Okay, I had my mom and step-dad both try this. They were both able to get her to go both ways, by focusing on her legs, not on her head. I tried it, and it worked! She still mostly goes clockwise for me, but sometimes counterclockwise. I also had my DH do it, and he saw her going clockwise on my computer at the same time I saw her going counterclockwise, so it's definitely a brain thing and not a program that randomly changes direction, as I was beginning to think (my conspiracy theory) last night!

I am not sure if it really measures left- and right-brainedness, as my DH is the most left-brained person I know (logical, analytical, all that), and yet he sees her going in the right-brained direction. But it definitely measures some sort of perception something-or-another. How's that for a technical explanation!?

Emily