I had a longer more incoherent post about neuroimaging, models of consciousness and the like but decided it would be better to start over and question the assertion that if the mind is a product of brain it is an illusion.
Digestion is the function of a stomach. Is digestion an illusion? No it is a process, a real process that depends upon physical structures but is still real and can be talked about sensibly without reference to the underlying mechanisms.
Likewise computer programs aren’t illusions, they are functions of the computer’s machinery that have coherent structure and behavior that does not need to be reduced to the level of electrical impulse to be understood.
Like computers do programs and stomachs do digestion so do brains do minds. The mind is something you can talk about coherently without appeal to the brain. The aspect of mind that is conscious experience is like the rest of the mind, an emergent property from the neurological circuitry of the brain. It functions on the process of distributed representations of various sparseness and transformation of information by passing it through intermediate (hidden) layers from input to output.
Why we experience something as opposed to nothing remains unexplained in that we haven’t localized an area or proposed a mechanisms that has been tested. There exist models ranging from competition of high level representations to areas of the brain that represent what other areas of the brain are doing/have done. Many of these are plausible sketches for why a rich experience filled mental existence would emerge from a lump of nerves and support cells.
It occurs to me on preview that I should define representation in the psychology/neural modeling sense. A representation is the internal thing that signifies external things. Some psychological models of the mind include representations that are in the form of prototypical objects and other abstract things to compare stimuli against by various mechanisms. Neural network representations are patterns of neurons with each neuron coding either very basic features of the environment or weird conjunctions of these (the work of Tanaka on the visual system is especially interesting in this regard as it showed that in monkeys these very weird conjunctions are used). An example of an odd conjunction is a blob with a bulb with different brightness for blob and bulb. Things like that. As you get “higher” up in the brain you have richer representations that have more information drawn from multiple modalities of perception. The sum of activation of the neurons is the representation of a certain stimuli. The whole brain is constantly engaged in tug of war over representing what is going on in the world with inhibitory mechanisms allowing only the most excited neurons to continue tugging. While so far no explanation of consciousness has just fallen out of this like explanations of attention have there is a lot of hope for neural networks, especially ones that are embodied, to develop consciousness.