This is too weird. Check out the dancer (chances are you've already seen it before, but hey). Supposedly, if you see her moving clockwise, you use more of the right side of the brain, vs counterclockwise for the left side.
I saw her moving clockwise, then at some point she started turning counterclockwise, then clockwise again, then counterclockwise. Right now she seems to pretty steady at clockwise again. And yes, I can make it change by focusing, although it's not easy. What does this all tell me?