title: Transcranial direct current stimulation and simultaneous functional magnetic resonance imaging.
abstract: Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses weak electrical currents administered to the scalp to manipulate cortical excitability and, consequently, behavior and brain function. In the last decade, numerous studies have addressed short-term and long-term effects of tDCS on different measures of behavioral performance during motor and cognitive tasks, both in healthy individuals and in a number of different patient populations. So far, however, little is known about the neural underpinnings of tDCS-action in humans with regard to large-scale brain networks. This issue can be addressed by combining tDCS with functional brain imaging techniques like functional magnetic resonance imaging (fMRI) or electroencephalography (EEG). In particular, fMRI is the most widely used brain imaging technique to investigate the neural mechanisms underlying cognition and motor functions. Application of tDCS during fMRI allows analysis of the neural mechanisms underlying behavioral tDCS effects with high spatial resolution across the entire brain. Recent studies using this technique identified stimulation induced changes in task-related functional brain activity at the stimulation site and also in more distant brain regions, which were associated with behavioral improvement. In addition, tDCS administered during resting-state fMRI allowed identification of widespread changes in whole brain functional connectivity. Future studies using this combined protocol should yield new insights into the mechanisms of tDCS action in health and disease and new options for more targeted application of tDCS in research and clinical settings. The present manuscript describes this novel technique in a step-by-step fashion, with a focus on technical aspects of tDCS administered during fMRI.
authors.affiliation: Centre for Clinical Research, University of Queensland; Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin; m.meinzer@uq.edu.au.
authors.forename: Marcus
authors.initials: M
authors.lastname: Meinzer
authors.affiliation: Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin.
authors.forename: Robert
authors.initials: R
authors.lastname: Lindenberg
authors.affiliation: Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin.
authors.forename: Robert
authors.initials: R
authors.lastname: Darkow
authors.affiliation: Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin.
authors.forename: Lena
authors.initials: L
authors.lastname: Ulm
authors.affiliation: Centre for Clinical Research, University of Queensland.
authors.forename: David
authors.initials: D
authors.lastname: Copland
authors.affiliation: Department of Neurology, NeuroCure Clinical Research Centre, and Centre for Stroke Research Berlin, Charité Universitätsmedizin.
authors.forename: Agnes
authors.initials: A
authors.lastname: Flöel
mesh_terms: D001921:Brain / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*