Carlos Ventura Bort

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javascript:void(0) Recently, we found that continuous transcutaneous auricular vagus nerve stimulation (taVNS) facilitates the encoding and later recollection of emotionally relevant information, as indicated by enhanced late positive potential (LPP), memory performance, and late ERP Old/New effect. Here, we aimed to conceptually replicate and extend these findings by investigating the effects of different time-dependent taVNS stimulation protocols. In Study 1, an identical paradigm to our previous study was employed with interval stimulation (30-sec on/off). Participants viewed unpleasant and neutral scenes on two consecutive days while receiving taVNS or sham stimulation and completed a recognition test one week later. In line with our previous results, unpleasant images encoded under taVNS, compared to sham stimulation, elicited larger LPP amplitudes and Old/New effects. However, no effects of taVNS on memory performance were found, suggesting that interval stimulation may lower the effects of taVNS on memory. In Study 2, we followed up on these findings by synchronizing the stimulation cycle with image presentation to determine the taVNS effects for images encoded during the on and off cycles. We could replicate the enhancing effects of taVNS on brain potentials (LPP and late Old/New effect) and found that taVNS improved recollection-based memory performance for both unpleasant and neutral images, independently of the stimulation cycle. Overall, our results suggest that taVNS increases electrophysiological correlates of emotional encoding and retrieval in a time-independent manner, substantiating the vagus nerve’s role in emotional processing and memory formation and opening new venues for improving mnemonic processes in both clinical and non-clinical populations.