Nested hierarchies have been discussed adequately, one should think. So here is an alternative matter.
I would propose that consciousness must be electrical in nature, due to two crucial facts:
1. The information that becomes conscious is some of the information being carried by the action-potentials of the nerve cells. It is not any other kind of information, such as quantum states of molecules, it is simply the information that nerve cells are known to carry via action-potentials.
2. Electric fields are the only physical phenomenon in the brain that have both the ability to extend in space significantly beyond nerve conduction itself and to be able to change and interact exceedingly swiftly, just as we experience conscious changes occurring “instantly.”
There are many other issues involved, of course, however, the fact remains that the physical phenomena underlying consciousness must be able to account for how consciousness appears to have the kind of extension and interactivity that creates consciousness, as electric fields would seem to be able to do. And that physical phenomenon must be tied to the information being carried as nerve impulses, as the electric fields of the nervous system ineluctibly are.
There does not seem to be a realistic option of a different sort of phenomenon that can unify that information encoded in the nerves into a conscious whole, and to do so exceedingly swiftly and surely. Certainly quantum physics offers nothing beyond electric fields interacting that could magically account for consciousness, no matter how much hocus-pocus people try to coax out of quantum phenomena. In the end it can’t be strange loops or the “illusion of consciousness” either, as one has to explain the difference between the consciousness and the unconscious (I would propose that the amount of, and type of, interaction of electric fields is what is crucial).
A great many issues could be discussed, however it seems to me that beginning with the basics is appropriate. There really is only one good candidate for consciousness in the physics of the brain at all, which is the electric fields that are unquestionably a necessary part of nerve conduction in the first place. If consciousness simply is what it is to be like a highly structured and unified (always becoming unified) electric field from the inside, so to speak, then it is the one phenomenon that we know not just abstractly, but as reality itself.