Cognitive control networks causally support implicit emotion regulation: evidence from dlPFC stimulation and directed functional connectivity.

Cognitive control networks support adaptive regulation of behavior and affect, yet their role in automatic forms of emotion regulation remains poorly understood. Here, we tested whether large-scale cognitive control networks causally support implicit emotion regulation, using a within-subject design combining offline inhibitory transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (dlPFC), EEG-based directed connectivity analyses, and a self-control priming paradigm. Across three sessions (sham, left cathodal, right cathodal), thirty-five female participants passively viewed negative and neutral images under implicit regulation or no regulation conditions. In the sham session, implicit regulation was associated with reduced indices of emotional processing, reflected in attenuated Late Positive Potential (LPP) amplitudes and modulation of prestimulus alpha activity in the visual cortex, indicating modulation of anticipatory and sustained processing stages. These sham-associated neural effects were attenuated (LPP) or altered (prestimulus alpha activity) following inhibitory dlPFC stimulation. Directed connectivity analyses further revealed tDCS-induced alterations in within-network frontoparietal and cingulo-opercular connectivity and cross-network interactions between frontoparietal and visual systems in the theta (3-7 Hz) and beta (15-30 Hz) bands. Together, these findings suggest that implicit regulation recruits large-scale cognitive control networks, with the dlPFC acting as a hub for dynamic coordination between executive and visual systems. Contrary to models that view implicit emotion regulation as independent of executive control, these results indicate that automatic regulatory processes depend on intact top-down control and frequency-specific communication across networks.