Transcranial Alternating Current Stimulation (tACS) in Aphasia

Inclusion Criteria: Healthy Controls * 18 years of age or older * Fluent in English * No history of neurological or psychiatric disorders Stroke Patients * Diagnosed with post-stroke aphasia by referring physician/neuropsychologist * Consent date \>=1 months after stroke onset * Right-handed * Fluent in English * 18 years of age or older Exclusion Criteria: * Severe cognitive, auditory or visual impairments that would preclude cognitive and language testing * Presence of major untreated or unstable psychiatric disease * A chronic medical condition that is not treated or is unstable * The presence of cardiac stimulators or pacemakers * Any metal implants in the skull * Contraindications to MRI or tACS * History of seizures * History of dyslexia or other developmental learning disabilities