Short-term laboratory stressors such as the Trier Social Stress Test (TSST) are used to investigate the acute stress response under experimentally controlled conditions. Studies typically report that approx. 20 – 30 % of participants do not show a substantial physiological stress response as measured by cortisol. Intriguingly, a lack of response does not appear to be simply coupled with a lack of subjective stress appraisal. Although exploring the influence of factors such as age, gender, and personality traits has provided some insight into variation of response, stress response variability, to date, cannot yet be successfully explained. This project aims to explore whether neural substrates, as measured by EEG, MRI, and fMRI can improve predictor models of the acute stress response in healthy individuals. The current investigation examines whether task-independent neural markers in neural networks associated with socio-emotional processing and regulation are indicative of the physiological response to stress. This work will be extended in the future to incorporate neural reactivity to tasks known to be associated with the stress networks, such as threat sensitivity and emotional regulation, in order to provide a more comprehensive evaluation of the neural signatures of responses to acute psychosocial stressors.
Duration: 12/23 - 12/25
Contact: Lisa Haase & Gregor Domes
in collaboration with Prof. med. Winfried Willinek (BKT)
Triple X syndrome (47,XXX) occurs with a frequency of 1:800 to 1:1000 in girls, although it is possible that the syndrome is not diagnosed due to the often inconspicuous symptomatology. Although there are some anecdotal reports of abnormalities in social interaction (e.g., in the regulation of closeness and distance and the decoding of social signals), and affected individuals and their relatives report problems in everyday social life, no systematic studies regarding socio-cognitive and socio-affective characteristics are available to date. Therefore, the present study aims at the cognitive, affective and behavioral characterization of women with 47,XXX in the context of social interactions. Another goal is to explore neural structural correlates of the presumed socio-cognitive features using functional and structural MRI. In addition to morphometric investigations, the focus will also be on investigations of structural connectivity.
We employ EEG to delve into the Binding and Retrieval in Action Control framework (BRAC, Frings et al., 2020). BRAC posits that (1) episodic feature binding and retrieval are key aspects of human action control, (2) binding and retrieval are distinct processes, and (3) both are influenced independently by top-down and bottom-up factors. This project pursues two strategies. Firstly, we aim to further clarify binding and retrieval by examining their electrophysiological (EEG) correlates during stimulus-response (S-R) binding. Secondly, we extend BRAC's applicability by applying the binding versus retrieval concept to a different experimental paradigm, specifically the visual search literature. We investigate intertrial priming effects in visual search to provide evidence for the separation of binding and retrieval in this context, broadening the explanatory scope of the BRAC framework.
We employ electroencephalography (EEG) to investigate Gilles de la Tourette syndrome (GTS) from a Theory of Event Coding (TEC) perspective. Our research confirms that GTS is characterized by altered binding of sensory and motor codes in dominant sensorimotor routines, highlighting the significance of altered perception-action processing in GTS. This project links GTS's hyperbinding to the Binding and Retrieval in Action Control (BRAC) framework, extending beyond TEC by emphasizing the separation of feature binding and retrieval. We aim to ascertain whether hyperbinding in GTS results from aberrant event-file integration (binding) or event-file retrieval, or both. Given the potential heightened deviant processes with tactile stimuli in GTS, we compare binding and retrieval in vision and touch. This approach enhances our comprehension of GTS-control differences in cognitive processes related to binding effects, offering insights for targeted interventions.
Shared Underlying Mechanisms of Long-COvid and Chronic Fatigue Syndrome – A psychoneuroendocrinological and psychoimmunological perspective (SUMCO) – funded by the Institute for Advanced Studies, University of Luxembourg. At least 10 % of patients recovering from Covid-19 develop persistent health consequences such as fatigue, myalgia, or post-exertional malaise. “Long-Covid” is one of the many terms used to describe the occurrence of respiratory, cardiovascular, neurological, and/or gastrointestinal symptoms weeks after the initial infection is resolved. Although some symptoms seem to be unique to Long-Covid (e.g., olfactory & gustatory dysfunction), there is a large symptom overlap with the condition of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). ME/CFS is a complex, multisystem condition affecting 0.89 % of the global population. Different factors have been hypothesized to be involved in the aetiology of ME/CFS, including immune system dysregulation, metabolic alteration, autonomic nervous system (ANS) and limbic system dysfunction, as well as abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis. One popular hypothesis postulates that ME/CFS is a post-infectious fatigue syndrome, as up to 50 % of ME/CFS cases develop after a viral infection (e.g., infection with Epstein-Barr Virus/EBV). This observation raises the question if Long-Covid and ME/CFS share similarities in underlying pathophysiology, as both conditions seem to occur after viral infections (SARS-CoV-2 & EBV), which trigger dysregulations in the immune system, the ANS, or the HPA axis. A proper characterization of Long-Covid and ME/CFS by a thorough, interdisciplinary psychological and physiological assessment may help to make a differential diagnostic distinction of the two patient groups. The aims of the current project are: (1) To reveal similarities and differences in the pathophysiology of Long-Covid and ME/CFS, as an in-depth understanding of the underlying psychobiology is essential to design adequate prevention in terms of early detection of pathological biomarkers and treatment interventions for Long-Covid syndromes and ME/CFS in terms of a graded exercise therapy. We specifically focus on potential alterations in the immune system, the ANS, and the HPA axis. (2) We aim to elucidate how these processes translate into severity of fatigue, as the relationship between these alterations and actual symptom distress remains yet unclear. Ultimately, as biological and psychological markers of Long-Covid and ME/CFS can help to monitor the course of symptoms and the potential responsiveness to treatment intervention, we aim (3) at investigating the effectiveness of a graded exercise therapy on symptom severity and potential improvement in alterations of the immune system, the ANS and the HPA axis.
Duration: 04/22 - 03/23
Funding: Institute for Advanced Studies of the University of Luxembourg
Contact: André Schulz, Nina Buntic, Jochen Schneider, Marc Schlesser
Associative memory refers to our ability to memorize and retrieve connections between different pieces of information, such as the connection between a name and a face. As people grow older, their associative memory declines more strongly than other forms of memory. The present project studies the perceptual, cognitive and neural mechanisms underlying this age-related change in memory processes. As a part of this larger research program, in a currently running DFG-funded project, we study the role of the complexity of individual information units in the difficulty of older adults with memorizing and retrieving associations.
Funding: German Research Foundation (DFG)
Patients in neurorehabilitation, such as those who have suffered from a stroke, frequently show difficulties with cognitive processes including episodic memory. This project aims to make use of the ample recent knowledge advances in the general psychology of memory in healthy humans, in order to more closely understand memory dysfunction in neurological patients, to evaluate and improve diagnostic instruments to detect memory dysfunction, and to develop strategies to alleviate the impact of memory dysfunction on the patients’ daily lives.
Contact: Siri-Maria Kamp