The Role of the Frontal and Parietal Cortex in Proactive and Reactive Inhibitory Control: A Transcranial Direct Current Stimulation Study

Abstract

Mounting evidence suggests that response inhibition involves both proactive and reactive inhibitory control, yet its underlying neural mechanisms remain elusive. In particular, the roles of the right inferior frontal gyrus (IFG) and inferior parietal lobe (IPL) in proactive and reactive inhibitory control are still under debate. This study aimed at examining the causal role of the right IFG and IPL in proactive and reactive inhibitory control, using transcranial direct current stimulation (tDCS) and the stop signal task. Twenty-two participants completed three sessions of the stop signal task, under anodal tDCS in the right IFG, the right IPL, or the primary visual cortex (VC; 1.5 mA for 15 min), respectively. The VC stimulation served as the active control condition. The tDCS effect for each condition was calculated as the difference between pre- and post-tDCS performance. Proactive control was indexed by the RT increase for go trials (or preparatory cost), and reactive control by the stop signal RT. Compared to the VC stimulation, anodal stimulation of the right IFG, but not that of the IPL, facilitated both proactive and reactive control. However, the facilitation of reactive control was not mediated by the facilitation of proactive control. Furthermore, tDCS did not affect the intraindividual variability in go RT. These results suggest a causal role of the right IFG, but not the right IPL, in both reactive and proactive inhibitory control.

A behavioral and cognitive neuroscience perspective on impulsivity, suicide, and non-suicidal self-injury: Meta-analysis and recommendations for future research

“…tDCS neuromodulation of various targets has been increasingly applied in treatment research (e.g., to relieve major depression Meron et al, 2015), but it has also been used for experimental manipulation of neural networks to enhance or diminish specific cognitive functions or symptoms, including impulsivity. Anodal tDCS applied to the rIFG appears to reduce behavioral impulsivity (Cai et al, 2016; Cunillera et al, 2014; Ditye et al, 2012; Stramaccia et al, 2015), whereas anodal tDCS to the left OFC has been found to lead to a reduction in cognitive impulsivity (Ouellet et al, 2015). If behavioral and cognitive impulsivity are implicated in short-term risk for self-injurious thoughts and behaviors, tDCS may therefore have potential to become a new protocol for addressing these clinical outcomes, through targeting the respective underlying neural circuitry of these facets of impulsivity.…”

tDCS to the left DLPFC improves cognitive control but not action cancellation in patients with ADHD: a behavioral and electrophysiological study

“…However, the lack of significant changes in the SSRT suggests no effects on reactive inhibition. Although there have been positive results in tDCS studies using the SST in a healthy population targeting other areas like the right inferior frontal gyrus [37][38][39][40][41][42] , previous tDCS studies with ADHD patients using the SST and targeting the DLPFC have also found a lack of significant effects on the SSRT and accuracy 28,43 . These results support the formulation of inhibitory control and impulsivity as complex multimodal processes with subdomain specificity (e.g.…”

Characterizing the course of non-suicidal self-injury: A cognitive neuroscience perspective

“…As mentioned above, such work is important for its potential to lead to the identification of potential targets for intervention. Within this context, the right inferior frontal gyrus (rIFG) may be a region of particular interest, as it has been observed in several studies to be responsive to anodal tDCS (Cai et al, 2016; Cunillera et al, 2014; Ditye et al, 2012; Stramaccia et al, 2015). The rIFG has been found to be involved in cognitive interference resolution (Berman et al, 2011).…”