More recommended reading on this:

http://scienceline. org/2007/10/29/ask-hsu-spinning-girl-right-left-brain-hemispheres/

..Modern neuroscience studies using brain imaging technology such as fMRI – which shows active areas of the brain while a person is trying to perform a task – have further suggested that language ability tends to be localized in the left hemisphere, while spatial ability tends to be in the right hemisphere.


However, neuroscience-minded blogs like Neurophilosophy point out that doing any complex mental activity requires cooperation from both sides of the brain, although certain processing tasks required for that activity may be concentrated on one side or the other. In other words, saying that “math and science are left brain functions” is an over-generalized statement.
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Hey Justin
Absolutely true, it is not about generalizing the right and left hemisphere of the brain, we know by now as it is written on the article you send that both hemisphere are working together, or that some task need part of the left and right brain, specially for cognition! but on the other side people do see the dancer spinning or toward the right or the left, i see it myself mostly clockwise (left brain oriented) and sometime if i stop to look and watch again from another angle, if i blink or blurry my sight i can see it for a short time counter clockwise...
it's a brain fuck
 

there are plenty of research and info but check this guy:

http://www.robertornstein.com/index.html
 

I didn't even know I could ever use my two brains! thank you baby, so now I'm aware of wich part of my head is awake...( the left of course) The right one must be dammaged then! kisses future brain