Transcranial direct current stimulation: A computer-based human model study

Wagner, Tim; Fregni, Felipe; Fecteau, Shirley; Grodzinsky, Alan J.; Zahn, M.; Pascual‐Leone, Álvaro

doi:10.1016/j.neuroimage.2007.01.027

Cited by 513 publications

(414 citation statements)

References 45 publications

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“…Taking into account the size of the stimulation electrode (here: 25 cm 2 ) and the rather broad distribution of the tDCS current under the stimulation electrode (Wagner et al, 2007), it is unlikely that the observed facilitatory effects of anodal tDCS were due to an isolated stimulation of area PFm. Area PFm lies inbetween areas PF and PG ( Fig.…”

Section: Discussionmentioning

confidence: 99%

Transcranial Direct Current Stimulation (tDCS) of Left Parietal Cortex Facilitates Gesture Processing in Healthy Subjects

et al. 2013

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Gesture processing deficits constitute a key symptom of apraxia, a disorder of motor cognition frequently observed after left-hemispheric stroke. The clinical relevance of apraxia stands in stark contrast to the paucity of therapeutic options available. Transcranial direct current stimulation (tDCS) is a promising tool for modulating disturbed network function after stroke. Here, we investigate the effect of parietal tDCS on gesture processing in healthy human subjects. Neuropsychological and imaging studies suggest that the imitation and matching of hand gestures involve the left inferior parietal lobe (IPL). Using neuronavigation based on cytoarchitectonically defined anatomical probability maps, tDCS was applied over left IPL-areas PF, PFm, or PG in healthy participants (n ϭ 26). Before and after tDCS, subjects performed a gesture matching task and a person discrimination task for control. Changes in error rates and reaction times were analyzed for the effects of anodal and cathodal tDCS (compared with sham tDCS). Matching of hand gestures was specifically facilitated by anodal tDCS applied over the cytoarchitectonically defined IPL-area PFm, whereas tDCS over IPL-areas PF and PG did not elucidate significant effects. Taking into account tDCS electrode size and the central position of area PFm within IPL, it can be assumed that the observed effect is rather the result of a combined stimulation of the supramarginal and angular gyrus than an isolated PFm stimulation. Our data confirm the pivotal role of the left IPL in gesture processing. Furthermore, anatomically guided tDCS of the left IPL may constitute a promising approach to neurorehabilitation of apraxic patients with gesture processing deficits.

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Section: Discussionmentioning

confidence: 99%

Transcranial Direct Current Stimulation (tDCS) of Left Parietal Cortex Facilitates Gesture Processing in Healthy Subjects

et al. 2013

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“…Current-flow modeling approaches range from spherical models (Rush and Driscoll, 1969;Ferdjallah et al, 1996;Stecker, 2005;Miranda et al, 2006;Datta et al, 2008;Dmochowski et al, 2012) to more realistic individualized models derived from MRI (Wagner et al, 2004;Datta et al, 2009;Sadleir et al, 2010;Parazzini et al, 2011;Minhas et al, 2012;Datta et al, 2010;Wagner et al, 2007). Individualized modeling implies the need to consider the anatomy of individual subjects , in particular for patient populations that may have abnormal brain anatomy Dmochowski et al, 2013).…”

Section: Guidelines For Modelingmentioning

confidence: 99%

“…Unfortunately, despite increasing sophistication in these computational models (Wagner et al, 2004;Datta et al, 2009;Sadleir et al, 2010;Parazzini et al, 2011;Datta et al, 2012;Minhas et al, 2012;Datta et al, 2010;Wagner et al, 2007;Datta et al, 2011;Dmochowski et al, 2013;Luu et al, 2016), none of these model predictions have been directly validated to-date. Early validation efforts for simple spherical models used ex vivo recordings (Rush and Driscoll, 1968), surface recordings (Burger and Milaan, 1943) or in vivo recordings in simian (Hayes, 1950).…”

Section: Introductionmentioning

confidence: 99%

Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation

et al. 2017

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Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. We measured electric potentials intracranially in ten epilepsy patients and estimated electric fields across the entire brain by leveraging calibrated current-flow models. When stimulating at 2 mA, cortical electric fields reach 0.8 V/m, the lower limit of effectiveness in animal studies. When individual whole-head anatomy is considered, the predicted electric field magnitudes correlate with the recorded values in cortical (r = 0.86) and depth (r = 0.88) electrodes. Accurate models require adjustment of tissue conductivity values reported in the literature, but accuracy is not improved when incorporating white matter anisotropy or different skull compartments. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation to target stimulation and interpret clinical trials.

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“…To predict the distribution of the electric field induced by tDCS in the brain, various electrode positions have been mathematically modeled (Miranda et al, 2006(Miranda et al, , 2009Wagner et al, 2007). Using a standard spherical head model together with different bipolar electrode montages at 2 mA stimulation intensity (electrode size 25 cm 2 ), cortical current densities of ϳ0.01 mA/cm 2 were calculated (Miranda et al, 2006).…”

Section: Effects Of Tdcs In Models and Imaging Studiesmentioning

confidence: 99%

“…Using a standard spherical head model together with different bipolar electrode montages at 2 mA stimulation intensity (electrode size 25 cm 2 ), cortical current densities of ϳ0.01 mA/cm 2 were calculated (Miranda et al, 2006). However, Wagner et al (2007) found current density maxima between 0.77 and 2 mA/cm 2 for different electrode montage using 1 mA tDCS on a realistic MRI-derived finite-element model. Thus, previous models resulted in a considerable range of assumed induced peak current densities and showed a nonfocal electric field close to the electrode positions (Miranda et al, 2006;Wagner et al, 2007).…”

Section: Effects Of Tdcs In Models and Imaging Studiesmentioning

confidence: 99%

Prefrontal Transcranial Direct Current Stimulation Changes Connectivity of Resting-State Networks during fMRI

Keeser¹,

Meindl²,

Bor³

et al. 2011

J. Neurosci.

526

363

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Transcranial direct current stimulation (tDCS) has been proposed for experimental and therapeutic modulation of regional brain function. Specifically, anodal tDCS of the dorsolateral prefrontal cortex (DLPFC) together with cathodal tDCS of the supraorbital region have been associated with improvement of cognition and mood, and have been suggested for the treatment of several neurological and psychiatric disorders. Although modeled mathematically, the distribution, direction, and extent of tDCSmediated effects on brain physiology are not well understood. The current study investigates whether tDCS of the human prefrontal cortex modulates resting-state network (RSN) connectivity measured by functional magnetic resonance imaging (fMRI). Thirteen healthy subjects underwent real and sham tDCS in random order on separate days. tDCS was applied for 20 min at 2 mA with the anode positioned over the left DLPFC and the cathode over the right supraorbital region. Patterns of resting-state brain connectivity were assessed before and after tDCS with 3 T fMRI, and changes were analyzed for relevant networks related to the stimulation-electrode localizations. At baseline, four RSNs were detected, corresponding to the default mode network (DMN), the left and right frontal-parietal networks (FPNs) and the self-referential network. After real tDCS and compared with sham tDCS, significant changes of regional brain connectivity were found for the DMN and the FPNs both close to the primary stimulation site and in connected brain regions. These findings show that prefrontal tDCS modulates resting-state functional connectivity in distinct functional networks of the human brain.

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Transcranial direct current stimulation: A computer-based human model study

Cited by 513 publications

References 45 publications

Transcranial Direct Current Stimulation (tDCS) of Left Parietal Cortex Facilitates Gesture Processing in Healthy Subjects

Transcranial Direct Current Stimulation (tDCS) of Left Parietal Cortex Facilitates Gesture Processing in Healthy Subjects

Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation

Prefrontal Transcranial Direct Current Stimulation Changes Connectivity of Resting-State Networks during fMRI

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