Effects of high-definition transcranial direct current stimulation on implicit emotion regulation of social pain in healthy individuals

Implicit emotion regulation (ER), a form of ER, is essential for protecting mental health in the process of social interaction. Both the ventrolateral prefrontal cortex (VLPFC) and the dorsolateral prefrontal cortex (DLPFC) have been shown to be involved in ER processes, including explicit ER of social pain, but whether they play a role in implicit ER is unclear.We investigated whether anodal high-definition transcranial direct current stimulation (HD-tDCS) of the right VLPFC (rVLPFC) or the right DLPFC (rDLPFC) influences implicit ER. In total, 63 healthy participants completed an emotion priming task, which measures the implicit ER of social pain, before and after receiving active or sham HD-tDCS (2 mA for 20 min, 10 consecutive days). Event-related potentials (ERPs) were recorded during task performance.Combined with the results of the behavioral and electrophysiological indices indicated that stimulation of both the rVLPFC and the rDLPFC by anodic HD-tDCS could significantly reduce the affective responses caused by social exclusion. The further results also suggested that rDLPFC activation may contribute to promoting the involvement of early cognitive resources in the implicit ER process of social pain, thus helping to reduce the subjective negative experience of individuals.There were no dynamic interactive emotional stimuli to induce social pain, and only static images of social exclusion were used.Our study provides cognitive and neurological evidence that expands our knowledge of the role of the rDLPFC and the rVLPFC in social ER. It can also serve as a reference for targeted intervention of implicit ER in social pain.