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Updated: Jun 12, 2026
Electrode Positioning and Montage in Transcranial Direct Current Stimulation
Published on: May 23, 2011
Electrode-distance dependent after-effects of transcranial direct and random noise stimulation with extracephalic
Vera Moliadze1, Andrea Antal, Walter Paulus
1Department of Clinical Neurophysiology, Georg-August University, Robert-Koch- Strasse 40, Göttingen, Germany. vmoliadze@med.uni-goettingen.de
Objective:
To evaluate the importance of the distance between stimulation electrodes, in various montages, on the ability to induce sustained cortical excitability changes using transcranial direct and random noise stimulation.
Methods:
Twelve healthy subjects participated in four different experimental conditions. The stimulation electrode was always placed over the primary motor cortex; the reference electrode was placed at the contralateral orbit or at the ipsilateral/contralateral arm. MEPs were recorded in order to measure changes in cortical excitability over time.
Results:
The distance between the two electrodes correlates negatively with the duration and magnitude of induced after-effects.
Conclusions:
In particular when using extracephalic reference electrodes with transcranial electric stimulation techniques, the stimulation intensity has to be adapted to account for interelectrode distance.
Significance:
Electrode distance plays a critical role in the induction for stimulation after-effects in tDCS and tRNS studies, and must be taken into account in future studies and also when making comparisons with the published literature.
