Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Brain Dynamic Functional Connectivity

This research examines how transcutaneous auricular vagus nerve stimulation (taVNS) influences the brain's dynamic neural interactions, as well as offering a detailed comparison of different dynamic functional connectivity (DFC) techniques. Using simulated data, we generated four dynamic patterns to evaluate the performance of multiplication of temporal derivatives (MTD), dynamic conditional correlation (DCC), flexible least squares (FLS), and sliding window functional connectivity (SW). The results demonstrated that FLS consistently achieved the lowest root mean square error (RMSE) across all patterns, with particularly notable advantages in stepwise and change point scenarios. Employing the FLS method, we further analyzed the dynamic connectivity changes in key brain networks before and after taVNS stimulation. The findings revealed that taVNS significantly modulated the interactions among the default mode network (DMN), salience network (SN), sensorimotor network (SMN), and dorsal attention network (DAN). This modulation facilitated the integration and adaptive response to emotional conflicts, thereby enhancing emotion regulation functions. This research offers in-depth mechanistic understandings regarding the utilization of taVNS in neuromodulation as well as the therapy of emotional disorders, while also offering direction for the selection of fMRI dynamic functional connectivity analysis techniques.