High-definition transcranial direct current stimulation (HD-tDCS), with its 4x1-ring montage, is a noninvasive brain stimulation technique that combines both the neuromodulatory effects of conventional tDCS with increased focality. This article provides a systematic demonstration of the use of 4x1 HD-tDCS, and the considerations needed for safe and effective stimulation.
Villamar, M. F., Volz, M. S., Bikson, M., Datta, A., DaSilva, A. F., Fregni, F. Technique and Considerations in the Use of 4x1 Ring High-definition Transcranial Direct Current Stimulation (HD-tDCS). J. Vis. Exp. (77), e50309, doi:10.3791/50309 (2013).