A concept introduced in
Douglas R. Hofstadter's great book
Godel, Escher, Bach.
The self-subsystem is what Hofstadter believes may be the origin of consciousness. The self-subsystem, like other subsystems of the brain, is a series of highly entangled symbols (sets of neurons that hold declerative or procedural information) that relate to the self, these symbols are so naturally linked to one another that they tend to set one another off in such a way that as a whole they have nearly become autonomous from the rest of the brain.
Particularly, Hofstadter envisions that the self-subsystem is linked to the rest of the brain as a sort of arbiter. It monitors what symbols or subsystems are going off and how, in other words, the self-subsystem creates symbols of symbols and symbols of symbolic action. Because the self-subsystem exerts autonomy it is able to be "aware" of what is going on in the brain while still being artificially distinct.
Because the self-subsystem requires only enough symbols about the self to start acting autonomously, it is possible to infer that any sufficently large neural network will naturally acquire a self-subsystem, and, therefore, that consciousness is a self-emergent property of neural networks.