Volpe 2014.

Methods	Randomised cross‐over trial
Participants	Country: USA Actual enrolment: 15 Inclusion criteria: ≥ 18 years of age, first single focal unilateral left hemisphere lesion with diagnosis verified by brain imaging (MRI or CT scans) that occurred at least 6 months prior, pre‐morbidly right handed, pre‐morbidly fluent English speaker, cognitive function sufficient to understand the experiments and follow instructions (per interview with Speech Pathologist), a baseline Aphasia Quotient score between 10 and 94 out of 100 points on the Western Aphasia Battery (neither completely without language comprehension/expression nor fully recovered from aphasia). Exclusion criteria: ongoing use of CNS‐active medications, ongoing use of psychoactive medications, such as stimulants, antidepressants, and anti‐psychotic medications, 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 (jewellery 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, pregnancy in women, as determined by self‐report
Interventions	Each participant underwent all of the following conditions, separated by 1 week of wash‐out: ‐ A‐tDCS with 1 mA once for 20 minutes during computerised aphasia therapy ‐ S‐tDCS once for 20 minutes during computerised aphasia therapy
Outcomes	Outcomes were recorded at baseline and at the end of intervention Primary outcome measure: ‐ mean change in picture‐naming accuracy score
Notes	Study description and results were published on the clinicaltrials.gov website
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described by the study authors
Allocation concealment (selection bias)	Unclear risk	Not described by the study authors
Blinding of participants and personnel (performance bias) Objective outcomes	Low risk	Quote: "Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)"
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Quote: "Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)"
Incomplete outcome data (attrition bias) Objective outcomes	Low risk	All participants completed the study and there were no losses to follow‐up, no treatment withdrawals, no trial group changes and no major adverse events
Selective reporting (reporting bias)	Low risk	All outcome measures listed in the protocol have been reported
Other bias	Low risk	Results were published on the clinicaltrials.gov website