Are you right or left brained?

Procrastinating on Youtube, I ended up on this video. Watch it first, following the instructions (and then come back!).

The aim of this video is spotting the rotation direction of the silhouette (clockwise or counter-clockwise). There is no right answer, because it works either way (being a silhouette), and with some effort you can switch her rotation direction.
Surprisingly the first time I saw this video, the dancer was rotating clockwise and it took me some effort to let her rotate anti-clockwise. I say surprisingly because the maker of the video claims that people seeing the silhouette rotating anti-clockwise are right brained and then imaginative, religious, impetuous, risk taking and so on. That doesn't really fit my personality, I would say, but is this test valid?


There aren't any sources about who created this test, then I decided to read some material myself about the sides of the brain and what do real neuroscientists think about the asymmetry of the brain.
Unfortunately, the result is that now I am even more confused.

What I inferred from the small research is that even scientists are not sure if someone can have a dominant part of the brain and there are a lot of contrasting opinions, being the brain one of the most difficult parts of the body to understand.

What is surely known, is that brain is not merely divided in creative side (right-side) and logic side (left-side). Both sides cooperate when someone is thinking, but one can be used more when doing some specific tasks.
Experiments have been done on people who have damages on one side of the brain or on people who have the corpus callosum surgically cut off (such as to alleviate epilepsy). The corpus callosum is the structure that links right and left side of the brain, so missing it, it is like having two separate brains.
It has been discovered that, in general, left brain hosts (for most of right-handed people) most of linguistic skills, and the ability to see details. The general view and the "emotional" side of language are host by the right brain. It is unclear if someone can have a remarkably dominant side of the brain.

However, that is not linked to how much you are creative or logical.
An individual with a certain dominant side of the brain is not necessary inclined to have innate skills in what the dominant side hosts.
We know that there are people more "emotional" and people more "analytic", but it is wrong to consider that the more emotional individual has a right dominant side of the brain and vice-versa.
If you are doing maths you are not only using your left brain and if you are doing arts you are not only using your right brain.

So the answer to "Is this test really valid?" is no.

Nonetheless, the video is cool as it represents how humans perceive shapes and link them to familiar situation. I'll explain:
we see the dancer rotating but it isn't, actually. The image shown is a 2D image, then if you see it as a plane image changing shape, all the parts of the figure are just oscillating.
Since our brain recognize the image as a human, it is seen as a 3D object, so our brain gives her a rotation that could be clockwise or anti-clockwise because the original image is not making any rotation.

The claim of associating a brain side to the interpretation of the rotation is an far-stretched and there is no evidence about it.
What is surely wrong is to presume that a "right brained" person is creative and a "left brained" person is logical.



Main source: New Scientist