2024 No Green Walls for a Restorative Classroom Environment: A Controlled Evaluation Study https://doi.org/10.1177/0013916516667976 van den Berg, Agnes E. Europe Experimental Students Elementary (K-5) Green space Cognitive Function green walls Schoolchildren plants classroom Attention Controlled study in Dutch elementary schools found classrooms with green walls improved selective attention and room perception. Suggests nature supports learning environments. 2017