Examining the Role of Left Prefrontal Cortex in Emotion Regulation Using Noninvasive Transcranial Direct Current Stimulation

Abstract

Emotion regulation (ER) is the set of processes that support the flexible adjustment of emotional responses to valenced stimuli depending on context. Evidence from healthy and psychiatric populations has linked ER mechanisms to the dorsolateral prefrontal cortex (dlPFC). This region shows reliable engagement in ER tasks, especially in the left hemisphere. Few studies, however, have examined whether dlPFC causally supports up- or down-regulation of emotional responses. We used transcranial direct current stimulation (tDCS)—a noninvasive brain stimulation technique involving the application of small currents through electrodes placed over the scalp—to examine the causal contributions of left dlPFC in ER. Healthy participants (N = 95) performed a standard ER task before and during either excitatory (anodal), inhibitory (cathodal), or sham tDCS over left PFC. Performance differences at baseline among the conditions minimized the ability to detect tDCS effects. We discuss these findings in the context of the literature on ER.