Bizarre Illusions

11 points

Jan 27, 2010

Illusions are cool. They make me think something is happening when it isn't. When offered the classic illusion pictured to the right, I wonder at the color of A and B. How weird, bizarre, and incredible.

Today I looked at the above illusion and thought, "Why do I keep thinking A and B are different colors? Obviously, something is wrong with how I am thinking about colors." I am being stupid when my I look at this illusion and I interpret the data in such a way to determine distinct colors. My expectations of reality and the information being transmitted and received are not lining up. If they were, the illusion wouldn't be an illusion.

The number 2 is prime; the number 6 is not. What about the number 1? Prime is defined as a natural number with exactly two divisors. 1 is an illusionary prime if you use a poor definition such as, "Prime is a number that is only divisible by itself and 1." Building on these bad assumptions could result in all sorts of weird results much like dividing by 0 can make it look like 2 = 1. What a tricky illusion!

An optical illusion is only bizarre if you are making a bad assumption about how your visual system is supposed to be working. It is a flaw in the Map, not the Territory. I should stop thinking that the visual system is reporting RGB style colors. It isn't. And, now that I know this, I am suddenly curious about what it is reporting. I have dropped a bad belief and am looking for a replacement. In this case, my visual system is distinguishing between something else entirely. Now that I have the right answer, this optical illusion should become as uninteresting as questioning whether 1 is prime. It should stop being weird, bizarre, and incredible. It merely highlights an obvious reality.

Addendum: This post was edited to fix a few problems and errors. If you are at all interested in more details behind the illusion presented here, there are a handful of excellent comments below.

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MrHen

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wedrifid

18 points

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8 years ago

Why do I keep thinking A and B are different colors?

Meanwhile I am thinking 'Wow! My brain can automatically reconstruct a 3D image from limited 2D input and even compensate for shadows and lighting. That is orders of magnitude more complex than the reverse, generating such images from a model such as those we add 3D cards to computers for'.

I don't particularly consider this an 'illusion', especially when it is not simultaneously acknowledged that it is an 'illusion' that A and B are squares on a 3D 'square X a bit' thing that also has a cylinder on top of it.

18 points

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SilasBarta

8 points

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8 years ago

Wow, good point! I never thought about it like that. It raises the question: Why are people amazed when you say, "Tiles A and B are actually the same color -- check for yourself!" but they roll their eyes when you say, "There are no squares in this image -- check for yourself!"? In both cases, you can respond with, "Well, yeah -- if you don't interpret it like the scene it's trying to represent!"

I'm not a very good artist, so learning about how to create these illusions sounds like a good reason to take an art class, and help me appreciate what artists are doing. (Why didn't the first major breakthrough in cognitive science come from painters and sketchers?)

Of course, it probably wouldn't do much to help me understand why they can count random smears on a canvas as "art"...

8 points

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AndyWood

14 points

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8 years ago

I am being stupid when my eye looks at this illusion and I interpret the data in such a way to determine distinct colors.

Not at all. In the context of the scene that this picture represents, A and B are absolutely different shades. On the contrary, I think your perceptual system would be poor indeed if it did not reconstruct context, and under-interpreted the picture as a meaningless 2D array of pixels.

(BTW, as with the necker cube, I find that I can consciously exert to experience the interpretation that I choose, without too much difficulty.)

14 points

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byrnema

11 points

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8 years ago

I identified a useful and cogent point in your post and it was this: Whenever you receive data from any source (your brain, your eyes, a drug study, Less Wrong) you've got to be aware of how that data has already been packaged. Taking the data at face value -- for example imagining your brain is actually making a claim about the RGB values of the pixels -- can lead to problems, misconceptions, mistakes.

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bgrah449

8 points

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8 years ago

Your eye didn't evolve to report trivia like, "These two colors are actually the same." Your eye is reporting the most useful information - from which direction the light is coming, the shaded region under it, and the fact that the floor is tiled.

Which is more amazing - this picture, or a picture that somehow tricked the average person into noticing two colors were the same, but didn't notice the picture also had floor tiling, light directionality, and shading? I'd say this picture is pretty tame in comparison to the picture that could do that.

8 points

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Jack

5 points

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8 years ago

I am being stupid when my eye looks at this illusion and I interpret the data in such a way to determine distinct colors.

Tell that to your ancestors who escaped from the saber-tooth cat hiding in the shadows at dusk.

5 points

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