Non-invasive transcutaneous vagus nerve stimulation during memory retrieval enhances recollection of emotionally salient memories

Remembering emotionally significant events is critical for the organisms' behavior and survival. While the mechanisms underlying the formation of such memories are well understood and closely linked to the vagus nerve and the brain's arousal system, less is known about its contribution to memory retrieval. The current study tested whether non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) applied during a long-term recognition memory task influenced retrieval of unpleasant and neutral scenes that had been incidentally encoded one week earlier. Results showed that taVNS, compared to a sham condition, selectively enhanced the recollection of unpleasant images. Despite a modest effect size (d = 0.33), these findings provide initial human support suggesting a role of the vagus nerve in emotional memory retrieval, thus extending current theoretical models of emotional memory retrieval and opening a new pathway for memory modulation and non-invasive therapeutic interventions.