Meta-analysis of the effects of transcranial direct current stimulation on inhibitory control

Abstract

Background: Inhibitory control refers to a central cognitive capacity involved in the interruption and correction of actions. Dysfunctions in these cognitive control processes have been identified as major maintaining mechanisms in a range of mental disorders such as ADHD, binge eating disorder, obesity, and addiction. Improving inhibitory control by transcranial direct current stimulation (tDCS) could ameliorate symptoms in a broad range of mental disorders. Objective: The primary aim of this pre-registered meta-analysis was to investigate whether inhibitory control can be improved by tDCS in healthy and clinical samples. Additionally, several moderator variables were investigated. Methods: A comprehensive literature search was performed on PubMed/MEDLINE database, Web of Science, and Scopus. To achieve a homogenous sample, only studies that assessed inhibitory control in the go-/no-go (GNG) or stop-signal task (SST) were included, yielding a total of 75 effect sizes from 45 studies. Results: Results of the meta-analysis indicate a small but significant overall effect of tDCS on inhibitory control (g ¼ 0.21) which was moderated by target and return electrode placement as well as by the task. The small effect size was further reduced after correction for publication bias. Conclusion:Based on the studies included, our meta-analytic approach substantiates previously observed differences between brain regions, i.e., involvement of the right inferior frontal gyrus (rIFG) vs. the right dorsolateral prefrontal cortex (rDLPFC) in inhibitory control. Results indicate a small moderating effect of tDCS on inhibitory control in single-session studies and highlight the relevance of technical and behavioral parameters.

Effects of tDCS during inhibitory control training on performance and PTSD, aggression and anxiety symptoms: a randomized-controlled trial in a military sample

“…on position F4 to focus the field on the dorsolateral PFC (Dousset et al, 2020;Salehinejad, Wischnewski, Nejati, Vicario, & Nitsche, 2019). However, tDCS with the anode placed on the F8-Cz Fz-T4 crossing, as in our study, has also shown successful response inhibition enhancement (Mayer et al, 2020;Schroeder et al, 2020). Technical tDCS parameter settings therefore do not seem to fully explain our null results.…”

“…While tDCS alone may not effectively modulate emotional distress (Smits, Schutter, van Honk, & Geuze, 2020), deficient cognitive processes underlying stress-related disorderssuch as inhibitory controlcould comprise convenient tDCS targets in this context. For example, single-session tDCS over the right IFG has shown to increase inhibitory control task performance (Mayer et al, 2020;Schroeder, Schwippel, Wolz, & Svaldi, 2020). Inhibitory control can also be enhanced with other techniques used to modulate right IFG functioning (e.g.…”

Modulation of impulsive behaviours using transcranial random noise stimulation

“…A recent meta-analysis by Schroeder et al (2020) [1] thoroughly summarised the accumulated knowledge on the potential of transcranial direct current stimulation (tDCS) in modulating inhibitory control. They concluded that the overall effect of tDCS appears to be small but significant and that targeting the right inferior frontal gyrus (rIFG) over the dorsolateral prefrontal cortex (DLPFC) might be more effective.…”

“…Nevertheless, time predicted an improvement in performance in both tasks, suggesting a learning effect. In their meta-analysis, Schroeder et al (2020) suggested that the overall effect of tDCS was small but significant. Targeting the right inferior frontal gyrus (rIFG) appeared to surpass the DLPFC in effect, which may partially explain our findings.…”

Intensified stimulation targeting lateral and medial prefrontal cortices for the treatment of social anxiety disorder: A randomized, double-blind, parallel-group, dose-comparison study

“…tDCS is increasingly used for studying physiological and neurocognitive functions in the healthy brain, and for clinical applications (for a detailed review see [30,31]). Cognitive, emotional and motivational functions of the lateral and medial PFC are increasingly being studied with tDCS [32][33][34][35][36]. The efficacy of tDCS, especially for therapeutic purposes, depends on different factors including stimulation parameters (e.g.…”