Hypnosis and the brain separation

Hypnotists often talk about the separate hemispheres of the brain and their different functions. I often feel like most of what they say is based on conjecture from research done in the past that was never really fully understood. This TED talk is a great example of how far we have come to understanding the separations in the brain. The thing that blows my mind is how quickly everyone throws away past discoveries when new information comes out.
Like I said many hypnotist a have based some of their techniques on old information that has been proven to be inaccurate but that does not mean that their techniques no longer work. It would be equivalent to deciding that you could no longer use a light switch because your theory on electricity was wrong. The switch still works!
I found this video fascinating. I think you will too.

The divided brain