I’d say, don’t worry about the neural hardware too too much. I guess check that it’s not totally inconsistent with the hypothesis, but if it’s unclear (like usual), focus on the theory instead.
I’ll try to answer your questions, but to really give anything useful, I’d need to know the algorithm and spend like a month reading papers to check each thing. For AI, neuroscience facts are a tricky thing, because it’s not really about individual facts, but generic cortical principles. Exceptions don’t exactly invalidate them, because the hypothesized principle could just be slightly wrong. Lack of exceptions don’t validate them, because there’s always a lot going on so cherrypicking things is too easy.
I don’t mean to discourage you from learning about neuroscience, though. Some facts are more straightforward than they usually are, and it’s good to know what tools you have to work with. There are also ways to use neuroscience for designing AI besides generic cortical principles. For example, sometimes things seem to contradict assumptions, and sometimes things inspire theoretical ideas.
When I started, the terminology alone was pretty overwhelming. It’s a bit better in things besides papers, like wikipedia articles, but still takes time. It’s probably easiest to focus on something specific, like a specific topic or part of the brain. Every time I read about a new topic, there’s lots of words and concepts I don’t understand.
I don’t think so, but I’m not sure.
I’d worry about this part’s being true last.
Generally, plasticity is asymmetric, although I’d guess not always. The order in which cells fire is usually, presynaptic cell fires first and then postsynaptic cell fires second → reinforce the synapse, otherwise weaken the synapse. In layer 5, the order can reverse. The scholarpedia article on spike timing dependent plasticity seems to say that in general, but I’m not sure it’s always true, because I recall it being based on burst firing mode.
As far as I know, basal ganglia doesn’t project directly to the cortex. Instead, they project to the thalamus.
There are multiple classes / groups of cells in each layer, each with distinct connections and properties. One of the most prominent connections between layers is from L2/3 to L5. I’m not sure whether they’re proximal, so maybe the proximal ones are rare. There are connections in layer 5, but I don’t know whether they’re dense and distal.
This is definitely possible, at least for sensory input sent by the thalamus.