The science of Consciousness is a tricky topic, not least because different people mean different things by the C-word. For example some people mean merely "awareness" or "the waking or attentive state", and others mean something like "the ability to understand, or, "that which happens when you understand something" and yet others equate C with "mind", whatever that is.
One meaning that I think we can get rid of from the start is "the way it feels to be conscious" - what Koch (who is smart and has written extensively and well about C) calls the "hard problem" - and I call the non-problem. Just ask yourself how it feels to be unconscious......
The first type of meaning is straightforward though not yet worked out in complete detail. There are brainstem and thalamic systems (e.g. cholinergic and adrenergic) that become active in awareness and attention and trigger global electrical changes (eg EEG desynchronization) that appear necessary for coordinated behavior and the ability to process and understand external (and less obviously internal) information.
This type of C links to the idea of "understanding", which is to me more interesting than C itself. I would rather talk to someone who's unconscious but seems to understand well than to someone whose fully awake but has little understanding.
In a nutshell, the science of AI, especially the new version that goes under the name "machine learning", is starting to make real progress, and also starting to forge links with the latest neuroscience e.g. of cortical circuits and physiology. This is the way science will provide real insight to C. One important last point: whenever we do have a good account of C, it will likely be rather counter-intuitive and difficult to thoroughly grasp, rather like electromagnetism, relativity and quantum mechanics. So if you are really interested in the C-problem, you need a lot of patience, hard-work and smarts!
I'm fairly confident that we will end up with a purely "mechanical" accounts of C, akin (and perhaps even closely related to) our current picture of "Life", but it's still a generation ahead, and will not be very satisfying to the average layperson, or not easily emulable electronically.
ACIB final.pdf