This test has made it my way a few times in the past month and it fascinates me everytime.
Do you see her turning clockwise or anti-clockwise? If she’s moving clockwise you use more of your right brain, and vice versa.
I am able to see her turning both ways but it’s random. I haven’t been able to figure out how to control it or what triggers the change. Some people say you can use your peripheral vision to alter the brain’s perception but that hasn’t worked for me. Instead I’ve been experimenting with language and different daydreams to figure it out.
Source and to read more about the right-side and left-side functions of the brain: Australia Herald Sun