Transcranial Direct Current Stimulation Alters Functional Network Structure in Humans: A Graph Theoretical Analysis

• Published in: IEEE transactions on medical imaging Vol. 38; no. 12; pp. 2829 - 2837
• Main Authors: Ruttorf, Michaela, Kristensen, Stephanie, Schad, Lothar R., Almeida, Jorge
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.12.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Brain; Brain architecture; Brain mapping; Direct current; Electrical stimulation of the brain; Electronics packaging; ESB; Functional magnetic resonance imaging; graph theory; Magnetic resonance imaging; Nervous system; network analysis; Network architecture; Neural networks; Neuroimaging; Polarity; Stimulation; Task analysis; Theoretical analysis; tool network; Topology; Transcranial direct current stimulation
• ISSN: 0278-0062; 1558-254X
• DOI: 10.1109/TMI.2019.2915206

Transcranial direct current stimulation (tDCS) is routinely used in basic and clinical research, but its efficacy has been challenged on a methodological, statistical and technical basis recently. The arguments against tDCS derive from an insufficient understanding of how this technique interacts with brain processes physiologically. Because of its potential as a central tool in neuroscience, it is important to clarify whether tDCS affects neuronal activity. Here, we investigate influences of offline tDCS on network architecture measured by functional magnetic resonance imaging. Applied to one network node only, offline tDCS affects the architecture of the entire functional network. Furthermore, offline tDCS exerts polarity-specific effects on the topology of the functional network attached. Our results confirm in a functioning brain and in a bias free and independent fashion that offline tDCS influences neuronal activity. Moreover, our results suggest that network-specific connectivity has an important role in improving our understanding of the effects of tDCS.