TY - JOUR A1 - Ventura-Bort, Carlos A1 - Wirkner, Janine A1 - Wendt, Julia A1 - Hamm, Alfons O. A1 - Weymar, Mathias T1 - Establishment of emotional memories is mediated by vagal nerve activation BT - evidence from noninvasive taVNS JF - The journal of neuroscience : the official journal of the Society for Neuroscience N2 - Emotional memories are better remembered than neutral ones, but the mechanisms leading to this memory bias are not well under-stood in humans yet. Based on animal research, it is suggested that the memory-enhancing effect of emotion is based on central nor-adrenergic release, which is triggered by afferent vagal nerve activation. To test the causal link between vagus nerve activation and emotional memory in humans, we applied continuous noninvasive transcutaneous auricular vagus nerve stimulation (taVNS) during exposure to emotional arousing and neutral scenes and tested subsequent, long-term recognition memory after 1 week. We found that taVNS, compared with sham, increased recollection-based memory performance for emotional, but not neutral, material. These findings were complemented by larger recollection-related brain potentials (parietal ERP Old/New effect) during retrieval of emotional scenes encoded under taVNS, compared with sham. Furthermore, brain potentials recorded during encoding also revealed that taVNS facilitated early attentional discrimination between emotional and neutral scenes. Extending animal research, our behavioral and neu-ral findings confirm a modulatory influence of the vagus nerve in emotional memory formation in humans. KW - emotion KW - ERPs KW - memory KW - Old KW - New effect KW - LPP KW - vagus nerve KW - tVNS Y1 - 2021 U6 - https://doi.org/10.1523/JNEUROSCI.2329-20.2021 SN - 1529-2401 VL - 41 IS - 36 SP - 7636 EP - 7648 PB - Society for Neuroscience CY - Washington, DC ER - TY - JOUR A1 - Wirkner, Janine A1 - Ventura-Bort, Carlos A1 - Schulz, Paul A1 - Hamm, Alfons O. A1 - Weymar, Mathias T1 - Event-related potentials of emotional and neutral memories BT - the role of encoding position and delayed testing JF - Psychophysiology : journal of the Society for Psychophysiological Research N2 - Previous research found that memory is not only better for emotional information but also for neutral information that has been encoded in the context of an emotional event. In the present ERP study, we investigated two factors that may influence memory for neutral and emotional items: temporal proximity between emotional and neutral items during encoding, and retention interval (immediate vs. delayed). Forty-nine female participants incidentally encoded 36 unpleasant and 108 neutral pictures (36 neutral pictures preceded an unpleasant picture, 36 followed an unpleasant picture, and 36 neutral pictures were preceded and followed by neutral pictures) and participated in a recognition memory task either immediately (N=24) or 1 week (N=25) after encoding. Results showed better memory for emotional pictures relative to neutral pictures. In accordance, enhanced centroparietal old/new differences (500-900 ms) during recognition were observed for unpleasant compared to neutral pictures, most pronounced for the 1-week interval. Picture position effects, however, were only subtle. During encoding, late positive potentials for neutral pictures were slightly lower for neutral pictures following unpleasant ones, but only at trend level. To summarize, we could replicate and extend previous ERP findings showing that emotionally arousing events are better recollected than neutral events, particularly when memory is tested after longer retention intervals. Picture position during encoding, however, had only small effects on elaborative processing and no effects on memory retrieval. KW - attention KW - emotion KW - ERPs KW - memory KW - old KW - new effect KW - serial position effect Y1 - 2018 U6 - https://doi.org/10.1111/psyp.13069 SN - 0048-5772 SN - 1469-8986 VL - 55 IS - 7 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Ventura-Bort, Carlos A1 - Dolcos, Florin A1 - Wendt, Julia A1 - Wirkner, Janine A1 - Hamm, Alfons O. A1 - Weymar, Mathias T1 - Item and source memory for emotional associates is mediated by different retrieval processes JF - Neuropsychologia : an international journal in behavioural and cognitive neuroscience N2 - Recent event-related potential (ERP) data showed that neutral objects encoded in emotional background pictures were better remembered than objects encoded in neutral contexts, when recognition memory was tested one week later. In the present study, we investigated whether this long-term memory advantage for items is also associated with correct memory for contextual source details. Furthermore, we were interested in the possibly dissociable contribution of familiarity and recollection processes (using a Remember/Know procedure). The results revealed that item memory performance was mainly driven by the subjective experience of familiarity, irrespective of whether the objects were previously encoded in emotional or neutral contexts. Correct source memory for the associated background picture, however, was driven by recollection and enhanced when the content was emotional. In ERPs, correctly recognized old objects evoked frontal ERP Old/New effects (300-500 ms), irrespective of context category. As in our previous study (Ventura-Bort et al., 2016b), retrieval for objects from emotional contexts was associated with larger parietal Old/New differences (600-800 ms), indicating stronger involvement of recollection. Thus, the results suggest a stronger contribution of recollection-based retrieval to item and contextual background source memory for neutral information associated with an emotional event. KW - event-related potentials KW - emotion KW - source memory KW - remember/know KW - old/new KW - effect Y1 - 2017 U6 - https://doi.org/10.1016/j.neuropsychologia.2017.12.015 SN - 0028-3932 SN - 1873-3514 VL - 145 PB - Elsevier CY - Oxford ER -