Its a while since I have done any serious study of the area but any idea that talks of seperate bits of the brain which do not communicate well with eachother is pretty outmoded. I have never heard of any serious neuropsychology work that talks about big brain and little brain in this way. It sounds more like the sort of internet pop psychology that talks about left brained and right brained people by completely misunderstanding the real science. The nearest real work I can think of would be that work showing the pre frontal cortex is important in decision making and planning etc. And there is no suggestion that this area is in any way isolated from the rest of the brain. On the contrary, it needs to be well connected in order to synthesise all the different inputs that go into decision making.

It lookws like you have taken the stuff about the enteric nervous system being fairly autonomous and misapplied it to some pop psychology rubbish about big brain little brain. By the way I was the guest that pointed it out and I honestly thought it was a deliberate joke along the lines of the DHMO scare stuff.

I would be able to go into more detail if I managed to get more than 5 hours sleep per night at the moment.

Someone should summon wolfgang to this thread, he always seems to be knowledgable on any area of science you care to mention!