Expectations and transcranial direct current stimulation-induced brain modulation: independent and additive effects on experimental pain

aDepartment of Pain and Translational Symptom Science, School of Nursing, University of Maryland, Baltimore, MD, United States bPlacebo Beyond Opinions Center, University of Maryland, Baltimore, MD, United States cDepartment of Anesthesiology & Psychiatry, University of Maryland, School of Medicine, Baltimore, MD, United States dCenter to Advance Chronic Pain Research, University of Maryland, Baltimore, MD, United States Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.