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Updated: Oct 7, 2025
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Neuronavigated Focalized Transcranial Direct Current Stimulation Administered During Functional Magnetic Resonance Imaging
Published on: November 15, 2024
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Modulation of brain networks during MR-compatible transcranial direct current stimulation
Amber M Leaver1, Sara Gonzalez2, Megha Vasavada2
1Department of Radiology, Northwestern University, Chicago, IL, 60611, United States; Department of Neurology, University of California Los Angeles, Los Angeles, CA, 90095, United States.
Neuroimage
|January 12, 2022
Summary
Transcranial direct current stimulation (tDCS) alters brain connectivity, with effects varying by stimulation site. This research highlights both intended and unintended impacts of tDCS on brain networks.
Area of Science:
- Neuroscience
- Cognitive Science
- Medical Imaging
Background:
- Transcranial direct current stimulation (tDCS) is used to modulate brain activity and improve cognitive function or neurological symptoms.
- The precise mechanisms by which tDCS influences brain function and functional connectivity (FC) remain incompletely understood.
Purpose of the Study:
- To investigate the effects of tDCS on whole-brain functional connectivity using BOLD fMRI.
- To compare the impact of different tDCS montages on brain network activity.
- To differentiate between intended and unintended effects of tDCS on brain connectivity.
Main Methods:
- MR-compatible tDCS was administered to 64 volunteers using three distinct electrode montages (DLPFC, LTA, STC).
- Blood-oxygenation-level-dependent (BOLD) fMRI data were acquired during active tDCS, sham tDCS, and rest conditions.
- Whole-brain functional connectivity analyses were performed with corrections for false discovery rate.
Main Results:
- Active tDCS reduced connectivity between specific brain networks and remote nodes, depending on the montage.
- DLPFC-tDCS decreased fronto-parietal network connectivity with subgenual ACC and increased orbitofrontal network connectivity.
- LTA-tDCS decreased auditory-somatomotor network connectivity with the frontal operculum.
- Increased FC in sensorimotor and attention regions was observed during both active and sham tDCS, potentially due to task demands.
Conclusions:
- tDCS can induce both targeted and non-specific changes in brain functional connectivity.
- The findings underscore the necessity of rigorous control conditions (sham, rest) in tDCS research and clinical trials.
- Understanding these complex network effects is crucial for optimizing tDCS applications.
