drei fMRT-Studien

Die vorliegende publikationsbasierte Promotion untersucht die neurobiologischen Grundlagen motivationaler und emotionaler Verarbeitungsprozesse bei Patienten mit Panikstörung (PS) mit und ohne Agoraphobie. Es soll eine Aussage darüber getroffen werden, ob Patienten mit PS Dysfunktionen in der Belohnungsverarbeitung aufweisen, die im Zusammenhang mit bestimmten Temperamentsmerkmalen stehen. Zum anderen soll untersucht werden, ob sich ihre Aktivierungsmuster bei emotionalen visuellen Reizen von Gesunden und anderen Diagnosegruppen unterscheiden. Außerdem ist es Ziel, für Patienten mit PS charakteristische funktionelle Aktivierungsmuster bei der Ankündigung Angstspezifischer Reize zu identifizieren. Es wurden Patienten mit Panikstörung sowie Kontrollgruppen mittels funktioneller Magnetresonanztomographie (fMRT), während der Darbietung affektiver Bilder und während der Durchführung eines Belohnungsparadigmas (Monetary Incentive Delay Task) untersucht. Bei dem Belohnungsparadigma wird den Teilnehmern in Aussicht gestellt, dass sie im nächsten Moment Geld gewinnen oder verlieren können. Währenddessen kann die Aktivierung im ventralen Striatum (VS) untersucht werden, einer Region des mesolimbischen Systems, welches eine zentrale Rolle im Belohnungssystem spielt. Zusätzlich wurde der Einfluss von den Temperamentdimensionen Schadensvermeidung und Neugierde-Verhalten (Das Temperament- und Charakter-Inventar, TCI) geprüft. Bei dem Experiment zur Emotionsinduktion wurden den Teilnehmern im Scanner positive und aversive Bilder dargeboten. Um Einblicke in die für Panikstörung mit und ohne Agoraphobie spezifische funktionelle Neuroanatomie zu gewinnen, wurde ein Experiment (Westphal-Paradigma) mit Agoraphobie-spezifischen Bildszenen durchgeführt, welche entweder angekündigt oder unangekündigt dargeboten wurden. Die Ergebnisse zeigen, dass Patienten mit PS, während der Erwartung eines Gewinns im Vergleich zu Gesunden eine verminderte Aktivität im ventralen VS aufweisen, während sie bei der Erwartung eines Verlusts stärkere Aktivierungen als die gesunden Kontrollprobanden zeigen. Dabei hatte auch eine spezifische Temperamentkomponente einen Einfluss: Patienten mit PS, die hohe Punktwerte in Schadensvermeidung aufweisen, hatten stärkere Aktivierungen im VS bei Verlust-Antizipation und niedrigere Aktivierungen bei Gewinn-Antizipation. Patienten mit PS unterschieden sich in ihrer Emotionsverarbeitung bei positiven oder aversiven Bildern nicht signifikant von gesunden Kontrollen oder Patienten mit anderen psychiatrischen Erkrankungen. Für die Angstbezogenen Bildinhalte zeigten sich Aktivierungen in rechter Insula, Precuneus (bilateral) und parahippocampalen Kortex. Die Aktivierung unterschied sich dabei in Abhängigkeit, ob eine agoraphobische Bildszene vorher angekündigt wurde oder nicht. Angekündigte Angst- Bilder evozierten eine verstärkte Amygdala-Aktivierung. Darüber hinaus zeigte sich während 3 der Antizipation eines folgenden Angstbildes eine signifikante Aktivierung in Insula und Amygdala. Diese Ergebnisse legen nahe, dass Diagnosebezogene neuronale Dysfunktionen bei Patienten mit Panikstörungen die Antizipationsverarbeitung betreffen. Eine mögliche Implikation für die psychotherapeutische Behandlung könnte eine stärkere Fokussierung auf die Erwartungsprozesse der Patienten sein.This dissertation investigates neurobiological correlates of motivational and emotional processing in patients with panic disorder (PD) with and without agoraphobia. A statement is to be made about potential dysfunctions in the reward system of patients with PD and related temperament characteristics. Besides we examined, whether their activation patterns in response to emotional visual stimuli differ from those of healthy controls and other diagnostic groups. Another aim is to identify characteristic functional activation patterns for PD-patients, while expecting anxiety-specific stimuli. Patients with PD and controls were examined with functional magnetic resonance imaging, during the presentation of affective images and during the performance of a reward paradigm (Monetary Incentive Delay Task). In the reward paradigm, participants were announced to win or lose money in the next moment, while activation in the ventral striatum, a region of the mesolimbic system that plays an important role in the reward system can be assessed. In addition, the influence of harm avoidance and novelty seeking (The Temperament and Character Inventory (TCI)) was examined. In the experiment on emotional processing, the participants saw affectively positive and aversive images. In order to gain insights into the functional neuroanatomy specific for PD with agoraphobia, an experiment (Westphal paradigm) was performed, with agoraphobia-specific images, which were either announced before or not. The results show that patients with PD show decreased activity in the ventral striatum (VS) during the expectation of gain compared to healthy individuals, while patients with panic disorder show stronger activations than healthy control subjects during the expectation of loss. A specific temperament component also had an influence: Patients with PD scoring high at harm avoidance had stronger activations in the VS, while loss anticipation and lower activations while gain anticipation. Patients with PD did not differ significantly in their emotion processing from healthy controls or patients with other psychiatric diseases. A specific activation pattern was found for the agoraphobia-related images. The activation differed depending on whether an agoraphobic image scene was previously announced or not. While uncued images caused a stronger BOLD response in the right precuneus, an increased amygdala activation could be observed when an anxiety image was previously announced. In addition, a significant amygdala and Insula activation was already observed during the anticipation of a subsequent anxiety image. These results suggest that neuronal dysfunctions affects anticipation processing in patients with PD. A possible implication for psychotherapeutic treatment could be a stronger focus on patients' expectation processes

Affective responses across psychiatric disorders: A dimensional approach

Studying psychiatric disorders across nosological boundaries aims at a better understanding of mental disorders by identifying comprehensive signatures of core symptoms. Here, we studied neurobiological correlates of emotion processing in several major psychiatric disorders. We assessed differences between diagnostic groups, and investigated whether there is a psychopathological correlate of emotion processing that transcends disorder categories. 135 patient with psychiatric disorders (alcohol dependence, n = 29; schizophrenia, n = 37; major depressive disorder (MDD), n = 25; acute manic episode of bipolar disorder, n = 12; panic disorder, n = 12, attention deficit/hyperactivity disorder (ADHD), n = 20) and healthy controls (n = 40) underwent an functional magnetic resonance imaging (fMRI) experiment with affectively positive, aversive and neutral pictures from the International Affective Picture System (IAPS). Between-group differences were assessed with full-factorial ANOVAs, with age, gender and smoking habits as covariates. Self-ratings of depressed mood and anxiety were correlated with activation clusters showing significant stimulus-evoked fMRI activation. Furthermore, we examined functional connectivity with the amygdala as seed region during the processing of aversive pictures. During the presentation of pleasant stimuli, we observed across all subjects significant activation of the ventromedial prefrontal cortex (vmPFC), bilateral middle temporal gyrus and right precuneus, while a significant activation of the left amygdala and the bilateral middle temporal gyrus was found during the presentation of aversive stimuli. We did neither find any significant interaction with diagnostic group, nor any correlation with depression and anxiety scores at the activated clusters or with amygdala connectivity. Positive and aversive IAPS-stimuli were consistently processed in limbic and prefrontal brain areas, irrespective of diagnostic category. A dimensional correlate of these neural activation patterns was not found

The Sydney Dance Music Scene and the Global Diffusion of Contemporary Club Culture

The development of contemporary, post-disco dance music and its associated culture, as representative of a (supposedly) underground, radical subculture, has been given extensive consideration within popular music studies. Significantly less attention has been given to the commercial, mainstream manifestations of this music. Furthermore, demonstrating the influence of subculture theory, existing studies of dance culture focus largely on youth-based audience participation, and as such, those who engage with dance music on a professional level have been somewhat overlooked. In an attempt to rectify these imbalances, this paper examines the contemporary commercial dance music scene in Sydney, Australia, incorporating an analytical framework that revolves mainly around the work of DJs and the commercial scene they operate within. Given the increasingly global and corporate nature of the dance music scene, there is a sense that the music and culture are becoming less ‘local’ and more ‘international’, with this global movement affecting the identity and development of local scenes, the understandings and practices of those who are involved with these scenes, and the very definition of a ‘scene’ itself. The ideas, opinions and interpretations of a selection of local DJs and other music industry practitioners who work in Sydney are central to the paper’s analysis of DJ culture within the city. It is my intention to place the local scene in Sydney into some sort of wider cultural and global context, but at the same time to highlight what aspects of the scene give it a unique local identity. Being a scene that relies quite heavily on overseas dance culture, and indeed places a certain emphasis on the cultural value of overseas music and international DJs, it can be somewhat difficult for local DJs and producers to establish themselves, and thus a certain tension exists between the local and the global