tACS to Enhance Language Abilities

Inclusion Criteria for Persons with Aphasia:

• Presence of aphasia
• Suffered a single, left hemisphere stroke
• Stroke ≥6 months old (chronic) at the time of enrollment

Inclusion Criteria for Healthy Controls

• Right-handedness
• Must be able to understand the nature of the study, and give informed consent

Exclusion criteria for Persons with Aphasia:

• Inability to understand the nature of the study
• Marked naming impairment
• Impaired non-verbal, conceptual processing
• History of significant medical or neurological disorder (other than stroke)
• History of significant or poorly controlled psychiatric disorders
• Current abuse of alcohol or drugs, prescription or otherwise
• Nursing a child, pregnancy, or intent to become pregnant during the study
• Clinically significant hearing loss
• Contraindications to tACS
• Contraindications to MRI

Exclusion Criteria for Healthy Controls

• Diagnosis of a neurodegenerative disease or clinically significant cognitive complaint
• Any unrelated neurologic or physical condition that impairs communication ability
• History of unrelated neurological conditions including but not limited to traumatic brain injury, stroke, or small vessel disease that has resulted in a neurologic deficit
• Any additional neurological condition that would likely reduce the safety of study participation, including central nervous system (CNS) vasculitis, intracranial tumor, intracranial aneurysm, multiple sclerosis or arteriovenous malformations
• A medically unstable cardiopulmonary or metabolic disorder
• Terminal illness associated with survival \<12 months
• Major active psychiatric illness that may interfere with required study procedures or treatments as determined by the enrolling physician
• Current abuse of alcohol or drugs, prescription or otherwise
• Contraindications to tACS
• Contraindications to MRI