From Caloric Load to the Measurement of Fear and Anxiety - Contributions to the Improvement of Methods in Biopsychological Stress Research

Reliable and valid standardised laboratory paradigms are a key element of modern empirical research. Biological psychology is an intersectional field of research, in-between basic and clinical disciplines, with the capability and expertise to develop and improve laboratory paradigms to help assess biological markers in the context of cognitive, emotional or socially challenging tasks. Such standardised laboratory tasks are both, essential to uncover mechanisms mediating between health and disease and can cover different kinds of stressors and stimuli. Two widely renown examples are the Trier Social Stress Test (TSST, Kirschbaum et al., 1993), primarily used for the induction of psychosocial stress leading to a reliable activation of the HPA axis, and the NPU-threat test (Schmitz & Grillon, 2012), a psychophysiological paradigm to assess fear- and anxiety-potentiated startle reactions. Both challenges have proven useful tools for experimental research. However, a need to improve meta-methodological knowledge and more rigour when implementing biopsychological laboratory paradigms has been expressed. The first part of the thesis thus introduces stress research with the Trier Social Stress Test (TSST). Research with the TSST, without a doubt, improved our current understanding of the stress system. However, there still remains a wide range of inconsistent results. This thesis contributes an overview on sources of intra- and interindividual variability of the response to psychological stress in form of a narrative review in chapter 3. The second part of chapter 2 elaborates on the association between energy load and the cortisol stress reaction. The aim of the empirical investigation was to further elucidate the association between glucose availability and the cortisol response to acute psychosocial stress. The NPU-threat test is investigated from a different perspective. Combined lab-field studies can be used to investigate the translation of laboratory measures to real-world emotional, cognitive or behavioural experiences. The NPU-threat test modulates predictability of threat of shock to elicit either fear- or anxiety-potentiation. In order to investigate the association between laboratory physiological markers for fear and anxiety with everyday anxious experiencing in healthy individuals, a lab-field study is presented in chapter 5. An ambulatory assessment proved to be sensitive to dispositional and context variation. However, there was no significant association between NPU-threat test measures and everyday worry and emotionality. It is concluded that due to underlying biological mechanisms, an effect might only be detectable in clinical populations with, for example, exaggerated anxiety- and fear-potentiated startle compared to healthy participants.   Reliable und valide standardisierte Laborparadigmen sind ein Schlüsselelement der modernen empirischen Forschung. Die biologische Psychologie ist ein interdisziplinäres Forschungsgebiet, das zwischen Grundlagenforschung und klinischen Disziplinen angesiedelt ist und über das Fachwissen verfügt, Laborparadigmen zu entwickeln und zu verbessern, mit denen biologische Marker im Zusammenhang mit kognitiven, emotionalen oder sozial anspruchsvollen Aufgaben bewertet werden können. Solche standardisierten Tests sind wesentlich für die Aufdeckung von Mechanismen, die zwischen Gesundheit und Krankheit vermitteln. Zwei weit verbreitete Beispiele sind der Trier Social Stress Test (TSST, Kirschbaum et al., 1993), der in erster Linie zur Induktion von psychosozialem Stress eingesetzt wird und zu einer zuverlässigen Aktivierung der HPA-Achse führt und der NPU-Threat-Test (Schmitz & Grillon, 2012), ein psychophysiologisches Paradigma zur Bewertung von Angst- und Furchtpotenzierung. Beide Tests haben sich als nützliche Instrumente für die experimentelle Forschung erwiesen. Es wurde jedoch der Bedarf erkannt, meta-methodologisches Wissen zu verbessern. Der erste Teil der Arbeit stellt die Stressforschung mit dem TSST vor, welche zweifelsohne unser derzeitiges Verständnis des Stresssystems verbessert hat. Dennoch gibt es nach wie vor eine große Bandbreite an widersprüchlichen Ergebnissen. Die vorliegende Arbeit gibt einen Überblick über die Quellen der intra- und interindividuellen Variabilität der Reaktion auf psychosozialen Stress in Form einer narrativen Reviews. Der zweite Teil befasst sich mit dem Zusammenhang zwischen der Glukoseverfügbarkeit und der Cortisol-Stressreaktion und umfasst eine empirische Untersuchung des Zusammenhangs in Bezug auf akuten psychosozialen Stress. Der NPU-Threat-Test wird aus einer anderen Perspektive untersucht. Kombinierte Labor-Feld-Studien können genutzt werden, um die Übertragbarkeit von Labormessungen auf reale emotionale, kognitive oder verhaltensbezogene Erfahrungen zu untersuchen. Der NPU-Threat-Test moduliert die Vorhersagbarkeit eines Schocks, um entweder Angst- oder Furchtpotenzierung auszulösen. Um den Zusammenhang zwischen physiologischen Labormarkern für Furcht und Angst und dem ängstlichen Erleben im Alltag bei gesunden Personen zu untersuchen, wird eine Labor-Feld-Studie vorgestellt. Eine ambulante Assessmentstudie erwies sich als sensitiv, um dispositionelle und kontextuelle Variationen zu erfassen. Es wurde jedoch kein signifikanter Zusammenhang zwischen NPU-Threat-Test und Alltagssorgen und Emotionalität festgestellt. Es wird geschlussfolgert, dass aufgrund der zugrunde liegenden biologischen Mechanismen ein Effekt nur in klinischen Populationen mit z. B. übertriebenem angst- und furchtpotenziertem Schreck im Vergleich zu gesunden Teilnehmern nachweisbar sein könnte

Effect of sugar administration on cortisol responses to acute psychosocial stress

Sugar administration prior acute psychosocial stress exposure was shown to enhance subsequent salivary cortisol responses. However, this finding is based on studies that have administered high doses of glucose to male subjects after long fasting periods. Therefore, in the present study, we investigated the effect of different sugar-containing drinks on acute cortisol stress responses under experimental conditions that are commonplace in stress research and our sample included females and males. Our primary aim was to derive feasible recommendations for a standardized sugar administration in future studies. Of the 103 healthy young participants (49 females, 54 males), 72 were confronted with the Trier Social Stress Test after being randomly assigned to one of three sugar conditions (200 ml of grape juice, a 75 g glucose or a 75 g maltodextrin drink); 31 subjects served as control sample and were exposed to the TSST without sugar administration. Cortisol stress responses were significantly enhanced in the grape juice as well as the glucose group as compared to the control group. Post hoc analysis revealed that this effect seemed to be more pronounced in males than in females. We did not find a significant effect of maltodextrin. Cortisol responder rates in all three experimental groups were higher than in the control group. Our results suggest that, at least in males, the administration of 200 ml of grape juice is sufficient to facilitate HPA axis reactivity and to minimize confounding effects due to interindividual differences in energy availability while being exposed to a laboratory stress paradigm. The unexpected gender-specific effect is of potential relevance and should be scrutinized in future studies

Establishing discipline-specific Data Stewardship at the Data Science Center of the University of Bremen – One Year Review

<p>Since summer 2022, Data Stewards have extended the DSC services and have complemented the RDM support landscape at the University of Bremen and the U Bremen Research Alliance. The Data Stewards are discipline-specific experts acting as an interface between researchers and RDM-infrastructures. They offer RDM-trainings and consultation. Their overarching goal is to reduce barriers associated with RDM for scientists and to promote a FAIR-data culture. </p><p>This poster looks back at the achievements of the last year and gives a preview of the road ahead.</p&gt

HPA axis responses to psychological challenge linking stress and disease: What do we know on sources of intra- and interindividual variability?

Stress is an ubiquitous phenomenon with significant impact on human physiology when it lasts too long, when it is too intense, or when it hits vulnerable individuals. Examining the mechanisms linking stress exposure with health and disease is an important endeavor in psychoneuroendocrine research. Empirical evidence so far revealed large intra- as well as inter-individual variability in hypothalamic-pituitary-adrenal (HPA) axis responses to acute psychosocial stress, showing that the HPA axis is a highly adaptive system. Thus, the characterization of intra- and inter-individual patterns of HPA axis reactivity is of high scientific interest and forms the basis on which mechanistic links between stress response (dys)regulation and health impairments can be examined. To date, basic knowledge has been, and still is, accumulated on demographic, biological (including genetic and epigenetic) factors, lifestyle behavioral variables, consumption of substances and medication, psychological and personality factors, as well as on methodological aspects. Besides this, there is also very recent progress in respect to the development of laboratory stress paradigms that can be applied in virtual reality or inside an MRIscanner. In sum, the present review updates our current knowledge on moderating and intervening factors as sources of intra- and inter-individual variability in human cortisol stress responses and offers recommendations for future research designs

Data Stewards at the Data Science Center of the University of Bremen: Establishing Domain-Specific Data Stewardship

Three Data Stewards complemented the Research Data Management (RDM) support infrastructure at the University of Bremen in summer 2022. They are located at the Data Science Center (DSC), an interdisciplinary institute founded in 2019 that acts as hub for dataintensive research. The DSC’s main task is to promote excellent research, education and interdisciplinary collaboration in the field of data science. For this purpose, the DSC provides researchers from all disciplines with a wide range of services, such as computing capacities, data literacy trainings, financial support as well as technical and methodological consultancy on the implementation of data science methods (e.g. machine learning). With the three Data Stewards, these services have been extended to include the RDM aspect. The DSC's Data Stewards are discipline-specific experts acting as an interface between researchers and RDM-infrastructure. They offer trainings and consultations along the research data lifecycle following the FAIR principles. Their overarching goal is to reduce the barriers associated with RDM for scientists and to promote a cultural shift towards a FAIRdata-culture. According to their professional backgrounds, they support the following research domains: (1) Social Sciences and Humanities, (2) Natural and Marine Sciences, and (3) Natural and Health Sciences. With their diverse backgrounds and experience, the Data Stewards form a well-balanced team which will be capable of addressing a wide range of RDM-related topics. During the start-up phase, the Data Stewards gained an overview about digital services useful for RDM at the University of Bremen, participated in workshops (e.g. a DIOSI train-the-trainer workshop on European level) and conferences. They presented their services to a wider audience at the DSC’s virtual “Data Science Forum” seminar series. In addition, the Data Stewards have reached out to University of Bremen scientists, research groups, institutes and data repositories to find out first-hand about specific needs but also to identify existing expertise and already established best practice workflows. The Data Stewards provide support for researchers during the preparation of Data Management Plans (DMPs) for funding applications as well as throughout the research process. A service that is likely to become even more prominent in the work of the Data Stewards in the near future. The first discipline-specific trainings offered by the Data Stewards include an Introduction to Research Data Management in Marine Sciences and How to Write Your DMP as a Social Scientist. Sensitised by replication crises in science, especially in the fields of psychology and marine ecology, the Data Stewards have a particular interest in all things open science, especially reproducibility of research results. To raise awareness to this issue and activate the scientific community, they also hosted a Reproducibility Hackathon (ReproHack). The Data Stewards also engage with local networks like the “Research Data Working Group”, which connects initiatives in the fields of RDM and Data Science and is organised under the umbrella of the U Bremen Research Alliance (UBRA) – a cooperation network of the University of Bremen and twelve state-financed non-university research institutes. At the same time, UBRA member institutions are involved in eight of 19 consortia of the first two funding rounds of the German National Research Data Infrastructure (Nationale Forschungsdateninfrastruktur, NFDI) and therefore provide valuable networking opportunities for the Data Stewards. Another important initiative is the “Data Stewardship Network”, where UBRA scientists interested in sustainable and collaborative RDM have the opportunity to exchange with colleagues on a regular basis. In addition, the Data Stewards work closely together with the central “Research Services” unit of the University of Bremen, which provides general support on DMPs, and the library with its expertise in open-access publishing and data archiving. Links with these already existing networks and support infrastructures will not only be important for joint activities and synergies at the operational level, but also to benefit from collegial advice across disciplines. The DSC’s Data Stewards are only at the beginning of their work. For the future, they plan to advance their activities in fields of data-lifecycle support, RDM policies, best practices, data repository selection, DMP writing, and data literacy training. In order to provide the best possible support to researchers in the aforementioned disciplines and beyond, they will continue to refine their RDM services in collaboration with existing RDM structures at the University of Bremen and UBRA. The aim is to increase the visibility of their services, activate researchers, as well as to pool and expand RDM resources. Three Data Stewards complemented the Research Data Management (RDM) support infrastructure at the University of Bremen in summer 2022. They are located at the Data Science Center (DSC), an interdisciplinary institute founded in 2019 that acts as hub for dataintensive research. The DSC’s main task is to promote excellent research, education and interdisciplinary collaboration in the field of data science. For this purpose, the DSC provides researchers from all disciplines with a wide range of services, such as computing capacities, data literacy trainings, financial support as well as technical and methodological consultancy on the implementation of data science methods (e.g. machine learning). With the three Data Stewards, these services have been extended to include the RDM aspect. The DSC's Data Stewards are discipline-specific experts acting as an interface between researchers and RDM-infrastructure. They offer trainings and consultations along the research data lifecycle following the FAIR principles. Their overarching goal is to reduce the barriers associated with RDM for scientists and to promote a cultural shift towards a FAIRdata-culture. According to their professional backgrounds, they support the following research domains: (1) Social Sciences and Humanities, (2) Natural and Marine Sciences, and (3) Natural and Health Sciences. With their diverse backgrounds and experience, the Data Stewards form a well-balanced team which will be capable of addressing a wide range of RDM-related topics. During the start-up phase, the Data Stewards gained an overview about digital services useful for RDM at the University of Bremen, participated in workshops (e.g. a DIOSI train-the-trainer workshop on European level) and conferences. They presented their services to a wider audience at the DSC’s virtual “Data Science Forum” seminar series. In addition, the Data Stewards have reached out to University of Bremen scientists, research groups, institutes and data repositories to find out first-hand about specific needs but also to identify existing expertise and already established best practice workflows. The Data Stewards provide support for researchers during the preparation of Data Management Plans (DMPs) for funding applications as well as throughout the research process. A service that is likely to become even more prominent in the work of the Data Stewards in the near future. The first discipline-specific trainings offered by the Data Stewards include an Introduction to Research Data Management in Marine Sciences and How to Write Your DMP as a Social Scientist. Sensitised by replication crises in science, especially in the fields of psychology and marine ecology, the Data Stewards have a particular interest in all things open science, especially reproducibility of research results. To raise awareness to this issue and activate the scientific community, they also hosted a Reproducibility Hackathon (ReproHack). The Data Stewards also engage with local networks like the “Research Data Working Group”, which connects initiatives in the fields of RDM and Data Science and is organised under the umbrella of the U Bremen Research Alliance (UBRA) – a cooperation network of the University of Bremen and twelve state-financed non-university research institutes. At the same time, UBRA member institutions are involved in eight of 19 consortia of the first two funding rounds of the German National Research Data Infrastructure (Nationale Forschungsdateninfrastruktur, NFDI) and therefore provide valuable networking opportunities for the Data Stewards. Another important initiative is the “Data Stewardship Network”, where UBRA scientists interested in sustainable and collaborative RDM have the opportunity to exchange with colleagues on a regular basis. In addition, the Data Stewards work closely together with the central “Research Services” unit of the University of Bremen, which provides general support on DMPs, and the library with its expertise in open-access publishing and data archiving. Links with these already existing networks and support infrastructures will not only be important for joint activities and synergies at the operational level, but also to benefit from collegial advice across disciplines. The DSC’s Data Stewards are only at the beginning of their work. For the future, they plan to advance their activities in fields of data-lifecycle support, RDM policies, best practices, data repository selection, DMP writing, and data literacy training. In order to provide the best possible support to researchers in the aforementioned disciplines and beyond, they will continue to refine their RDM services in collaboration with existing RDM structures at the University of Bremen and UBRA. The aim is to increase the visibility of their services, activate researchers, as well as to pool and expand RDM resources

Acute psychosocial stress and everyday moral decision-making in young healthy men: The impact of cortisol

In everyday life, moral decisions must frequently be made under acute stress. Although there is increasing evidence that both stress and cortisol affect moral judgment and behavior as well as decision-making in various domains unrelated to morality, surprisingly few attempts have been made to explore the effects of stress on everyday moral decision-making. Therefore, in the present study, we exposed 50 young healthy men to the Trier Social Stress Test (TSST) or its non-stressful placebo version (PTSST). We investigated the impact of acute stress exposure and stress-related cortisol levels on decision-making, decision certainty, and emotions in 28 everyday moral conflict situations with altruistic versus egoistic response alternatives. Results showed that the TSST-exposed group made more altruistic decisions than the non-stress control group, while groups did not differ in decision certainty and emotion ratings. Moreover, in correlational as well as regression analyses, additionally controlling for confounding variables, we observed significant positive associations between cortisol levels and altruistic decision making. Further analyses revealed that altruistic decisions came along with significantly higher decision certainty and significantly more positive emotion ratings than egoistic decisions. Notably, our data also raise the idea that the personality trait agreeableness plays an important role in everyday moral decision-making. In sum, our findings provide initial evidence that both acute stress exposure and cortisol levels have prosocial effects on everyday moral decision-making in young healthy men. (C) 2017 Elsevier Inc. All rights reserved

Sustained threat and phasic fear in the laboratory and cognitive-emotional processes of anxiety in everyday life - An ambulatory assessment study

Fear is a phasic state of apprehension to an imminent threat, whereas anxiety is a more sustained state of expecting a potential threat leading to tension and worry. The NPU-threat test is a laboratory startle paradigm allowing a reliable and valid assessment of both, fear-and anxiety-potentiated reactions. It is suggested to differentiate between anxiety disorders, but little is known on associations with everyday life experiences of cognitive-emotional processes regarding anxiety in non-clinical samples. In the present project, the NPU-threat test was applied in three studies with (1) unselected healthy individuals, (2) participants with extreme manifestations of trait anxiety (low vs. high) and (3) individuals preparing for a high-stakes exam. Self-reported states of emotionality and worry were assessed during a four-day ambulatory assessment (AA). Overall, NPU-threat test measures did not significantly differ between studies, while the AA dependent measures were sufficiently sensitive to capture differences between groups. However, there was no significant association between psychophysiological measures of the NPU-threat test and AA state measures across partic-ipants. In participants recruited for low vs. high trait anxiety we found an association with AA worry and emotionality, but no interaction with potentiated startle. The present findings do not support the idea of a link between our laboratory biomarker and adaptive regulation of cognitive-emotional states in everyday life in healthy individuals. We speculate that an association between laboratory physiological measures and everyday experience of anxious states may be detectable in clinical samples

Testing the ecological validity of the Trier Social Stress Test: Association with real-life exam stress

The Trier Social Stress Test (TSST) is the most widely used laboratory stress protocol in psychoneuroendocrinology. Despite its popularity, surprisingly few attempts have been made to explore the ecological validity of the TSST. In the present study, 31 young healthy subjects (24 females) were exposed to the TSST about 4 weeks before completing an oral exam on a separate day. Salivary cortisol levels increased significantly in response to both stimuli (TSST: F(2.21, 66.33) =5.73, p =0.004; oral exam: F(1.98, 59.28)=4.38, p =0.017) with similar mean response curves and significant correlations between cortisol increases and areas under the response curves (increase: r=0.67; AUC: r =0.56; both p <= 0.01). Correspondingly, changes in positive and negative affect did also show significant correlations between conditions (increase: positive affect: r =0.36; negative affect: r=0.50; both: p <= 0.05; AUC: positive affect: r =0.81; negative affect: r =0.70; both p <= 0.01) while mean time course dynamics were significantly different (positive affect: F(2.55, 76.60)=10.15, p =0.001; negative affect: F(1.56, 46.82) =23.32, p =0.001), indicating that the oral exam had a more pronounced impact on affect than the TSST. Our findings provide new evidence for the view that cortisol as well as subjective stress responses to the TSST are indeed significantly associated with acute stress responses in real life. (C) 2016 Elsevier Ltd. All rights reserved