ScienceDaily (Feb. 9, 2009) — Researchers at the Swedish medical university Karolinska Institutet have shown for the first time that the active training of the working memory brings about visible changes in the number of dopamine receptors in the human brain. The study, which is published in the journal Science, was conducted with the help of PET scanning and provides deeper insight into the complex interplay between cognition and the brain’s biological structure.
http://www.sciencedaily.com/releases/2009/02/090206081507.htm