@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{WeckGrikscheitHoeflingetal.2016, author = {Weck, Florian and Grikscheit, Florian and H{\"o}fling, Volkmar and Kordt, Anne and Hamm, Alfons O. and Gerlach, Alexander L. and Alpers, Georg W. and Arolt, Volker and Kircher, Tilo and Pauli, Paul and Rief, Winfried and Lang, Thomas}, title = {The role of treatment delivery factors in exposure-based cognitive behavioral therapy for panic disorder with agoraphobia}, series = {Journal of anxiety disorders}, volume = {42}, journal = {Journal of anxiety disorders}, publisher = {Elsevier}, address = {Oxford}, issn = {0887-6185}, doi = {10.1016/j.janxdis.2016.05.007}, pages = {10 -- 18}, year = {2016}, abstract = {Treatment delivery factors (i.e., therapist adherence, therapist competence, and therapeutic alliance) are considered to be important for cognitive behavioral therapy (CBT) for panic disorder and agoraphobia (PD/AG). In the current study, four independent raters conducted process evaluations based on 168 two-hour videotapes of 84 patients with PD/AG treated with exposure-based CBT. Two raters evaluated patients' interpersonal behavior in Session 1. Two raters evaluated treatment delivery factors in Session 6, in which therapists provided the rationale for conducting exposure exercises. At the 6-month follow-up, therapists' adherence (r = 0.54) and therapeutic alliance (r = 0.31) were significant predictors of changes in agoraphobic avoidance behavior; therapist competence was not associated with treatment outcomes. Patients' interpersonal behavior in Session 1 was a significant predictor of the therapeutic alliance in Session 6 (r = 0.17). The findings demonstrate that treatment delivery factors, particularly therapist adherence, are relevant to the long-term success of CBT for PD/AG.}, language = {en} } @article{WendtHufenbachKoenigetal.2020, author = {Wendt, Julia and Hufenbach, Miriam Catrin and K{\"o}nig, J{\"o}rg and Hamm, Alfons O.}, title = {Effects of verbal instructions and physical threat removal prior to extinction training on the return of conditioned fear}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, publisher = {Macmillan Publishers Limited, part of Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-020-57934-7}, pages = {14}, year = {2020}, abstract = {Instructions given prior to extinction training facilitate the extinction of conditioned skin conductance (SCRs) and fear-potentiated startle responses (FPSs) and serve as laboratory models for cognitive interventions implemented in exposure-based treatments of pathological anxiety. Here, we investigated how instructions given prior to extinction training, with or without the additional removal of the electrode used to deliver the unconditioned stimulus (US), affect the return of fear assessed 24 hours later. We replicated previous instruction effects on extinction and added that the additional removal of the US electrode slightly enhanced facilitating effects on the extinction of conditioned FPSs. In contrast, extinction instructions hardly affected the return of conditioned fear responses. These findings suggest that instruction effects observed during extinction training do not extent to tests of return of fear 24 hours later which serve as laboratory models of relapse and improvement stability of exposure-based treatments.}, language = {en} } @misc{WendtHufenbachKoenigetal.2020, author = {Wendt, Julia and Hufenbach, Miriam Catrin and K{\"o}nig, J{\"o}rg and Hamm, Alfons O.}, title = {Effects of verbal instructions and physical threat removal prior to extinction training on the return of conditioned fear}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {599}, issn = {1866-8364}, doi = {10.25932/publishup-44479}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-444796}, pages = {16}, year = {2020}, abstract = {Instructions given prior to extinction training facilitate the extinction of conditioned skin conductance (SCRs) and fear-potentiated startle responses (FPSs) and serve as laboratory models for cognitive interventions implemented in exposure-based treatments of pathological anxiety. Here, we investigated how instructions given prior to extinction training, with or without the additional removal of the electrode used to deliver the unconditioned stimulus (US), affect the return of fear assessed 24 hours later. We replicated previous instruction effects on extinction and added that the additional removal of the US electrode slightly enhanced facilitating effects on the extinction of conditioned FPSs. In contrast, extinction instructions hardly affected the return of conditioned fear responses. These findings suggest that instruction effects observed during extinction training do not extent to tests of return of fear 24 hours later which serve as laboratory models of relapse and improvement stability of exposure-based treatments.}, language = {en} } @article{WendtWeymarJungeetal.2018, author = {Wendt, Julia and Weymar, Mathias and Junge, Martin and Hamm, Alfons O. and Lischke, Alexander}, title = {Heartfelt memories}, series = {Emotion : a new journal from the American Psychological Association}, volume = {19}, journal = {Emotion : a new journal from the American Psychological Association}, number = {1}, publisher = {American Psychological Association}, address = {Washington}, issn = {1528-3542}, doi = {10.1037/emo0000396}, pages = {178 -- 182}, year = {2018}, abstract = {During social interactions, we rapidly judge others' trustworthiness on basis of their facial characteristics. Face-based trustworthiness judgments may not only affect our current but also our future interactions because we seem to be more inclined to remember untrustworthy than trustworthy faces. Memory formation of salient stimuli like untrustworthy faces may be modulated by the interplay between the autonomic and central nervous system, which can be indexed by changes in vagally mediated heart rate variability (HRV). To test this assumption, we investigated whether differences in HRV would be associated with differences in memory formation of untrustworthy faces in a sample of healthy participants (n = 34, all female). Untrustworthy faces were remembered more accurately than trustworthy faces, albeit only by participants with high and not low HRV. Across participants, increased memory accuracy for untrustworthy faces was associated with increased HRV. We discuss these findings in the context of neurobiological theories regarding the interplay between the autonomic and central nervous system during the regulation of autonomic, emotional and cognitive processes. (PsycInfo Database Record}, 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} } @article{LischkeJungeHammetal.2018, author = {Lischke, Alexander and Junge, Martin and Hamm, Alfons O. and Weymar, Mathias}, title = {Enhanced processing of untrustworthiness in natural faces with neutral expressions}, series = {Emotion : a new journal from the American Psychological Association}, volume = {18}, journal = {Emotion : a new journal from the American Psychological Association}, number = {2}, publisher = {American Psychological Association}, address = {Washington}, issn = {1528-3542}, doi = {10.1037/emo0000318}, pages = {181 -- 189}, year = {2018}, abstract = {During social interactions, individuals rapidly and automatically judge others' trustworthiness on the basis of subtle facial cues. To investigate the behavioral and neural correlates of these judgments, we conducted 2 studies: 1 study for the construction and evaluation of a set of natural faces differing in trustworthiness (Study 1: n = 30) and another study for the investigation of event-related potentials (ERPs) in response to this set of natural faces (Study 2: n = 30). Participants of both studies provided highly reliable and nearly identical trustworthiness ratings for the selected faces, supporting the notion that the discrimination of trustworthy and untrustworthy faces depends on distinct facial cues. These cues appear to be processed in an automatic and bottom-up-driven fashion because the free viewing of these faces was sufficient to elicit trustworthiness-related differences in late positive potentials (LPPs) as indicated by larger amplitudes to untrustworthy as compared with trustworthy faces. Taken together, these findings suggest that natural faces contain distinct cues that are automatically and rapidly processed to facilitate the discrimination of untrustworthy and trustworthy faces across various contexts, presumably by enhancing the elaborative processing of untrustworthy as compared with trustworthy faces. (}, language = {en} } @article{VenturaBortWirknerDolcosetal.2019, author = {Ventura-Bort, Carlos and Wirkner, Janine and Dolcos, Florin and Wendt, Julia and Hamm, Alfons O. and Weymar, Mathias}, title = {Enhanced spontaneous retrieval of cues from emotional events: an ERP study}, series = {Biological psychology}, volume = {148}, journal = {Biological psychology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-0511}, doi = {10.1016/j.biopsycho.2019.107742}, pages = {7}, year = {2019}, abstract = {Recent evidence points to enhanced episodic memory retrieval not only for emotional items but also for neutral information encoded in emotional contexts. However, prior research only tested instructed explicit recognition, and hence here we investigated whether memory retrieval is also heightened for cues from emotional contexts when retrieval is not explicitly probed. During the first session of a two-session experiment, neutral objects were presented on different background scenes varying in emotional and neutral contents. One week later, objects were presented again (with no background) intermixed with novel objects. In both sessions, participants were instructed to attentively watch the stimuli (free viewing procedure), and during the second session, ERPs were also collected to measure the ERP Old/New effect, an electrophysiological correlate of episodic memory retrieval. Analyses were performed using cluster-based permutation tests in order to identify reliable spatiotemporal ERP differences. Based on this approach, old relative to new objects, were associated with larger ERP positivity in an early (364-744 ms) and late time window (760-1148 ms) over distinct central electrode clusters. Interestingly, significant late ERP Old/New differences were only observed for objects previously encoded with emotional, but not neutral scenes (504 to 1144 ms). Because these ERP differences were observed in a non-instructed retrieval context, our results indicate that long-term, spontaneous retrieval for neutral objects, is particularly heightened if encoded within emotionally salient contextual information. These findings may assist in understanding mechanisms underlying spontaneous retrieval of emotional associates and the utility of ERPs to study maladaptive involuntary memories in trauma- and stress-related disorders.}, 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{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} }