I call this the "attractor basin hypothesis" of problem solving- your mental state is in one attractor basin and you need to be in a different one; a break gives you another chance to enter the right one. If true, it may be possible to get the same benefit as taking a break and returning to the work by doing something that jolts you out of your current attractor basin. Maybe that just means asking the right question (c.f. oblique strategies).
Interesting idea. I'm currently learning German, which is rather similar to my native Dutch. Yet I'm learning most of it through English, because that's simply the language people tend to use for instruction material.
Every now and then when I'm doing English to German translation, I find myself puzzled and then have to remind myself "think about the Dutch word" only to then immediately understand/recall the German cognate. I'm sure someone talking to me in Dutch could have the same effect, and more broadly speaking, another 'attractor basin' may be activated by random chance, like the tired cliche of someone in a movie figuring out the 'case' as a result of their spouse or child mentioning something unrelated yet apparently analogous.
