Can you make your brain not see this circle illusion? | Hacker News Reader

Can you make your brain not see this circle illusion?

syfy.com

186 pointssohkamyung71 comments

Illusions like this always remind me of failure modes of image classifiers - where an AI thinks a sunflower is a panda or whatever, because it's never seen a sunflower before.

That is, presumably the illusion works because it depicts something we've never needed to distinguish before, in such a way that it shares salient features with something more familiar (in this case, oddly-textured concentric rings and normally textured spirals, respectively). Or am I spouting nonsense?

I've always thought of it this way:

Over millions and millions of years of evolution, many mammals (including us) adapted our vision centers to quickly process large chunks of environmental information by developing a series of beneficial hard-wired processing networks in the visual cortex. These neural pathways allow us to do things like subconsciously notice small movement or even judge distances fairly accurately without parallax. Most of the time it works pretty well; I mean, it kept us as a species alive up to today. However, illusions like this "exploit" the "visual hacks" our brain uses (that allow us to process such large amounts of visual data so quickly) by creating objects that don't (or can't) exist in nature. Our brains are fairly picky about things like depth-of-field and textural shading and oftentimes their limits can be demonstrated by simply playing with a few colors and changing a few angles.

Cats that grow up in an environment without any horizontal lines are unable to see horizontal lines [1]. This indicates that it might not be as much "evolution made me recognize these shapes" as it is "I learned to recognize these shapes since I see them often", which is more inline with OP's explanation. Of course evolution plays into what you are able to learn to recognize in the first place.

[1] https://www.psychologytoday.com/blog/brain-food/201404/the-c...

I wonder why evolution has not exploited this more.

It probably has, it's just that after it has been exploited it becomes a default part of everythings sensory kit.

It has, think about natural camouflage like zebras. It short circuits the predators ability to pick out individual herd members.

Minor correction: Predators like lions have no problem distinguishing individual members of a herd. The stripes pattern messes with the way blood-sucking, disease-spreading flies (such as horse flies or tsetse flies) see the world.

https://motherboard.vice.com/en_us/article/kbzwpv/the-reason...

The illusion creator's homepage is an old favorite of mine.

http://www.ritsumei.ac.jp/~akitaoka/index-e.html

The illusions discussed in the article are the Cyanophyceae under the shape illusions category.

http://www.ritsumei.ac.jp/~akitaoka/ACSwamp2010.jpg got me. But there's a catch: it only works when you scroll. So you have to go to http://www.ritsumei.ac.jp/~akitaoka/index-e.html and scroll down till you see it. It looks bizarre.

Wow, and it doesn't even require color. There's a grayscale illusion which behaves similarly -- maybe even a bit stronger! -- at:

http://www.psy.ritsumei.ac.jp/~akitaoka/mesh-driftillusion01...

Works for me without scrolling.

Yeah, that set is a great one. I've noticed the scrolling effect too, it definitely intensifies the movement. I suspect the cause of the movement is the saccades shifting where it is in the visual field slightly, and scrolling is a much bigger shift.

Bobbing my head up and down also works.

He's also very friendly on his Facebook account. He's got quite a few fans there.

I noticed that the rotating snake illusion only seems to occur when my eyes are actually moving; if I focus on a specific spot for long enough, they seem to all stop spinning.

Really neat stuff.

Are there examples of these patterns in use in real world logos or, e.g., website designs? Not designed to make people dizzy, but used to give an illusion of animation maybe?

> Yup. Those aren’t spirals. They’re all concentric circles.

Except they are spirals. The black patches form the implication of a spiral - this is where your visual system picks out the spiral from.

If you were to say that there are technically no spirals in that image because they're not contiguous, then you could equally say that there are technically no circles either, only an arrangement of square boxes that is strongly suggestive of a circle.

Either way, it's a very powerful illusion.

>If you were to say that there are technically no spirals in that image because they're not contiguous, then you could equally say that there are technically no circles either, only an arrangement of square boxes that is strongly suggestive of a circle.

There are circles though. The grey concentric rings.

If you removed them, you'd see the black and white pattern spirals towards the center.

This is something I've been tempted to blog about. As you and my sibling poster point out, the illusion is actually essentially composed of the things they claim aren't there. The same goes for the Kanizsa triangle, Fraser's illusion and many others. The simplest description of each image matches what our eyes see, but the creators say "Ah, but I created it this other way, so your eyes are wrong".

For me the illusion here is no trick. Looking at it I have considerable difficulty not seeing a single unbroken line spiraling out from the center to the perimeter. In reality there are huge disconnects, it is concentric rings and not a continuous line at all. Even when I force myself to see the circles they look like they are all trying to float away from each other in opposite directions. Almost poetic, really.

The spirals are actually there, partially concealed by plain circles, so seeing spirals is not really incorrect. Your visual system is good at seeing concealed things. That's why I disagree with it being classified as an illusion. Though not as much as with the Kanizsa triangle.

"The spirals are actually there" - the unbroken spiral is not there, and it is an illusion of one, not multiple. At least to me. I guess if you want to be particular, the circles are broken by the pixels on my monitor, but at 4k that isn't perceptible. I guess if one gets far enough away from the monitor that one can no longer resolve the space between the circles it could be said that the spiral is actually there.

The black patches form the implication of a spiral

Indeed, it reminded me of the triangle illusion: https://en.wikipedia.org/wiki/Illusory_contours

The brain is very good at "filling in", so what it's doing in this case is perceiving the image as a masked-off spiral.

That also brings to mind, what would the "content-aware fill" tool in newer versions of Photoshop do to the image...?

If you like this sort of thing, and haven't heard of the McGurk Effect before, take a look at this: https://www.youtube.com/watch?v=G-lN8vWm3m0 .

Wow. I can close my eyes and picture the two different speech patterns and hear different results. Bizarre.

Focus on the gray, and let your mind put it as the foreground, and circles, let them be a low frequency background. It may be your best chance to not see the illusion.

Worked for me on the squared circle but took concentration on the spiral. It changed as I looked at it but not like before. Different ways of focusing on it made it go static vs moving.

What made you recommend that?

Negative space is easy to see when you focus on it. In these examples, the negative space is flat color, so it's not affected by the illusion.

Good advice.

You feel it, it's almost there... and no. It's gone. The spiral won.

So close !

I do better on the spiral one when I imagine I am slowly floating down a tunnel, like a game of Luxuria Superbia. I can see an individual circle or two pop out at a time, except for the smallest ones :/.

And after sleeping on it it is much easier now :/.

I also think that as you become more trained in graphics (and illusions in general?) you become more adept at stripping the component that makes up the illusion.

Also the challenge that comes with "Warning!! You cannot unsee this!!!" probably helps too.

It could be said that his explanations of the illusions are wrong: there is a spiral in the final image, it's just masked out by concentric circle outlines. Particularly toward the center of the image where the resolution is so low that it all blurs together anyway it is hard to argue that is not a genuine (if blurry) spiral.

I had no problem seeing circles and not a spiral. If I stare at it, it sort of looks like a tunnel deep into the ground.

Just kind of look at the whole thing and then the details, alternate your attention back and forth and you can see circles and not a spiral.

When learning to parse the concentric circles with eighteen patches of mirror-spiraling dot sequences, my thought was: "Look at the gray areas, duh. Just like life. They're what's actually there, the rest is a distraction designed to deceive your natural perception." > woah.jpg

It's like generative adversarial samples for biological neural nets. I wonder is someone could weaponize this so if would cause lasting dizziness and disorientation after a prolonged exposure.

Similar device was used in the sci-fi novel Snow Crash. It appeared like a black and white image of static but in fact contained a subliminal message which tapped into some subconscious low-level cognitive functions of the brain. Just by looking at it, it reprogrammed the victim's brain and made them into a mindless zombie.

https://vimeo.com/118342272