The cognitive control mechanism of improving emotion regulation: A high-definition tDCS and ERP study

Cognitive reappraisal as a commonly used emotion regulation strategy includes reinterpretation and detachment and is associated with the activity of the dorsolateral prefrontal cortex (DLPFC). However, the neuroenhancement mechanisms of transcranial direct current stimulation (tDCS) over DLPFC that modulate cognitive reappraisal are not yet fully understood. This work aims to verify the causal role of DLPFC in different tactics of cognitive reappraisal and further explore the cognitive control mechanisms of emotion regulation.A single-blind, within-subjects, sham-controlled design was adopted. Twenty-nine healthy subjects underwent two sessions of offline high-definition tDCS (HD-tDCS) that were targeted at the right DLPFC. Participants completed the cognitive control (Flanker) and cognitive reappraisal task in each session. We quantified the efficacy of cognitive control using N2 and P3 of the evoked brain responses and cognitive reappraisal using the late positivity potential (LPP).Anodal HD-tDCS resulted in the decrease of LPP for reinterpretation and detachment. The cognitive control increased after stimulation, indicated by the increase of P3 and decrease of N2 amplitude. The increased cognitive control mediated the effect of HD-tDCS on modulating reinterpretation, but not for detachment.The single-blind design, absence of the lasting-effects measure, and the intrinsically limited focality of tDCS are limitations of this study.Increasing the activity of DLPFC would facilitate emotion regulation and increase cognitive control. Cognitive control may be a significant potential mechanism for reinterpretation. Both tDCS and cognitive control interventions may be possible approaches to enhance emotion regulation.