TY - THES A1 - Dresler, Thomas T1 - Die neuronale Verarbeitung emotionaler Reize bei Patienten mit Panikstörung – eine Betrachtung der neuroanatomischen Hypothese T1 - The neural processing of emotional stimuli in panic disorder – a reflection of the neuroanatomical hypothesis N2 - Hintergrund: Die Panikstörung ist eine die Lebensqualität beeinträchtigende psychische Störung, die unbehandelt einen chronischen Verlauf zeigt, jedoch sowohl durch Psychotherapie als auch Psychopharmakotherapie erfolgreich behandelt werden kann. Die der Panikstörung zugrundeliegenden neuronalen Schaltkreise werden in der von Gorman et al. (1989, 2000) veröffentlichten neuroanatomischen Hypothese beschrieben. In der stark an der Tierforschung angelehnten revidierten Version (2000) wird die Amygdala als Zentrum eines komplexen Furchtnetzwerks angesehen, deren Aktivität durch höhere kortikale Areale im präfrontalen Kortex moduliert wird. Trotz der Popularität der Hypothese sind deren Annahmen bislang kaum explizit überprüft worden. Ziel: Ziel der Untersuchung war es, die neuronale Verarbeitung emotionaler Reize in empirischen Experimenten genauer zu untersuchen, da die Datenlage in diesem Bereich noch gering und inkonsistent ist und Replikationsstudien fehlen. Außerdem sollte ein Überblick über die bereits veröffentlichten empirischen Studien gegeben werden, welche mit bildgebenden Verfahren Aussagen über die Beteiligung bestimmter neuronaler Strukturen bei der Panikstörung erlauben. Methoden: An den Standorten Würzburg und Hamburg wurden Patienten mit Panikstörung (n = 18/20) und gesunde Kontrollen (n = 27/23) mit zwei Paradigmen zur Verarbeitung emotionaler Reize (emotionaler Stroop-Test und Gesichterverarbeitung) mit der funktionellen Magnetresonanztomographie untersucht. Hierbei sollten insbesondere die in der neuroanatomischen Hypothese wichtigen Strukturen Amygdala und präfrontaler Kortex betrachtet werden. Bildgebende Studien, die Patienten mit Panikstörung untersuchten, wurden über eine Literaturrecherche ermittelt, in Untergruppen von Studien eingeteilt und bewertet. Ergebnisse: In beiden untersuchten Stichproben zeigten die Patienten im Vergleich zu den Kontrollen auf Reaktionszeitebene einen signifikanten emotionalen Stroop-Effekt mit verlängerten Antwortlatenzen für panikrelevante Wörter. In den funktionellen Daten zeigten sich keine Unterschiede in der Amygdalaaktivierung, jedoch zeigten die Patienten für den Kontrast ‚panikrelevante vs. neutrale Wörter‘ im Gruppenvergleich eine erhöhte Aktivierung in präfrontalen Arealen. Bei der Verarbeitung emotionaler Gesichter gab es kaum Unterschiede zwischen den Gruppen, ängstliche Gesichter lösten im Vergleich zu neutralen Gesichtern keine erhöhte Amygdalaaktivierung aus. Hinweise auf eine generelle Hypofrontalität ließen sich bei den Patienten – zumindest bei der Verarbeitung emotionaler Reize – in den angewandten Paradigmen nicht finden. Schlussfolgerung: Die Ergebnisse der experimentellen Untersuchung und des Literaturüberblicks zeigen, dass – trotz durchaus mit der neuroanatomischen Hypothese in Einklang stehender Befunde – Inkonsistenzen zu finden sind, die mit der aktuellen Hypothese nicht erklärt werden können. Die Ergebnisse der vorliegenden Untersuchung im emotionalen Stroop-Test konnten bisher gefundene präfrontale Aktivierungsmuster replizieren, für die Amygdala gilt das nicht. Eine Erweiterung der Hypothese durch die Berücksichtigung neuer Aspekte könnte helfen, diese Befunde besser zu erklären und zu einem umfassenderen Bild der neuronalen Grundlagen der Störung beitragen. Modifikationen werden vorgeschlagen, die der Weiterentwicklung der Hypothese dienen könnten und bei der Planung zukünftiger Studien berücksichtigt werden sollten. Die vermutete prominente Rolle der Amygdala bei der Panikstörung ist nach wie vor nicht hinreichend untersucht und der modulierende Einfluss präfrontaler Strukturen sollte zukünftig insbesondere im direkten Zusammenspiel mit der Amygdala, z. B. im Rahmen psychotherapeutischer Interventionen, genauer analysiert werden. N2 - Background: Panic disorder is a life quality impairing disorder that has a chronic course when being untreated, though it can be treated successfully by psychotherapy as well as psychopharmacological therapy. The underlying neural circuits of panic disorder are described in the neuroanatomical hypothesis as published by Gorman et al. (1989, 2000). In its revised version (2000), mainly derived from animal research, the amygdala is assumed to be the centre of a complex fear network that is modulated by higher cortical structures in the prefrontal cortex. Despite the popularity of the hypothesis, its assumptions have rarely been investigated explicitly. Objective: The present study aimed at investigating the processing of emotional stimuli in patients with panic disorder in empirical experiments, since the available data are scarce and inconsistent and replication studies are missing. Moreover, empirical studies published so far that give some indication of the specific structures involved in panic disorder were reviewed. Methods: In the two centres Würzburg and Hamburg, patients with panic disorder (n = 18/20) and healthy controls (n = 27/23) underwent two emotion-processing paradigms (emotional Stroop test, face processing) using functional magnetic resonance imaging. Especially the structures important for the neuroanatomical hypothesis, amygdala and prefrontal cortex, were focussed. Imaging studies investigating panic disorder were identified using literature search, classified into subgroups and evaluated. Results: In both samples, patients with panic disorder displayed a significant emotional Stroop effect in reaction time data with prolonged response latencies for panic-related words. The functional data did not indicate any apparent differences in amygdala activation. However, for the contrast ‘panic-related vs. neutral words’, panic disorder patients displayed increased relative activation in prefrontal cortical areas. Processing of emotional faces did hardly yield any differences; fearful faces did not elicit increased amygdala activation as compared with neutral faces. There was no evidence – at least in emotion stimuli processing – for the assumed general hypofrontality in panic disorder patients in the used paradigms. Conclusion: The results of the experimental investigation and the literature review show that – in spite of findings consistent with the neuroanatomical hypothesis – inconsistencies emerged that cannot be explained by the current neuroanatomical hypothesis. The results in the emotional Stroop test could replicate earlier findings of prefrontal activation, but not for the amygdala. An extension of the hypothesis considering new aspects may help to better explain the findings and add to a comprehensive picture of the disorder’s neural underpinnings. Modifications are proposed that may serve further developments of the hypothesis and should be considered in the planning of future studies. The assumed prominent role of the amygdala is still not investigated sufficiently and the modulating influence of prefrontal cortical structures, particularly in interplay with the amygdala, should be investigated in more detail, e. g., within the context of psychotherapeutic interventions. KW - Paniksyndrom KW - Funktionelle NMR-Tomographie KW - Informationsverarbeitung KW - Panikstörung KW - funktionelle Magnetresonanztomographie KW - Klinische Psychologie KW - Emotionaler Stroop-Test KW - Emotionale Verarbeitung KW - Hirnforschung KW - panic disorder KW - functional magnetic resonance imaging KW - clinical psychology KW - emotional Stroop test KW - emotional processing Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-64932 ER - TY - JOUR A1 - Biehl, Stefanie C. A1 - Dresler, Thomas A1 - Reif, Andreas A1 - Scheuerpflug, Peter A1 - Deckert, Jürgen A1 - Herrmann, Martin J. T1 - Dopamine Transporter (DAT1) and Dopamine Receptor D4 (DRD4) Genotypes Differentially Impact on Electrophysiological Correlates of Error Processing JF - PLoS One N2 - Recent studies as well as theoretical models of error processing assign fundamental importance to the brain's dopaminergic system. Research about how the electrophysiological correlates of error processing—the error-related negativity (ERN) and the error positivity (Pe)—are influenced by variations of common dopaminergic genes, however, is still relatively scarce. In the present study, we therefore investigated whether polymorphisms in the DAT1 gene and in the DRD4 gene, respectively, lead to interindividual differences in these error processing correlates. One hundred sixty participants completed a version of the Eriksen Flanker Task while a 26-channel EEG was recorded. The task was slightly modified in order to increase error rates. During data analysis, participants were split into two groups depending on their DAT1 and their DRD4 genotypes, respectively. ERN and Pe amplitudes after correct responses and after errors as well as difference amplitudes between errors and correct responses were analyzed. We found a differential effect of DAT1 genotype on the Pe difference amplitude but not on the ERN difference amplitude, while the reverse was true for DRD4 genotype. These findings are in line with predictions from theoretical models of dopaminergic transmission in the brain. They furthermore tie results from clinical investigations of disorders impacting on the dopamine system to genetic variations known to be at-risk genotypes. KW - haplotypes KW - electroencephalography KW - basal ganglia KW - reaction time KW - dopaminergics KW - dopamine KW - ADHD KW - research errors Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137930 VL - 6 IS - 12 ER - TY - JOUR A1 - Hahn, Tim A1 - Dresler, Thomas A1 - Pyka, Martin A1 - Notebaert, Karolien A1 - Fallgatter, Andreas J. T1 - Local Synchronization of Resting-State Dynamics Encodes Gray's Trait Anxiety JF - PLoS ONE N2 - The Behavioral Inhibition System (BIS) as defined within the Reinforcement Sensitivity Theory (RST) modulates reactions to stimuli indicating aversive events. Gray's trait Anxiety determines the extent to which stimuli activate the BIS. While studies have identified the amygdala-septo-hippocampal circuit as the key-neural substrate of this system in recent years and measures of resting-state dynamics such as randomness and local synchronization of spontaneous BOLD fluctuations have recently been linked to personality traits, the relation between resting-state dynamics and the BIS remains unexplored. In the present study, we thus examined the local synchronization of spontaneous fMRI BOLD fluctuations as measured by Regional Homogeneity (ReHo) in the hippocampus and the amygdala in twenty-seven healthy subjects. Correlation analyses showed that Gray's trait Anxiety was significantly associated with mean ReHo in both the amygdala and the hippocampus. Specifically, Gray's trait Anxiety explained 23% and 17% of resting-state ReHo variance in the left amygdala and the left hippocampus, respectively. In summary, we found individual differences in Gray's trait Anxiety to be associated with ReHo in areas previously associated with BIS functioning. Specifically, higher ReHo in resting-state neural dynamics corresponded to lower sensitivity to punishment scores both in the amygdala and the hippocampus. These findings corroborate and extend recent findings relating resting-state dynamics and personality while providing first evidence linking properties of resting-state fluctuations to Gray's BIS. KW - reward KW - bold activity KW - amygdala KW - brain KW - personality KW - sensitivity KW - punishment KW - dimensions KW - modulation KW - predict Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131057 VL - 8 IS - 3 ER - TY - JOUR A1 - Kopf, Juliane A1 - Dresler, Thomas A1 - Reicherts, Philipp A1 - Herrmann, Martin J. A1 - Reif, Andreas T1 - The Effect of Emotional Content on Brain Activation and the Late Positive Potential in a Word n-back Task JF - PLoS ONE N2 - Introduction There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task. Methods We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects. Results Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed. Conclusions Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content. KW - analysis of variance KW - electrode recording KW - electroencephalography KW - emotions KW - eyes KW - near-infrared spectroscopy KW - reaction time KW - working memory Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96687 ER - TY - JOUR A1 - Hahn, Tim A1 - Karolien, Hilde A1 - Dresler, Thomas A1 - Kowarsch, Linda A1 - Reif, Andreas A1 - Fallgatter, Andreas J. T1 - Linking online gaming and addictive behavior: converging evidence for a general reward deficiency in frequent online garners JF - Frontiers in Behavioral Neuroscience N2 - Millions of people regularly play so-called massively multiplayer online role playing games (MMORPGs). Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal, and craving have been described. Based on behavioral, resting state, and task-related neuroimaging data, we test whether frequent players of the MMORPG "World of VVarcraft" (WoW) similar to drug addicts and individuals with an increased risk for addictions show a generally deficient reward system. In frequent players of the MMORPG "World of VVarcraft" (WoW-players) and in a control group of non-gamers we assessed (1) trait sensitivity to reward (SR), (2) BOLD responses during monetary reward processing in the ventral striatum, and (3) ventral-striatal resting-state dynamics. We found a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state). On the behavioral level, we found differences in trait SR, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers. KW - behavioral activation system KW - video-game KW - drug-addiction KW - sensitivity KW - dopamine KW - anticipation KW - massively multiplayer online role playing games KW - world of warcraft KW - resting-state fMRI KW - monetary incentive delay task KW - reward deficiency syndrome Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114737 SN - 1662-5153 VL - 14 IS - 8 ER - TY - JOUR A1 - Guhn, Anne A1 - Dresler, Thomas A1 - Andreatta, Marta A1 - Müller, Laura D. A1 - Hahn, Tim A1 - Tupak, Sara V. A1 - Polak, Thomas A1 - Deckert, Jürgen A1 - Herrmann, Martin J. T1 - Medial prefrontal cortex stimulation modulates the processing of conditioned fear N2 - The extinction of conditioned fear depends on an efficient interplay between the amygdala and the medial prefrontal cortex (mPFC). In rats, high-frequency electrical mPFC stimulation has been shown to improve extinction by means of a reduction of amygdala activity. However, so far it is unclear whether stimulation of homologues regions in humans might have similar beneficial effects. Healthy volunteers received one session of either active or sham repetitive transcranial magnetic stimulation (rTMS) covering the mPFC while undergoing a 2-day fear conditioning and extinction paradigm. Repetitive TMS was applied offline after fear acquisition in which one of two faces (CS+ but not CS−) was associated with an aversive scream (UCS). Immediate extinction learning (day 1) and extinction recall (day 2) were conducted without UCS delivery. Conditioned responses (CR) were assessed in a multimodal approach using fear-potentiated startle (FPS), skin conductance responses (SCR), functional near-infrared spectroscopy (fNIRS), and self-report scales. Consistent with the hypothesis of a modulated processing of conditioned fear after high-frequency rTMS, the active group showed a reduced CS+/CS− discrimination during extinction learning as evident in FPS as well as in SCR and arousal ratings. FPS responses to CS+ further showed a linear decrement throughout both extinction sessions. This study describes the first experimental approach of influencing conditioned fear by using rTMS and can thus be a basis for future studies investigating a complementation of mPFC stimulation to cognitive behavioral therapy (CBT). KW - fear conditioning KW - memory consolidation and extinction KW - learning KW - transcranial magnetic stimulation (TMS) KW - medial prefrontal cortex (mPFC) Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111309 ER - TY - JOUR A1 - Biehl, Stefanie C. A1 - Merz, Christian J. A1 - Dresler, Thomas A1 - Heupel, Julia A1 - Reichert, Susanne A1 - Jacob, Christian P. A1 - Deckert, Jürgen A1 - Herrmann, Martin J. T1 - Increase or Decrease of fMRI Activity in Adult Attention Deficit/ Hyperactivity Disorder: Does It Depend on Task Difficulty? JF - International Journal of Neuropsychopharmacology N2 - Background: Attention deficit/hyperactivity disorder has been shown to affect working memory, and fMRI studies in children and adolescents with attention deficit/hyperactivity disorder report hypoactivation in task-related attentional networks. However, studies with adult attention deficit/hyperactivity disorder patients addressing this issue as well as the effects of clinically valid methylphenidate treatment are scarce. This study contributes to closing this gap. Methods: Thirty-five adult patients were randomized to 6 weeks of double-blind placebo or methylphenidate treatment. Patients completed an fMRI n-back working memory task both before and after the assigned treatment, and matched healthy controls were tested and compared to the untreated patients. Results: There were no whole-brain differences between any of the groups. However, when specified regions of interest were investigated, the patient group showed enhanced BOLD responses in dorsal and ventral areas before treatment. This increase was correlated with performance across all participants and with attention deficit/hyperactivity disorder symptoms in the patient group. Furthermore, we found an effect of treatment in the right superior frontal gyrus, with methylphenidate-treated patients exhibiting increased activation, which was absent in the placebo-treated patients. Conclusions: Our results indicate distinct activation differences between untreated adult attention deficit/hyperactivity disorder patients and matched healthy controls during a working memory task. These differences might reflect compensatory efforts by the patients, who are performing at the same level as the healthy controls. We furthermore found a positive effect of methylphenidate on the activation of a frontal region of interest. These observations contribute to a more thorough understanding of adult attention deficit/hyperactivity disorder and provide impulses for the evaluation of therapy-related changes. KW - working memory KW - clinical trial KW - child memory KW - short-term methylphenidate brain KW - methylphenidate KW - adult attention deficit/hyperactivity disorder KW - fMRI KW - functional magnetic resonance imaging Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147551 VL - 19 IS - 10 ER - TY - JOUR A1 - Kopf, Juliane A1 - Glöckner, Stefan A1 - Althen, Heike A1 - Cevada, Thais A1 - Schecklmann, Martin A1 - Dresler, Thomas A1 - Kittel-Schneider, Sarah A1 - Reif, Andreas T1 - Neural responses to a working memory task in acute depressed and remitted phases in bipolar patients JF - Brain Sciences N2 - (1) Cognitive impairments such as working memory (WM) deficits are amongst the most common dysfunctions characterizing bipolar disorder (BD) patients, severely contributing to functional impairment. We aimed to investigate WM performance and associated brain activation during the acute phase of BD and to observe changes in the same patients during remission. (2) Frontal brain activation was recorded using functional near-infrared spectroscopy (fNIRS) during n-back task conditions (one-back, two-back and three-back) in BD patients in their acute depressive (n = 32) and remitted (n = 15) phases as well as in healthy controls (n = 30). (3) Comparison of BD patients during their acute phase with controls showed a trend (p = 0.08) towards lower dorsolateral prefrontal cortex (dlPFC) activation. In the remitted phase, BD patients showed lower dlPFC and ventrolateral prefrontal cortex (vlPFC) activation (p = 0.02) compared to controls. No difference in dlPFC and vlPFC activation between BD patients’ phases was found. (4) Our results showed decreased working memory performance in BD patients during the working memory task in the acute phase of disease. Working memory performance improved in the remitted phase of the disease but was still particularly attenuated for the more demanding conditions. KW - verbal n-back KW - fNIRS KW - prefrontal cortex KW - cognitive deficits KW - bipolar disorder KW - remitted/acute phase Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313509 SN - 2076-3425 VL - 13 IS - 5 ER -