Brain Tricks

[Lei]

well if I take off my glassess they both look the exact same...

 semi-dark blurs...

[djfenix]

Slowly move your head towards the screen whilst staring at the blue circle in the center

[Chow]

I've done this about a million times and it never gets old

http://www.grand-illusions.com/programs/Optical.exe

The .exe just runs a spiraling image.

1) Stare at the pinhole in the middle for 30 seconds (really stare, and make sure it's at least 30 sec!)

2) Then look at something fairly close to you (I do the back of my hand)

3) Try not to be freaked out.

[Databits]

I don't download and run any executable stuff. Anything simple thing graphically that the exe could do can be done in flash or java as well. But downloading and running any executable on the internet is just plain, out right, a risk.

That said, not to offend you or anyone else here but, download and run at your own risk.

[Xepher]

Well, on the downside, I run Linux, so I can't run windows code native. On the upside, I can't run windows viruses native... so I ran it. Also, my virusscanner gave it a clean bill, and it looks like a legit site, but... make your own call. As for the illusion itself, I had to try it several times to get the effect. When you say "stare" you need to be more specific. You can't just keep your eyes not moving and pointed at it. You have to have it in focus and also not be too close... the majority of the image needs to be in your forward (non-peripheral) vision. Also, for me, it took a lot longer than 30 seconds to get a noticable effect when I looked away.

The reason is that your eyes have a built-in mechanism to prevent just such a thing. Since sometimes people have imperfections in their eye or retina (everyone has the nerve dark-spot) your brain adapts so that percieved imput doesn't show such static things. Of course, if you stare without your eyes moving for long enough, those same adaptions can actually make objects in the real world disappear from your perception. To prevent that, your eyes have tiny muscles that do nothing but basically "tap" your eye from time to time, making your view shift just slightly, thus preventing your brain from editing out anything that's not part of your eye (which wouldn't "move" even when your eye twitches.) Concious effort can overcome those twitches though... It's easier in a darker room too. I've actually had a window with the blinds closed, and the faint light from outside casts a soft glow on it. If I stared at it long enough, the window would vanish entirely, and the whole room would feel perfectly cave-dark, even though my eyes were open, and there's actually enough light to see anything in the room. Soon as I blinked or moved my view in the slightest, everything instantly came back. This effect seems to utilize the same mechanism. The spiral basically looks like it's "rippling waves" from a center. So while your brain can't edit the whole thing to nothing (it's moving) it can still adjust average values. That effect lasts a few seconds when you look away, and your brain is still doing the adaptation trying to cancel out the "ripples" but now the thing you're looking at has none, so your brain actually creates them in inverse.

[pigeon-wing]

Yay, I love these! My Spanish 4 teacher had an optical illusions book on the shelf next to my desk, so whenever I finished a test I'd flip through it and be amazed :3

[Cassiopeia]

OMG... this is so weird, in my math class we just had an optical illusion warm up since it's almost the end of the school year... So many optical illusions. It's where you have this black and white circle object, similar to one of the designs in xepher's first optical illusion, and you spin it, like with a drill or something and look at the center for a while. Once you take your eyes off it seems like the next object you stare at get's smaller then bigger, and smaller and bigger... @_@ Optical illusions make me dizzy @_@... I don't know how anybody could stand waking up and looking at a poster like that, I think I'd go blind...

[Xepher]

This one... BLEW MY FRACKING MIND! http://scienceblogs.com/neurophilosophy/2007/10/the_left_brain_right_brain_myt.php


You have to look at it for a while for it to happen. The dancer can appear to be spinning either direction depending on how you first interpret it. The author of that blog suggests covering the dancer and seeing only the shadow to make it switch. That didn't work for me. I had to cross/unfocus my eyes as hard as I could to where I could only see a vague suggestion of light and dark. I focused on the leg going around the outside, and thought of it as a rope or some such swinging back and forth, instead of in a circle, and then imagined it going back into a circle movement (but the other direction fromthe start) around the center dark (the body) before I let my eyes refocus. It took a few tries, but once my eyes locked into it and stayed focus, no amount of mental jiggering could make it switch direction. I had to blur things, and think of it as back-and-forth again for a minute each time. It really stunned me the first time, because I'm a bit dyslexic, so I had told myself my initial view was clockwise, and when it was spinning counter-clockwise it seemed just the same somehow (because it is) but it was the exact same sensation I get from dyslexia when I suddenly can't remember which is right or left. I thought at first I'd just called my initial impression "clockwise" by mistake and wasn't really seeing an illusion.

[Databits]

What's even more weird is when you take the gif and mirror it, then go back and forth between the two. Because despite the fact that the image is mirrored, it still appears to be spinning the same as the other till you switch.

[Xepher]

That's an interesting, additional complication to it methinks. Though what you said about them being the same isn't true for me. I can alternately see them moving with the same spin, or alternate spins. It's highly based on what point you see the first image at. So if you cover one and wait until the other is in the right spot and then uncover it, you can get one to swap independent of another... at least it works for me. :-)

[cha0s]

Coool. But yeah, when I see the two, it appears the right one spins clockwise and the left one spins counter-clockwise!

[fesworks]

Whenever I saw that spinning dancer GIF, I always saw it rotate the way it actually rotates in the GIF. I had to load it into my GIF Animator to check for sure how it rotated.

In fact, every time. I only see it rotate the correct way.

*shrug*

[Xepher]

Umm... you realize it doesn't actually have a "correct" way, yes? Even if you go frame-by-frame and designate a particular start point (like "the actual gif") it can still be seen as going either way. That's what makes it so weird.

[Xepher]

Woah!

http://www.neave.com/strobe/

That is just... Woah! I mean... Woah! :-)

[taboo]

Woah!

http://www.neave.com/strobe/

That is just... Woah! I mean... Woah! :-)

holy wow

i did it twice and my brain started hurting, lol