A taste from his article for aeon.com:
[T]o control its own state of attention, the brain needs a constantly updated simulation or model of that state. Like the general’s toy armies, the model will be schematic and short on detail. The brain will attribute a property to itself and that property will be a simplified proxy for attention. It won’t be precisely accurate, but it will convey useful information. What exactly is that property? When it is paying attention to thing X, we know that the brain usually attributes an experience of X to itself — the property of being conscious, or aware, of something. Why? Because that attribution helps to keep track of the ever-changing focus of attention. I call this the ‘attention schema theory’. It has a very simple idea at its heart: that consciousness is a schematic model of one’s state of attention. […]
If I am looking at a blue sky, my brain doesn’t merely register blue as if I were a wavelength detector from Radio Shack. I am aware of the blue. Did my neurons create that feeling? […]
Consciousness isn’t a non-physical feeling that emerges. Instead, dedicated systems in the brain compute information. Cognitive machinery can access that information, formulate it as speech, and then report it. When a brain reports that it is conscious, it is reporting specific information computed within it. It can, after all, only report the information available to it. In short, Arrow A and Arrow B remain squarely in the domain of signal-processing. There is no need for anything to be transmuted into ghost material, thought about, and then transmuted back to the world of cause and effect. […]
When you look at the colour blue, for example, your brain doesn’t generate a subjective experience of blue. Instead, it acts as a computational device. It computes a description, then attributes an experience of blue to itself. The process is all descriptions and conclusions and computations. Subjective experience, in the theory, is something like a myth that the brain tells itself. The brain insists that it has subjective experience because, when it accesses its inner data, it finds that information.