QR6.3.11 The Silicon Chip Speculation

The classic argument for brain information theories is the silicon chip thought experiment, that replacing every brain nerve with an equivalent silicon chip wouldn’t alter consciousness:

… imagine that one of your neurons is replaced by a silicon chip prosthesis that has the exact same input/output profile as the neuron it replaces. At the core of this thought experiment is the presumption that such a replacement would be unnoticeable to you or to anyone observing your behavior. Presumably, you would continue to experience pain even though the physical realization of those mental events includes a silicon chip where an organic neuron used to be. Now imagine that, one by one, the rest of your neurons are swapped for silicon prostheses. Presumably there would be no change in your mental life even though your brain, which was once made of lipid and protein neurons, is now entirely composed of silicon neuronoids.(Mandik, 2004).

No evidence supports this speculation except the belief that brains are biological computers.  That the brain equates to a set of wired chips isn’t supported by neuroscience as transistors are insulated from electromagnetic fields but nerves broadcast them, as brainwaves show.

Even if a chip replaced a nerve and its synapses, it doesn’t transmit as nerves do. Just as replacing cellphone network nodes with computers that can’t transmit would diminish the network, so every nerve replaced would diminish the brain. If consciousness is in the electromagnetic field, replacing every nerve with a chip would destroy it. The silicon experiment would give a supercomputer with the consciousness of a mass of metal. The silicon chip speculation is science fiction posing as science fact, just like the singularity prediction (Kurzweil, 1999).

Consider another thought experiment: if in the future we could copy a physical table atom-for-atom, would replicating me and my brain also copy my “I”? Physical realism says it would, as the result is physically identical to the original and the physical world is all there is. But if one “me” gardens while another cooks dinner, it might look like two of me but I can’t experience both events. If a copy of me went to work while “I” lay in the sun, I experience the sun not a day at work, so the physical copy didn’t replace me at all.  For Chalmers, the original is conscious and the copy is a zombie while for Dennett, both are zombies imagining they are conscious. One assumes that consciousness adds to physical reality while the other assumes it doesn’t exist at all. Either way, we don’t know how to duplicate a conscious experience.

Split-brain studies show that if the corpus callosum is cut, each hemisphere creates its own consciousness and they can come into conflict, so in this case, having two “I”s isn’t beneficial. If in the future I made a perfect copy of myself that was also conscious, who is to say it wouldn’t decide to kill me? The brain evolved to unify consciousness, not to divide it, for a reason.