Personnally I came accross "fundamentals of piano practice" by Chuan C Chang, you could find it on the web easily. That it is how I understood the use of mental play.
That's the best thing I read about piano practice so far (even if my knowledge is very limited), but it boosted my learning.
Look also for "mental play" or "mental practice" on this forum. You need to memorize the pieces via mental play first, and not via muscle memory, which comes after. It's what I've understood.
By the way, if any people have other references or views on the subject, please share !