Can you reverse her direction of rotation?
Cognitive Daily at ScienceBlogs took a reader poll and found that two-thirds saw the silhouetted woman rotating clockwise. About the same number were able to reverse her direction.
Those who initially saw the woman rotating counter-clockwise found it easier to reverse her direction — much as the Necker cube‘s orientation can be reversed at will. How did you fare? (Check out more illusions in TEDTalks by Al Seckel and Dan Dennett.)