LiveScience.com - Why Great Minds Can't Grasp Consciousness:

"Almost everyone agrees that there will be very strong correlations between what's in the brain and consciousness," says David Chalmers, a philosophy professor and Director of the Center for Consciousness at the Australian National University. "The question is what kind of explanation that will give you. We want more than correlation, we want explanation -- how and why do brain process give rise to consciousness? That's the big mystery."