Related Experiment Video
Updated: Apr 20, 2026
Electrode Positioning and Montage in Transcranial Direct Current Stimulation
Published on: May 23, 2011
Mitigating cutaneous sensation differences during tDCS: comparing sham versus low intensity control conditions
Tad T Brunyé1, Julie Cantelon1, Amanda Holmes1
1US. Army Natick Soldier Research, Development, and Engineering Center, RDNS-SEW-THC, 15 Kansas St., Natick, MA, USA; Tufts University, Department of Psychology, 490 Boston Ave., Medford, MA, USA.
Background:
Cutaneous sensations at electrode sites during the administration of direct current brain stimulation may inadvertently influence participants' subjective experience and task performance.
Objective:
The present study evaluated the utility of a methodological variation that substitutes sham administration with very low intensity (0.5 mA) current delivery.
Methods:
We used a 4 × 1 high-definition ring electrode transcranial direct current (HD-tDCS) system to target the left dorsolateral prefrontal cortex (Brodmann's Area 9). Four stimulation conditions were compared in a repeated-measures design: sham 2.0 mA and 0.5 mA intensity, versus active 2.0 mA and 0.5 mA intensity. During stimulation participants performed a cognitive interference task that activates the cingulo-frontal-parietal network, and periodically provided perceived sensation ratings.
Results:
We demonstrate that a relatively low intensity control condition attenuates otherwise large differences in perceived sensation between active and sham conditions. Critically, behavioral task differences maintained between the two active conditions.
Conclusion:
A low intensity control stimulation condition may prove a viable methodological alternative to conventional sham techniques used in repeated-measures designs, though important limitations are discussed.
