AUTHOR=Opie George M. , Cirillo John TITLE=Commentary: Preconditioning tDCS facilitates subsequent tDCS effect on skill acquisition in older adults JOURNAL=Frontiers in Aging Neuroscience VOLUME=Volume 9 - 2017 YEAR=2017 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2017.00084 DOI=10.3389/fnagi.2017.00084 ISSN=1663-4365