“The holy grail of brain training is [. . .] physical exercise. Simple aerobic exercise, such as walking 45 minutes a day three times a week, improves episodic memory and executive-control functions by about 20 percent, finds Art Kramer of the University of Illinois at Urbana-Champaign.” http://www.thedailybeast.com/newsweek/2011/01/03/can-you-build-a-better-brain.html “Kramer finds that a year
