[rcxdude]

Yes, there's more of a degree of redundancy in brains than microprocessors, but the 'lesion' approach tends to involve affecting more than just one neuron. The main point of that section is that you've got to be careful about what you define as a 'function'. In the processor case, if you defined function in terms of a register or instruction working properly, then this approach could actually give you a pretty good map. But if you've defined it as whether a particular game runs, it doesn't give you a good map at all, because most games exercise most functions of the microprocessor, and so which small parts aren't important to that particular game is only incidental. With brains the main thing is the underlying functions are not really known, so you need to approach with care.

[bonoboTP]

I used to have the impression that the brain is more "mixed up" than it really is. It's quite hard to get the right impression as a layman. Experts push too hard towards the extreme that makes us think that everything is involved in everything and it's all thoroughly uniformly mixed, advising against believing those old naive brain charts etc. But really, certain functions are remarkably well localized. This kind of overcorrection is quite common if one often reads HN-like "well actually"-content, which is supposed to supplement a common perception with a small caveat. Beware of internalizing just the caveat and forgetting the main thrust.