I get far too much amusement out of optical illusions, little puzzles, those 3D pictures of sailboats that you have to cross your eyes to see.

So, it’s little surprise that when I ran across the picture below, I spent a good 20 minutes staring at it – and not (just) because if you look closely you can tell the dance studio is chilly.

The photo is a test to see which side, the left or right, of your brain is more dominant. If you see the dancer spinning counter-clockwise, then you are left-brain dominant, if clockwise, you use the…