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Background Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has received tremendous attention as a potential neuromodulator of cognitive and affective functions, which likely exerts its effects via activation of the locus coeruleus-noradrenaline (LC-NA) system. Reliable effects of taVNS on markers of LC-NA system activity, however, have not been demonstrated yet. Methods The aim of the present study was to overcome previous limitations by pooling raw data from a large sample of ten taVNS studies (371 healthy participants) that collected salivary alpha-amylase (sAA) as a potential marker of central NA release. Results While a meta-analytic approach using summary statistics did not yield any significant effects, linear mixed model analyses showed that afferent stimulation of the vagus nerve via taVNS increased sAA levels compared to sham stimulation (b = 0.16, SE = 0.05, p = 0.001). When considering potential confounders of sAA, we further replicated previous findings on the diurnal trajectory of sAA activity. Conclusion(s) Vagal activation via taVNS increases sAA release compared to sham stimulation, which likely substantiates the assumption that taVNS triggers NA release. Moreover, our results highlight the benefits of data pooling and data sharing in order to allow stronger conclusions in research., Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 808

The Covid-19 pandemic imposed new constraints on empirical research and forced researchers to transfer from traditional laboratory research to the online environment. This study tested the validity of a web-based episodic memory paradigm by comparing participants’ memory performance for trustworthy and untrustworthy facial stimuli in a supervised laboratory setting and an unsupervised web setting. Consistent with previous results, we observed enhanced episodic memory for untrustworthy compared to trustworthy faces. Most importantly, this memory bias was comparable in the online and the laboratory experiment, suggesting that web-based procedures are a promising tool for memory research., Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 780

This study aims at answering the question whether heart rate variability biofeedback has a beneficial effect on the extinction of conditioned fear.

Evidence is pointing to a modulatory role of transcutaneous auricular vagus nerve stimulation (taVNS) on the LC-norepinephrine (NE) system. However, there is currently no reliable noradrenergic biomarker of taVNS that produces replicable results across studies (see Burger et al., 2020; Farmer et al., 2020). Possible reasons for this lack of replicability are relatively small sample sizes and the heterogeneity of stimulation procedures used across studies. The aim of the present study is to overcome these limitations by pooling existing data from a large sample of studies that examined the effects of taVNS on salivary-alpha amylase (sAA; as indirect marker for noradrenergic activity) in healthy subjects.

In this online study we want to examine the relation between subjective interoceptive attention and accuracy and the ability to reverse a learned response, using a reversal learning task.

It has frequently been observed that single emotional events are not only more efficiently processed, but also better remembered, and form longer-lasting memory traces than neutral material. However, when emotional information is perceived as a part of a complex event, such as in the context of or in relation to other events and/or source details, the modulatory effects of emotion are less clear. The present work aims to investigate how emotional, contextual source information modulates the initial encoding and subsequent long-term retrieval of associated neutral material (item memory) and contextual source details (contextual source memory). To do so, a two-task experiment was used, consisting of an incidental encoding task in which neutral objects were displayed over different contextual background scenes which varied in emotional content (unpleasant, pleasant, and neutral), and a delayed retrieval task (1 week), in which previously-encoded objects and new ones were presented. In a series of studies, behavioral indices (Studies 2, 3, and 5), event-related potentials (ERPs; Studies 1-4), and functional magnetic resonance imaging (Study 5) were used to investigate whether emotional contexts can rapidly tune the visual processing of associated neutral information (Study 1) and modulate long-term item memory (Study 2), how different recognition memory processes (familiarity vs. recollection) contribute to these emotion effects on item and contextual source memory (Study 3), whether the emotional effects of item memory can also be observed during spontaneous retrieval (Sstudy 4), and which brain regions underpin the modulatory effects of emotional contexts on item and contextual source memory (Study 5). In Study 1, it was observed that emotional contexts by means of emotional associative learning, can rapidly alter the processing of associated neutral information. Neutral items associated with emotional contexts (i.e. emotional associates) compared to neutral ones, showed enhanced perceptual and more elaborate processing after one single pairing, as indexed by larger amplitudes in the P100 and LPP components, respectively. Study 2 showed that emotional contexts produce longer-lasting memory effects, as evidenced by better item memory performance and larger ERP Old/New differences for emotional associates. In Study 3, a mnemonic differentiation was observed between item and contextual source memory which was modulated by emotion. Item memory was driven by familiarity, independently of emotional contexts during encoding, whereas contextual source memory was driven by recollection, and better for emotional material. As in Study 2, enhancing effects of emotional contexts for item memory were observed in ERPs associated with recollection processes. Likewise, for contextual source memory, a pronounced recollection-related ERP enhancement was observed for exclusively emotional contexts. Study 4 showed that the long-term recollection enhancement of emotional contexts on item memory can be observed even when retrieval is not explicitly attempted, as measured with ERPs, suggesting that the emotion enhancing effects on memory are not related to the task embedded during recognition, but to the motivational relevance of the triggering event. In Study 5, it was observed that enhancing effects of emotional contexts on item and contextual source memory involve stronger engagement of the brain's regions which are associated with memory recollection, including areas of the medial temporal lobe, posterior parietal cortex, and prefrontal cortex. Taken together, these findings suggest that emotional contexts rapidly modulate the initial processing of associated neutral information and the subsequent, long-term item and contextual source memories. The enhanced memory effects of emotional contexts are strongly supported by recollection rather than familiarity processes, and are shown to be triggered when retrieval is both explicitly and spontaneously attempted. These results provide new insights into the modulatory role of emotional information on the visual processing and the long-term recognition memory of complex events. The present findings are integrated into the current theoretical models and future ventures are discussed., Es wurde häufig beobachtet, dass einzelne emotionale Ereignisse effizienter verarbeitet und besser erinnert werden und länger anhaltende Gedächtnisspuren bilden als neutrales Material. Wenn jedoch emotionale Informationen als Teil eines komplexen Ereignisses wahrgenommen werden, wie beispielsweise im Kontext oder in Bezug auf andere Ereignisse und/oder Quellendetails, sind die modulierenden Einflüsse von Emotionen weniger klar. Die vorliegende Arbeit zielt darauf ab zu untersuchen, wie emotionale, kontextuelle Quelleninformationen die anfängliche Kodierung und den anschließenden langfristigen Abruf von zugehörigem neutralen Material (Itemgedächtnis) und kontextuellen Quellendetails (Quellengedächtnis) modulieren. Dazu wurde ein Zwei-Aufgaben-Experiment verwendet, bestehend aus einer nicht instruierten Enkodierungsaufgabe, bei der neutrale Objekte eingebettet in verschiedene kontextuelle Hintergrundszenen dargeboten wurden, die in ihrem emotionalen Inhalt variierten (unangenehm, angenehm und neutral), und einer verzögerten Abrufaufgabe (1 Woche), bei der zuvor enkodierte und neue Objekte präsentiert wurden. In einer Reihe von Studien wurden Verhaltensindizes (Studien 2-5), ereigniskorrelierte Potenziale (EKPs; Studien 1-4) und funktionelle Magnetresonanztomographie (Studie 5) verwendet, um zu untersuchen, ob emotionale Kontexte die visuelle Verarbeitung der zugehörigen neutralen Informationen kurzfristig verändern können (Studie 1) und das Langzeitgedächtnis modulieren (Studie 2), wie verschiedene Prozesse des Wiedererkennens (Vertrautheit vs. Rekollektion) zu diesen Emotionseffekten auf das Item- und das kontextuelle Quellengedächtnis beitragen (Studie 3), ob die emotionalen Effekte auf das Itemgedächtnis auch bei der spontanen Abfrage beobachtet werden können (Studie 4) und über welche Hirnregionen die modulierenden Effekte emotionaler Kontexte auf das Item- und kontextuelle Quellengedächtnis vermittelt werden (Studie 5). In Studie 1 wurde beobachtet, dass emotionale Kontexte durch emotionales assoziatives Lernen die Verarbeitung der zugehörigen neutralen Informationen kurzfristig verändern können. Neutrale Elemente, die mit emotionalen Kontexten verbunden sind (im Folgenden „emotional Assoziierte“ genannt), zeigten nach einer einzigen Paarung im Vergleich zu neutralen Elementen eine verbesserte perzeptuelle und elaboriertere Verarbeitung, wie durch höhere Amplituden in den P100- bzw. LPP-Komponenten nachgewiesen wurde. Studie 2 zeigte, dass emotionale Kontexte länger anhaltende Gedächtniseffekte erzeugen, was sich in einer besseren Itemgedächtnisleistung und größeren EKP-alt/neu Unterschieden für emotional Assoziierte zeigte. In Studie 3 wurde eine mnemonische Differenzierung zwischen Item- und kontextuellem Quellengedächtnis beobachtet, die durch Emotionen moduliert wurde. Das Itemgedächtnis wurde durch den Prozess der Vertrautheit getrieben unabhängig von den emotionalen Kontexten während der Enkodierung. Das kontextuelle Quellengedächtnis wurde dagegen durch Rekollektion getrieben und war besser für emotionales Material. Wie in Studie 2 wurden in EKPs, die mit Rekollektionsprozessen in Verbindung stehen, verstärkende Effekte von emotionalen Kontexten für das Itemgedächtnis beobachtet. Ebenso wurde für das kontextuelle Quellengedächtnis eine ausgeprägte Rekollektionsbezogene Potenzierung der EKPs ausschließlich für emotionale Kontexte beobachtet. Studie 4 zeigte, dass die langfristige Verstärkung der Rekollektion, die emotionale Kontexten im Itemgedächtnis verursachen, auch dann beobachtet werden kann, wenn der Abruf nicht explizit instruiert wird. Dieser Befund zum spontanen Erinnern deutet darauf hin, dass die gedächtnissteigernden Effekte von Emotionen nicht mit der Aufgabe zusammenhängen, die während des Abrufs gestellt wurde, sondern mit der motivationalen Relevanz des auslösenden Ereignisses. In Studie 5 wurde beobachtet, dass an der verstärkenden Wirkung von emotionalen Kontexten auf das Item- und kontextuelle Quellengedächtnis solche Hirnregionen beteiligt sind, die mit der Rekollektionsprozessen assoziiert werden, einschließlich der Bereiche des medialen Temporallappens, des posterioren parietalen Kortex und des präfrontalen Kortex. Zusammengenommen deuten diese Ergebnisse darauf hin, dass emotionale Kontexte die anfängliche Verarbeitung der zugehörigen neutralen Informationen und der nachfolgenden, langfristigen Erinnerungen an Items und kontextuelle Quellen schnell modulieren. Die durch emotionaler Kontexte ausgelösten Gedächtniseffekte werden eher durch Rekollektions- und weniger durch Vertrautheitsprozesse vermittelt und zeigen sich sowohl bei expliziten als auch bei spontanen Abruf. Diese Ergebnisse liefern neue Erkenntnisse über die modulierende Rolle emotionaler Informationen bei der visuellen Verarbeitung und der Langzeiterinnerung an komplexe Ereignisse. Die vorliegenden Erkenntnisse werden in aktuelle theoretische Modelle integriert und zukünftige Forschungsperspektiven werden diskutiert.

Processing of internal bodily signals (i.e., interoception), and associated impairments are thought to be implicated in the development of psychopathology. Recent proposals highlight the need to differentiate between dimensions of interoception (i.e., accuracy and attention) to better understand its relation to mental health. In the current study, we validated the German version of the recently developed Interoceptive Accuracy Scale (IAS; Murphy et al., 2020) and investigated its relation to clinical outcomes, across seven samples from four research centers (Ntotal = 3462). The German IAS version was best explained by a one-factor structure that showed acceptable psychometric properties. Concerning clinical outcomes, we replicated previous findings showing a negative association between IAS scores and measures of alexithymia. Furthermore, we found that IAS scores were negatively related to measures of clinical symptomatology (e.g., anxiety, depressive, and somatoform symptoms) and neurotic traits. These findings suggest that the German validation of the IAS is a reliable and valid instrument for measuring subjective interoceptive accuracy and emphasize the importance of distinguishing between dimensions of interoception to understand its modulatory and protective role in the existence of psychopathology.

The theory of constructed emotions suggests that different psychological components, including core affect (mental and neural representations of bodily changes), and conceptualization (meaning-making based on prior experiences and semantic knowledge), are involved in the formation of emotions. However, little is known about their role in experiencing emotions. In the current study, we investigated how individual differences in interoceptive sensibility and emotional conceptualization (as potential correlates of these components) interact to moderate three important aspects of emotional experiences: emotional intensity (strength of emotion felt), arousal (degree of activation), and granularity (ability to differentiate emotions with precision). To this end, participants completed a series of questionnaires assessing interoceptive sensibility and emotional conceptualization and underwent two emotion experience tasks, which included standardized material (emotion differentiation task; ED task) and self-experienced episodes (day reconstruction method; DRM). Correlational analysis showed that individual differences in interoceptive sensibility and emotional conceptualization were related to each other. Principal Component Analysis (PCA) revealed two independent factors that were referred to as sensibility and monitoring. The Sensibility factor, interpreted as beliefs about the accuracy of an individual in detecting internal physiological and emotional states, predicted higher granularity for negative words. The Monitoring factor, interpreted as the tendency to focus on the internal states of an individual, was negatively related to emotional granularity and intensity. Additionally, Sensibility scores were more strongly associated with greater well-being and adaptability measures than Monitoring scores. Our results indicate that independent processes underlying individual differences in interoceptive sensibility and emotional conceptualization contribute to emotion experiencing., Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe; 769

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.

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS – or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between cortical thickness and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.

Previous clinical research found that invasive vagus nerve stimulation (VNS) enhanced word recognition memory in epileptic patients, an effect assumed to be related to the activation of brainstem arousal systems. In this study, we applied non-invasive transcutaneous auricular VNS (tVNS) to replicate and extend the previous work. Using a single-blind, randomized, between-subject design, 60 healthy volunteers received active or sham stimulation during a lexical decision task, in which emotional and neutral stimuli were classified as words or non-words. In a subsequent recognition memory task (1 day after stimulation), participants' memory performance on these words and their subjective memory confidence were tested. Salivary alpha-amylase (sAA) levels, a putative indirect measure of central noradrenergic activation, were also measured before and after stimulation. During encoding, pleasant words were more accurately detected than neutral and unpleasant words. However, no tVNS effects were observed on task performance or on overall sAA level changes. tVNS also did not modulate overall recognition memory, which was particularly enhanced for pleasant emotional words. However, when hit rates were split based on confidence ratings reflecting familiarity- and recollection-based memory, higher recollection-based memory performance (irrespective of emotional category) was observed during active stimulation than during sham stimulation. To summarize, we replicated prior findings of enhanced processing and memory for emotional (pleasant) words. Whereas tVNS showed no effects on word processing, subtle effects on recollection-based memory performance emerged, which may indicate that tVNS facilitates hippocampus-mediated consolidation processes., Postprints der Universität Potsdam : Humanwissenschaftliche Reihe, 649