Right Brain v Left Brain

[AndrewX]

How rude!  She bent over and mooned me!

LOLOL  Half your luck William, I stared at the image till I went crosseyed hoping she would but no chance. lolol 

I can only see it rotating counterclockwise but I can understand that it would change rotation to some viewers bcause of the lacking of the inner contour lines of her body as Sily showed in the diagrams. 

It's an optical illusion that simply triggers itself depending on the viewer.  I also tried viewing it through 1 eye at a time but no change for me. 

...and tell me William, when she mooned you, what color was it?:big grin:

[Polly]

I tried holding one nostril closed, then the other a few days ago to see if my perception of the spin would change while doing that but it didn't.

I even think there is a pattern to the seeming randomness of when that image comes up in the twirl during which the brain's perception can change the direction of the twirl due to what you just wrote, Andrew, about the contour lines.  It has to be watched long enough though.

The author is very clever.

 

[Reader]

I can still make her turn whichever way I want and go back and forth and so on whenever I look at it.

[Polly]

Reader, Consistently and repeatedly, for an extended period of time?

If so, it looks like that blows my reasoning.  :-)

I have been trying to do it consistently and I am not able to.  I have tried to do it with each spin, when her legs appear to cross over, but I cannot.

 

[Reader]

Yes Polly, consistantly and repeatedly, for as long as I want to look at the image.  I have one of those 3-D pictures that were popular (here anyway) about 14-15 years ago, which looks like a lot of multicoloured scribbles in lines across the picture at first glance.  Mine is in colours that match my decor.  It is in fact a picture of sharks, a treasure chest, and a sunken galleon.  Hardly anyone who has looked at it over the years can see the picture in it.  The trick is to focus on the black border (easier at the bottom) and gradually move one's gaze up into the picture.  Even when I explain this, no-one seems able to see it.  The shop which sold these pictures always had one in the window and people would stop and try to see what was there - not many could, and I didn't buy any others as they didn't match the house (I probably should have and just put them somewhere where only I would observe them).  Mine is called "Guardians of the Deep" - I love it and the family hate it ('cos they can't see it!)  Optical illusions always fascinated me - the mind can play such tricks!  The spinning figure is probably something similar.

[DreamTime]

Reader: I have a book with those kind of pictures. I love bringing it out and asking people what they see, because, like you said, most people can not see anything but the surface colored design.  But even though I can see those pictures, I still can not get the girl to do anything but spin clockwise.

[Polly]

All right. I can get her to keep switching direction if I focus on a spot below the border of the image but still able to discern her direction.

[Sily]

Got an email yesterday with the picture below of a frog/horse.  Made me think of this older post/thread here of the twirling lady, and of 2 possibilities seen within one image.

[Polly]

Cool, Sily.  :D  I like how the artist did that.

[DreamTime]

That's neat, Sily! Thanks for sharing.