A not quite nit-picking critique of this phenomenon is that it's treating a complex cluster of abilities as a unitary one.
In some of the (non-Olympic!) distance races I've run, it's seemed to me that I just couldn't move my legs any faster than they were going. In others, I've felt great except for a side stitch that made me feel like I'd vomit if I pushed myself harder. And in still others, I couldn't pull in enough air to make my muscles do what I wanted. In the latter case, I'd definitely notice the lower oxygen levels but in the former cases, maybe I wouldn't.
So dial down my oxygen and ask to do a road race? Maybe I'll notice, maybe I won't. But ask me to do a decathlon, and some medley swimming, and a biathlon? I bet I'll notice the low oxygen on at least some of those subtasks, whichever of them that require just the wrong mix of athletic abilities.
For the reading one, I can believe this if I'm doing some light pleasure reading and just trying to push plot into my brain as fast as possible. But if I'm reading math research papers, getting the words and symbols into my head is not the rate-limiting step. If there are some typos in the prose, or even in the results or proofs, it doesn't make much of a difference. There might be some second-order effects--when I try to fill in details and an equation doesn't balance, I can be less certain that the error is mine--but these are minor.
So maybe sharpen your claim down to unitary(-ish) abilities?
Do you have any suggestions for such unitary(ish) abilities?
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