The purpose of this study is to determine if non-invasive brain stimulation (transcranial direct current stimulation) delivered prior to language therapy will improve word-finding in individuals with aphasia who are 6 months or greater post-stroke.

Inclusion Criteria:

1. ≥ 18 years of age
2. First single focal unilateral left hemisphere lesion with diagnosis verified by brain imaging (MRI or CT scans) that occurred at least 6 months prior
3. Pre-morbidly right handed
4. Pre-morbidly fluent English speaker
5. Cognitive function sufficient to understand the experiments and follow instructions (per interview with Speech Pathologist)
6. A baseline Aphasia Quotient score between 10 to 94 out of 100 points on the Western Aphasia Battery (neither completely without language comprehension/expression nor fully recovered from aphasia).

Exclusion Criteria:

1. Ongoing use of CNS-active medications

2. Ongoing use of psychoactive medications, such as stimulants, antidepressants, and anti-psychotic medications

3. Presence of additional potential tDCS risk factors:

   • Damaged skin at the site of stimulation (i.e., skin with ingrown hairs, acne, razor nicks, wounds that have not healed, recent scar tissue, broken skin, etc.)
   • Presence of an electrically, magnetically or mechanically activated implant (including cardiac pacemaker), an intracerebral vascular clip, or any other electrically sensitive support system
   • Metal in any part of the body, including metal injury to the eye (jewelry must be removed during stimulation)
   • A history of medication-resistant epilepsy in the family
   • Past history of seizures or unexplained spells of loss of consciousness during the previous 36 months

4. Pregnancy in women, as determined by self-report

Two weeks for each intervention

Safety population included all participants who received at least one dose of intervention.

Sequence of stimulation conditions was randomized across subjects.