I've thought about this study for a while now. I found the "no distractions" classroom pictured to be grim and institutional, yet I have no doubt that a lovely, calm, pleasant room with unadorned walls could be designed. My worry is that this study will lead to just ripping down every bit of color and decoration but otherwise leaving it the same, making classrooms feel like jail. However, I guess most teachers are too Pinterest-addicted to do this.
My own DD has actually learned some things from staring idly at the materials on the walls of her classroom. I remember she was able to recite/fully regurgitate the content of some space- and earth-science posters in one room. Of course, one could argue that she should have been on task instead. Which leads to the question: why are those learning materials on the walls??? When is one meant to be studying them?