I love to read about the intersection of science, music, and psychology.
I encourage all musicians to read this article reviewing research on effective practice skills by Robert Duke at the University of Texas:
The researchers discovered that it doesn’t matter how long a musician practices something. It doesn’t even matter how many times something difficult is practiced. What does make a difference is how few times the musician makes a mistake. It’s not how many times a section is played right, its the high ratio of right to wrong.
I encourage you to read the article because it lays out the findings of the research much more eloquently than I can here.
My takeaway: The researchers found that the best musicians identified where the problems were and isolated them to figure out a solution. The pianists in this study practiced right notes more often than wrong ones and they slowed down for the hard parts. These practice skills are what teachers have been emphasizing all along. But sometimes we have to hear it in a new way before it really sinks in.