Try this bizarre audio illusion! 👁️👂😮 - BBC

There is a considerable body of evidence that "top-down" processes affect not only how sensory evidence is processed, but how the sensations themselves are experienced. In other words, high-level (but subconscious) neural "judgments" about the statistics of the world, actually influence how you perceive it. To put it still another way: sensations aren't simply passively experienced; they are actively constructed by the brain. Phantom phone vibration is, in many ways, just as "constructed" as real phone vibration. Perceptual illusions provide one of the clearest ways to show that sensations reflect factors other than external stimuli. Here are two illusions, in different sensory modalities, that demonstrate the strong top-down influence of the brain on perception: The rubber hand illusion [1,2] and the McGurk effect [3,4]. The rubber hand illusion is particularly relevant because it is quite similar to the phantom phone vibration effect. 1. [link] 2. [link] 3. [link] 4. [this video] EDIT: Here's an additional example to consider. People generally can't tickle themselves. The sensations are less strong when one touches oneself than when someone else does so. The explanation for this is that the brain automatically discounts sensations which arise as a result of self-motion. This has obvious advantages, namely that you don't constantly overstimulate yourself just in the process of moving through the world and are as such better able to attend to important externally generated stimuli

It is really interesting and amusing how persistent certain 'illusions' can be even when one is exposed to it just once and for a short time. Fun story, this was a long time ago: I was interning at Google at that time. One day I tell my then cube neighbor about an interesting experiment on visual perception that I had read about. A professor at MIT had carried out experiments on his class. Students were asked to wear prismatic goggles that shifted their vision and then try to catch objects. Hilarity ensued, but soon enough the brain adapted to the shift. Same with inverting glasses, soon the students would not even realize that their vision was inverted. The fun part was when they took their glasses off, their motor reflexes would still compensate assuming that they were wearing those glasses. Much hilarity again. I was telling all this to my cube neighbor Michael Riley, not knowing who he was, he says with a twinkle in his eye "Yeah, that was us". The most remarkable thing about these experiments that I learned from him was that the professor would provoke an illusion on the students on the first day of class. I dont remember exactly what the illusion was, but it was some visual artifact, seeing patterns that werent visible a moment ago, much like the OP. At the end of the semester the professor would demonstrate that the entire class could still see that illusion, although they have not been exposed to it in the intervening 4 months ! I tried hard to find an articles on the

I originally started with web resources, but here's the stuff I credit with really advancing me properly, roughly in the order I read or used it: 1. TTMIK's Hangeul Master . It's really easy to pick up hangul basics so spending $20 on a book that's superficially just about the alphabet might seem silly. But the harder part to learn isn't really the symbols, it's the pronunciation. You need to get to grips with the various sound change rules that apply when various characters are adjacent to each other, and with the pronunciation differences between the normal and tense consonants, and so on. If you can't look at a word and confidently form its sound in your head you can't read or write efficiently, so this is crucial. TTMIK's book is really a solid package: You get the basics (the symbols, the stroke order, etc.) but also a good introduction to the sound change rules, not just on paper but also in really well-done supplementary audio resources and quizzes (where many books fail). Finally there's a second section on various Korean handwriting styles that I found surprisingly useful (Korean TV shows and other materials often use pen scripts that can be hard to read without spending some time with this). 2. To complement the above, the Korean Wiki Project has a lot of good sound files for various character combinations. 3. Billy Go's two Korean Made Simple books are just great. They're highly accessible introductions to core grammar and core vocab, with short, digestible chapter