# New optical illusion: motion "silences" changes in color, shape, size or brightness! **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [January 8, 2011, 5:02am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849 "2011-01-08T05:02:01Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [January 8, 2011, 5:02am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/1 "2011-01-08T05:02:01Z")
A startling illusion I’ve never seen before. Via Slashdot. > **[Demonstrations of silencing, a visual illusion](https://visionlab.harvard.edu/silencing/)** > > A demonstration of silencing, an illusion in which a set of objects that change rapidly in luminance, hue, size, or shape appears to stop changing when it moves. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [January 8, 2011, 5:06am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/2 "2011-01-08T05:06:03Z")
Huh. It’s not exactly silenced. I could tell in all cases in my peripheral vision that the dots were changing. But yeah, it was definitely a different “feel” when the ring was in motion. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [January 8, 2011, 6:12am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/3 "2011-01-08T06:12:13Z")
Interesting illusion! The color one didn’t work for me. I can still see the dots changing color even when in motion, though it’s definitely harder to see when the ring is moving. The gray-scale ones were much more subtle, though. With these I saw much less change when the ring was moving. ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [January 8, 2011, 1:06pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/4 "2011-01-08T13:06:35Z")
I don’t think that’s an illusion. When two things are happening at once, and you’re not looking directly at them, one of those things will dominate. ---
**Author:** ![E-Sabbath](https://avatars.discourse-cdn.com/v4/letter/e/e19adc/32.png) [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)\ **Post date:** [January 8, 2011, 3:46pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/5 "2011-01-08T15:46:26Z")
I’m colorblind, so I might have a different reaction to the color one, but as to the others… maybe it’s my MMO playing, but I locked onto and tracked a segment of the moving object naturally (top right corner, generally) and observed it was changing. If I attempted to view the entire object in situ, the specific internal object changes were dumped as ‘not critical information’. It’s more like the bear walking through the basketball game. It’s information that can be tossed out as noise. ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [January 8, 2011, 4:17pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/6 "2011-01-08T16:17:46Z")
> [@GuanoLad](#): > > I don’t think that’s an illusion. When two things are happening at once, and you’re not looking directly at them, one of those things will dominate. That’s a type of illusion. An optical illusion is simply the delta between what you perceive and what is objectively there. If your brain “dominates” one perception over another, that’s an optical illusion. Optical illusions are fascinating because they’re the easiest way to demonstrate that there is a real difference between how our brain processes sensory input and what is objective fact. Illusions aren’t your brain being wrong, they’re your brain choosing how to process information. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [January 8, 2011, 5:20pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/7 "2011-01-08T17:20:10Z")
For me, the color one worked the worst. It was easy to see that they were changing. Why? Well because of the reason the rest of the illusion works: It’s not about filtering out differences. It’s just that if you have a row of objects where one is different, like “ooooooooaooooo”, it’s hard to see if it changes to “oooooooaoooooo”. It looks the same but if you look closely, you’ll see that I moved the ‘a’ over by one. It gets harder when there are several a’s or more than two variations, such as “geavgrafvlaflg” vs. “geavgrafvalflg”. It’s even harder when they’re arranged in a “nonsense” pattern instead of a line or grid. Then there’s the fact that we’re biased toward motion. Consider those Christmas lights where the bulbs light up in sequence. It looks like the light is moving through all the bulbs, but we know that’s not the case. So when you look at the wheel, what is your brain really seeing? Not that things become static, just that some things move more than others. Say that dot 34 and dot 33 are next to each other. 34 starts red and 33 starts brown. When the wheel moves, 33 turns red and 34 turns green. Both dots, however, move half an inch. Does our brain detect two changes and two moves? No. It will detect that the ‘red’ dot moved just a little farther than the other dot, just like the Christmas lights. But wait…if the red moved dots, where did the brown go? It didn’t go to a dot nearby, so your brain detects that it’s gone. That’s when you realize that the dots are changing color, not just moving, and the illusion breaks down. But check out the other wheels again. The size dots only have two or three choices- big, small, or vaguely in between. Sure, there’s a technical difference in the sizes, but 60% big and 70% big aren’t nearly as noticeably different as green and blue. So it’s likely that when a big dot changes to medium, that some nearby dot went from medium to big. So it doesn’t look like anything disappeared, just that those two dots ‘stirred’ a little more than other dots, again just like the Christmas lights. The same goes for brightness. So how can you make this most effective? 1. Use similar states that are hard to distinguish. 2. Make small movements. 3. Make snap changes instead of gradual. 4. Reverse direction like they did in the video. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [January 8, 2011, 5:24pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/8 "2011-01-08T17:24:58Z")
Funny thing I just realized: If you have Firefox, you’ve seen this illusion countless times. Look at this tab’s icon (the SD logo) and reload the page. It changes to a “loading” symbol. Notice what it’s supposed to look like- motion. But what is it really? Color change. Very fast color change. Your brain doesn’t see 8 color-changing dots, though. It sees a spinning ‘wheel’. Same illusion. ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [January 9, 2011, 12:50am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/9 "2011-01-09T00:50:56Z")
> [@E-Sabbath](#): > > I’m colorblind, so I might have a different reaction to the color one, but as to the others… maybe it’s my MMO playing, but I locked onto and tracked a segment of the moving object naturally (top right corner, generally) and observed it was changing. > > If I attempted to view the entire object in situ, the specific internal object changes were dumped as ‘not critical information’. It’s more like the bear walking through the basketball game. It’s information that can be tossed out as noise. The instructions say to stare at the white dot in the middle. Anyone can continue to see the dots changing if they stare at the dots. ---
**Author:** ![E-Sabbath](https://avatars.discourse-cdn.com/v4/letter/e/e19adc/32.png) [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)\ **Post date:** [January 9, 2011, 1:49pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/10 "2011-01-09T13:49:08Z")
Right. I’m saying that my natural inclination was to lock on, rather than to focus on the center or the object as a whole. ---
**Author:** ![Dragwyr](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dragwyr/32/2855_2.png) [@Dragwyr](https://boards.straightdope.com/u/Dragwyr)\ **Post date:** [January 10, 2011, 12:48pm UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/11 "2011-01-10T12:48:38Z")
Magicians have been using this principle for years. Large motions always make great cover for small motions. ---
**Author:** ![Rich\_Mann](https://avatars.discourse-cdn.com/v4/letter/r/ce73a5/32.png) [@Rich\_Mann](https://boards.straightdope.com/u/Rich_Mann)\ **Post date:** [January 11, 2011, 3:48am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/12 "2011-01-11T03:48:20Z")
I think this effect has an evolutionary advantage. It would tend to help one see the tiger sneaking through the breeze-blown, high grass as a single moving object rather than just a huge field of stripes changing hue and tone. ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [January 11, 2011, 3:53am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/13 "2011-01-11T03:53:09Z")
> [@Rich\_Mann](#): > > I think this effect has an evolutionary advantage. It would tend to help one see the tiger sneaking through the breeze-blown, high grass as a single moving object rather than just a huge field of stripes changing hue and tone. Man, if I have to go back and check, you’ll be sorry! 🙂 ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [January 11, 2011, 4:44am UTC](https://boards.straightdope.com/t/new-optical-illusion-motion-silences-changes-in-color-shape-size-or-brightness/566849/14 "2011-01-11T04:44:02Z")
Even while staring at the white dot, I can detect changes in the ring while in motion if I know what to look for. However, it looks like the changes are much diminished during the motion time. That doesn’t seem like a fair way to test the phenomena. Of course you don’t notice the change as much; there isn’t as much change to notice.