According to "Torkel Klingberg, MD, PhD, an assistant cognitive neuroscience professor at the Karolinska Institute in Sweden, 'It could be that working memory problems give rise to observable behavioral symptoms of ADHD: distractibility and also poor academic achievement.' Working memory deficits might also underpin some reading disabilities, as it controls the ability to recall words read earlier in a sentence. New research suggests that working memory capacity could expand with practice--a finding that could shed new light on this central part of the mind's architecture, as well as potentially lead to treatments for ADHD or other learning disabilities."

http://www.apa.org/monitor/sep05/workout.aspx