This thesis gives an overview on how to estimate changes in functional brain networks using graph theoretical measures. It explains the assessment and definition of functional brain networks derived from fMRI data. More explicitly, this thesis provides examples and newly developed methods on the measurement and visualization of changes due to pathology, external electrical stimulation or ongoing internal thought processes. These changes can occur on long as well as on short time scales and might be a key to understanding brain pathologies and their development. Furthermore, this thesis describes new methods to investigate and visualize these changes on both time scales and provides a more complete picture of the brain as a dynamic and constantly changing network.:1 Introduction 1.1 General Introduction 1.2 Functional Magnetic Resonance Imaging 1.3 Resting-state fMRI 1.4 Brain Networks and Graph Theory 1.5 White-Matter Lesions and Small Vessel Disease 1.6 Transcranial Direct Current Stimulation 1.7 Dynamic Functional Connectivity 2 Publications 2.1 Resting developments: a review of fMRI post-processing methodologies for spontaneous brain activity 2.2 Early small vessel disease affects fronto-parietal and cerebellar hubs in close correlation with clinical symptoms - A resting-state fMRI study 2.3 Dynamic modulation of intrinsic functional connectivity by transcranial direct current stimulation 2.4 Three-dimensional mean-shift edge bundling for the visualization of functional connectivity in the brain 2.5 Dynamic network participation of functional connectivity hubs assessed by resting-state fMRI 3 Summary 4 Bibliography 5. Appendix 5.1 Erklärung über die eigenständige Abfassung der Arbeit 5.2 Curriculum vitae 5.3 Publications 5.4 Acknowledgements

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In vorliegender Studie wurden 48 gesunde ProbandInnen dazu aufgefordert, kurz dargebotenen Gesichtsausdrücken eine emotionale Qualität (freudig, wütend, ängstlich, neutral) zuzuordnen. Die Detektionsleistungen wurden auf mögliche Zusammenhänge mit der selbstbeurteilten Verträglichkeit der ProbandInnen untersucht. Mittels funktioneller Magnetresonanztomographie wurde die neuronale Verarbeitung der präsentierten Gesichtsausdrücke als eine Funktion von Verträglichkeit und als Funktion des Detektionsvermögens der Emotionen erfasst. Die Ausprägung des Persönlichkeitsmerkmals Verträglichkeit wurde durch die ProbandInnen mit Hilfe des NEO-FFI selbst beurteilt. In der untersuchten Stichprobe konnte der vermutete positive Zusammenhang zwischen dem Detektionsvermögen emotionaler Gesichter und dem Persönlichkeitsmerkmal Verträglichkeit bestätigt werden. Eine signifikante positive Korrelation bestand im Falle freudiger und ängstlicher Gesichter. In den fMRT-Daten wurden Mehraktivierungen im linken präfrontalen Kortexbeim Betrachten negativer Gesichtsausdrücke im Zusammenhang mit Verträglichkeit ermittelt. Eine bessere Detektionsleistung ging für alle drei präsentierten Emotionen (Freude, Wut, Furcht) mit einer höheren Aktivität in anteriorem Cingulum, Hippocampus, Insula und Brodmann-Areal 6 einher. Weder in den behavioralen Daten noch in den neuronalen Daten zeigten sich Zusammenhänge für die neutrale Ausdrucksbedingung.:Abbildungsverzeichnis …................................................................................................................. 1 Tabellenverzeichnis …................................................................................................................. 2 Abkürzungsverzeichnis .................................................................................................................... 3 1 Einleitung ….................................................................................................................. 4 1.1 Persönlichkeit …................................................................................................................... 4 1.1.1 Begriffsherkunft und Definition …....................................... 4 1.1.2 Persönlichkeitstheorien und Paradigmen der Persönlichkeitspsychologie …................................................................... 5 1.1.3 Die lexikalische Hypothese und das Fünf-Faktoren-Modell der Persönlichkeit …........................................................................................ 7 1.1.4 Verträglichkeit …........................................................................................................ 10 1.1.5 Neuronale Korrelate des Persönlichkeitsmerkmals Verträglichkeit …....................... 10 1.2 Emotionen ............................................................................................................................. 12 1.2.1 Das Konzept der Basisemotionen ............................................................................... 13 1.2.2 Emotionstheorien ….................................................................................................... 14 1.2.3 Der emotionale Gesichtsausdruck ….......................................................................... 15 1.2.4 Die Perzeption emotionaler Gesichtsausdrücke …..................................................... 17 1.2.5 Neuronale Korrelate der Verarbeitung emotionaler Gesichtsausdrücke in der funktionellen Magnetresonanztomographie …........................................................... 19 1.3 Zusammenhänge zwischen Emotionsperzeption und Verträglichkeit ….............................. 22 2 Fragestellungen und Hypothesen …......................................................................................... 25 3 Methoden …................................................................................................................................ 28 3.1 Stichprobe …......................................................................................................................... 28 3.2 Untersuchungsinstrumente ................................................................................................... 28 3.2.1 Intelligenz- und Leistungstests …............................................................................... 28 3.2.2 Selbstbeurteilungsinstrumente …................................................................................ 29 3.3 fMRT-Experiment …............................................................................................................. 31 3.3.1 Ablauf …..................................................................................................................... 32 3.3.2 Stimuli ….................................................................................................................... 32 3.3.3 Detektionsaufgabe ….................................................................................................. 32 3.4 Datenanalyse …..................................................................................................................... 34 3.4.1 Daten aus Selbstbeurteilungsinstrumenten, Leistungstests und Detektionsaufgabe .. 34 3.4.2 Analyse der fMRT-Daten …........................................................................................ 34 4 Ergebnisse …............................................................................................................................... 37 4.1 Ergebnisse aus Fragebögen und Leistungstests …................................................................ 37 4.1.1 Werte in der untersuchten Stichprobe …..................................................................... 37 4.1.2 Korrelationen von Fragebogen- und Leistungswerten mit Verträglichkeit …............ 39 4.2 Ergebnisse der Detektionsaufgabe ….................................................................................... 40 4.2.1 Detektionsleistung ….................................................................................................. 40 4.2.2 Korrelationen der Detektionsleistung mit Verträglichkeit …..................................... 42 4.3 Ergebnisse aus den fMRT-Daten …...................................................................................... 44 4.3.1 Haupteffekte …........................................................................................................... 44 4.3.1.1 Haupteffekt des Kontrasts freudig vs. neutral …................................................ 44 4.3.1.2 Haupteffekt des Kontrasts wütend vs. neutral …................................................ 45 4.3.1.3 Haupteffekt des Kontrasts ängstlich vs. neutral …............................................. 45 4.3.2 Korrelationen zwischen Hirnaktivierung und Verträglichkeit …................................ 47 4.3.2.1 Korrelationen zwischen Hirnaktivierung und Verträglichkeit in der Bedingung freudig …......................................................................................... 47 4.3.2.2 Korrelationen zwischen Hirnaktivierung und Verträglichkeit in der Bedingung wütend …......................................................................................... 49 4.3.2.3 Korrelationen zwischen Hirnaktivierung und Verträglichkeit in der Bedingung ängstlich …...................................................................................... 51 4.3.2.4 Überblick über die Zusammenhänge zwischen Hirnaktivierung und Verträglichkeit …........................................................................................ 52 4.3.3 Korrelationen zwischen Hirnaktivierung und Detektionsleistung …......................... 53 4.3.3.1 Korrelationen zwischen Hirnaktivierung und Detektionsleistung in der Bedingung neutral …......................................................................................... 53 4.3.3.2 Korrelationen zwischen Hirnaktivierung und Detektionsleistung in der Bedingung freudig …......................................................................................... 54 4.3.3.3 Korrelationen zwischen Hirnaktivierung und Detektionsleistung in der Bedingung wütend …......................................................................................... 56 4.3.3.4 Korrelationen zwischen Hirnaktivierung und Detektionsleistung in der Bedingung ängstlich …...................................................................................... 58 4.3.3.5 Überblick über die Zusammenhänge zwischen Hirnaktivierung und Detektionsleistung ….................................................................................. 59 5 Diskussion …............................................................................................................................... 61 5.1 Interpretation der Ergebnisse …........................................................................................... 61 5.1.1 Der Zusammenhang zwischen Verträglichkeit und Detektionsleistung …................ 61 5.1.2 Ergebnisse der fMRT-Messung ….............................................................................. 63 5.1.2.1 Haupteffekte …................................................................................................... 63 5.1.2.2 Der Einfluss von Verträglichkeit auf die Gehirnresponsivität während der Emotionswahrnehmung …........................................................................... 64 5.1.2.3 Zusammenhänge zwischen Gehirnresponsivität und Detektionsleistung …...... 65 5.1.3. Zusammenfassung der Ergebnisse …......................................................................... 67 5.2 Methodische Kritik und Forschungsperspektiven …............................................................ 68 5.3 Ausblick …............................................................................................................................ 70 6 Zusammenfassung der Arbeit …............................................................................................... 72 7 Literaturverzeichnis …............................................................................................................... 74 8 Erklärung über die eigenständige Abfassung der Arbeit ….................................................... 88 9 Danksagung …............................................................................................................................. 89 10 Lebenslauf …............................................................................................................................. 90

Störungen der Sprache, sogenannte Aphasien, zählen zu den häufigsten Folgen nach ischämischem Schlaganfall. Es kommt hierbei zu einer Schädigung von Arealen und deren Verbindungen im Gehirn, die mit dem Sprachnetzwerk assoziiert sind. In der Folge können verschiedene Kompensationsmechanismen in Kraft treten, die im Verlauf eine sprachliche Erholung ermöglichen. Wenngleich das Sprachnetzwerk im gesunden Gehirn vor allem in der linken Hemisphäre lokalisiert ist, so konnten bisherige Studien zeigen, dass an der Spracherholung nach einem Schlaganfall auch die rechte Hemisphäre beteiligt ist. In dieser Promotionsarbeit soll die Rolle der rechten Hemisphäre für die Spracherholung nach Schlaganfall durch einen innovativen Ansatz aus Läsionsanalyse und funktioneller Sprachaktivierung an Schlaganfallpatienten mit Aphasie untersucht werden.

Intentionale Kontrolle ist ein fundamentaler Aspekt menschlichen Verhaltens. Jedoch gibt es bei der neuronalen Basis solcher Kontrollprozesse noch immer viele offene Fragen. Bis heute bleibt beispielsweise umstritten wie das frontoparietale Intentions-Netzwerk organisiert ist. Weiterhin üben motivationale Prozesse einen großen Einfluss auf intentionale Kontrollprozesse aus. In früheren Studien wurden motivationale und intentionale Kontrollprozesse jedoch oft als unabhängige Funktionen verstanden und untersucht. Diese Dissertation untersucht die neuronalen Grundlagen intentionaler Kontrolle, vor allem auf den Einfluss zweier motivationaler Variablen (Aufgabenschwierigkeit, monetäre Belohnungen) und die funktionelle Organisation des Kontrollnetzwerkes fokussierend. Experiment 1 untersuchte Effekte motivationaler Prozesse auf volitionales Verhalten sowie die neuronale Grundlage dieser Effekte. Experiment 2 untersuchte welche Hirnregionen Verhalten mit seinen Konsequenzen assoziiert. Dies ist eine zentrale Funktion, möchte man die positiven Konsequenzen eigenen Verhaltens maximieren. Experiment 3 untersuchte direkt die Repräsentationen frei gewählter und extern determinierter Intentionen und somit auch die funktionale Architektur des intentionalen Kontrollnetzwerkes. Die Ergebnisse aller drei Studien betonen die Wichtigkeit des anterioren zingulären Kortex, dorsomedialen Präfrontalkortex und des parietalen Kortex für die Vermittlung motivationaler Effekte auf intentionale Kontrolle. Weiterhin deuten die Ergebnisse darauf hin, dass das frontoparietale Kontrollnetzwerk sowohl für die Kontrolle frei gewählten als auch extern determinierten Verhaltens wichtig ist. Diese Ergebnisse stellen einen wichtigen Beitrag für aktuelle Debatten über die neuronale Grundlage intentionalen Verhaltens dar, und erweitern aktuelle Theorien über motivationale und intentionale Kontrolle. / Freely choosing one’s own course of action is a fundamental aspect of human behavior. Yet, despite its importance, there remain many open questions about the neural basis underlying intentional control of action. On the one hand, the functional organization of the fronto-parietal brain network associated with intentional control remains a debated topic. On the other hand, motivational processes evidently affect intentional control, as we often choose actions which promise desirable outcomes. Despite this, previous research largely treated intentional and motivational control as two independent functions. This thesis aims at shedding light on the neural basis of intentional control, focusing on the effects of two motivational variables on intentional control processes (effort, monetary rewards), as well as the functional organization of the intentional control network. Experiment 1 investigated the effect of motivational processes on voluntary behavior and its neural basis. Experiment 2 assessed which brain regions associate behaviors with their outcomes, an important piece of information for choosing actions which lead the most desirable outcomes. Experiment 3 directly contrasted the representations of freely chosen and externally cued intentions, in this way investigating the functional organization of the intentional control network. Overall, results from those three experiments highlight the role of the dorsal anterior cingulate, dorso-medial prefrontal, and parietal cortex in mediating motivational effects on intentional control. They further suggest that the fronto-parietal intentional control network likely has a role in both controlling behavior that is freely chosen and externally cued. These results inform debates on the neural basis of intentional control and extend some recent theories of motivational and intentional control functions. They provide a promising starting point for a systematic investigation of the neural basis of intentional control.

Introduction: Face-identity recognition is crucial for human communication and is likely based on a hierarchical process, initiated by face perception, followed by face-identity recognition and semantic association (Bruce & Young, 1986). At the neural level, this maps to cognitive models proposing a core-face and extended network that interact to support recognition. Posterior core-face regions process face perception (occipital face area: OFA; posterior fusiform face area: pFFA) and anterior regions (anterior FFA: aFFA; anterior temporal lobe face area: aTL-FA) familiar face-identity recognition. The extended network supports semantic association. Developmental prosopagnosia (DP) is a disorder marked by profound difficulties in recognizing faces, even highly familiar faces, in the absence of brain injury. To date, there is limited consensus regarding the underlying neural mechanisms of the disorder. Behavioral evidence highlights heterogeneity in DP, implying potential subtypes - apperceptive DP with face perception deficits, and associative DP with intact face perception, but difficulty recognizing familiar faces. Here, we applied a functional magnetic resonance imaging (fMRI) design with natural ambient images of familiar and unfamiliar faces to investigate and contrast the neural mechanisms of familiar and unfamiliar face-identity recognition in typically developed (TD) individuals and DPs who were meticulously characterized into potential behavioral subtypes. Hypotheses: Based on the hierarchical model of face-identity processing we predicted: H1) TD individuals recruit anterior core-face regions (aTL-FA and aFFA) during familiar face-identity processing and posterior core-face regions (OFA and pFFA) during unfamiliar face-identity processing. H2) DP individuals can be characterized into distinct behavioral phenotypes, i.e., apperceptive and associative subtypes, based on performance in face perception and face memory tasks. H3) The behavioral subtypes of DP are reflected in distinct neural response profiles: apperceptive DPs show overall reduced responses in all core-face regions to familiar and unfamiliar faces, while associative DPs show intact responses in posterior core-face regions, but reduced recruitment of anterior regions. Methods: To examine the core-face and extended network, functional imaging data was acquired using a multi-echo gradient echo planar imaging sequence optimized to image regions susceptible to signal drop-out, including the aTL, during the performance of a face-identity recognition task. In total, we recruited 33 TD and 18 DP participants. Before the fMRI task, DP cases were behaviorally characterized into an apperceptive and associative subtype according to their results on face memory and face perception tasks. Each DP subtype group was compared to an equal number of age- and sex-matched controls from the TD group. All participants were familiarized with one of two sets of face-identities via video. These identities were used as familiar face stimuli in the face-identity recognition task inside the scanner, with the untrained set serving as unfamiliar face stimuli. In the fMRI task, familiar or unfamiliar faces were presented in separate blocks (i.e., block design). In each block, participants determined if ‘test faces’ matched an initially presented ‘target face’. fMRI analyses focused on blood oxygenation level dependent (BOLD) responses during familiar and unfamiliar face-identity recognition within pre-defined regions of interest (ROIs): bilateral core-face network (OFA, pFFA, aFFA, aTL-FA) and extended network. Results: Behavioral deficits in 12 individuals were in accordance with an apperceptive DP subtype and 6 with an associative DP subtype. Behaviorally, in the face-identity recognition fMRI task, DPs performed significantly worse than matched controls during familiar (U = 12, p < 0.001) and unfamiliar (U = 12, p < 0.001) trials. On the neural level: the TD group recruited all pre-defined core-face regions during familiar and unfamiliar face-identity recognition. The OFA was more engaged during unfamiliar than familiar face-processing and responses in this region correlated with unfamiliar face-identity recognition performance. Unexpectedly, the aTL-FA was not more sensitive to familiar than unfamiliar faces. In DPs, distinct response profiles in apperceptive and associative subtypes were observed. Apperceptive DPs’ within-group analysis showed the aTL-FA is more sensitive to familiar than unfamiliar faces, while the OFA showed no increased sensitivity to unfamiliar faces. Compared to matched controls, they demonstrated overall reduced BOLD responses in specific core-face ROIs (i.e., bilateral OFA, pFFA, and aFFA) to unfamiliar faces (relative to familiar), most evident in the left OFA. In the same core-face ROIs increased responses to familiar than unfamiliar faces were detected. Responses in the bilateral OFA of apperceptive DPs positively correlated with unfamiliar face-identity recognition task performance. Associative DPs’ within-group analysis found no responses in the aTL-FA to either familiar or unfamiliar faces. Relative to matched controls, they had reduced responses in the right aFFA to both familiar and unfamiliar faces, as well as reduced left OFA responses to unfamiliar faces. In the extended network, both DP subtypes showed compensatory increased responses relative to their matched controls during familiar face-identity processing, with the apperceptive DP group exhibiting greater recruitment. Conclusion: In the TD brain, the present findings partially support a hierarchical model of face-identity processing: there was stronger recruitment of the bilateral OFA during unfamiliar face-identity recognition, underlining the increased perceptual processing necessary for recognizing unfamiliar faces. However, no elevated recruitment of anterior ROIs (i.e., aFFA, aTL-FA) during familiar face-identity recognition was found. In DPs, we find the characterization into subtypes is manifested in distinct neural response profiles. In apperceptive DPs, the behavioral face perception deficit may be attributed to reduced responses to unfamiliar faces in bilateral core-face ROIs (OFA, p/aFFA). The increased responses to familiar faces in core-face regions like the aTL-FA and extended network of this group may indicate compensatory recruitment or an interplay between the core-face and extended network. In associative DPs, we propose the exclusive face memory deficit may be reflected in reduced/missing responses in anterior core-face regions, i.e., aFFA and aTL-FA. Unexpectedly, the OFA of associative DPs does not respond like the TD group with higher sensitivity to unfamiliar faces. Associative DPs potentially recruit posterior core-face regions as compensation. Altogether, the findings emphasize the importance of bilateral posterior core-face regions for face perception, while challenging the notion of a strictly hierarchical face network. Based on these observations, we pose new questions regarding the organization of face-identity processing in TD and DP individuals and suggest a direct comparison of DP subtypes for future investigations.

Obesity is associated with structural and functional alterations in brain areas that are often functionally distinct and anatomically distant. This suggests that obesity is associated with differences in functional connectivity of regions distributed across the brain. However, studies addressing whole brain functional connectivity in obesity remain scarce. Here, we compared voxel-wise degree centrality and eigenvector centrality between participants with obesity (n=20) and normal-weight controls (n=21). We analyzed resting state and task-related fMRI data acquired from the same individuals. Relative to normal-weight controls, participants with obesity exhibited reduced degree centrality in the right middle frontal gyrus in the resting-state condition. During the task fMRI condition, obese participants exhibited less degree centrality in the left middle frontal gyrus and the lateral occipital cortex along with reduced eigenvector centrality in the lateral occipital cortex and occipital pole. Our results highlight the central role of the middle frontal gyrus in the pathophysiology of obesity, a structure involved in several brain circuits signaling attention, executive functions and motor functions. Additionally, our analysis suggests the existence of task-dependent reduced centrality in occipital areas; regions with a role in perceptual processes and that are profoundly modulated by attention.

Happiness, anger, surprise, irritation… if we note down the emotions that we go through on a given day, the list will most probably be quite long. A surge of studies on the bidirectional interaction between emotion and cognition suggests that we need emotional appraisals in order to lead a successful life and maintain our personal, social and economic integrity (Bechara, 2005; Damasio, 1994; Fox, 2008; Gross &amp;amp; Thompson, 2007; Walter, 2005). And yet, we seldom ‘just’ experience emotions, but often try to influence them to best fit our current goals. Based on the assumption that emotional reactions entail changes on various levels, and that these changes happen in- or outside of our awareness, affective science has adopted emotion regulation as one of its major research topics (Beauregard, Levesque, &amp;amp; Paquette, 2004; Gross, 1999; Ochsner, 2007). In fact, neural (e.g. amygdala activation) and behavioral (e.g. feeling of negativity) correlates of emotional reactions are effectively reduced by top-down processes of explicit and implicit control (Drabant, McRae, Manuck, Hariri, &amp;amp; Gross, 2009; Levesque, et al., 2003; Ochsner, Ray, et al., 2004). Furthermore, evidence from studies investigating voluntary thought control suggests that control strategies may have lasting and paradoxical consequences (Abramowitz, Tolin, &amp;amp; Street, 2001; Wegner, 2009). In a very recent investigation, lasting effects of regulation were also shown after the cognitive control of emotions: the activation timecourse of the amygdala was significantly increased immediately following regulation, and this difference was also related to the activation of the amygdala to the same stimuli a few minutes later (Walter, et al., 2009). Aside from these contextual or qualitative influences, emotional processing also differs between individuals: genetic variation within the serotonergic system for instance is known to affect emotional reactivity both on the behavioral and on the neural level (Hariri, et al., 2005; Hariri, et al., 2002; Lesch, et al., 1996). In the present work, the temporal dynamics of volitional emotion regulation were investigated in three studies. It was hypothesized that both the subjective experience of negativity and the amygdala activation can be attenuated by the detachment from negative emotions, which in turn leads to an immediate neural aftereffect after the offset of regulation. Furthermore, volitional emotion regulation was expected to be capable of reducing or even obliterating genetically mediated amygdala hyperreactivity to negative emotional cues. Similar to previous investigations (Walter, et al., 2009), pictures of aversive or neutral emotional content were presented while participants were instructed to react naturally to half of the pictures, and to regulate their emotional response upon the other half of the stimuli. The first two studies of the present work were designed to further characterize the immediate aftereffect of volitional regulation in the amygdala: Study 1 included behavioral ratings of negativity at picture offset and at fixation offset in order to provide behavioral measures of experiential changes, while in Study 2, participants continued to experience or regulate their emotions during a “maintain” phase after picture offset. The primary goal of Study 3 was to evaluate whether volitional emotion regulation can reduce genetically mediated amygdala hyperreactivity to aversive emotional material in individuals with the short variant of the serotonin transporter genotype (Hariri, et al., 2005; Hariri, et al., 2002), and whether the immediate aftereffect is also influenced by the serotonin transporter genotype. In all three studies, the amygdala was significantly activated by aversive versus neutral stimuli, while cognitive emotion regulation attenuated the activation in the amygdala and increased the activation in a frontal-parietal network of regulatory brain regions. This neural effect was complemented by the behavioral ratings which show that the subjective experience of negativity was also reduced by detachment (Study 1). Also in all three studies, an immediate aftereffect was observed in the amygdala following the end of regulation. Moreover, the preoccupation with the previously seen pictures after the scanning session varied across the experimental conditions (Studies 2 and 3). Volitional regulation proved effective in reducing amygdala activation to negative stimuli even in 5-HTTLPR short allele carriers that show an increased reactivity to this type of cue. At the same time, functional coupling of the ventrolateral and medial orbital prefrontal cortex, the subgenual and the rostral anterior cingulate with the amygdala was higher in the s-group. However, in Study 3 the immediate aftereffect was found only in l/l-homozygote individuals following the regulation of fear. Taken together, the results of the three studies clearly show that volitional regulation is effective in reducing behavioral and neural correlates of the experience of negative emotions (Levesque, et al., 2003; Ochsner, Bunge, Gross, &amp;amp; Gabrieli, 2002; Ochsner, Ray, et al., 2004), even in the case of a genetically mediated hyperreactivity to such materials. Thus, it seems reasonable to assume that conscious will can effectively counteract genetic determinants of emotional behavior. Moreover, the present results suggest that the temporal dynamics of volitional emotion regulation are characterized by a paradoxical rebound in amygdala activation after regulation, and that the immediate aftereffect is a marker of the efficiency of the initial and the sustained effects of emotion regulation (Walter, et al., 2009). In summary, the successful replication of the immediate aftereffect of emotion regulation in all three studies of this dissertation opens up exciting new research perspectives: a comparison of the short- and long-term effects of different regulatory strategies, and the investigation of these effects also in positive emotions would complement the present results, since the neural mechanisms involved in these processes show some characteristic differences (Ochsner, 2007; Staudinger, Erk, Abler, &amp;amp; Walter, 2009). A comprehensive characterization of this neural marker and its implications for emotional experience might also be useful with respect to clinical applications. The detailed examination of the various time scales of emotional regulation might for instance inform the diagnostic and therapeutic interventions in affective disorders that are associated with emotional dysfunctions (Brewin, Andrews, &amp;amp; Rose, 2000; Johnstone, van Reekum, Urry, Kalin, &amp;amp; Davidson, 2007). Ultimately, we might thus come to understand the neural underpinnings of what the feelings we have today have to do with the feelings we had yesterday – and with the feelings with might have tomorrow.

Exekutivfunktionen sind die Grundlage der Aufmerksamkeitssteuerung, Handlungsplanung, Impulskontrolle, und notwendig für zielgerichtetes Handeln. Impulskontrolle bedeutet dabei die Fähigkeit, behaviorale Impulse und Gedanken zu unterdrücken (Evenden, 1999). Erkrankungen, wie die Borderline Persönlichkeitsstörung (BPS) oder die Aufmerksamkeitsdefizit-/ Hyperaktivitätsstörung (ADHS), die sich durch Einschränkungen der Impulskontrolle auszeichnen, gehören zu den häufigsten psychiatrischen Erkrankungen unserer Zeit und sind schwer zu behandeln. Klinische Beobachtungen (Linehan, 1996) wie auch aktuelle Forschungsergebnisse (Silbersweig et al., 2007) zur BPS lassen einen engen Zusammenhang der affektiven und impulsiven Symptomatik vermuten. Ziel der Studie war zum einen, die gestörte Impulskontrolle bei BPS mit Hilfe psychometrischer und neuropsychologischer Verfahren zu bestätigen und zum anderen die komplexe Interaktion affektiver und inhibitorischer Netzwerke mit Hilfe funktioneller Magnetresonanztomographie zu untersuchen. Dazu wurde ein fMRI-Paradigma entwickelt, dass Emotionsinduktion (Ärger, Freude, Neutral) mit einer Impulskontrollaufgabe (Go/NoGo) verband. Neben dem Vergleich mit einer gesunden Kontrollgruppe wurden zur störungsspezifischen Abgrenzung auch Frauen mit ADHS untersucht. Patientinnen mit BPS gaben dabei in Selbstbeurteilungsmaßen höhere Impulsivitätswerte als gesunde Kontrollen und ähnlich hohe Werte wie Patientinnen mit ADHS an, waren aber in den Aufgaben behavioraler Impulskontrolle nicht beeinträchtigt. In allen drei Versuchsgruppen ergab sich eine emotionale Modulation durch die vorher induzierten Emotionen. Während aber gesunde Kontrollen für erfolgreiche Inhibition v. a. den inferioren Präfrontalkortex verstärkt rekrutieren, war sowohl in der BPS- als auch in der ADHS eine Modulation im Nucleus subthalamicus zu beobachten. Während Patienten mit BPS entsprechend früherer Befunde mit verstärkter Amygdalaaktivierung auf die Emotion Ärger reagierten, zeigten die Patientinnen mit ADHS veränderte Aktivierungen des affektiven Netzwerkes bei der Emotion Freude. Emotionsunabhängig zeigten sich in der ADHS-Gruppe Hypoaktivierungen im mittleren Cingulum und dorsolateralen Präfrontalkortex. Zusammengefasst entsprechen die Ergebnisse der Annahme eines hyperaktivierten limbischen affektiven Systems und eines hypoaktivierten präfrontalen Kontrollsystems bei Borderline Persönlichkeitsstörung (Depue &amp; Lenzenweger, 2005; Dinn et al., 2004; Posner et al., 2003). Eine emotionale Modulation scheint zu einer kompensatorischen Aktivierung von Hirnregionen des Hemmungsnetzwerkes zu führen. Eine generell beeinträchtige neutrale Impulskontrollfähigkeit scheint in Abgrenzung zur ADHS jedoch nicht vorzuliegen.

No description available.