This Phase II study aims to ascertain the effectiveness of HD-tDCS for adjunctive treatment of anomia in chronic aphasia post stroke. Furthermore, it will help explore factors such as alternate outcome measures, subject selection criteria, and benefits of extended treatment duration. These results will be compared to an existing trial using conventional non-targeted tDCS with the same design and outcomes. Patients will be treated with HD-tDCS while performing computerized anomia treatment. The basis behind this method is that language therapy is mediated by cortical areas that are most effectively activated during the training tasks, thus increasing electric stimulation in these areas may improve learning outcomes. To better understand the long term benefits of the adjunctive treatment, patients will be screened again four weeks and six months after study using the same anomia tests. If HD-tDCS shows promising results in increasing the learning outcomes of anomia treatment, a Phase III trial can be considered.

Inclusion Criteria:

• one-time ischemic stroke in the left hemisphere
• greater than 6-months post-stroke onset
• between 25 and 75 years of age
• aphasia diagnosis (as determined by pre-treatment language-based testing)
• right-handed (before the stroke)
• native speaker of English
• ability to provide informed written or verbal consent

Exclusion Criteria:

• clinically reported history of dementia, alcohol abuse, psychiatric disorder, traumatic brain injury, or extensive visual acuity or visual-spatial problems
• factors contraindicative of tDCS administration (sensitive scalp, previous brain surgery)
• prior history of epileptic or unprovoked seizures occurring during the previous 12 months.
• Presence of Metal implants of claustrophobia (not able to undergo MRI)
• Pregnancy
• Presence of any other neurological disease than stroke
• Childhood history of speech, language, hearing, or intellectual impairment