The neurobiology of prefrontal transcranial direct current stimulation (tDCS) in promoting brain plasticity: A systematic review and meta-analyses of human and rodent studies

Neurophysiological and behavioral effects of multisession prefrontal tDCS and concurrent cognitive remediation training in patients with autism spectrum disorder (ASD): A double-blind, randomized controlled fNIRS study

“…Consistent with a meta-analysis of neuroimaging studies showing that prefrontal tDCS enhances the rsFC of the right medial prefrontal regions in the DMN [63], we showed that tDCS with left dlPFC cathode placement and right supraorbital region anode placement significantly enhanced rsFC of the right medial PFC but not the other ROIs, and had a large effect size. This effect was only observed in individuals in the active tDCS group.…”

“…There are three possible explanations for the observed rsFC changes. First, the diffused electric current distribution induced by the montage of tDCS with left dlPFC cathode placement and right supraorbital region anode placement might yield the observed increase in rsFC in the medial PFC, given that a previous simulation study showed that the electric field generated by tDCS induced the highest electric current density over the frontal midline regions, including the medial PFC [64] and electric field strength has been found to be positively correlated with rsFC changes in this region [63]. However, it should be noted that the applied current most likely affected an entire constellation of distributed brain regions, in part due to the spreading of the applied current interacting with the folded cortical surface, and indirectly through the network-level organization of the brain.…”

The Efficacy of Transcranial Direct Current Stimulation in Enhancing Surgical Skill Acquisition: A Preliminary Meta-Analysis of Randomized Controlled Trials

“…Transcranial direct-current stimulation (tDCS) may improve both the executive function and motor-learning function in healthy volunteer through brain function modulation [12], which two functions were the key components in surgical skill acquisition/training. The potential beneficial effect on executive function might be derived from its enhancing effect on long-term potentiation and brain-derived neurotrophic factor expression in the stimulated brain regions [13]. The motor function improving effect might be contributed by increasing or decreasing neuronal activity based on stimulation polarity and its current intensity [14][15][16][17].…”

Effects of Multisession Transcranial Direct Current Stimulation on Stress Regulation and Emotional Working Memory: A Randomized Controlled Trial in Healthy Military Personnel

“…[22][23][24][25][26][27] Transcranial direct current stimulation modulates subthreshold cortical excitability and plasticity by polarizing nerve tissue using low-intensity electrical currents (1-2.5 mA) administered over the scalp. Cortical excitability is generally assumed to increase by anodal tDCS and decrease by cathodal tDCS, although the exact mechanisms underlying tDCS effects are still unclear (further reading 28,29 ). Single-session tDCS, however, yields transient neurophysiological effects that typically fade out within a few hours, 30 and single-session tDCS over the DLPFC does not always effectively modulate stress regulation.…”

“…Such processes are, for instance, indicated by markers from electroencephalography (EEG). [60][61][62] One EEG marker that could be related to tDCS effects on emotional working memory is the power ratio between slow-wave theta band activity (4-7 Hz) and fast-wave beta band activity (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) in resting-state EEG, that is, the theta/beta ratio. [63][64][65] The theta/beta ratio is thought to reflect the balance between subcortical-based emotional and motivational drives and cortical-based cognitive control, based on associations between the theta/beta ratio and cognitive control over emotional input, [66][67][68] reward-motivated learning on cognitive tasks, [69][70][71] and working memory training gains.…”