One of Akiyoshi Kitaoka's recent work that I found absolutely stunning is the following illusion where a ring of one colour appears to be either in front of or behind two rings of another colour:
To my perception, the blue ring appears to float above the red rings. It feels a bit like an autostereogram where a 3-dimensional image emerges out of a 2-dimensional image. However, there is no autostereogram in this image and there is no crossing of eyes involved. The 3-dimensional image arises out of an otherwise plain image of differently coloured rings on a dark background.
If you wear glasses I suggest trying both with and without your glasses on while moving your head. For me, there is almost no effect without my glasses on. But with glasses, it is quite strong... but I'm not even sure if what I'm seeing when I have my glasses on is actually the intended effect. I've become used to that effect with blue and red light moving in opposite directions relative to each other when I move my head.
I see the red rings in front. I tried adding some depth cues to see if I could see it both ways - https://i.imgur.com/LsPtsRr.png
It kind of works, but for me it feels more like the blue ring now has a variable depth, with parts below and parts above the red rings, kind of like a piece of fabric draped over a bar.
I wonder how it feels for people who see blue in front?
then: blue ring appeared "closer" to me (very similar to a stereogram - yes)
I was able to "force" the blue ring to snap to being "behind" the red rings by rapidly blinking but the effect wouldnt stick .... the perception would slowly snap back to my default - blue in the front
That one, for me, is sorta like the ballerina thing, in that with a small mental effort I can make it switch between the two states. But honestly my first glance at it, they look largely "flush" - not a super strong 3d effect in either direction.
I've noticed the same effect with stained glass, that blue tends to recede for me and red comes forward.
I spend a lot more time in churches, especially ones with stained glass, than most people, but I hadn't thought to ask if it happens to other people too.
> More specifically, a closer object projects to a more temporal part in the retina and so does red light. This suggestion, however, made Bruecke immediately reject his hypothesis because some of his observers reported red receding with respect to blue.
> The Stiles-Crawford effect is a phenomenon that the rays entering the eye through the peripheral regions of the pupil are less efficient than those through the central region [24]. This two-factor model, which Vos [4] called the “generalized Bruecke-Einthoven explanation,” has been widely accepted, while a few authors did not approve it [25]. Many studies suggested that pupil size affects chromostereopsis [19, 21–23], which supports the generalized Bruecke-Einthoven explanation. Simonet and Campbell [26], however, did not find any consistent relationship between pupil size and chromostereopsis.
Maybe the explanation is not 100% physiological in nature.
Human Perception as a Phenomenon of Quantization – Diederik Aerts, Jonito Aerts Arguëlles – 2022
> For two decades, the formalism of quantum mechanics has been successfully used to describe human decision processes, situations of heuristic reasoning, and the contextuality of concepts and their combinations. The phenomenon of 'categorical perception' has put us on track to find a possible deeper cause of the presence of this quantum structure in human cognition. Thus, we show that in an archetype of human perception consisting of the reconciliation of a bottom up stimulus with a top down cognitive expectation pattern, there arises the typical warping of categorical perception, where groups of stimuli clump together to form quanta, which move away from each other and lead to a discretization of a dimension. The individual concepts, which are these quanta, can be modeled by a quantum prototype theory with the square of the absolute value of a corresponding Schrödinger wave function as the fuzzy prototype structure, and the superposition of two such wave functions accounts for the interference pattern that occurs when these concepts are combined. Using a simple quantum measurement model, we analyze this archetype of human perception, provide an overview of the experimental evidence base for categorical perception with the phenomenon of warping leading to quantization, and illustrate our analyses with two examples worked out in detail.
> in this article, we would like to pay attention to visual perception that takes place in this more primitive first-line phase and quantum structures that would be present there. A specific situation in visual perception, namely, the bi-stability that occurs when viewing figures drawn on a two-dimensional background that we nevertheless visually reconstruct into ‘seeing three dimensional entities’, of which the ‘Necker cube’ is the archetypal example, was studied within the quantum cognition approach. The presence of quantum structure was investigated and convincingly demonstrated (Conte at al., 2009; Atmanspacher & Filk, 2010).
Am I alone in not understanding this black hole one... it's a sequence of three obviously distinct still images in which the black center is larger than the previous image.
Meanwhile, each image on its own is offering no kind of perceptive illusion to me...
For me it doesn’t seem to grow. But the blurred edges definitely show movement from my perception with both eyes open. If I close one eye the effect goes away altogether.
Yes each image independently shows the illusion -- different images are only to provide a variation i guess, since some proportions work better for some people than others
I personally found the illusion not strong though definitely present
This similar illusion but done with different colors and patters was much more vivid and strong for me ...
I don't intuitively understand any illusion. I don't have conscious introspection into what the layers of neurons are doing between the retina and conscious visual perception. The layers of neurons use certain indirect cues in order to detect size, depth and movement. Those cues do their job in most circumstances, but test cases can be constructed which falsely trigger those cues. That's just an intellectual generality that doesn't explain anything specific.
You should add shadow to the list of important cues. Something light in shadow can be the same color as something white in direct light. You can see that optical illusion in https://en.wikipedia.org/wiki/Checker_shadow_illusion.
My favorite example of where shadow matters is "the dress". As https://slate.com/technology/2017/04/heres-why-people-saw-th... explains, those whose brains assumed it was in shadow saw it as white and gold. Those whose brains thought it was in light saw it as blue and black. (It was actually a blue and black dress, in light. But the photo was taken in such a way that most people thought it was in shadow.)
This one drives me crazy because even having seen a picture of the same blue and black dress in direct light, my brain simply will not see this as anything but white and gold. I know I'm seeing it wrong and still can't see it right.
Can these affect your vision (long-term) if you stare at them for too long? I feel like many of these images produce similar effects to the McCollough effect. https://en.wikipedia.org/wiki/McCollough_effect
When I was young (maybe 8 or so?) my mom got me a book of B&W moiré patterns. It consisted of a book of B&W patterns and a clear plastic sheet also with similar patterns. When you overlaid the plastic sheet over the patterns in the book is when you got the moiré patterns.
Besides seeing yellows and other fringe colors appear from the moiré, I always wondered if the patterns were linked to ocular migraines I would have for some decades after.
I could imagine that it will change the way you perceive things. There are experiments where people got goggles that switched the left and right eyes and people adjusted after a few days.
I had a copy of some Merleau-Ponty work in which this experiment was commented, IIRC the experimenter did really think his brain was damaged when the world appeared upside down to him without the glasses.
Oof. Yes. I don't get the speckles, but the middle portions of the tunnel "shudder" like looking a something slightly out of focus at extremely high power through a telescope, and it feels like I'm about to get a migraine.
I used to have a high quality printout of the rotating snakes illusion by my desk.
I had people who refused to be at my desk because it creeped them out that they absolutely knew the paper couldn't be moving, but their brains kept seeing the snakes rotate.
Some of the movement illusions really pop out if you slowly move your finger across the image and track it with your eyes. Or use a mouse pointer similarly if you're on desktop.
> Some of the pictures on this website can cause dizziness or might possibly epileptic seizures. The latter happens when the brain can't handle the conflicting information from your two eyes. If you start feeling unwell when using this website, immediately cover one eye with your hand and then leave the page. Do not close your eyes because that can make the attack worse.
I wonder whether the “Rauschenberg Illusion” would count. Named after Robert Rauschenberg’s blank white canvases which show that big white fields are filled with illusions of color and form from our visual system. (Or at least, they are for me. I’m not nuts, am I?)
Persistent Visual cortex defects. Now imagine the brain riddled with similar defects, when it's comes to reasoning and learning. If there was one creature not defect, the whole rest of the zoo would be sad.
A lot of the movement ones are more noticeable with actual movement so scrolling a little bit could help. I notice them popping more when I scroll through his twitter feed.
Mark Changizi had an interesting insight on how some illusions work [1].
What we see is a reconstruction by the brain interpolated from our sensors. The idea of Mark is that the image is not only an interpolation of the present, but actually also an extrapolation of what the image will be in the next tenth of a second. For tasks such as catching a ball, this would allow us to compensate for the delay of the signal between our brain and our muscles.
Based on this idea, he wrote a classification of many illusions [2].
I'm very shocked that these were only discovered so recently (Well. If you consider the early 2000's to be "recent". I'd have assumed that we'd have found these out earlier)
I suppose that's why they were all the rage in childrens' books and museums around that time.
https://twitter.com/AkiyoshiKitaoka/status/16812686184854568...
https://nitter.net/AkiyoshiKitaoka/status/168126861848545689...
To my perception, the blue ring appears to float above the red rings. It feels a bit like an autostereogram where a 3-dimensional image emerges out of a 2-dimensional image. However, there is no autostereogram in this image and there is no crossing of eyes involved. The 3-dimensional image arises out of an otherwise plain image of differently coloured rings on a dark background.
An analysis of this illusion is available here: http://www.psy.ritsumei.ac.jp/~akitaoka/Kitaoka2015_Referenc...