Friday, March 28, 2008

Right Brain/Left Brain


I found this at Joel's Thoughts and traced it back to the Where-what-How-Why blog. It's one of those optical illusions that you can see two ways.

Supposedly if you see the girl spinning clockwise you are using the right side of your brain, and if you see her spinning counterclockwise, you are using the left side of your brain. The left side of your brain if supposed to be the creative side. Again, I'm no expert, but this is what the proverbial "they" say. If you can make it switch directions, you are apparently in the small sector (14%) of people who can see a situation from either side.

So which way did you see it?

(By the way, I'm pretty sure this is the first time there is a visible nipple outline on my blog.)

Update: Apparently the info is wrong. It has nothing to do with left brain/right brain. Thanks for Mark for pointing us to this blog that seems to clear things up.

This news article, like many others, ignores the true source of this optical illusion and instead claims it is a quick test to see if you use more of your right brain or left brain. This is utter nonsense, but the “right-brain/left brain” thing is in the public consciousness and won’t be going away anytime soon. Sure, we have two hemispheres that operate fine independently and have different abilities, but they are massively interconnected and work together as a seamless whole (providing you have never had surgery to cut your corpus callosum).

These kinds of optical illusions are always fun. What they reveal is how our brain processes visual information in order to create a visual model of the world. The visual system evolved to make certain assumptions that are almost always right (like, if something is smaller is it likely farther away). But these assumptions can be exploited to created a false visual construction, or an optical illusion.

8 comments:

Chip Burkitt said...

I've seen this before. The spinning dancer changes direction for me willy-nilly. I can't make the change happen; it just does. Either my brain keeps flipping for no apparent reason (a distinct possibility, I'll admit) or the explanation attributing the direction of spin to right brain or left brain is just bogus.

Nick said...

Both are distinct possibilities, Chip. I thought that too, that it could be bogus. I always try and have a healthy suspicion of things like this. I guess I figured either way, it was a cool exercise, even if it doesn't "mean" anything.

mark said...

Hi, Nick. I'd like to contribute to this topic with a VERY pertinent video regarding the left and right hemispheres of the brain...

Jill Bolte Taylor: My stroke of insight

"Neuroanatomist Jill Bolte Taylor had an opportunity few brain scientists would wish for: One morning, she realized she was having a massive stroke. As it happened -- as she felt her brain functions slip away one by one, speech, movement, understanding -- she studied and remembered every moment. This is a powerful story about how our brains define us and connect us to the world and to one another."

Nick said...

Wow, very interesting, Mark. Thanks for sharing that.

Do you have any insight on this spinning lady exercise and whether or not it is valid?

mark said...

I did a little digging. I found this...

"This news article, like many others, ignores the true source of this optical illusion and instead claims it is a quick test to see if you use more of your right brain or left brain. This is utter nonsense, but the “right-brain/left brain” thing is in the public consciousness and won’t be going away anytime soon."

The true source is...

"The spinning girl is a form of the more general spinning silhouette illusion. The image is not objectively “spinning” in one direction or the other. It is a two-dimensional image that is simply shifting back and forth. But our brains did not evolve to interpret two-dimensional representations of the world but the actual three-dimensional world. So our visual processing assumes we are looking at a 3-D image and is uses clues to interpret it as such. Or, without adequate clues it may just arbitrarily decide a best fit - spinning clockwise or counterclockwise. And once this fit is chosen, the illusion is complete - we see a 3-D spinning image.

By looking around the image, focusing on the shadow or some other part, you may force your visual system to reconstruct the image and it may choose the opposite direction, and suddenly the image will spin in the opposite direction."


from: NeuroLogica Blog

mark said...

Nick, here is my favorite illusion. Enjoy!!

Shepard’s “Turning the Tables”

"The human brain runs first-class simulation software. Our eyes don't present to our brains a faithful photograph of what is out there, or an accurate movie of what is going on through time. Our brains construct a continuously updated model: updated by coded pulses chattering along the optic nerve, but constructed nevertheless. Optical illusions are vivid reminders of this. A major class of illusions, of which the Necker Cube is an example, arise because the sense data that the brain receives are compatible with two alternative models of reality. The brain, having no basis for choosing between them, alternates, and we experience a series of flips from one internal model to the other. The picture we are looking at appears, almost literally, to flip over and become something else." - Richard Dawkins

Matt Brinkman said...

Motion Induced Blindness is probably my favorite optical illusion. It is freaky.

Nick said...

Very cool, Matt.

As I'm sure you guys noticed, I updated the post based on the info Mark found. It isnt really a left/right brain thing.