The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning by Daniel Bor Page B

point, imagine that four centuries into the future, neuroscience is so sophisticated that scientists can perfectly model all the neurons in the human brain. 6 The most famous neuroscientist in China, Professor Nao, is dying, but just before his death he is willing to be a guinea pig in a grand experiment. A vast array of wonderfully skilled robotic micro-surgeons opens up Nao’s skull and begins replacing each and every neuron, one by one, with artificial neurons that are the same size and shape as the natural kind. This includes all the connections, which are transformed from flesh to silicon. Each silicon neuron digitally simulates every facet of the complex neuronal machinery. It could just as easily do this via an Internet link with a corresponding computer in a processing farm nearby, such that there are 85 billion small computers in a warehouse a kilometer away, each managing a single neuron. But although it makes little real difference for this argument, let’s assume instead that miniaturization is so advanced in this twenty-fifth-century world that each little silicon neuron embedded within Nao’s brain is quite capable of carrying out all the necessary calculations itself, so that inside Nao’s head, by the end, is a vast interacting collection of micro silicon computers.
    Nao is conscious throughout his operation, as many patients are today when brain surgery is conducted (there are no pain receptors in the brain). Eventually, every single neuron is replaced by its artificial counterpart. Now, the processing occurring in Nao’s brain is no longer biological; it is run by a huge bank of tiny PCs inside his head (or, if you prefer, all his thoughts could occur a kilometer away in this bank of 85 billion small yet powerful computers). Is there any stage at which this famous scientist stops grasping meaning, or stops becoming aware? Is it with the first neuronal replacement? Or midway through, when half his thoughts are wetware and half are software? Or when the last artificial PC neuron is in place?
    Or, instead, does Nao feel that his consciousness is seamless, despite the fact that a few hours ago his thoughts were entirely biological, and now they are entirely artificial? It is entirely conceivable, I would propose, that as long as the PC versions of his neurons are properly doing their job and running programs that exactly copy what his neurons compute, then his awareness would never waver throughout the process, and he wouldn’t be able to tell the difference in his consciousness between the start and end of surgery.
    Now let’s say that Nao goes into the Chinese Room with his new silicon brain intact. Any Chinese person that passes by would have a perfectly normal paper-based conversation with him via the IN and OUT letterboxes, even though his brain is no longer biological. And both the outside conversationalists and the newly cyborg neuroscientist inside the room would assume that he, Professor Nao, was fully conscious, and that he understood every word. Is this not formally identical to the rule book that John Searle had in mind when he originally presented his Chinese Room thought experiment? We could even, for the sake of completeness, swap the book for Nao. We tie Nao’s hands behind his back and bring back the young man who was in the room before, but this time with no book. The young man would duly show Nao the Chinese characters that rain down on the floor from the IN letterbox, and then follow Nao’s instructions for copying out reply characters and posting them in the OUT box. The young man would still have no clue what he was helping to communicate, of course, but something in the room would—namely Nao!
    And, of course, if the Turing’s Nemesis gang offered the passing group of Chinese people the bet that any local guy could speak Mandarin, the situation would quickly turn sour: The Chinese group would cry foul as soon as Nao was led into the room with their choice of Caucasian subject.