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Optical Illusion

Discussion in 'BBS Hangout' started by reggietodd, Nov 4, 2005.

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  1. reggietodd

    reggietodd Contributing Member

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  2. PhiSlammaJamma

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    It worked on me. Now the ? is, why?
     
  3. LonghornFan

    LonghornFan Member

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    That temporarily blinded me.

    I'm still seeing those dots 3 minutes later. If I start barking or fall asleep when someone snaps, I'm gonna be quite angry,
     
  4. Pole

    Pole Houston Rockets--Tilman Fertitta's latest mess.

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    That is the coolest one ever. Holy cow.
     
  5. pgabriel

    pgabriel Educated Negro

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    MR. PITT: (staring at 3-D poster) I think I'm on to something!

    ELAINE: Mr. Pitt! The board of directors is on the phone. They've called an emergency meeting. They want you to be there to discuss the merger!

    MR. PITT: You said keep your eyes out of focus, which is misleading. You want DEEP focus!

    ELAINE: (on phone) Yes, hi. Okay, fine, yeah, hold on just a second. Lemme just... (reaches into purse) Yeah, I've got it... (pulls out both hands completely covered in black ink) Oh! Oh! Yeah, yeah, he'll be there. (drops phone, rushes to Pitt) Mr. Pitt, you have GOT to stop staring at that poster!

    MR. PITT: I see something that could be a spaceship. Is it round? Is it pointy?

    ELAINE: (grabs poster, smashes it) No, you don't see it, and you're never going to see it! (grabs Pitt by the lapels, getting ink all over his jacket) Mr. Pitt, you have to meet with the shareholders, you have to leave now. Do you hear me? Do you hear me?!
     
  6. The Real Shady

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    It worked on me. Then I stepped away from my computer and felt nauseated.
     
  7. Ubiquitin

    Ubiquitin Member
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    It's our brains ability to ignore old stimuli in the presence of new stimuli. This's why we have the ability to make discoveries.
     
  8. The Real Shady

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    I'll be sure to use that next time my girl catches me checking out someone else.
     
  9. PhiSlammaJamma

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    Here it is....

    The temporal presentation enhances the well-known afterimage in complementary colour.

    Jeremy Hinton, the ‘inventor’, writes: “The illusion illustrates Troxler fading, complementary colours, negative after-effects, and is capable of showing colours outside the display gamut.”

    I have been repeatedly asked to explain this in more detail, so here goes:

    There is something called the “negative retinal afterimage”. It becomes visible when one given hue stays on the same retinal position for several seconds (usually we would move our eyes typically 3 times per second, so this is no disadvantage in normal viewing). The afterimage builds up as that retinal location adapts to this special hue, and when looking at a neutral background the complementary colour is seen.
    This is a good thing, normally, because it helps “colour constancy”, that is we see colours somewhat independent of the ambient illumination (compare the bluish glacier noon sun with a reddish tint in the evening living room by the fireside).
    Ok, so the afterimage is “burnt in”, that is that retinal location is adapted. Now the magenta patch is suddenly switched to grey. Because of the adaptation, the complementary colour is now seen, which would be green for magenta, or light grey for a dark grey.
    The retinal afterimage typically fades away rapidly (over a few seconds under normal conditions). But here this fade-out does not reduce the perception of the afterimage, because a new one is uncovered right after at the next location.
    In addition, a Gestalt effect, here the “phi phenomenon” comes into play: the afterimage from the successive retinal locations is integrated and perceived as one single moving object, namely the green disk.
    In summary, the following factors make this illusion rather compelling:
    it is rather easy to steadily fixate on the centre
    most of the time the retinal locations are re-adapted and the afterimage is uncovered only briefly
    a Gestalt effect leads to the perception of a flying green disk.
     
  10. Svpernaut

    Svpernaut Member

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    that is pretty impressive.
     
  11. TMac640

    TMac640 Contributing Member

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    pretty damn cool
     
  12. Miguel

    Miguel Member

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  13. TMac640

    TMac640 Contributing Member

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    man I've got a headache now from that lol

    excellent
     
  14. lpbman

    lpbman Member

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    Schizophrenics fall for no illusions

    The paranoia, or sense of persecution, experienced by some schizophrenics could be due to a problem they have processing contextual information, according to researchers at University College London (UCL).

    Researchers at the London university found that schizophrenics are not fooled by visual illusions that easily trick non-schizophrenics.

    Volunteers were shown high-contrast black and white patterned images, with sections altered so that the level of contrast is much lower. They were then asked effectively to match the contrast of the altered section to its twin in a line up of otherwise identical shapes.

    The illusion. Image credit: UCL

    Schizophrenics find this task relatively easy, because their brain takes no account of the surrounding information when judging the level of contrast in the altered section of the pattern. Non-schizophrenic brains, however, make relative judgments about the altered section, because of the surrounding higher contrast pattern.

    Dr Steven Dakin, of the UCL Institute of Ophthalmology, commented: "We often think of people with schizophrenia as not seeing the world the way it really is - for example, during hallucinations - but we have shown that sometimes their vision can be more accurate than non-sufferers."

    He explained that people who do well at this kind of task, tend to do so for a very specific reason, while poor performance can be due to a number of different factors.

    "Our findings may shed some light on the brain mechanisms involved in schizophrenia," he added.

    "Normally, contextual processes in the brain help us to focus on what’s relevant and stop our brains being overwhelmed with information. This process seems to be less effective in the schizophrenic brain, possibly due to insufficient inhibition - that is, the process by which cells in the brain switch each other off."

    He suggests that if this is part of a more general problem in dealing with information about context, it could explain why many schizophrenics misinterpret people's actions, and can feel persecuted.

    The research is reported in the journal Biology.

    http://www.theregister.co.uk/2005/10/27/paranoid_illusion/
     
  15. RocketForever

    RocketForever Member

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    10 mins after watching that thing, I am still seeing a lot of stars (floaters) in front of me.
     
  16. PhiSlammaJamma

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    Which is why all the schizos will be the only ones left alive when the flying alligators optical illude the non schizos and eat 'em.
     
  17. david_rocket

    david_rocket Member

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    WOW!!

    Cool, :cool:

    It worked for me
     
  18. Rule0001

    Rule0001 Contributing Member

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    that was probably the single greatest thing I've ever seen in my lifetime
     
  19. Mr. Brightside

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    overstatement? you have obviously never seen my lego land collection.
     

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