back to article Famous 'Silhouette' Flash illusion unravelled

The "silhouette illusion" used in many online quizzes to indicate things about a user's personality, whether he or she is left- or right-brained etc, is actually of no use for finding such things out. Youtube Video The illusion, in which a silhouetted woman is seen turning on the spot, arises from the fact that - from the …

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  1. moonface
    Coat

    Brain!=Reality

    Things like this silhouette illusion and especially the the McGurk Effect prove to me, that I have absolutely no idea, when it comes to reality!

    http://www.youtube.com/watch?v=ypd5txtGdGw

    Gets Coat....it's the yellow one that's grey.

    1. Spartacus
      Boffin

      Proof...

      if it were needed that eyes see only wavelengths (as three discreet bands defined by the three types of cones in the retina - RGB wavelengths only) and the brain sees colour. In reality colour just does not exist. as a result its assumed that everyones perception of colour is actually different, but as only you see your perception it is impossible to know for sure!

      1. Anonymous Coward
        FAIL

        as three discreet bands defined by the three types of cones in the retina.

        And who was it introducing Yellow Pixels??!?

  2. Tonyl

    Confused

    I have no stereoscopic vision so see either from the left or right eye but not both simultaneously. I seem to see the 3 images initially turning clockwise but after a few seconds turning the other and eventually one turning one way and the other two turning the other way.

    Do I need to see a doctor or a psychiatrist?

    1. Manas Straw
      Coffee/keyboard

      Preferably both

      and at the same time too!

  3. Tonyl
    WTF?

    Confused?

    I have no stereoscopic vision so see either from the left or right eye but not both simultaneously. I seem to see the 3 images initially turning clockwise but after a few seconds turning the other and eventually one turning one way and the other two turning the other way.

    Do I need to see a doctor or a psychiatrist?

    1. Steve X
      Pint

      doctor or a psychiatrist?

      I'drecommend a barman.

    2. JP19

      confused? the same way

      I also lack stereoscopic vision and have the same view that you do, clockwise all followed by the reversal in direction of one of the objects.

    3. jonathanb Silver badge
      Pint

      re: Confused

      The lack of stereoscopic vision has nothing to do with it as you are seeing 2d images on this website and you use only perspective to render them in 3d. The reason they change direction is because additional visual clues are introduced in the two outside women in the form of the light shining on their curves, which tells you which way they are rotating. So you don't need any medical help at all.

  4. Ol'Peculier
    Happy

    Try this

    I wondered when I looked back from another screen to the flash anomation she was going counter-clockwise, and a tried this:

    Close your eyes, and pan across your monitor left to right and open them. Going clockwise?

    Now try and open your eyes whilst panning right to left. Whad'ya'get?

  5. Kevin Johnston

    Wow, Gosh etc etc

    Don't see what is so clever here.. I have never had a problem with this style of 'illusion' in seeing either. Does that make me good-special or bad-special, or just less likely to be led by the nose?

  6. Anonymous Coward
    Anonymous Coward

    I'm shocked

    Shouldn't this have an adult-content warning?

  7. viet 1
    WTF?

    Funny trick

    In the 1st half of the video, I see the 3 identical black silhouettes spinning clockwise, but when the left and right ones are lighted, I see the left one and the sillhouette spinning clockwise while the right one spins anti-clockwise.

    Is it normal ?

    1. Graham Marsden

      It is normal?

      Well if it isn't, we both have the same problem!

      Although with a bit of concentration (I find it best to watch the extended leg) you can convince your brain to swap the direction she's going.

  8. vulcan
    Alert

    Confused

    Well confirmation that my brain is scrambled, 2 were turning clockwise while the right hand one was turning anti-clockwise!

    1. Anonymous Coward
      Boffin

      Me too

      Yes, I also saw this and assumed it was part of the effect.

      I have to say that I don't understand the boffinly (is that a word?) argument related to seeing it from above as apposed to below. Is this some quantum spin effect where things always have to rotate clockwise when viewed from above and anti-clockwise from below?

      1. Allan George Dyer
        Pint

        No quantum spin effects

        When the image is a silhouette, it could represent a clockwise-turning woman, seen from above, or an anti-clockwise-turning woman, seen from below. If your brain assumes it is seeing the silhouette from above, then you see it as clockwise-turning.

        I could also flip the direction of rotation by concentrating. I tried lowering my chair to see if my angle of view to the monitor would modify my perception, but the result was inconclusive. I did start hearing some cheesy music and see a pole...

  9. Andrew Moore

    Is it just me...

    I can see her revolving in either direction. And I can change the 'direction of spin' while viewing.

  10. Jeff Green

    Undecided

    She spins one way then the other for me, am I just weird?

  11. Anonymous Coward
    Anonymous Coward

    Top down illusion

    Scarily good example:

    http://blogs.discovermagazine.com/badastronomy/2010/05/19/a-lunar-illusion-youll-flip-over/

  12. davethedormouse
    Coat

    Maybe I'm Just Potty...

    The silhouettes were rotating anticlockwise for me. Fair enough. But when the left and right ones started showing details, the left one started to spin clockwise, while the right one carried on spinning anticlockwise...

  13. Anonymous Coward
    Anonymous Coward

    viewing angle

    sliding your head from one side to the other makes the direction of rotation appear to change.

    I'm amazed it has taken any time at all to figure that out!

  14. Anonymous Coward
    Anonymous Coward

    Midgets?

    "As people are naturally predisposed to assume they are looking at things from above, they tend to assume they are and so decide that the lady is spinning clockwise."

    Does this mean that the people who think it's spinning anti-clockwise expect things to be above them, that is, they're all midgets?

  15. mrmond
    Alert

    I see both.

    Maybe both sides of my brain or dominant,or weak. I see then spin clockwise,then one or two anti-clockwise.

    I'm getting a headache.

  16. raivn

    help!

    they all appear to be spinning in different directions!

    1. Stewart Haywood
      WTF?

      Re help!

      Raivn, there are three of them and they all appear to be spinning in different diractions? How many dimensions can you see in?

  17. Wayland Sothcott 1

    As above, so below

    It makes sense then that I would first see the clockwise lady since most of the time I am sober and standing up, but once I am flat on the floor I would see her from below and she would look anticlockwise!

  18. as2003

    Huh?

    What does "trick-cyclist" have to do with any of that?

  19. Ragarath
    Pint

    Strange happenings in my brain then

    Never seen this before but when I started playing it was going anti-clockwise.

    Then the video buffered so I paused and rewound and waited for it all to load. Played it again and it was going clockwise.

    Next saw the part that had the silhouettes revealed and tried again. Was going anti-clockwise again.

    Beer: Must have had 1 to many.

  20. Fading
    Thumb Down

    Headache time

    Always gives me a headache when I look at the spinning woman for too long and she'll frequently switch direction as I'm looking (saucy minx) .....

    I await the pseudo science explaining I am neither right brain nor left brain more no brain.

    1. raivn

      science!

      FACT: spinning direction is depended on the hemisphere your ISP is located in.

  21. stucs201
    WTF?

    Above == Clockwise?

    How's that work then? Looking down could still mean either way. The only logic I can find why brains might prefer one way to the other would be if it was natural to assume that the start position was with the model facing towards the viewer. But that assumption gives anti-clockwise (as viewed from above), so even that obviously isn't how most peoples brains work either.

    1. Charles 9

      Natural rotations, maybe?

      It may have to do with geography. The Japanese scientist, indeed most of the western world, lives in the Northern Hemisphere. The natural tendency of spinning motions (like water drains and so on) is to spin clockwise because of the influence of the Earth's rotation.

      So how about this for a loop? Try the test on a South African or Australian? Being in the Southern Hemisphere, their natural rotational tendencies will be reversed and will tend toward anticlockwise.

    2. Pablo

      Take a look at the lighted version

      The counterclockwise one (on the right) is clearly viewed from below.

    3. Patrick R
      Paris Hilton

      above==clockwize indeed

      If you imagine her spinning anti-clockwise, then her leg pointing your direction and going to the right seems higher than when pointing away. This would be true only if you look up. If you look down, from above, the leg pointing your way will pass lower, then to the left, hence she turns clockwize.

  22. Anonymous Coward
    Anonymous Coward

    Did anyone else...

    ...get turned on watching the 3 naked girlies spin?

    They spin in different directions.

  23. IsJustabloke
    Stop

    I refuse to enoble a simple forum post....

    Strangely, I looked at the image and when I first looked it appeared to be going anti-clockwise, I glanced away and when I looked back she was spinning clockwise...

    what would that have told anybody about me

  24. AndyG_IOM
    WTF?

    Errrr

    Im the only one in our office who sees her spinning anit clockwise. everyone else sees clockwise....

    lol what does this say about me ???!!!

  25. MaXimaN
    Joke

    An interesting illusion

    When viewing this video from the start all three naked figures are rotating clockwise, but about five seconds in I find tha.... *fap fap fap fap fap*

  26. Ned Ludd
    Thumb Up

    She goes both ways...

    ...and that's fine by me!

  27. Anonymous Coward
    Flame

    Flash?

    What the @#$% do you need @#$%ing Flash for? All this needs is an animated gif.

  28. stuartnz

    Weird!

    I saw all 3 turning anti-clockwise and was busy trying to figure out how anybody could see them as turning clockwise when all of a sudden the one on the left atarted turning clockwise while the other two carried on turnning anti-clockwise.

  29. heyrick Silver badge

    Um... you CAN actually tell?

    Play the silhouette part of that video. I'm going to say a very "bloke" thing now. Stare at her breasts. No, really. If you look you can tell from how one moves relative to the other in which direction she is turning.

  30. Michael 36
    IT Angle

    General Election now!

    The woman is clearly an MP as she spins both ways.

  31. Martin H Watson

    With the London Eye...

    ...when I travel in to London each day, I 'amuse' my self by letting my brain wonder which side of it I am lookg at. You can fool yourself into seeing the other side of it.

  32. Displacement Activity
    Happy

    Anticlockwise for me...

    ...so apparently I'm looking at her from below. Yup, that figures.

  33. bert_fe

    Perceptual Rivalry

    For the full explanation see here

    http://www.uq.edu.au/nuq/jack/InterhemisphericSwitching.html

    bert

  34. Sam Therapy
    Happy

    Fot those who don't know...

    The figure is Posette, the Poser Nude Female.

  35. Big Al
    WTF?

    @Tonyl, JP19 etc.

    I too lack stereoscopic vision.

    Initially I saw all three images rotating the same way, but eye movement (e.g. the reaction caused by the detail change) caused certain images to appear to be rotating in reverse.

    Fun.

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