Jaynes is first mentioned on p. 221 of Consciousness Explained, and I haven't got that far yet. I'm really rather perplexed about this; I have a distinct memory of reading about Jaynes' bicameral mind, in some detail, in something by Dennett (around the same time I was reading Neal Stephenson's Snow Crash, oddly enough--which was late last fall, I think). The slight reference in DDI that I can find almost certainly wouldn't have been enough to prompt me to look it up (although I looked up and learned about a lot of things as a result of reading that book).