Saying awareness happens because of neural activity is a bit like saying Ahab pursues the whale because of the placement of ink, or because of the sequencing of letters of the alphabet. It's technically true—no ink, no letters, no Ahab—but it leaves out some very important structure in between.
Annnnoid assures me (above and in thread after thread on this topic) I do not know what consciousness actually is, nor does anyone else. But I believe I do know what it is. It's a consequence of the brain's ability to not just sense threats and opportunities represented by shapes or sounds or smells or patterns or movements, but to interpret the world as things and beings having thoughts and performing actions for reasons. None of those elements—things, beings, thoughts, actions, or reasons—are entirely concrete or fully bounded. They are instead components of narrative.
Generating such narrative from raw sensory input and memory is an enormous and expensive computation. But it has large rewards in the form of ways to address threats (not just imminent ones but future ones) and exploit opportunities (likewise).
Now, in theory this could be done in the third person; that is, omitting the being performing the computation from the narrative being computed. We might imagine aliens or artificial intelligences thinking that way, but the process is unlikely to emerge in that form via evolutionary development of nervous systems, for several reasons. Chief among those reasons are that a first-person narrative is more likely to derive the evolutionary advantage of better negotiating the world for the being doing it (rather than, for instance, putting its results into effect by advising others); and that it is efficient to re-use the same computational structures needed to derive the actions and reasons of beings like oneself to also include the actions and reasons of the self. (It would probably be more complex to prevent that from happening; that is, to somehow build in special rules for leaving the self out of the narrative.)
So what is consciousness? It's the self as a role (a role much like the other things and beings) in the generated narrative.
… which will no doubt bring up the inevitable infinite regress argument: "But who is observing this self or this narrative?"
The process of generating the narrative is the observer. That's what an observer, in that ordinary sense of the word (we're not talking quantum physics here), is. A process that generates a narrative from sensory input and memory content.
"But that alone wouldn't or couldn't feel like awareness."
Why wouldn't or couldn't it?
… to which the only coherent answer I've ever gotten amounts to, "because no process possibly can," which of course is begging the question, introducing dualism (in the form of something that exists, that's not a process, and also not a material substance, that accounts for awareness) as an axiom. Which is one way to answer the thread title: "Why dualism?" But not, to me, in an adequately justified way.
