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It's Surprisingly Hard To Notice When Moving Objects Change
An anonymous reader writes "Scientists at Harvard have found that people are remarkably bad at noticing when moving objects change in brightness, color, size, or shape. In a paper published yesterday (PDF) in Current Biology, the researchers present a new visual illusion that 'causes objects that had once been obviously dynamic to suddenly appear static.' The finding has implications for everything from video game design to the training of pilots."
Is that why my wife is always running around ?
Everything I write is lies, read between the lines.
It's Surprisingly Hard To Notice That It's Moving!
I think this was fairly well known (at least intuitively) by magicians. As long as you keep your hands moving, people can't tell what you are doing with them.
Our eyes are trained to do a whole lot of quick thinking and estimates before sending the raw data to our brain. This is one of the many reasons why simply hooking a camera up to the optic nerve doesn't quite produce the desired results - though our brains seem to be super-learning computers able to interact with almost any other kind of Input - Output, given enough time for trial and error.
I imagine our Eyes are trained to generalize the colour it sees and focus on the appearance of motion, because thats usually more important and relevant to survival, and our eyes are just like technology: Limited bandwidth.
You might call it a defect, I might think of it as evolutionary design.
IAAVN (I am a Visual Neuroscientist). It's a compelling illusion. I have not read the original paper, but will speculate nevertheless in true Slashdot fashion. The change that's perceived before the ring rotates is not so much due to the colors changing -- if you pay close attention -- but something that's called apparent motion. The classic example of apparent motion is the sequencing of lights around a movie marquis -- they appear to move, although the lights themselves are not actually moving. In the same way, the static ring has internal apparent motion as the colors change, because your brain is interpreting, for example, one dot turning yellow next to a dot that was previously yellow, as motion of a yellow dot, even though the underlying dots do not move. While apparent motion can be very strong, it is not the same as true motion.
Then, when the ring starts to rock back and forth, there is a true motion signal that swamps the apparent motion. If you pay attention to a given dot while holding your gaze still fixed at the central white point (not as hard as it sounds), you can clearly still see the colors changing.
So without having read the paper, I reserve some skepticism that they have not actually measured what they think they have. Change is still perceptible, but it would seem that real motion interferes with apparent motion.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
those idiots running red lights.
captcha: sleepy. Maybe sleep deprived drivers too
demonstration of how when the brain receives two different associated inputs and determines one is much more important than the other, how well it focuses you on just the important one.
In a predator-prey situation, prey are usually excellent at spotting movement. It's not surprising that when we see something start to move that's a bit dynamic, (like a tiger running through our view among the grass) how our brain "freezes" the image and allows us to process a more static interpretation of it while we track its movement through a visually very noisy environment.
Sort of along that line, after seeing that tiger race through the grass, you'd probably have completely missed the other three just standing there as the tiger you were tracking ran past them
I work for the Department of Redundancy Department.
Switching something when it is in the middle of fast movement is the basis of all kinds of slight of hand tricks. There's just a certain state where the mind identifies something just as a blurb of overlapping color, rather than anything processed meaningfully, and you can freely swap it with a similar item without any notice. Mix in basic misdirection, and you can fool almost anyone's expectations. It's also why you kind of have to learn to juggle by feel & pattern rather than just sight - because the hand really does have to be faster than the (mind's ability to process information from the) eye to keep up with the pattern.
Ryan Fenton
Yeah, that's often a problem for fighter piolts... They're about to engage an enemy when all the sudden the aircraft changes size and color. Better update the training manuals right away.
Site appeared to be slashdotted. Here are the youtube links extracted from the page:
Motion silences awareness of hue changes
Motion silences awareness of luminance changes
Motion silences awareness of size changes
Motion silences awareness of shape changes
As a magician, I have known this for years. Dai Vernon, The Professor, explains that concept the scientists just discovered as a simplistic beautiful statement, "A larger action covers (or hides) a smaller action." Science finally catches up to the magicians.. Damn them. :-)
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
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-- The Doctor, "Doctor
Unfortunately the video player had no indication that it was not loading at all (likely slashdoted), instead just sits static on the first frame. However, it took me about 30 seconds of staring at the static image wondering if my since of perception was so bad I -didn't see anything moving at all-
Turns out it is pretty bad, just not in the way I thought; I recommend going straight to the youtube versions linked on the article.
It's a pretty neat effect, sort of one of those things that become pretty obvious once you see it.
"Scientists at Harvard have found that people are remarkably bad at noticing when moving objects change in brightness, color, size, or shape..."
That may be because our eyes are exposed to so many different lighting conditions that our auto-white-balance is kicking in.
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I'll bet Monk doesn't have this problem!
As a former competitor at the world-level in first person shooters, perhaps my cortex has adapted differently, because when I stare at the dots in the center, I can always tell that the shape or hue or brightness are changing. I can tell when they change and how they change. I can see how in many ways this might be true for 99.99% of the population, but when you spend man-years staring at stationary dots in the center of a screen (crosshair) while "looking around" in-game waiting to notice single-pixel changes out of the ordinary, maybe you learn to notice it?
I'm surprised to report that this one doesn't affect me; I can definitely perceive that the dots change color, even when they're moving around.
Nebulo
Who only noticed a *diminished* sense of the colors changing? I could still see the colors changing, it just didn't seem to be nearly as much as before the dots started moving. My experience was as follows: 1) Ok, colors changing 2) dots moving and wow the changes stopped! 3) oh wait, no I'm seeing a few changes still....
Nice illusion indeed, and at least partially new. A while back, I combined two different illusions to make a single more effective illusion. I wonder if there's any connection with the one in the news article as they both seem to rely on the movement of peripheral vision confusing other aspects of change in peripheral vision:
http://www.skytopia.com/project/illusion/ipage-vb.html
The effect this one achieves is the disappearence of visual areas rather than 'merely' lessening the effect. Although mine is arguably more dramatic once it happens, it can be slightly tricky to see the effect immediately compared to the one in the news article.
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Nothing to see here move along
If enithin kan gow rong it whil. (Murfey)
Because in a primitive, hostile environment, the main thing is to see the enemy / victim coming. That's one of the reasons why people keep watching anything that moves above static parts. That it also changes color.. well.. big deal. Noticing it moving is much more important.
News Flash:
Humans find it difficult to notice things they are not looking at! Film at 11.
...that our brain is really great at recognizing objects despite changes in "brightness, color, size, or shape"?
bickerdyke
This is from 1999. http://www.youtube.com/watch?v=vJG698U2Mvo
Many of you might already know this, but this is the original.
It is even used in an add against cyclist(1) http://www.youtube.com/watch?v=Ahg6qcgoay4
A much more interesting one is to be seen at http://www.youtube.com/watch?v=W92tDI4RYCw Almost the same difference.
(1) You are to hit them and not miss them. At least that is what I get as message.
Don't fight for your country, if your country does not fight for you.
In the example videos, the changes are not random, they are a pattern that rotates around the group. (Watch the shape change and size change to see it most obviously, but it's there in the color/brightness ones as well.)
So when the group starts rotating, it is actually counter-balancing the individual item change. You're losing sight of the trees for the forest.
Example: a group of people are on a merry-go-round. Each one is holding paper with a symbol on it facing up. They start passing their papers around counter-clockwise. So each person's "symbol" is changing. You see it happening easily. Then the merry-go-round itself starts rotating, which counter-balances the rotation of the moving symbols. Even if you quickly reverse the merry-go-round motion every so often, as they do in their examples, you will see the 'overall pattern' seem stationary, followed by VERY QUICK movement, followed by stationary.
A better example would have each individual item's changes be completely random, not following an overarching rotating pattern.
Another non-functioning site was "uncertainty.microsoft.com."
The purpose of that site was not known.
It's got one test where there are 4 animations, and you have to pick out the one slightly different. It's quite difficult!
The reef squid has the ability to quickly change colors and patterns on it's body, and seems to signal other squids in this fashion (as well as for camouflage). I wonder if they would be fooled by this illusion or if their neural optics are wired very differently than ours. It would be challenging to try to create an objective test that you could do with them.
I won't necessarily claim to be one here, since anyone can claim anything on the internet. But I wonder how well experienced MTI analysts (http://en.wikipedia.org/wiki/Moving_target_indication) would perform against these videos. Quite literally, it is the job of an MTI analyst to distinguish coherent from non-coherent changes across a vast number of moving dots displaying all sorts of crazy behaviors.
Additionally, I would prefer to see this experiment run under different conditions, such as having the videos begin with dots in apparent motion for many seconds, then having them stop moving. I do think the results of the experiment are damaged by having the motion segment (3 secs) be significantly shorter than the non-motion segment (5 secs) and always happening after the eyes and brain have adjusted to the lack of apparent motion.
I think another big problem with the videos provided is that the motion segment alters direction 9 times (counting first and last) within a short window -- this may not result in the human mind having difficulty seeing change in moving objects, but a difficulty in adjusting the perspective of the total scene to something observing rapid fluxuation in velocity. (I.E. The circle constantly rotates back and forth, preventing the brain from "getting used to" the scene, whereas when the dots are stationary and only changing in specific property, they remain in this configuration for a much longer period of time).
It's a interesting topic, but research could have focused more on overall configuration of how viewers were presented with the experiment. There isn't enough information present to draw an accurate conclusion from these observed results.
It seems to me that this is a fairly simple illusion: the frequent event is "more interesting" hence the brain focuses on that. Color change in this example is happening slower than rotation hence motion is favored instead of colors.
Maybe if our ancestors had fed on flocks of fast moving chameleons we would be better at this.
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I suspect that this is an optical illusion triggered because the brain is trying to match items by color and size. When color or size changes, the brain matches the wrong blob (which hasn't changed, or just happens to have changed to what the other one was, or to something closer to what the other one was than the other now is) to the original item.
I'd like to see a video with just the fixation point and one datapoint in the periphery. If we still lose track of shape and color changes then that will be harder to explain and more interesting.
I'd also like to see the same multi-blob video done with everything changing in the same way at the same time. I suspect the result would be the same as the one-blob video condition.
Not that this isn't a neat demo as is. I'm just hungry for some more conditions.
instead of making a video, couldn't they have made a flash thingie, so that you could change the parameters of the illusion too? maybe we could then tell at what rotation speed color change becomes hard to notice.
Wealth is the gift that keeps on giving.
The video directs the user to state at a stationary object (and even then it's not hard to notice some progression). If you actually look at the moving objects (you know, like the way people who aren't undergoing the Ludovico Technique normally look at stuff), it's quite easy to notice what's going on.
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"people are remarkably bad at noticing when moving objects change in brightness, color, size, or shape"
I think you left out an important qualifier:
people are remarkably bad at noticing when moving objects change in brightness, color, size, or shape IN THEIR PERIPHERAL VISION
If you look directly at any of the moving objects you can see any of them change in brightness, color, size, or shape. Your peripheral vision is not your focus for good reason, and of course its not going to track every single change like at the center of your focus of vision, its not supposed to and is better that it doesn't.
I'd like to see if there's a culture bias to this. Get someone from a very non-westernized culture and ask what they see. They're regularly not fooled by these kinds of "illusions":
Which line is longer:
>----------
Their eyes just aren't trained to see geometry the same way as westerners who are faced with tons of man-made things everyday.
"That which does not kill us makes us stranger." -Trevor Goodchild
I remember watching a documentary 5 years ago which focused on this phenomenon, showed some practical examples too with driving safety and magic tricks.
When looking at the video I see all of the color changes, even when the ring is in motion. Then again, I am also one of those who can see the cycle rate of flourescent lights. Perhaps my eyes are hyper sensitive or have a higher bandwidth path to my brain than most people. I was in Vegas in November and saw the David Copperfield show and was in the front row. I was able to see the slight of hand that was being used to swap objects and figure out how he was doing the tricks. Made it somewhat boring for me, but my sisters enjoyed the show.
We learn about an objects characteristics when it changes through time. The reason why an infant would rotate an object in his hands to see all its facets, is to record it in its mind and learn that it is indeed one object by connected still images at t seconds with the one at t+1 seconds. It is the difference in rate of change of visual feedback that enables us to distinguish between objects in our sight. It is entirely possible, that during motion, our brain engages a learning process and thus suppresses the ability to distinguish between still images of the time slices during motion
I think I can address this with confidence as a trained and experienced ex-US Army sniper with the ranking in the top ten US military snipers[1] until the Iraq war...
Two things can foil a good sniper consistently...an alert individual that pays attention to detail(a surprisingly small subset of humans!), and an individual who is good at pattern recognition(another extremely small subset of humans. Fortunately, there is only a small overlap with these two subsets!(from a sniper POV)).
For example:
Few people will catch me stalking them until i make the shot. This includes trained observers on a staged training/qualification exercise. I could stalk my target to a surprising distance and take my shot...even when the target had a time frame and specific area I would be operating in. I could usually get within 30(thirty) meters of my target to take my shot.
In the 'real world' (for me, that was Berlin, and my targets were the STASI and their Soviet advisors/watchdogs), the odds were much better in my favor...I never got caught as a sniper! 67 confirmed, 183 probable FTW! No Regrets.
Where I got 'busted' on training/qualification courses was when the observer was alert and paying attention to detail. 'Hey, that clump of grass wasn't there fifteen minutes ago?!? Maybe i need to keep an eye on that?'
Or the 'pattern recognition' type: 'What doesn't belong in this picture?...Hmmm...when this started, that clump wasn't there...it was over there...Hmmm'
End result....busted!
However, most people just don't pay attention, and are super-easy targets. It's just a small subset of panicky, paranoid individuals that make work hard for snipers. I would postulate that 99.8% of humans are easy targets, in my experience.
Snipers and stage magicians both take advantage of human psychology and visual misdirection. It just plain Works.
You are correct IMHO about the evolutionary need for detecting movement as a visual priority over detail
[1] 67 confirmed kills, with 183 'probable kills', I was #6 or #7 until the Iraq war. I haven't felt the need to check on my 'current status', as that is a past I still have mixed feelings about, but colleagues and peers inform me that I am now #13. For reference, I served 1977-1980 In the US Army- before the Berlin Wall came down.
Curious what effects the results of this study would have on user interface and game design.
Especially with games I can be quite focused on one area of the screen, and do not notice a blinking icon in the corner. Game and user interface designers may consider different ways to visually notify the user of something, that are harder to miss.
Next someone will publish a paper on how talking faster makes it more difficult to the listener to spot logical incongruencies.
- "They misunderestimated me."
It's not really what most women are like, but it is pretty funny.
If you ignore their instructions and stare at the ring while it is rotating you will notice that the colors change a lot slower while the ring is in motion than when it is static. When I look at the white dot I notice the surrounding change, it just seems a lot slower. Slower change is a lot harder to detect, especially when it's whirling past your vision.
A real test would involve changing the colors at the same speed whether the ring was moving or not.
Color viewing is great for detecting the ripest berries and seeing spoiled food.
The only reason that colorblindness evolutionary still exist is that the B/W sight is better in detecting movement (prey/hunter). The color blind person disadvantage in recognizing some thing of food is still acceptable.
And besides... colorblindness os sex linked. It proves that woman traditionally are more gatherers/ food preparation and men have stronger task for hunting (where color vision is less important but movement detection is more important).
--AC to protect me from my better half.
This video is a lie...
The brightness changes very fast when it's not rotating... when it starts to rotate the brightness changes less fast.
This can be cleared seen by run/pause/run/pause/run/pause.
Obviously a programming bug/mistake.
I've noticed it can be hard to notice a single change-of-state such as BRAKE LIGHTS! Was it already on . . . or not!?!?!?!?! Unless one is paying EXTRA close attention and maybe looking DIRECTLY at it, is easy to miss a brake light going on.
When braking (if there's at all time, and maybe ESPECIALLY if traffic is heavy), I now tap the brake light a couple of times quickly before applying real braking pressure. I notice that whoever is following me usually notices, they brake more quickly, and my chances of getting rear-ended are considerably diminished.
This trick now got some scientific proof :)
Coding etudes
I remember some interview with an onLive tech representative talking about leveraging psychovisual properties. They could use these illusion videos as marketing materials!
bite my glorious golden ass.
It seems to me the reason for the effect is that all the dots are moving together making it look like they are part of a single object...a ring. It would be interesting if all of the dots moved individually and not collectively.