Inclusion Criteria:  Chronic ischemic or hemorrhagic left hemisphere stroke Fluent speaker of English by self-report Age 18 or older Premorbidly right handed 6 months post onset of stroke Diagnosis of aphasia and naming impairment using the Western Aphasia Battery-Revised  Exclusion Criteria:  Lesion in the right cerebellum Previous neurological disorder (other than stroke) affecting the brain, or any other neurodegenerative disorder or psychiatric disorder Seizures during the previous 6 months Uncorrected visual loss or hearing loss by self-report Use of medications that lower the seizure threshold (e.g., methylphenidate) Use of N-methyl-D-aspartate (NMDA) antagonists (e.g., memantine) >80% correct response on the Philadelphia Naming Testing at baseline History of brain surgery or any metal in the head Severely impaired auditory comprehension (lower than 2 on the Comprehension subscore on the Western Aphasia Battery-Revised) Severely limited verbal output (lower than 2 on the Spontaneous Speech rating scale on the Western Aphasia Battery-Revised) Individuals with severe claustrophobia, cardiac pacemakers or ferromagnetic implants, and pregnant women will be excluded from the MRI portion of the study.