I think a distinction worth tracing here is the diferrence between "learning" in the neural-net-sense and "learning" in the human pedagogical/psychological sense.

This is a good point Gust and I agree that there is a distinction at the high level in terms of the types of concepts that are learned, the complexity of the concepts, and the structures involved - even though the same high level learning algorithms and systems are much the same.

The "learning" done by a piece of cortex becoming a visual cortex after receiving neural impulses from the eye isn't something you can override by teaching a person (in the usual sense o the word "teaching") - you'd need to rewire their brain.

Well all learning involves brain rewiring - that's just how the brain works at the low level. And you can actually override the neural impulses from the eye and cause them to learn new things - learning to read is one simple example, another more complex example is the reversed vision goggle experiments that MIT did so long ago - humans can learn to see upside down after - I believe a week or so of visual experience with the goggles on.

I don't think you can call it cultural/memetic because this neural learning does not (seem to) occur through the mechanism(s) that deals with concepts, ideas and feelings, which is involved in learning a language or a social custom or a scientific theory.

I agree that learning complex linguistic concepts requires learning over more moving parts in the brain - the cortical regions that specialize in language along with the BG, working memory in the PFC, various other cortical regions that actually model the concepts and mental algorithms represented by the linguistic symbols, memory recall operations in the hippocampus, etc etc. So yes learning cultural/memetic concepts is more complex and perhaps qualitatively different.

If that's the case, I wouldn't say it's a cultural/memetic construct (although it is an environmental construct).

Yeah I probably should have said 99.999% environmental construct.