Left-brain/right-brain -- the dancer illusion debunked
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:
...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...
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!