

Left-brain/right-brain -- the dancer illusion debunked - altay

In regards to the purported test for right/left-brain dominance (<a href="http://news.ycombinator.com/item?id=78295" rel="nofollow">http://news.ycombinator.com/item?id=78295</a>)...<p>I suspected this article was bunk, so I went straight to the source -- a scientist friend whose research focus is binocular rivalry.  Here's her (entertaining) reply:<p><i>...as for your question, you have definitely asked the right person. The idea about the left and right hemispheres comes from my old phd supervisor. The guy is awesome but completely insane. I can guarantee it has absolutely nothing to do with hemispheres, but it is a very cool illusion anyway.  The idea is published, though, so if you wanted it for some crazy trivia question you could use it, but nobody in science believes the idea...</i><p><i>If you did want to use the fact.. the more interesting fact is the experiments that he used to work it out. It is called caloric stimulation and involves injecting freezing cold water into someone's ear, with the aim of activating the other hemisphere (I was a subject and it hurts like hell and then your eyes start spinning around and you feel seasick).  So my boss Jack worked out that if you squirt freezing water into someone's ear they tend to see it go one way rather than the other.  He also published (citing personal observations) that the only thing that stops rivalry is laughter, sneezing and orgasm..  he says that during these three events you end up seeing a combination of the two images... the guy is crazy!</i>

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greendestiny
The freakonomics guys did a pretty unscientific study, the result of which was
the test had some limited predictive power - but opposite to the original
hypothesis.

[http://freakonomics.blogs.nytimes.com/2007/10/23/right-
versu...](http://freakonomics.blogs.nytimes.com/2007/10/23/right-versus-left-
brain-what-does-the-spinning-dancer-teach-us)

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dood
Some more info and a link to the original from Michael's Optical Illusions &
Visual Phenomena [<http://www.michaelbach.de/ot/sze_silhouette/index.html>].
Check out the 'eyes' on the enhansed version. Freaky.

Also, Michael provides a little info on what goes on in the brain when the
figure reverses [[http://www.uniklinik-
freiburg.de/augenklinik/live/homede/edg...](http://www.uniklinik-
freiburg.de/augenklinik/live/homede/edg/misc/ambi_en.html)]

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amalcon
As I said the previous time it was posted (the url you posted was to the
dupe), it is just badly rendered. A badly rendered image is not going to have
any special predictive power about mid-level brain functions, especially since
the information that's extracted (clockwise vs. counterclockwise) makes no
sense in this context.

Spinning is neither clockwise nor counterclockwise unless you are looking
along its axis of rotation. In that image, we're looking perpendicular to the
axis of rotation.

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trekker7
Uhh is it just me, or does the ballerina switch her direction of spin every
now and then... it starts off clock-wise, then after a while it changes
direction, and then back again...

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qaexl
I've been working on being able to switch the direction at will.

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kirubakaran
Just focus on her extended foot.

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qaexl
I did. Then I moved onto her head. From there, to the picture as a whole. I'm
now working on reducing the latency between willing for the shift, and
actually having the shift happen.

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kajecounterhack
oh. well yeah. like someone commented, its like an advanced necker cube
<http://en.wikipedia.org/wiki/Necker_cube>

As far as the brain thing goes...whatever...

It was pretty accurate for me though. I saw it clockwise. Right brain? lol

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bluishgreen
I don't clearly see how it de-bunked the bunk. Infact I think it still
supports the fact.Coldwater disables one hemisphere at which time they see it
one way implies illusion could have something to do with the active
hemisphere?

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acgourley
When I start to look at it, I get a random direction every time. I suspect
this means the test isn't very good.

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amichail
Is the paper online?

