Well, there is Gulio Tononi's Information Integration Theory (http://www.biolbull.org/content/215/3/216.long, see also Christof Koch's summary in SciAm at http://www.scientificamerican.com/article.cfm?id=a-theory-of...). Personally, I don't find it particularly compelling at present, since the claims made are much stronger than the evidence to support them and I'm not entirely sure I believe the assumptions necessary to test the theory empirically. But it's out there.