HD-tDCS for Phonological Impairment in Aphasia

Inclusion Criteria: * Patients must be 18 or older. Patients may not be older than 85. Patients must have a language deficit from left-sided focal neurologic damage (e.g. stroke, tumor). Patients must be adults and have English-language fluency. Patients must be eligible to undergo MRI. Beyond meeting the inclusion criteria, no preference will be given on the basis of race, ethnicity or gender. Exclusion Criteria: * Advanced neurodegenerative disease (i.e. Stage 3 Alzheimer's disease) Neurologic disease (e.g. idiopathic epilepsy, seizure disorders that are not well managed, Parkinson's disease, ALS), Severe psychopathology (e.g. schizophrenia, bipolar disorder, acute major depressive episode) Suspected or diagnosed uncorrectable hearing or vision difficulties, or developmental disabilities (i.e. intellectual disability or learning disability). Contraindications to MRI such as claustrophobia, implanted electronic devices, MRI-incompatible metal in the body, extreme obesity, pregnancy, inability to lie flat, inability to see or hear stimulus materials. Younger than 18 or older than 85. \< 6 months post tumor resection.