We are exploring whether anodal tDCS when administered in combination with spelling, naming, or working memory therapy can improve language performance of PPA and MCI participants at least in the short term more than behavioral therapy alone. We are also investigating whether and how tDCS alters the neuropeptide signature in participants with PPA and MCI. We use proton magnetic resonance spectroscopy (1H-MRS) to monitor neuropeptide concentrations at the areas of stimulation. We hypothesize that tDCS will stabilize the decline of specific neuropeptides, but only in those areas of the brain where tDCS effectively results in more efficient gains in language compared to language therapy alone (with sham tDCS). Study results may help optimize future intervention in individuals with PPA and MCI by providing treatment alternatives in a neurodegenerative condition with no proven effective treatment. A better understanding of the therapeutic and neuromodulatory effects of tDCS in PPA and MCI will offer insight into ways of impeding neurodegeneration that may improve quality of life for individuals with PPA and MCI and may provide insights into the mechanisms of this treatment for augmenting therapy for stroke as well.