By the Way, Is She Supposed to Be Naked?

Here's a picture that's been making its rounds on the Intertubes lately. The idea of it is to find out whether you are a left-brained or right-brained individual. Now, look at the dancer, and see if she is spinning clockwise or counterclockwise.Now, according to some guy, if you see the dancer spin clockwise, you are primarily a right-brained individual. Conversely, if you see it spin counter-clockwise, you are a left-brained individual. What these titles mean are as follows:

LEFT BRAIN FUNCTIONS
-Uses Logic
-Detail-Oriented
-Facts Rule
-Words and Language
-Present and Past
-Math and Science
-Can Comprehend
-Knowing
-Acknowledges
-Order/Pattern Perception
-Knows Object Name
-Reality Based
-Forms Strategies
-Practical
-Safe

RIGHT BRAIN FUNCTIONS
-Uses Feeling
-"Big Picture"-Oriented
-Imagination Rules
-Symbols and Images
-Present and Future
-Philosophy & Religion
-Can "Get It" (i.e. Meaning)
-Believes
-Appreciates
-Spatial Perception
-Knows Object Function
-Fantasy Based
-Presents Possibilities
-Impetuous
-Risk-Taking

Now, here's some interesting things I've noticed when I did this little test. They say that if you focus hard enough, you can make it change directions. I, for one, found this near-impossible.

However!

I noticed that I would look at the picture, with no other distractions, and there would be what seemed to be a quick skip in animation, and all of a sudden, it would be going the other direction. Then, after a while longer, there would be another quick jump, and it be going in the original direction again. Truth be told, I found it very suspicious, and so I actually downloaded the GIF to make sure it wasn't just some scan that would flip occasionally. However, it was legit. So, the issue was not in the image, but rather, in my mind. What seemed to be weird was the fact that no matter what happened, it would always flip every so often. So, I decided to do a little experiment and test how much time passed betwixt directional flips. Here are my results (and trust me, it was a long 10 minutes):

Clockwise: 14 seconds
Counter-Clockwise: 68 seconds
Clockwise: 69 seconds
Counter-Clockwise: 73 seconds
Clockwise: 70 seconds
Counter-Clockwise: 67 seconds
Clockwise: 71 seconds
Counter-Clockwise: 71 seconds
Clockwise: 70 seconds
Counter-Clockwise: 69 seconds

...Huh.

While I know that I have properties (sometimes strong properties) of both brain sides, I wasn't expecting something like this. Apparently, my brain switches sides about every 70 seconds. That means that at any point, I will be a right-brained, emotionally-driven, fantasy-based individual, and 70 seconds later, I will be a left-brained, logic-driven, reality-based one.

...Is that normal?