Research on the brain and learning has shown that a change of activity can help the retention of new learning.

This effect was demonstrated again in a recent study from the University of Edinburgh.  Not only can this be used in formal learning settings but students, teachers and the rest of us can all utilize this effect to help us become better learners.

http://www.spring.org.uk/2012/08/memory-enhanced-by-a-simple-break-after-reading.php