@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{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} } @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} } @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} } @article{FischerVenturaBortHammetal.2018, author = {Fischer, Rico and Ventura-Bort, Carlos and Hamm, Alfons O. and Weymar, Mathias}, title = {Transcutaneous vagus nerve stimulation (tVNS) enhances conflict-triggered adjustment of cognitive control}, series = {Cognitive, affective, \& behavioral neuroscience : a journal of the Psychonomic Society}, volume = {18}, journal = {Cognitive, affective, \& behavioral neuroscience : a journal of the Psychonomic Society}, number = {4}, publisher = {Springer}, address = {New York}, issn = {1530-7026}, doi = {10.3758/s13415-018-0596-2}, pages = {680 -- 693}, year = {2018}, abstract = {Response conflicts play a prominent role in the flexible adaptation of behavior as they represent context-signals that indicate the necessity for the recruitment of cognitive control. Previous studies have highlighted the functional roles of the affectively aversive and arousing quality of the conflict signal in triggering the adaptation process. To further test this potential link with arousal, participants performed a response conflict task in two separate sessions with either transcutaneous vagus nerve stimulation (tVNS), which is assumed to activate the locus coeruleus-noradrenaline (LC-NE) system, or with neutral sham stimulation. In both sessions the N2 and P3 event-related potentials (ERP) were assessed. In line with previous findings, conflict interference, the N2 and P3 amplitude were reduced after conflict. Most importantly, this adaptation to conflict was enhanced under tVNS compared to sham stimulation for conflict interference and the N2 amplitude. No effect of tVNS on the P3 component was found. These findings suggest that tVNS increases behavioral and electrophysiological markers of adaptation to conflict. Results are discussed in the context of the potentially underlying LC-NE and other neuromodulatory (e.g., GABA) systems. The present findings add important pieces to the understanding of the neurophysiological mechanisms of conflict-triggered adjustment of cognitive control.}, 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} } @misc{BortHammWeymar2017, author = {Bort, Carlos Ventura and Hamm, Alfons O. and Weymar, Mathias}, title = {ENHANCED VOLUNTARY AND SPONTANEOUS MEMORY RETRIEVAL OF EMOTIONAL ASSOCIATES: AN ERP STUDY}, 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 = {S129 -- S129}, year = {2017}, language = {en} } @article{WirknerWeymarLoewetal.2017, author = {Wirkner, Janine and Weymar, Mathias and Loew, Andreas and Hamm, Carmen and Struck, Anne-Marie and Kirschbaum, Clemens and Hamm, Alfons O.}, title = {Cognitive functioning and emotion processing in breast cancer survivors and controls: An ERP pilot study}, 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}, doi = {10.1111/psyp.12874}, pages = {1209 -- 1222}, year = {2017}, abstract = {Diagnosis and treatment of breast cancer is a very emotionally aversive and stressful life event, which can lead to impaired cognitive functioning and mental health. Breast cancer survivors responding with repressive emotion regulation strategies often show less adaptive coping and adverse outcomes. We investigated cognitive functioning and neural correlates of emotion processing using ERPs. Self-report measures of depression, anxiety, and fatigue, as well as hair cortisol as an index of chronic stress, were assessed. Twenty breast cancer survivors (BCS) and 31 carefully matched healthy controls participated in the study. After neuropsychological testing and subjective assessments, participants viewed 30 neutral, 30 unpleasant, and 30 pleasant pictures, and ERPs were recorded. Recognition memory was tested 1 week later. BCS reported stronger complaints about cognitive impairments and more symptoms of depression, anxiety, and fatigue. Moreover, they showed elevated hair cortisol levels. Except for verbal memory, cognitive functioning was predominantly in the normative range. Recognition memory performance was decreased in cancer survivors, especially for emotional contents. In ERPs, survivors showed smaller late positive potential amplitudes for unpleasant pictures relative to controls in a later time window, which may indicate less elaborative processing of this material. Taken together, we found cognitive impairments in BCS in verbal memory, impaired emotional picture memory accuracy, and reduced neural activity when breast cancer survivors were confronted with unpleasant materials. Further studies and larger sample sizes, however, are needed to evaluate the relationship between altered emotion processing and reduced memory in BCS in order to develop new treatment strategies.}, language = {en} } @article{WendtLoewWeymaretal.2017, author = {Wendt, Julia and Loew, Andreas and Weymar, Mathias and Lotze, Martin and Hamm, Alfons O.}, title = {Active avoidance and attentive freezing in the face of approaching threat}, series = {NeuroImage : a journal of brain function}, volume = {158}, journal = {NeuroImage : a journal of brain function}, publisher = {Elsevier}, address = {San Diego}, issn = {1053-8119}, doi = {10.1016/j.neuroimage.2017.06.054}, pages = {196 -- 204}, year = {2017}, abstract = {Defensive behaviors in animals and humans vary dynamically with increasing proximity of a threat and depending upon the behavioral repertoire at hand. The current study investigated physiological and behavioral adjustments and associated brain activation when participants were exposed to dynamically approaching threat that was either inevitable or could be avoided by motor action. When the approaching threat was inevitable, attentive freezing was observed as indicated by fear bradycardia, startle potentiation, and a dynamic increase in activation of the anterior insula and the periaqueductal grey. In preparation for active avoidance a switch in defensive behavior was observed characterized by startle inhibition and heart rate acceleration along with potentiated activation of the amygdala and the periaqueductal grey. Importantly, the modulation of defensive behavior according to threat imminence and the behavioral option at hand was associated with activity changes in the ventromedial prefrontal cortex. These findings improve our understanding of brain mechanisms guiding human behavior during approaching threat depending on available resources.}, language = {en} } @misc{WirknerLowStrucketal.2017, author = {Wirkner, Janine and Low, Andreas and Struck, Anne-Marie and Hamm, Alfons O. and Weymar, Mathias}, title = {DOES AGE INFLUENCE BRAIN POTENTIALS DURING AFFECTIVE PICTURE PROCESSING IN MIDDLE-AGED WOMEN?}, 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 = {S40 -- S40}, year = {2017}, language = {en} } @article{VenturaBortDolcosWendtetal.2017, author = {Ventura-Bort, Carlos and Dolcos, Florin and Wendt, Julia and Wirkner, Janine and Hamm, Alfons O. and Weymar, Mathias}, title = {Item and source memory for emotional associates is mediated by different retrieval processes}, series = {Neuropsychologia : an international journal in behavioural and cognitive neuroscience}, volume = {145}, journal = {Neuropsychologia : an international journal in behavioural and cognitive neuroscience}, publisher = {Elsevier}, address = {Oxford}, issn = {0028-3932}, doi = {10.1016/j.neuropsychologia.2017.12.015}, pages = {11}, year = {2017}, abstract = {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.}, 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} }