I wrote the first draft of this in roughly 2017 but left lots of details out. I happened to run across this again about 2 weeks ago and it now seems quite apropos for the time we're living it, so I spruced it up a bit, added some of the missing details, and here I'm publishing it. Enjoy!
I know it has to be true – The magic of human-level cognition isn't the result of a brain in which every single piece is perfectly tuned for its very special and isolated task. Instead, there has to be some simple "principle of computation" that is repeated throughout the brain; some component that, when replicated throughout the brain, gives rise to this emergent property we call intelligence. Sure, we have a motor cortex, specialized to control movement. We have a visual cortex, specialized to process information from our eyes. And we have a pre-frontal cortex that assimilates all this information together and plans what to do next – "That's a snake! Don't step on it!" But there is evidence that the base circuitry that makes up all these modules is actually quite general. At every point on the neocortex, you see basically the same pattern - an interwoven computational "component" composed of 6 layers of stacked neurons. At every portion of our cortex this pattern is, with very little modification, repeated. Besides the similar morphology, there is other evidence that the computational components are general. In several really weird brain rewiring studies, they have redirected visual input to the auditory pathway and shown that animals can compensate quite well - effectively "seeing" with the part of their brain that was rightfully intended to hear stuff! (Mice (Lyckman et al., 2001), ferrets (Sur et al., 1988; Roe et al., 1990; Roe et al., 1992; Roe et al., 1993; Sharma et al., 2000), and hamsters (Schneider, 1973; Kalil & Schneider, 1975; Frost, 1982; Frost & Metin, 1985).)