Study on School Recess and Group Classroom Behaviour
http://pediatrics.aappublications.org/cgi/content/abstract/123/2/431
http://www.nytimes.com/2009/02/24/health/24well.html?em
Excerpts:
New research suggests that play and down time may be as important to a childs academic experience as reading, science and math, and that regular recess, fitness or nature time can influence behavior, concentration and even grades.
Its pretty clear that all human beings experience attentional fatigue, Dr. Faber Taylor said. Our attention has to be restored from that fatigue, and there is a growing body of research evidence that nature is one way that seems particularly effective at doing it.
Hat-tip: Jaya