Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on Conflict-Related Behavioral Performance and Frontal Midline Theta Activity

Several previous studies have highlighted the potential of transcutaneous vagus nerve stimulation (tVNS) to enhance executive control of action. In the present study, we tested for effects of tVNS on behavioral performance and frontal midline theta activity during response conflicts. Frontal midline theta reflects transient activation of the posterior midfrontal cortex in situations requiring increased executive control of action. It is an established marker for top-down action control. We carried out a combined behavioral and electroencephalography (EEG) within-subjects experimental study employing a cued go-no-go-change task. Twenty-two healthy young adults participated. We found that tVNS enhanced global behavioral accuracy, i.e., decreased the proportion of erroneous and missed responses, compared with sham (placebo) stimulation, and reduced conflict costs on behavioral performance in go/change response conflicts. Furthermore, in trials eliciting go/stop conflicts, frontal midline theta was enhanced under tVNS. These findings corroborate the potential of tVNS to enhance executive control of action. For the first time, we show an effect of tVNS on frontal midline theta activity, which suggests that tVNS specifically interacts with the neural mechanisms underlying action control. We conclude that tVNS is a promising method to enhance executive control and recommend the further investigation of tVNS as a candidate treatment of clinically relevant executive control deficits.