can take two identical squares, put them in light and dark surrounds, and the one on the dark surround
looks lighter than on the light surround. What’s significant is not simply the light
and dark surrounds that matter. It’s what those light and dark surrounds
meant for your behavior in the past. So I’ll show you what I mean. Here we have that exact same illusion. We have two identical tiles on the left, one in a dark surround,
one in a light surround. And the same thing over on the right. Now, I’ll reveal those two scenes, but I’m not going to change
anything within those boxes, except their meaning. And see what happens to your perception. Notice that on the left the two tiles look nearly
completely opposite: one very white and one very dark, right? Whereas on the right,
the two tiles look nearly the same. And yet there is still one
on a dark surround, and one on a light surround. Why? Because if the tile in that shadow
were in fact in shadow, and reflecting the same
amount of light to your eye as the one outside the shadow, it would have to be more reflective
— just the laws of physics. So you see it that way. Whereas on the right,
the information is consistent with those two tiles
being under the same light. If they’re under the same light reflecting
the same amount of light to your eye, then they must be equally reflective. So you see it that way. Which means we can bring
all this information together to create some incredibly
strong illusions. This is one I made a few years ago. And you’ll notice you see
a dark brown tile at the top, and a bright orange tile at the side. That is your perceptual reality. The physical reality
is that those two tiles are the same. Here you see four gray tiles on your left, seven gray tiles on the right. I’m not going to change
those tiles at all, but I’m going to reveal
the rest of the scene. And see what happens to your perception. The four blue tiles on the left are gray. The seven yellow tiles
on the right are also gray. They are the same. Okay? Don’t believe me? Let’s watch it again. What’s true for color is also true
for complex perceptions of motion. So, here we have — let’s turn this around — a diamond. And what I’m going to do is,
I’m going to hold it here, and I’m going to spin it. And for all of you, you’ll see it
probably spinning this direction. Now I want you to keep looking at it. Move your eyes around,
blink, maybe close one eye. And suddenly it will flip, and start
spinning the opposite direction. Yes? Raise your hand if you got that. Yes? Keep blinking. Every time you blink, it will switch. So I can ask you,
which direction is it rotating? How do you know? Your brain doesn’t know,
because both are equally likely. So depending on where it looks, it flips between the two possibilities. Are we the only ones that see illusions? The answer to this question is no. Even the beautiful bumblebee, with its mere one million brain cells, which is 250 times fewer cells
than you have in one retina, sees illusions, does
the most complicated things that even our most
sophisticated computers can’t do. So in my lab we work on bumblebees, because we can completely
control their experience, and see how it alters
the architecture of their brain. We do this in what we call the Bee Matrix. Here you have the hive. You can see the queen bee,
the large bee in the middle. Those are her daughters, the eggs. They go back and forth between this hive
and the arena, via this tube. You’ll see one of the bees come out here. You see how she has
a little number on her? There’s another one coming out,
she also has a number on her. Now, they’re not born that way, right? We pull them out, put them
in the fridge, and they fall asleep. Then you can superglue
little numbers on them. (Laughter) And now, in this experiment they get
a reward if they go to the blue flowers. They land on the flower, stick their tongue in there,
called a proboscis, and drink sugar water. She’s drinking a glass of water
that’s about that big to you and I, will do that about three times, then fly. And sometimes they learn
not to go to the blue, but to go where the other bees go. So they copy each other. They can count to five.
They can recognize faces. And here she comes down the ladder. And she’ll come into the hive,
find an empty honey pot, and throw up, and that’s honey. (Laughter) Now remember, she’s supposed
to be going to the blue flowers, but what are these bees doing
in the upper right corner? It looks like they’re
going to green flowers. Now, are they getting it wrong? And the answer to the question is no.
Those are actually blue flowers. But those are blue flowers
under green light. So they’re using the relationships
between the colors to solve the puzzle, which is exactly what we do. So, illusions are often used, especially in art, in the words
of a more contemporary artist, “to demonstrate the fragility
of our senses.” Okay, this is complete rubbish. The senses aren’t fragile.
And if they were, we wouldn’t be here. Instead, color tells us
something completely different, that the brain didn’t actually evolve
to see the world the way it is. We can’t. Instead, the brain
evolved to see the world the way it was useful to see in the past. And how we see is by continually
redefining normality. So, how can we take this incredible
capacity of plasticity of the brain and get people to experience
their world differently? Well, one of the ways we do it
in my lab and studio is we translate the light into sound, and we enable people to hear
their visual world. And they can navigate
the world using their ears. Here’s David on the right,
and he’s holding a camera. On the left is what his camera sees. And you’ll see there’s a faint line
going across that image. That line is broken up into 32 squares. In each square,
we calculate the average color. And then we just simply
translate that into sound. And now he’s going to turn around, close his eyes, and find a plate on the ground
with his eyes closed. (Continuous sound) (Sound changes momentarily) (Sound changes momentarily) (Sound changes momentarily) (Sound changes momentarily) (Sound changes momentarily) Beau Lotto: He finds it. Amazing, right? So not only can we create a prosthetic
for the visually impaired, but we can also investigate how people literally
make sense of the world. But we can also do something else. We can also make music with color. So, working with kids, they created images, thinking about what might
the images you see sound like if we could listen to them. And then we translated these images. And this is one of those images. And this is a six-year-old child
composing a piece of music for a 32-piece orchestra. And this is what it sounds like. (Electronic representation
of orchestral music) So, a six-year-old child. Okay? Now, what does all this mean? What this suggests is that no one
is an outside observer of nature, okay? We’re not defined
by our central properties, by the bits that make us up. We’re defined by our environment
and our interaction with that environment, by our ecology. And that ecology is necessarily
relative, historical and empirical. So, what I’d like to finish with
is this over here. Because what I’ve been trying to do
is really celebrate uncertainty. Because I think only through uncertainty
is there potential for understanding. So, if some of you are still
feeling a bit too certain, I’d like to do this one. So, if we have the lights down. And what we have here — Can everyone see 25
purple surfaces on your left, and 25, call it yellowish,
surfaces on your right? So now, what I want to do, I’m going to put
the middle nine surfaces here under yellow illumination, by simply putting a filter behind them. Now you can see that changes the light
that’s coming through there, right? Because now the light is going
through a yellowish filter and then a purplish filter. I’m going to do the opposite
on the left here. I’m going to put the middle nine
under a purplish light. Now, some of you will have noticed
that the consequence is that the light coming through those
middle nine on the right, or your left, is exactly
the same as the light coming through the middle
nine on your right. Agreed? Yes? Okay. So they are physically the same. Let’s pull the covers off. Now remember — you know that the middle nine
are exactly the same. Do they look the same? No. The question is, “Is that an illusion?” And I’ll leave you with that. So, thank you very much. (Laughter) (Applause)

Comments (100)

  1. The eye did not evolve. It was created to see from the beginning! How did the eye evolve if there was no eye to begin with? In fact, the eye is so complex with every component interdependent. Every one of the components including the three types of tears, each with a different responsibility (in a human) all had to be functioning at the same time in order for the eye to work properly. A partly developed eye would be of no use. It turns evolution on its head!

  2. Did a print screen of the 25 dots with cover, we see same color, and it is.
    When you remove the cover, did a print screen again and copy/paste one side to the other, and its not the same color. So.. Not an illusion. You sir did not just fail in the friggin button the damn shirt..

  3. 2009 cameras were the sexiest cameras

  4. Anyone else think the two brown squares on the cube were actually different colors? Take a screenshot before and after and the tones are different to my eyes.

  5. I think my brain got fried in the 70's……..

  6. the cameras are for too busy…….flick………..flick………….flick how can you concentrate on this?

  7. his untidy shirt put me off so much that…I couldn't watch it all. my bad

  8. why is this guy so out of breath??

  9. The only reason I didn't see the predator was because the subs were in the way. Way to rob me of that experience.

  10. His unbuttoned shirt is distracting.

  11. One green side, one red side to look through–isn't that a pair of 3-D glasses? Also, what was the whole point of this talk? To prove that there are optical illusions? Didn't we know that already. Lastly, I agree with what many others have said about the lack of clarity of his first question, and the lack of buttoning on his rumpled, unprofessional looking shirt.

  12. button your shirt up fool

  13. brain be like: context is everything

  14. this guy ruined honey for me.

  15. So, is this a Ted talk m

  16. I still didnt see the predator!!!!!!!!

  17. I SEE THE CAMERAMAN ON STAGE!!!! Was that part of the illusion?

  18. Instructions unclear…..I still see everything as red and green for 10 years now!

  19. What I can't figure out is why he is dressed as an extra from Schindler's List……..

  20. Some of what he is saying isn´t right in terms of physics and/or chemistry. First of all, color doesn´t exist. It is only something our brain is processing by determin which wavelength of light means which color. And no one can say where color comes from. From where did a brain determin color when there is no color in the first place?

    So at 6:20 our brain doesn´t "learn" the condition of lighting. What happens is that the cells in our eyes for the color red and green is firing and gets excited for a long time. Then the cells need a few moments to recover, so they arent ready to see red and green when watching the desert picture. The green and red cells just cant fire as strong as the other cells (blue). So the picture on the left is less green and less red at the right picture. After a few seconds, the red and green cells recovered, so the picture of the desert will look normal again.

  21. 9 dots look the same to me.

  22. credibility ruined in the first 30 seconds

  23. Just another brainwave or color a.s.o. to music hoax. If you correlate parameters to freqs or rhythm you will not get music . Only if you just trigger premade events like a DJ on his launch pad.

  24. basically T.H.E.Y. removed all of the intentional Work Site blockage that T.H.E.Y. had used to cause traffic jams creating an illusion of a greater population in the first place so T.H.E.Y. could pretend TAXing you more is good for the environment,, Vancouver B.C. was / is famous for that,, Toronto did / does that quite a bit too (the intentional obstruction and likely the new TAXES as well ("g, where's all the Work Crews"))

  25. Here's a trick, how do we explain that, I'll show you another trick, and that trick is explained like with another trick, more a magic show than anything informative!

  26. Looked at another way: the congestion tax makes the poor folk have to strongly consider whether they can afford to go to the city, whereas the rich are pretty much mildly, if in any meaningful way, inconvenienced. Also, remember, there is data there to be mined. Patterns of travel and records of place and time to be recorded, stored, analyzed… and by nature identified, not depersonalized.

  27. brain washer. i stopped watching yr crap at 8 minutes. brown tile centre top… brown till right side centre

  28. i know how it rotates because i watch the string

  29. OK, I hope someone can explain my result for the GREEN/RED DESERT example: I followed the direction but my colors were flipped. The desert on the right was in green and the desert on the left was in red. So an inverse of what was above it. Any ideas? Thanks! Would love to hear from someone, anyone, even though this is a ten year old video. Thanks!

  30. The thing is you can train your brain to the point that illusions will have no effect on you.

  31. Guess I'm not a Realist

  32. I care about the invorment …but I don't think Americans will go for the fines for driving.

  33. Why is his shirt unbuttoned

  34. Find and read about the 5(eye,ear,nose,tongue,skin and there perception )secncus which describes in Buddhism

  35. I once had a dream that I could smell colors!!!

  36. Very useless information presented with above average speach.

  37. leider klappt es nicht bei einem Scan, wobei bei einer dreiteiligen Brieffaltung, wo man das Blatt in drei Kompartimente segmentiert faltet, die obere, untere und mittlere Ebene nicht übereinstimmen.

  38. I don't know if i'm broken or something, but the grey color…called that, and the illumination of the desert did nothing for me, it didn't change, and i tried 3 times.

  39. This guy is taking casual dress to its ultimate, awful extreme.

  40. What I think is the most amazing property of colour vision, which he just touched on indirectly, is that we can perceive the colour of objects more-or-less correctly independent of the colour (temperature) of the incident light, by the average colour context. Look at a flower outside in the sun: colour temperature 6500 K. Take it indoors, look at it under an old-fashioned incandescent light, colour temp 2400 K: it will appear the same colour! Not to the camera, unless you adjust it (or unless it's a very sophisticated one). Scientific American covered this in the 60s, when the research was new; I'm still amazed by it.

  41. …there is no spoon!

  42. none of these work for me. obviously my brain is better than yours.

  43. The most important thing I took away from this ? Honey is Bee barf.

  44. At 3:00 cameraman wanted to see colours through his microphone 😉

  45. He looks like he's hungover!!!

  46. I'm too high for this

  47. At 00:35 seconds I paused to comment a thought.
    –Let's start an optical illusion with a test about dots. Which two are "The Same". Everyone guess your best guess, and I won't tell you what I mean by "The Same" until you've all come to a conclusion using incomplete assessment criteria.
    At 00:45 I paused to add a thought.
    Which "One" is the same? Knowing that two shades of grey may appear lighter or darker when placed against a white or black background, I would surmise that it could be the two greys that exist at the same x,y coordinates, but surely he means to ask "Which Two?".
    As the answer is revealed, we find out that position doesn't matter and we are led to assume that all the greens on each board are the same shade.
    Maybe he could rephrase his inquiry to NOT make his audience question his intelligence?

  48. After looking at the red and green my brain actually made it seem green on the right side and red on the left. That's pretty wak

  49. Honey is Bee vomit?

  50. i wonder what it means that the desert scene still looked exactly the same to me when i looked back at that dot?

  51. I have been an enthusiast of how, why, and what we see for years but also what struck me about this video was how the government in Stockholm is monitoring the citizen's license plates to keep track of them. Furthermore, the citizens 'voted' to let them do this. I am sure that because they were convinced to vote for this, they would defend their government's position. The idea of reducing pollution is a great thing but "Congestion Charges"? But I am sure it's not the money is it? If it helps them sleep better at night then whatever. Hey everybody; let's vote for congestion charges and let the government track our movement! LOL!!!!!

  52. the benefit of this for visually impaired should be researched more. I hope we could in reality translate images to sound so the visually impaired can feel the world like any of us.

  53. Ah but how many noticed he was wearing a fake chest?

  54. What did I learn from this that will help me live a meaningful life…. nothing. And that is pretty much the result of every Ted talk I’ve ever watched.

  55. Pro tip: Our brains didnt evolve, they were designed. If you prove evolution, you will be the most famous and every one will know your name and it will no longer be called a theory. Absent those things, evolution is still not proven in any way, shape or form and no evidence exists other than wishful thinking and fairy tales.

  56. Am I the only one who wasn't effected by the desert picture?

  57. So a 10 year old video just show up in my feed

  58. my brain flipped the red and green when I looked back at the photos.I saw red on the left not right.

  59. Soooo when’s he going to finish taking off his shirt. Jeez. Sometimes inspired people need someone to remind them how to do basic things lol

  60. retinal cells work on chemicals, when we see different colors and look at a different picture, it takes time to get the chemicals giving signals from the retina to the optic nerve to get neutralize and process new information to pass it to optic nerve, essentially we are superimposing photos like in camera over exposure is used to create fancy effects on images

  61. I know it will be covered but WHAT'S UP WITH YOUR DAMN SHIRT? THAT'S what the eye is drawn to. Illusion? Self image? Ego? Waste of time? Ding Ding Ding!!!

  62. Do your shirt up mate.

  63. Fun observations to say the least. However, to observe that our brains rely on context to interpret visual input is very different from the conclusion that "we are defined by our ecology." That's too big of a leap. Is this just a predisposition towards metaphysical "relativism?" If one allows themselves to be defined by their environment (and others in their environment), they are yielding far too much control.

  64. •°▪●3:11" [..]that the same image can have an infinite number of possible (real world¿?) sources".
    Took me some time to figure out what he said. Is this the litteral version of "a slip of the tongue"?. ¤

  65. I wonder what the ticket price was? He talked a lot but said nothing but parlor tricks. “Step right up, look at this hand, put the cash in the other.”

  66. САААААМБАДИ ВОНТС ТОЛД МИИИИИИ….

  67. That 6 yr old is me from the future, i think

  68. See you think his shirt is unbuttoned, in actuality, his fly is down.

  69. why do things half assed? go ahead and unbutton your shirt down to your navel

  70. bi alt yazı koymak bu kadarmı zordu

  71. Om colorblind… I'm like… " uhh… same….same….same…"

  72. His shirt is killing me 😂

  73. maybe english isn't his first language….and the way he words everything is misleading. this would explain a lot of these weird misunderstandings lol

  74. is it bad if during the desert one, the desert on the left was red and the desert on the right was green? isnt it supposed to be the other way around?

  75. Now you see me….now you…the brain in all it's marvel, is still able to learn and also be fooled at the same time.

  76. Evolution is the dumbest religious cult in the history of the world

  77. 受験勉強そっちのけで見ちゃうヤバイヤバイ

  78. This guy is awesome! Genius

  79. Taking coffee in between

  80. Lol i would've been as good as dead with the jungle photo. Even after he put the color i still didnt see what it was

  81. 16:05 whats his point? I still see 25 purples and 25 yellows clearly…despite the yellow and purple glows

  82. In the first experiment 0:37 the greens and greys looks noticeably different. The oranges look the same

  83. something id known for a while: the light that enters our eyes, travels back along our optic cords, reaches our brains areas, arrives at the areas of translation, LETS us know we see something, plus–the time taken for us to both realize and recognize WHAT we're seeing—all that takes time…we dont see life NOW…we see things just a bit in the pAST…WE, THE HUMAN RACE, IS BLIND.we dont see things as they are NOW…always and only a bit in the past.

  84. I had to watch this for sociology. I'm supposed to summarize it, so I guess I'll do that now lmao.

  85. His voice is so creepy. Sounds like hopkins' portrayal of hannibal lectre.
    Hello Clarice….

  86. We don’t see we believe

  87. The looks made me feel that he is single!!! 🤣😝😝😝 No offence

  88. I wonder if this guy was aware that his pajamas were unbuttoned.

  89. ya. button the shirt.

  90. 6:22 i saw left side of desert red and right side desert green ?
    Anyone else

  91. How can i get my musician the living legend himself Tiny Giany aka Jeff Steinberg on one of these stages. Anyones help be appreciated.

  92. My brain could only see the direction he was actually spinning the diamond. It didn’t make sense the other way and I couldn’t picture it. Not even for a second

  93. Млять, меня одного вштырело или все-таки в названии написано сцука по-русски "Болото"? Если это не иллюминация, то что это? Ролик шалоболик с названием на русском, но без русского звукового ряда, а субтры опшин тютюб? Реально флойдовский зеволл…

  94. His accent is very strange

  95. So, it's not what we see, it's how we see? I need to find a "how to see man"

  96. Did anyone get the red on the left side and green on right after staring

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