@article{WirknerVenturaBortSchwabeetal.2019, author = {Wirkner, Janine and Ventura-Bort, Carlos and Schwabe, Lars and Hamm, Alfons O. and Weymar, Mathias}, title = {Chronic stress and emotion: Differential effects on attentional processing and recognition memory}, series = {Psychoneuroendocrinology}, volume = {107}, journal = {Psychoneuroendocrinology}, publisher = {Elsevier}, address = {Oxford}, issn = {0306-4530}, doi = {10.1016/j.psyneuen.2019.05.008}, pages = {93 -- 97}, year = {2019}, abstract = {Previous research indicates that acute stress around the time of learning facilitates attention and memory for emotionally salient information. Despite accumulating evidence for these acute stress effects, less is known about the role of chronic stress. In the present study, we therefore tested emotional and neutral scene processing and later recognition memory in female participants using hair cortisol concentrations as a biological marker for chronic stress. Event-related potentials recorded during picture viewing indicated enhanced late positive potentials (LPPs) for emotional, relative to neutral contents. These brain potentials varied as a function of long-term hair cortisol levels: hair-cortisol levels were positively related to overall LPP amplitudes. Results from recognition memory testing one week after encoding revealed better memory for emotional relative to neutral scenes. Hair-cortisol levels, however, were related to poorer memory accuracy. Taken together, our results indicate that chronic stress enhanced attentional processing during encoding of new stimuli and impaired later recognition memory. Results are discussed with regard to putatively opposite effects of chronic stress on certain brain regions (e.g., amygdala and hippocampus).}, language = {en} } @article{WirknerVenturaBortSchulzetal.2018, author = {Wirkner, Janine and Ventura-Bort, Carlos and Schulz, Paul and Hamm, Alfons O. and Weymar, Mathias}, title = {Event-related potentials of emotional and neutral memories}, series = {Psychophysiology : journal of the Society for Psychophysiological Research}, volume = {55}, journal = {Psychophysiology : journal of the Society for Psychophysiological Research}, number = {7}, publisher = {Wiley}, address = {Hoboken}, issn = {0048-5772}, doi = {10.1111/psyp.13069}, pages = {12}, year = {2018}, abstract = {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.}, language = {en} } @misc{WeymarVenturaBortWirkneretal.2018, author = {Weymar, Mathias and Ventura-Bort, Carlos and Wirkner, Janine and Wendt, Julia and Hamm, Alfons}, title = {Effects of Transcutaneous Vagus Nerve Stimulation (TVNS) on unpleasant picture processing and long-term memory}, series = {Psychophysiology : journal of the Society for Psychophysiological Research}, volume = {55}, journal = {Psychophysiology : journal of the Society for Psychophysiological Research}, publisher = {Wiley}, address = {Hoboken}, issn = {0048-5772}, pages = {S18 -- S18}, year = {2018}, language = {en} } @misc{WeymarVenturaBortWirkneretal.2019, author = {Weymar, Mathias and Ventura-Bort, Carlos and Wirkner, Janine and Genheimer, Hannah and Wendt, Julia and Hamm, Alfons O.}, title = {Effects of Transcutaneous Vagus Vagus Nerve Stimulation (TVNS) on selective attentions and emotional episodic memory : findings from ERP research}, series = {Psychophysiology : journal of the Society for Psychophysiological Research}, volume = {56}, journal = {Psychophysiology : journal of the Society for Psychophysiological Research}, publisher = {Wiley}, address = {Hoboken}, issn = {0048-5772}, doi = {10.1111/psyp.13501}, pages = {S12 -- S12}, year = {2019}, abstract = {Recent research indicates that non- invasive stimulation of the afferent auricular vagal nerve (tVNS) may modulate various cognitive and affec-tive functions, likely via activation of the locus coeruleus- norepinephrine (LC- NE) system. In a series of ERP studies we found that the attention- related P300 component is enhanced during continuous vagal stimula-tion, compared to sham, which is also related to increased salivary alpha amylase levels (a putative indirect marker for central NE activation). In another study, we investigated the effect of continuous tVNS on the late positive potential (LPP), an electrophysiological index for motivated atten-tion toward emotionally evocative cues, and the effects of tVNS on later recognition memory (1- week delay). Here, vagal stimulation prompted earlier LPP differences (300- 500 ms) between unpleasant and neutral scenes. During retrieval, vagal stimulation significantly improved memory performance for unpleasant, but not neutral pictures, compared to sham stimulation, which was also related to enhanced salivary alpha amylase levels. In line, unpleasant images encoded under tVNS compared to sham stimulation also produced enhanced ERP old/new differences (500- 800 ms) during retrieval indicating better recollection. Taken together, our studies suggest that tVNS facilitates attention, learning and episodic memory, likely via afferent projections to the arousal- modulated LC- NE system. We will, however, also show data that point to critical stimulation parameters (likely duration and frequency) that need to be considered when applying tVNS}, language = {en} } @misc{WeymarVenturaBortWendtetal.2019, author = {Weymar, Mathias and Ventura-Bort, Carlos and Wendt, Julia and Lischke, Alexander}, title = {Behavioral and neural evidence of enhanced long-term memory for untrustworthy faces}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {594}, issn = {1866-8364}, doi = {10.25932/publishup-44292}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-442925}, pages = {10}, year = {2019}, abstract = {In daily life, we automatically form impressions of other individuals on basis of subtle facial features that convey trustworthiness. Because these face-based judgements influence current and future social interactions, we investigated how perceived trustworthiness of faces affects long-term memory using event-related potentials (ERPs). In the current study, participants incidentally viewed 60 neutral faces differing in trustworthiness, and one week later, performed a surprise recognition memory task, in which the same old faces were presented intermixed with novel ones. We found that after one week untrustworthy faces were better recognized than trustworthy faces and that untrustworthy faces prompted early (350-550 ms) enhanced frontal ERP old/new differences (larger positivity for correctly remembered old faces, compared to novel ones) during recognition. Our findings point toward an enhanced long-lasting, likely familiarity-based, memory for untrustworthy faces. Even when trust judgments about a person do not necessarily need to be accurate, a fast access to memories predicting potential harm may be important to guide social behaviour in daily life.}, language = {en} } @article{WeymarVenturaBortWendtetal.2019, author = {Weymar, Mathias and Ventura-Bort, Carlos and Wendt, Julia and Lischke, Alexander}, title = {Behavioral and neural evidence of enhanced long-term memory for untrustworthy faces}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, publisher = {Macmillan Publishers Limited}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-019-55705-7}, pages = {8}, year = {2019}, abstract = {In daily life, we automatically form impressions of other individuals on basis of subtle facial features that convey trustworthiness. Because these face-based judgements influence current and future social interactions, we investigated how perceived trustworthiness of faces affects long-term memory using event-related potentials (ERPs). In the current study, participants incidentally viewed 60 neutral faces differing in trustworthiness, and one week later, performed a surprise recognition memory task, in which the same old faces were presented intermixed with novel ones. We found that after one week untrustworthy faces were better recognized than trustworthy faces and that untrustworthy faces prompted early (350-550 ms) enhanced frontal ERP old/new differences (larger positivity for correctly remembered old faces, compared to novel ones) during recognition. Our findings point toward an enhanced long-lasting, likely familiarity-based, memory for untrustworthy faces. Even when trust judgments about a person do not necessarily need to be accurate, a fast access to memories predicting potential harm may be important to guide social behaviour in daily life.}, language = {en} } @misc{WeymarVenturaBortGenheimeretal.2017, author = {Weymar, Mathias and Ventura-Bort, Carlos and Genheimer, Hannah and Wirkner, Janine and Wendt, Julia and Hamm, Alfons O.}, title = {THE P300 AND THE LC-NE SYSTEM: NEW INSIGHTS FROM TRANSCUTANEOUS VAGUS NERVE STIMULATION (TVNS)}, series = {Psychophysiology : journal of the Society for Psychophysiological Research}, volume = {54}, journal = {Psychophysiology : journal of the Society for Psychophysiological Research}, publisher = {Wiley}, address = {Hoboken}, issn = {0048-5772}, pages = {S145 -- S145}, year = {2017}, language = {en} } @article{VenturaBortWirknerWendtetal.2021, author = {Ventura-Bort, Carlos and Wirkner, Janine and Wendt, Julia and Hamm, Alfons O. and Weymar, Mathias}, title = {Establishment of emotional memories is mediated by vagal nerve activation}, series = {The journal of neuroscience : the official journal of the Society for Neuroscience}, volume = {41}, journal = {The journal of neuroscience : the official journal of the Society for Neuroscience}, number = {36}, publisher = {Society for Neuroscience}, address = {Washington, DC}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.2329-20.2021}, pages = {7636 -- 7648}, year = {2021}, abstract = {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.}, language = {en} } @misc{VenturaBortWirknerGenheimeretal.2018, author = {Ventura-Bort, Carlos and Wirkner, Janine and Genheimer, Hannah and Wendt, Julia and Hamm, Alfons O. and Weymar, Mathias}, title = {Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on the P300 and Alpha-Amylase Level}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {473}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419259}, pages = {12}, year = {2018}, abstract = {Recent research suggests that the P3b may be closely related to the activation of the locus coeruleus-norepinephrine (LC-NE) system. To further study the potential association, we applied a novel technique, the non-invasive transcutaneous vagus nerve stimulation (tVNS), which is speculated to increase noradrenaline levels. Using a within-subject cross-over design, 20 healthy participants received continuous tVNS and sham stimulation on two consecutive days (stimulation counterbalanced across participants) while performing a visual oddball task. During stimulation, oval non-targets (standard), normal-head (easy) and rotated-head (difficult) targets, as well as novel stimuli (scenes) were presented. As an indirect marker of noradrenergic activation we also collected salivary alpha-amylase (sAA) before and after stimulation. Results showed larger P3b amplitudes for target, relative to standard stimuli, irrespective of stimulation condition. Exploratory post hoc analyses, however, revealed that, in comparison to standard stimuli, easy (but not difficult) targets produced larger P3b (but not P3a) amplitudes during active tVNS, compared to sham stimulation. For sAA levels, although main analyses did not show differential effects of stimulation, direct testing revealed that tVNS (but not sham stimulation) increased sAA levels after stimulation. Additionally, larger differences between tVNS and sham stimulation in P3b magnitudes for easy targets were associated with larger increase in sAA levels after tVNS, but not after sham stimulation. Despite preliminary evidence for a modulatory influence of tVNS on the P3b, which may be partly mediated by activation of the noradrenergic system, additional research in this field is clearly warranted. Future studies need to clarify whether tVNS also facilitates other processes, such as learning and memory, and whether tVNS can be used as therapeutic tool.}, language = {en} } @article{VenturaBortWirknerGenheimeretal.2018, author = {Ventura-Bort, Carlos and Wirkner, Janine and Genheimer, Hannah and Wendt, Julia and Hamm, Alfons O. and Weymar, Mathias}, title = {Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on the P300 and Alpha-Amylase Level}, series = {Frontiers in Human Neuroscience}, volume = {12}, journal = {Frontiers in Human Neuroscience}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1662-5161}, doi = {10.3389/fnhum.2018.00202}, pages = {1 -- 12}, year = {2018}, abstract = {Recent research suggests that the P3b may be closely related to the activation of the locus coeruleus-norepinephrine (LC-NE) system. To further study the potential association, we applied a novel technique, the non-invasive transcutaneous vagus nerve stimulation (tVNS), which is speculated to increase noradrenaline levels. Using a within-subject cross-over design, 20 healthy participants received continuous tVNS and sham stimulation on two consecutive days (stimulation counterbalanced across participants) while performing a visual oddball task. During stimulation, oval non-targets (standard), normal-head (easy) and rotated-head (difficult) targets, as well as novel stimuli (scenes) were presented. As an indirect marker of noradrenergic activation we also collected salivary alpha-amylase (sAA) before and after stimulation. Results showed larger P3b amplitudes for target, relative to standard stimuli, irrespective of stimulation condition. Exploratory post hoc analyses, however, revealed that, in comparison to standard stimuli, easy (but not difficult) targets produced larger P3b (but not P3a) amplitudes during active tVNS, compared to sham stimulation. For sAA levels, although main analyses did not show differential effects of stimulation, direct testing revealed that tVNS (but not sham stimulation) increased sAA levels after stimulation. Additionally, larger differences between tVNS and sham stimulation in P3b magnitudes for easy targets were associated with larger increase in sAA levels after tVNS, but not after sham stimulation. Despite preliminary evidence for a modulatory influence of tVNS on the P3b, which may be partly mediated by activation of the noradrenergic system, additional research in this field is clearly warranted. Future studies need to clarify whether tVNS also facilitates other processes, such as learning and memory, and whether tVNS can be used as therapeutic tool.}, language = {en} }