[trentonstrong]

That's what came to mind first for me as well, but I think it's important to note that 'mindfulness' as defined in the paper is a specific type of "thinking harder".

I wonder if there would be similar results if the experiments were performed with new motor skill acquisition. I know that in my own experience it seems that a combination of "mindful" practice (especially at the beginning of the learning process) with "drill" type practice seems to seal the deal most efficiently. Basically the "engram" theory.