Published on in Vol 6 , No 1 (2018) :January
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/8815, first published
.

1 Hebrew SeniorLife Institute for Aging Research, Harvard Medical School, Roslindale, MA, US
2 Berenson-Allen Center for Noninvasive Brain Stimulation, Division of Interventional Cognitive Neurology, Beth Israel Deaconess Medical Center, Boston, MA, US