If brains are computers, what kind of computers are they? - Daniel Dennett keynote at PT-AI 2013

Abstract: Our default concepts of what computers are (and hence what a brain would be if it was a computer) include many clearly inapplicable properties (e.g., powered by electricity, silicon-based, coded in binary), but other properties are no less optional, but not often recognized: Our familiar computers are composed of millions of basic elements that are almost perfectly alike--flipflops, registers, or-gates--and hyper-reliable. Control is accomplished by top-down signals that dictate what happens next. All subassemblies can be designed with the presupposition that they will get the energy they need when they need it (to each according to its need, from each according to its ability). None of these is plausibly mirrored in cerebral computers, which are composed of billions of elements (neurons, astrocytes, ...) that are no-two-alike, engaged in semi-autonomous, potentially anarchic or even subversive projects, and hence controllable only by something akin to bargaining and political coalition-forming. A computer composed of such enterprising elements must have an architecture quite unlike the architectures that have so far been devised for AI, which are too orderly, too bureaucratic, too efficient.