I find the above paragraph confusing. There is no real difference between analog and digital computing. We can make massively parallel clockless logic in silicon if we want to, but while it is arguably more efficient it is also very difficult to engineer reliable systems using it. In other words, there is no economic incentive to go there because it can't do anything that the current easy to engineer logic systems can't also do. There is nothing instantaneous about analog computing, at least not any more instantaneous than digital computing. "Digital" refers to the encoding mechanism used for transmitting information on a carrier. Regardless of the encoding mechanism, the carrier moves as fast as the carrier moves through the processor, whether transmitting digital or analog coded data.
Note that the brain is in every way slower than modern silicon. There are still plenty of software issues that can be improved on silicon, but the hardware is plenty fast (even if the software isn't up to the task in many cases). The differences in fundamental structure between the human brain and silicon makes them highly optimized for very different tasks. But whereas the human brain has a fixed computational capacity, computers are getting exponentially more powerful. Also, computers are far more capable in theory because anything the brain does can be perfectly emulated in software, while the brain cannot add any signficant new capabilities to what it already has. Electronics went from being able to add 100 numbers per second to billions per second. The human brain still can't add 100 numbers per second.