visual field distortion

July 23, 2006 2:44 AM

visual field diffeomorphisms without having to buy anything of dubious legality.
posted by oonh (29 comments total)

Fun. I used to commute by ferry, and if I spent the trip staring out the window (at the uniformly textured, steadily moving water) I'd get a similar effect. I assumed that the reason is that any level of the visual system can have an "afterimage". Everyone's familiar with color/intensity afterimages, but a neural layer or two up from the color receptors is the motion-extraction layer, and you can have afterimages there too.

Why the label "diffeomorphism"? What does this have to do with diffemorphisms?
posted by hattifattener at 2:53 AM on July 23, 2006

free acid.
posted by Tryptophan-5ht at 3:01 AM on July 23, 2006

That was interesting, a tad short lived though as I became convinced about 3/4 of the way through that was one of those videos where a figure suddenly appears to scare the shit out of you. I'll have to try again.
posted by moonbird at 4:28 AM on July 23, 2006

There are several, offering different distortions, at Skytopia. Scroll down to "Vision Distorter".
posted by raygirvan at 4:32 AM on July 23, 2006

moonbird, that's EXACTLY what I was thinking. I also stopped looking because of it. :)
posted by Malor at 5:45 AM on July 23, 2006

I like the Tripwonker at verylowsodium.com best, personally. It is a small flash file that can be saved easily, works well for low-bandwidth connections and takes only a couple of seconds to talke effect. Plus, you don't have to listen to bad techno when using it.
Nice post, nevertheless - most people don't seem to know about the curiosities of human sight.
posted by PontifexPrimus at 5:48 AM on July 23, 2006

moonbird, me too. I had to fast forward to the end to check before I could watch it.

Cool effect.
posted by teem at 6:23 AM on July 23, 2006

Great post, oonh.

Moonbird, I was scared of the same thing.
posted by hifiparasol at 7:38 AM on July 23, 2006

There is nothing wrong with your television set. Do not attempt to adjust the picture. We are controlling transmission.
posted by Steven C. Den Beste at 8:02 AM on July 23, 2006

For those of you who have never tried LSD, the visual effect is similar. The effect of the Google video lasted only maybe 5 seconds, which is heavenly brevity compared to 4 hours. Your trip may vary. Thanks for the cool effect, oonh!
posted by squirrel at 8:36 AM on July 23, 2006

For two or three seconds after the video, I looked at the wall and it appeared to be "melting."

Reminds me very much of my first acid trip in whcih I ould stare at an oil painting melt, knowing it was a drug effect, but not being able to understand how the processs could work. Still don't.

Some effects of LSD are expainable...walking, I might feel the shock waves of the impact of my feet on the ground travel up my body...an effect the brain usually filters out, having better things to do (like worry about money, for example).

I'm sure someone has explained the most common visual effect of psychotropic drugs: their tendency to make us see patterns (eyes open or closed). The strangest one I remember seeing, and it happened a lot, was looking at, say, a piece of Wonder Bread and seeing literally thousands of tiny red randomally ordered letters. Different from most pattern-making, like looking up into the night sky and seeing it as perfectly symmetrical.

I realize the FPP was not about LSD, so you can go back to discussing optical illusions...unless you can explain LSD's pattern-making effects. I'd be interested.
posted by kozad at 8:38 AM on July 23, 2006

kozad - "was looking at, say, a piece of Wonder Bread and seeing literally thousands of tiny red randomally ordered letters"

A.k.a. the fractalization or "Escherization" of vision, likely due to a wrench in the visual binding circuitry.
posted by daksya at 9:01 AM on July 23, 2006

very trippy
posted by caddis at 9:40 AM on July 23, 2006

Thanks. I think Google now has my credit card number.
posted by rongorongo at 9:57 AM on July 23, 2006

I guess I just need acid. Didn't see anything.
posted by c13 at 10:00 AM on July 23, 2006

I love this stuff; first discovered it on a camping trip looking at rocks under a clear running stream. When I looked up, everything morphed in the opposite direction of the flowing water. I always figured these things have something to do with the brain trying to compensate for a consistent moving visual pattern. Remove the pattern, and the compensating effect remains for a while.
posted by mediareport at 10:00 AM on July 23, 2006

nice! Definitely tastes like acid.
But if I get a phone call, I'm going to be pissed!
seven days....
posted by zerokey at 10:20 AM on July 23, 2006

It made me feel a bit ill. And then I saw the smudge on my wall spin. Hun. All and all I'm not sure it was a net positive.
posted by ClaudiaCenter at 11:05 AM on July 23, 2006

This was a previous FPP with a YouTube link. I just can't find it. So there. And it does work.
posted by ninjew at 11:40 AM on July 23, 2006

What moonbird, teem, Malor and hifiparasol said.
posted by 2or3whiskeysodas at 11:53 AM on July 23, 2006

thanks daksya...I was afraid someone was going to give me a technical explanation I wouldn't understand....
posted by kozad at 11:59 AM on July 23, 2006

kozad, In case you were being sarcastic, visual binding means this. Suffice to say that at some stage of the binding hierarchy, the activity cascade initiated by hallucinogens throws a 'wrench'. If you're not being sarcastic, here is a technical explanation.
posted by daksya at 12:23 PM on July 23, 2006

What does it mean when your vision is clearer after looking away?
posted by CynicalKnight at 1:30 PM on July 23, 2006

Actually daksya, I was not being sarcastic...ideally I would have liked an explanation more technical than your original comment, and less techincal than your links, being pretty much a layman, but that's for someone being paid for the difficult and treacherous path of translating science for the mass reader, hardly your job on Metafilter.

In any case, after dinner, I will peruse the more techincal links and see how much my brain can make sense of it. Thanks.

A more difficult problem is how to tell when someone is being sarcastic on the Internet without facial expressions, vocal inflection, and knowledge of the speaker!
posted by kozad at 4:54 PM on July 23, 2006

Neato! Now, how do you make it stop?
posted by crunchland at 5:58 PM on July 23, 2006

I'm serious. How do you make it stop?
posted by crunchland at 6:01 PM on July 23, 2006

I'm serious. How do you make it stop?
posted by crunchland at 8:01 PM CST on July 23 [+fave] [!]

Pause button, lower left corner?
posted by Ynoxas at 8:00 PM on July 23, 2006

Ah, memories. Try it if you have a mirror near by...
posted by persona non grata at 11:46 PM on July 23, 2006

I always figured these things have something to do with the brain trying to compensate for a consistent moving visual pattern.

It's not about "trying" to compensate, it has more to do with 'fatiguing' certan parts of the visual system. Basically, cells "run out" of the neurotransmitter they use to communicate after firing for a long time. So if you stare at a red object for a long time, the red receptors run out and the signal from the green/blue receptors seems amplified. This fatiguing seems to be present in the entire visual pathway, including the parts of the brain that do things like detect motion.

That said, not everything with respect to the brain really has an explanation so it's not really possible to say why certain things happen while tripping.
posted by Paris Hilton at 1:00 AM on July 24, 2006