Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Conflict-Related Neural Processes: A Blinded, Crossover Study

Poster Session E - Monday, March 9, 2026, 2:30 – 4:30 pm PDT, Fairview/Kitsilano Ballrooms

Hector Sanchez Melendez¹ (hos6@duke.edu), Travis Larson¹, Kenneth C. Roberts¹, Hayden Kenny¹, Sloan Sloyster¹, Marty G. Woldorff¹, Leah Acker¹; ¹Duke University

Implanted vagus nerve stimulation (VNS) is an FDA-approved therapy for treatment-resistant depression; however, transcutaneous auricular VNS (taVNS) is a non-implanted alternative increasingly used in complementary medicine and described as inducing subjective “relaxation.” Despite its growing use, the neural mechanisms underlying taVNS and its cognitive effects remain unclear. We hypothesized that taVNS reduces external attentional engagement, which would lead to slower reaction times (RTs) and attenuated event-related potentials (ERPs) in a conflict-based attentional task. We used a single-blind, randomized, within-subject crossover study design to disambiguate the effects of taVNS from sensory stimulation (sham). Twenty-eight young adults (mean age=20.5y, SD=2.1; 13 males) completed a five-block color-Stroop task consisting of acclimation, stimulation (taVNS, no stimulation, or sham), washout, crossover stimulation, and final washout blocks. Preliminary analyses suggest taVNS modulated ERP components associated with cognitive control. Specifically, the frontocentral negative-polarity incongruency wave (Ninc, latency ~350-450ms), which has been linked to stimulus-conflict detection, was diminished during taVNS relative to sham. In contrast, the posterior Late Positive Complex (LPC, latency ~500-800), which has been associated with stimulus-conflict resolution, was enhanced during taVNS. Despite these differential effects, RT did not differ significantly between taVNS and sham conditions. These results suggest that neuromodulation via taVNS does not globally attenuate task performance but rather selectively modulates the instantiation of neural resources allocated across different processing stages in a cognitive-control conflict task. More broadly, brain state modulation by taVNS may influence task-related cognition by modifying the cascade of the task-elicited neural processes but without necessarily altering the final task performance.

Topic Area: METHODS: Electrophysiology