Arktis says: “Baltar has a Cylon device somewhere in his nervous system instead of his brain. This is why it didn’t show on his brain scan, why it doesn’t appear to have direct control, and why it has to spend a lot of time convincing him of things. Think of it as being similar to a “man in the middle attack” (you are aware of the term, I trust) on a computer. Head Six is between Baltar’s mind and his senses, in addition to being able to exert some control over his motor functions.
“The pills are just his attempt to “make the bad (wo)man go away;” he really thinks he’s crazy deep down. Of course, so do I— but that sort of easy explanation doesn’t account for head six’s knowledge about the Cylons at certain times.”
There’s an early-on RDM mention that most of what Head Six tells Baltar could come from his own experience, and there’s always the MRI from last season. (“Would you stop going crazy in there?”) But I suspect that even though RDM is (obviously) in the position to know, he and his crew can certainly change their minds at will — and I suspect this issue is far from resolved in their minds, anyway.
And Arktis’ theory could account for the negative MRI results.
What say you?