The User Illusion
Our sense of being inside a Cartesian theater is part of a user illusion. Dennett maintains that not only does the electronic computer have a user interface, but also our brain computer has one. Our brain is a sophisticated parallel-processing neurocomputer with a software user interface. Interacting with this user interface gives us an illusory view of the brain, just as interacting with your computer interface gives you an illusory view of your PC. The user interface masks your PC’s core processes behind a world of windows, icons, menus, pointers, and so on. Conscious experience is the ongoing user illusion created through the self interacting with the brain interface, which analogously masks your brain’s neurocomputational processes. Descartes could not see through to the level of the neurocomputational core of the brain when he introspected. It is the same for us; all we see or experience is an interface.
But how does Dennett understand the self? Is the self a homunculus inside the brain engaged in brain interaction? No, the self is the centerpiece of the user illu- sion—an illusion within an illusion.
How does it work? It is best to work our way up to the user illusion from ground level. Let us see how Dennett thinks the mind develops in the brain from birth.
-  Dennett argues at length for this position in Consciousness Explained (Dennett 1991) and gives abriefer explanation of what he means in Animal Consciousness: What Matters and Why (Dennett1995a, p. 702).