There has been a new hypnosis study mentioned in today's Los Angeles Times.
It states that " for the highly hypnotizable, a brain structure associated with purposeful attentional control -- the dorsolateral prefrontal cortex -- is activated alongside the Default Mode Network when the mind is at rest. This would suggest that the highly hynotizable have a tighter coordination between brain areas where attention, emotion, action and intention are processed, wrote the authors of the study"
A problem with this kind of study is the hypnotist her or himself, the technique used, any pre-talk to take away fear and the simple feeling of trust one develops with the client. I know of a hypnotist who worked with person from a previous Stanford study who couldn't "be hypnotized" . With his technique and personality and circumstances, the person was able to be hypnotized.