If you want to make this post even better (since apparently it's attracting massive viewage from the web-at-large!), here is some feedback:

I didn't find your description of the owl monkey experiment very compelling,

If a monkey was trained to keep a hand on the wheel that moved just the same, but he did not have to pay attention to it… the cortical map remained the same size.

because it wasn't clear that attention was causing the plasticity; the temporal association of subtle discriminations with rewards could plausibly cause plasticity directly, without attentional control being an intermediate causal link. I.e., because attention is a latent variable in the monkeys, either of the following could explain the observations:

(1) {attention} <-- {discrimination associated with reward} --> {plasticity}

(2) {discrimination associated with reward} --> {attention} --> {plasticity}

It's the human studies you cited but didn't describe, e.g. Heron et al (2010), that really pin down the {attention} --> {plasticity} arrow, because we can verbally direct humans to pay attention to something without requiring more discrimination from that group compared to a non-attentive group. In particular, Heron et al didn't just replicate the findings in the monkeys as you said...

This finding has since been replicated in humans, many times (for instance [5, 6]).

... they actually tested a direct causal link from {attention} to {co-opting neurons}, which makes your point much more convincing, I think :)

So if you're reading this, I suggest editing in the human study! And also this helpful comment you wrote.