Brain tricks

May 21, 2004 12:30 PM

Red and green dots have never been so interesting. At least to a geek like me. I love it when my brain plays tricks on me.
posted by jeremy (33 comments total)

the effect of the animation is fantastic. thank you jeremy.
posted by tcp at 12:42 PM on May 21, 2004

Be sure to read the whole set of instructions, though. I was really freaked out since I thought all the red dots really were moving down!
posted by MrMoonPie at 12:45 PM on May 21, 2004

I was really fascinated with optical illusions when I was in junior high. I borrowed books on the subject all the time, and just loved the tricks played on my eyes and brain...
That said, they're kind of like magic tricks you know the secret to now - I almost can't get my brain to see the "illusion" since I figured out beforehand that the image was sectioned.

Naivete, come back!
posted by ArsncHeart at 12:53 PM on May 21, 2004

Nifty!
posted by DrJohnEvans at 1:08 PM on May 21, 2004

So which way are they really moving?
posted by jjg at 1:12 PM on May 21, 2004

And if you're colorblind, like me, it's basically impossible to tell what's going where. Some dots were moving up and some down, and that's about all I can tell you.
posted by tommasz at 1:21 PM on May 21, 2004

hmmm... that didn't work for me... But I was getting some kind of strange effect where the green seemed considerably nearer than the red.
posted by twine42 at 1:25 PM on May 21, 2004

jjg, the red dots in the middle are moving down. The red dots on either side are moving up. Your brain just fools you into seeing them all moving one way or another.

On a sidenote, this is especially interesting to me because it's similar to the way an mp3 or even a movie in a theatre works. Our brains have this amazing (and sometimes faulty) ability to squish stuff together to help us make sense of the world.
posted by jeremy at 1:29 PM on May 21, 2004

wo. you're making me make myself dizzy.
posted by .kobayashi. at 1:31 PM on May 21, 2004

For some reason this makes me think of beer ...
posted by carter at 1:39 PM on May 21, 2004

I think my dots are broken.
posted by jacquilynne at 1:41 PM on May 21, 2004

Their instructions are confusing. Try this:

1. Look at the animation. The red dots should appear to be going down while the green dots move up.

2. Put your hand in front of you so that the middle of the animation is blocked out. You will notice that on the sides of the screen, the red dots are actualy going up!
posted by vacapinta at 1:45 PM on May 21, 2004

Did anyone else get a phone call just now?
Seven days was all the voice said.
posted by emelenjr at 1:57 PM on May 21, 2004

HAH! emelenjr, i'd think The Matrix would have been a more apt reference. But I'll take The Ring as a viable alternative.
posted by jeremy at 1:58 PM on May 21, 2004

My wife sent me to this page just now, and the illusion doesn't work for me. I'm significantly color blind, but not monochromasic. I'm actually pretty good at identifying distinct shades but not colors. The red dots in the animation are dark enough that I can distinguish them from the lighter green dots, and for me the red dots are clearly moving down in the middle and up on the sides. I'm puzzled.
posted by delapohl at 2:36 PM on May 21, 2004

If you stare at it too long, will a scary face suddenly appear?
posted by mkhall at 2:43 PM on May 21, 2004

Not colourblind at all, and it's not working for me either. I can see that the same coloured dots are moving in different directions, though I'll admit it doesn't draw much attention the the fact.

Also, it isn't perfect scrolling, at certain points the dot combinations just change (to prevent repeated patterns while still having a relatively small number of gif frames no doubt).
posted by fvw at 2:48 PM on May 21, 2004

When I look at the screen, it looks like all the red dots are going down and the green ones up. If I shift my eyes slightly to either side, it looks like all the dots reverse direction. I can go back and forth and say, "Whee!" It is pretty cool.
posted by callmejay at 2:53 PM on May 21, 2004

Try leaning back a bit, or getting out of the chair and moving back. From what I could tell, the red dots were moving both up and down in the entire picture.
posted by stoneegg21 at 2:57 PM on May 21, 2004

There are four dots.
posted by Wet Spot at 3:34 PM on May 21, 2004

"The illusion breaks down if you stand several feet away from the monitor, and watch the illusion (a long mouse cable or a friend is necessary to do this.)"

What? Why do you need a long mouse cable or a friend? Why can't you just click on the damn link and then walk a few feet away?

I ask that as a hypothetical for whoever wrote the article, since I have no problem doing exactly what I suggest. Maybe they live in bizarro universe?
posted by cortex at 3:39 PM on May 21, 2004

cortex: You just beat me to that nitpick. (What, will the Internet fly away if you let go of the mouse?)

Neat illusion, though!
posted by boredomjockey at 3:46 PM on May 21, 2004

There is no spoon.
posted by meehawl at 3:58 PM on May 21, 2004

I feel woozy now...
posted by JoanArkham at 4:33 PM on May 21, 2004

I'm not sure I buy the color binding explanation (though the posts in this thread by people with colorblindness go a long way towards convincing me). With the center column covered all I can see of the side columns is movement unless I look at them directly. That is, in peripheral vision I can't easily make out which color is going which direction, so I'm not ignoring data by guessing they are moving like the center, just making the wrong assumption. If I'm looking at the center column in which red is going down and green is going up, and my peripheral vision is telling me that there is vertical movement involving red and green dots at the edges, I can see why my brain assumes that the movement is consistent. Still an illusion, but one of assumption rather than binding. Or maybe it's the same thing and I'm just thinking about it sideways.

Either way, it's a neat trick.
posted by Nothing at 12:53 AM on May 22, 2004

Anyone else feel a slight sense of disappointment that their brain could be tricked in this way?

"it's incorrectly binding color and motion so it can tell us that all the red dots are moving in the same direction throughout our "world""

I mean..... duh.
posted by nthdegx at 12:53 AM on May 22, 2004

My brain is never tricked easily, and I plan to fund research to prove it as soon as I get that money from those nice Nigerian investors...
posted by Samizdata at 1:27 AM on May 22, 2004

I can make sense. I can make random on-the-fly-reconfiguring data out of the dotted noise.

Might have something to do with the acid I took earlier tonight.
posted by Gyan at 6:58 AM on May 22, 2004

Heh, yeah I didn't see anything illusiory here either. I mean, if I look at the middle of the screen it looks like the red dots are going down in the middle (because they are). I can't see the dots at the edges well enough to have any belief about how they're moving. (If you *asked* me I'd probably guess that they were moving down also, but that'd just be a wrong guess, not some cool optical illusion.)

Then if I look at the edge of the screen I see that the red dots there are going up (because they are).

This is surprising?
posted by davidchess at 9:55 AM on May 22, 2004

davidchess,

having "figured the illusion", try to pay simultaneous focus to all three segments of the field (pick red or green). If you're like us mortals, your eyes tell you that all of those same-colored dots move in the same direction. You don't *directly sense* the peripheral movement, you "intuite" it. If you try to verify the validity of that intuition by focusing on one of the opposing segments at the periphery, you've broken your earlier focus and your vision is dealing with a smaller domain within which to "bind", hence not presenting an obvious contradiction.
posted by Gyan at 11:54 AM on May 22, 2004

Also, everyone who is trying the "cover the center of the screen thing": it's not a bad idea, but it doesn't directly follow the instructions. And if that's all you've done, you're missing half the show.

After focussing on the center of the screen (and if you're like the rest of us mere mortals, figuring that all the red dots are moving down), pick a spot about 1 inch from the left side of the black rectangle.

Now without changing your eyes, try to figure what direction the red dots are moving. Again, if you're just a mere mortal like me, you'll figure that they're all moving up. Which you know can't possibly be true.

Now back away from the screen (and don't worry about a friend or a long mouse cord) and you should be able (with some work) to see all three columns. One on the left and one on the right, red going up and green going down; and one in the center, red going down and green going up.
posted by jeremy at 12:06 PM on May 22, 2004

Then if I look at the edge of the screen I see that the red dots there are going up (because they are).

This is surprising?
posted by davidchess at 9:55 AM PST on May 22

Actually, I still see the red dots as going down even if I look at the edge of the screen which is freaky. Thats why I actually had to use my hand to block out the center.

But since it didn't work for davidchess, I suggest this entire front-page post be removed immediately!
posted by vacapinta at 12:24 PM on May 22, 2004

I could see how the illusion was intended to work, but the moment I looked at the animation my brain told me that the red dots were moving in different directions by column. (Actually, the left/middle separation was immediately clear, the middle/right separation a moment later.) Then again, I have trouble with puzzles like this because of a lazy left eye which will not move all the way left, and which has always prevented me from seeing the "3-D illusion" puzzles.

I've often wondered how much a subtle problem like this has affected my view of the world overall. In this case, my brain couldn't be fooled, which might be seen as good -- but on the other hand, it suggests a broader inability to synthesize information, which if I had would have allowed me to see the illusion. I'm reluctant to draw a broader conclusion, of course, based on one type of experiment.
posted by dhartung at 11:07 PM on May 22, 2004