Human decision making is closely related to reward processing because many decisions rely to a certain degree on the evaluation of different outcome values. Reward-based decisions can be health-related, for example if someone has to compare the outcome value of the instant reward of smoking a cigarette to that of the long term goal of keeping well and fit. Such comparisons do not only rely on the nominal value of the alternatives but also on devaluation of rewards over time. The value of being healthy at older age might outweigh the value of smoking a cigarette but since the payoff of the health-outcome will be delayed, humans tend to decrease the value of this option. Therefore in this example one might choose the immediate reward of smoking a cigarette. The proclivity to devaluate the value of rewards over time has been widely investigated with experimental intertemporal choice tasks, in which subjects have to choose between smaller sooner rewards and larger later rewards. A stronger individual devaluation proclivity (i.e. discounting rate) has been reported to be related to addiction. Research in neuroeconomics has suggested the competing neurobehavioural decision systems (CNDS) theory, proposing that an imbalance between an executive (cortical prefrontal brain areas) and an impulsive (i.e. subcortical areas, such as ventral striatum (VS), amygdala) system in the brain leads to steeper discounting and a higher risk for addiction. Additionally, temporal discounting has been proposed as a transdisease process, i.e., “a process that occurs across a range of disorders, making findings from one disorder relevant to other disorders” (Bickel, Jarmolowicz, Mueller, Koffarnus, & Gatchalian, 2012, Abstract). Thus, the CNDS theory and temporal discounting might also have implications for other health-related behaviour than substance use. So far many factors have been shown to be associated with higher discount rates: for instance, adolescent age, lower intelligence and nicotine dependence. Further, it has been shown that adolescents are at highest risk to start smoking. On the other hand a higher education level has been shown to be associated to lower rates of smoking. Thus, it seems likely that a higher discount rate might be one reason why adolescents experiment with smoking, why lower education is associated to nicotine addiction and why dependent smokers are not successful in smoking cessation. But relatively little is known about the neural processes behind these variables, which could be also seen as exemplary risk- and protective factors regarding addiction. The 3 studies of the thesis at hand were conducted to extend the knowledge about neural processes associated to age, intelligence and smoking in their relation to intertemporal choice. The task was chosen because of its relevance for addiction and a variety of health-related behaviour. The first study was conducted to explore the neural correlates of age related differences between adolescents at age 14 and young adults during intertemporal choices. Additionally, the roles of discounting and choice consistency were investigated. Although adoles-cents discounted delayed rewards more steeply than adults, neural processing of reward value did not differ between groups, when controlling reward values for the individual discount rates. However, a higher discount rate was related to a lower responsivity in the ventral striatum to delayed rewards, independent of age. Concerning decision making, adolescents exhib-ited a lower consistency of choices and less brain activity in a parietal network than adults (i.e. posterior and inferior parietal regions). Thus, reward value processing might be more sensitive to the discount rate than to chronological age. Lower consistency of intertemporal choices might indicate ongoing maturation of parietal brain areas from adolescence to young adulthood. The second study was conducted to reveal the associations between neural processes of decision making and intelligence in adolescents. The results of study 2 revealed networks in the adolescent brain where brain activity was related to crystallised intelligence as well as to intertemporal choice behaviour. Specifically, during decision processing higher crystallised intelligence as well as more consistent decisions were associated with higher brain activity in the posterior parietal cortex. Processing of delayed rewards was also related to crystallised intelligence, i.e. more intelligent adolescents showed higher brain activation in the anterior cingulate cortex (ACC) and the inferior frontal gyrus (IFG), which was in turn related to a lower discount rate. Additionally, associations between the parental education level and crys-tallised intelligence of the adolescent participants of the study and their discount rate were found, indicating that parental education as an environmental factor could be related to a low-er risk for addiction. This protective effect might be mediated by the offspring’s crystallised intelligence and discount rate which are both related to brain activity in parts of the same brain networks (i.e. the IFG). The third study was done to investigate neural processes of intertemporal decisions in smokers and non-smokers. To test whether the effects of smoking on the discount rate are due to chronic or acute nicotine intake, non-smokers were additionally assessed under acute nico-tine administration. Study 3 revealed that the effects of nicotine on intertemporal choice behaviour were related to chronic intake of nicotine in smokers rather than to acute nicotine ad-ministration in non-smokers. Regarding the neural processes, smokers compared to non-smokers showed lower brain activity in the posterior parietal cortex. Comparable but weaker effects were found under acute nicotine in non-smokers. Although acute nicotine administra-tion altered neural processes, behavioural changes might only occur after repeated nicotine intake. However, the study did not preclude that the differences are predrug characteristics. Altogether the studies revealed overlapping neural correlates of intertemporal choices which are related to the individual age, the discount rate, the choice consistency, the individual intelligence as well as acute and chronic nicotine intake. This might provide an integrative view on how inter-individual differences and behaviour during intertemporal choices are based on common neural correlates which in turn might have implications for the development and the maintenance of addiction. Specifically, hyposensitivity towards delayed rewards in the adolescent ventral striatum, which has also been found in smokers compared to non-smokers, is associated with higher discount rates and higher risk for smoking initiation. In contrast, higher activation in the IFG and the ACC in more intelligent individuals during reward value processing might enhance behavioural inhibition and control and, hence, might prevent nicotine addiction. In line with the CNDS theory responsivity in subcortical brain areas (i.e. impulsive system), such as the VS was related to the risk factor of adolescent age, whereas activity in cortical areas (IFG and ACC) was related to the protective factors of high-er crystallised intelligence. Since there was only one study beside the studies of the current thesis reporting results regarding consistency, one can only speculate about implications for health-related behaviour, such as addiction. Consistency might play a role, especially for cessation success. Thus, the findings that adolescents as well as less intelligent individuals were less consistent might point to a higher risk for maintenance of nicotine addiction. The higher brain activity in a fronto-parietal network, which has been shown in studies 1 and 2 in adults as well as in more intelligent adolescents, was related to higher consistency of choices in both studies. Thus, the finding might be a possible neural correlate for the association between the risk factor of ado-lescent age, the protective factor of higher crystallised intelligence, and more consistent deci-sion making. In conclusion the findings of the current thesis contribute to a better understanding of how inter-individual differences and environmental factors might be accompanied by neural processes which in turn might be related to individual development of addiction. Further the results might extend the CNDS theory regarding neural correlates of exemplary risk and pro-tective factors regarding adolescents’ health behaviour and smoking in adults.

The frequency of social dysfunctions in a general population sample and in different diagnostic groups was investigated by using the Social Interview Schedule (SIS). Based on the results of the general population sample, several of the a priori derived cut-off scores of the SIS were modified. The analysis of the general population sample revealed sex-specific relationships between age and different aspects of social functioning. Especially for younger women significantly more objective social restrictions, were found due to the burden of multiple role responsibilities. With regard to different diagnostic subgroups including patients and mostly untreated cases from the community sample with Affective Disorders and Anxiety Disorders, results indicate that the degree of social impairment and dysfunctions and the degree of satisfaction with different role areas are strongly dependent on type of disorder and on former treatment status. Specific findings are: (1) The highest number of social impairments and dysfunctions were found in cases and patients with affective syndromes and in schizophrenic patients, but not in schizoaffective patients. (2) Management difficulties and dissatisfaction in intimate relationships were primarily found in depressed women. (3) Unlike anxiety patients, anxiety cases, although mostly chronically ill, had significantly less objective impairments and a lower rate of dissatisfaction than depressed cases. The results are discussed with special reference to the possible key role of depression for the development of social dysfunctions, as measured by the SIS. (4) Problems were, however, acknowledged concerning the use of the SIS with severely disturbed chronic schizophrenic patients.

Plasticity is a central concept within the life-span approach of development and is defined as the ability of an individual to change and reorganize in response to environmental challenges (e.g., Baltes & Singer, 20019. Such intraindividual changes can be induced by systematic cognitive training. Recent studies suggest that substantial amounts of plasticity can be induced in executive control functions with a process-based training approach. These newer studies show that repeated practice on executive control tasks not only improved performance on these trained tasks, but also led to improvements in nontrained tasks (i.e., transfer; e.g., Jaeggi, Buschkuehl, Jonides, & Perrig, 2008; Karbach & Kray, 2009). Executive control processes are especially relevant from a developmental perspective because executive control is involved in a wide range of complex cognitive activities (e.g., van der Sluis, de Jong, & van der Leij, 2007) and is one of the most central areas of cognitive development (e.g., Craik & Bialystok, 2006). The current thesis aimed at elucidating several important questions concerning the plasticity of executive control functions induced by systematic cognitive training. Firstly, the amount, range, and stability of plasticity in adolescents and older adults were investigated. Secondly, studies explored if training design, age, and interindividual differences moderate the amount and range of plasticity. Furthermore, the current thesis aimed at exploring how process-based training specifically leads to transfer effects. To explore these questions, all studies employed a pretest-posttest-design comparing a group of participants that was trained with a process-based training approach to a group of control partici-pants that did not receive the training. Pretraining and posttraining sessions incorporated systematic assessment of transfer measures in different cognitive domains. The first study set out to investigate if executive control can be trained in adolescents with a task switching training. Additionally, the study explored what particular domains of executive control may underlie training and transfer effects, and if acute bouts of exercise directly prior to cognitive training enhance training effects. Analyses indicated substantial training effects for both training groups (with or without acute exercise) and near transfer to a similar switching task. Other findings of transfer were limited to a speed task and a tendency for faster reaction times in an updating task. Thus, findings indicate, for the first time, that executive control can be enhanced in adolescents through a short training. Furthermore, analyses suggest that updating may be of particular relevance for the effects of the task switching training. Analyses revealed no additional effects of the exercise intervention. The second study set out to explore, for the first time, the effects of a process-based training ap-proach in old-old age (above 80 years). After ten sessions of practice on working memory tasks, the training group improved in four of the five trained tasks, emphasizing the potential for plasticity even in old-old age. The gains in the training group were largely driven by individuals who started out with a low capacity in the training tasks. Thus, findings suggest that working memory can be improved with a short executive control training even in old-old age, particularly for low-capacity individuals. The absence of transfer effects in this study may point to the limits of plasticity in this age group. The third study aimed at further elucidating the mixed findings regarding the amounts of training and transfer effects induced by executive control training in older adults. For that purpose, a sample of older adults covering a wide range from young-old to old-old age (65 to 95 years) was either trained for nine sessions on a visuospatial and a verbal working memory as well as an executive control task; or served as controls. Analyses revealed significant training effects in all three trained tasks, as well as near transfer to verbal working memory and far transfer to a nonverbal reasoning task. Remarkably, all training effects and the transfer effect to verbal working memory were even stable at a nine-month follow-up. These findings suggest that cognitive plasticity is preserved over a large range of old age and that even a rather short training regimen can lead to (partly specific) training and transfer effects. However, analyses also revealed that there are a range of factors that may moderate the amount of plasticity, e.g., age and baseline performance in the training domain. To summarize, the current thesis explored effects of short executive control trainings on cognitive functions in adolescents and older adults. The findings suggest a high potential for intraindividual variability across the whole life-span. Plasticity was shown on the level of training and transfer tasks, as well as on the level of stability of effects. Furthermore, results support the notion that process-based training improves executive control processes that in turn lead to improvements in tasks that rely on these processes. The current thesis makes important contributions to the conceptual debate about the potentials and limits of training-induced plasticity across the life-span. It benefits the debate in that it specifically delineates factors that moderate the obtained effects.:Abstract ..............................................................................................1 1 General Introduction .....................................................................3 1.1 Plasticity of cognitive functions ...................................................5 1.2 Executive control functions .........................................................6 1.3 Cognitive training of executive control functions .......................9 2 Outline and Central Questions ......................................................19 2.1 What amount of plasticity does executive control training induce in different age groups? .........................................................................19 2.2 Do training and transfer effects of executive control training remain stable over time? ....................................................................20 2.3 Do training design, age, and baseline performance moderate the amount of plasticity? ...........................................................................20 2.4 Are changes in trained tasks specifically related to changes in transfer tasks? .................................................................................21 3 Study 1 - Effects of a Task Switching Training in Adolescents .......22 3.1 Introduction ..............................................................................22 3.2 Methods ....................................................................................27 3.3 Results ......................................................................................33 3.4 Discussion .................................................................................43 4 Study 2 - Effects of a Working Memory Training in Old-Old adults .48 4.1 Introduction ...............................................................................48 4.2 Methods .....................................................................................51 4.3 Results .......................................................................................54 4.4 Discussion ..................................................................................59 5 Study 3 - Factors Moderating Effects of Working Memory Training in Older Adults .......................................................................63 5.1 Introduction ................................................................................63 5.2 Methods ......................................................................................67 5.3 Results .........................................................................................71 5.4 Discussion ...................................................................................78 6 General Discussion .........................................................................83 6.1 Summary of empirical findings .....................................................83 6.2 Integration of the main empirical findings ...................................85 6.3 Conclusion and Outlook ...............................................................95 6.4 Summary ......................................................................................98 References ..........................................................................................99 Appendix ............................................................................................112

The ability to read proficiently is key to social participation and an important premise for individual well-being and vocational success. Individuals with developmental dyslexia, a highly prevalent neurodevelopmental disorder affecting hundreds of millions of children and adults worldwide, face severe and persistent difficulties in attaining adequate reading levels. Despite years of extensive research efforts to elucidate the neurobiological origin of this disorder, its exact etiology remains unclear to date. In this context, most neuroimaging research on dyslexia in humans has focused on the cerebral cortex and has identified alterations in a distributed left-lateralized cortical language network. However, pioneering post-mortem human studies and animal models suggest that dyslexia might also be associated with alterations in subcortical sensory thalami and early sensory pathways. The largely cortico-centric view of dyslexia is due in part to considerable technical challenges in assessing the human sensory thalami non-invasively using conventional magnetic resonance imaging (MRI). As a result, the role that sensory thalami may play in dyslexia has been largely unaddressed. In this dissertation, I leveraged recent advances in high-field MRI to investigate the role of the human lateral geniculate nucleus (LGN) of the visual thalamus in adults with dyslexia in-vivo. In three multi-modal high-field MRI studies, I show that (i) dyslexia is associated with structural alterations in the direct V1-bypassing white matter pathway connecting the LGN with cortical motion-sensitive area V5/MT in the left hemisphere; (ii) the connectivity strength of which predicts a core symptom of the disorder, i.e., rapid naming ability. I further demonstrate that (iii) the two major functional subdivisions of the LGN can be distinguished non-invasively based on differences in tissue microstructure; and that (iv) adults with dyslexia show functional response alterations specifically in the magnocellular subdivision of the LGN. I also demonstrate that this subdivision deficit (v) is more pronounced in male than female dyslexics; and (vi) predicts rapid naming ability in male dyslexics only. The results of this doctoral thesis are the first to confirm previous post-mortem evidence of LGN alterations in dyslexia in-vivo and point to their relevance to key symptoms of the disorder. In synergy, our research findings offer new perspectives on explanatory models of dyslexia and bear potential implications also for prospective treatment strategies.:Contribution Statement i Acknowledgments iii Abstract v Table of Contents vii 1 General Introduction 1 1.1 Developmental Dyslexia 1 1.1.1 Diagnostic Criteria 1 1.1.2 Prevalence and Etiology 2 1.1.3 Cognitive and Behavioral Symptoms 3 1.1.4 Explanatory Models in Cognitive Neuroscience 4 1.2 Lateral Geniculate Nucleus 7 1.2.1 Anatomy and Function 7 1.2.2 Technical Challenges in Conventional MRI 8 1.2.3 High-Field MRI 9 1.3 Research Aim and Chapter Outline 10 2 Altered Structural Connectivity of the Left Visual Thalamus in Developmental Dyslexia 13 2.1 Summary 14 2.2 Results and Discussion 15 2.3 Conclusions 22 2.4 Materials and Methods 23 2.4.1 Subject Details 23 2.4.2 High-Resolution MRI Acquisition and Preprocessing 23 2.4.3 Lateral Geniculate Nucleus Definition 24 2.4.4 Cortical Region of Interest Definition 26 2.4.5 Probabilistic Tractography 27 2.4.6 Quantification and Statistical Analysis 29 2.5 Supplementary Information 30 3 Mapping the Human Lateral Geniculate Nucleus and its Cytoarchitectonic Subdivisions Using Quantitative MRI 33 3.1 Abstract 34 3.2 Introduction 35 3.3 Materials and Methods 37 3.3.1 In-Vivo MRI 37 3.3.2 Post-Mortem MRI and Histology 41 3.4 Results 44 3.4.1 Lateral Geniculate Nucleus Subdivisions in In-Vivo MRI 44 3.4.2 Lateral Geniculate Nucleus Subdivisions in Post-Mortem MRI 46 3.5 Discussion 50 3.6 Supplementary Information 54 3.6.1 In-Vivo MRI 54 3.6.2 Post-Mortem MRI and Histology 58 3.6.3 Data and Code Availability 60 4 Dysfunction of the Visual Sensory Thalamus in Developmental Dyslexia 61 4.1 Abstract 62 4.2 Introduction 63 4.3 Materials and Methods 66 4.3.1 Subject Details 66 4.3.2 High-Resolution MRI Experiments 66 4.3.3 High-Resolution MRI Acquisition and Preprocessing 67 4.3.4 Lateral Geniculate Nucleus Definition 68 4.3.5 Quantification and Statistical Analysis 69 4.4 Results 70 4.5 Discussion 75 4.6 Supplementary Information 77 4.6.1 Supporting Methods 77 4.6.2 Supporting Results 81 4.6.3 Data and Code Availability 82 5 General Conclusion 83 5.1 Summary of Research Findings 83 5.2 Implications for Dyslexia Models 84 5.2.1 Phonological Deficit Hypothesis 84 5.2.2 Magnocellular Theory 84 5.2.3 Model According to Ramus 85 5.2.4 Need for Revised Model 86 5.3 Implications for Remediation 87 5.4 Research Prospects 88 5.5 Brief Concluding Remarks 90 6 Bibliography 91 7 List of Tables 113 8 List of Figures 115 9 Selbstständigkeitserklärung 117

In der vorliegenden Arbeit wurde einem Phänomen nachgegangen, das bislang nur wenig wissenschaftliche Beachtung erfahren hat: der Stigmatisierung von leistungsstarken SchülerInnen als Streber. Da sich bislang kaum Forschung mit der Streber-Etikettierung beschäftigt hat, wurde in der vorliegenden Arbeit versucht, anhand quantitativer Studien ein umfassendes Bild von der Etikettierung, ihrer Prozesse und ihrer Konsequenzen zu erfassen. In diesem Rahmen wurde folgenden Fragen nachgegangen: 1) Welche individuellen Faktoren sagen die Etikettierung als Streber und die Stigmatisierung anderer SchülerInnen als Streber vorher? 2) Welche Prozesse liegen der Stigmatisierung als Streber zugrunde? 3) Mit welchen Konsequenzen geht die Stigmatisierung einher? 4) Welche Faktoren tragen zur sozialen Akzeptanz von SchülerInnen mit herausragenden schulischen Leistungen bei? Die vorliegenden Befunde deuten darauf hin, dass es sich dabei um ein relevantes Phänomen handelt, welches mit individuellen Faktoren nebst schulischen Leistungen verbunden ist, durch den Klassenkontext determiniert wird und zudem mit aversiven Konsequenzen für die Betroffenen einhergeht. Neben dieser eher negativen Konnotation zeigen die Befunde aber auch auf, dass es Möglichkeiten zum Umgang und zur Lösung gibt. Mit der vorliegenden Arbeit konnte ein wichtiger Schritt zur Schließung einer Forschungslücke getan werden. Nichtsdestoweniger zeigen die Befunde auch, dass für eine allumfassende Erklärung des Phänomens Streber weitere Forschung dringend benötigt wird.

Physical activity is positively related to cognitive functioning and brain volume in older adults. Interestingly, different types of physical activity vary in their effects on cognition and on the brain. For example, dancing has become an interesting topic in aging research, as it is a popular leisure activity among older adults, involving cardiovascular and motor fitness dimensions that can be positively related to cognition. However, studies on brain structure are missing. In this study, we tested the association of long-term senior dance experience with cognitive performance and gray matter brain volume in older women aged 65 to 82 years. We compared nonprofessional senior dancers (n=28) with nonsedentary control group participants without any dancing experience (n=29), who were similar in age, education, IQ score, lifestyle and health factors, and fitness level. Differences neither in the four tested cognitive domains (executive control, perceptual speed, episodic memory, and long-term memory) nor in brain volume (VBM whole-brain analysis, region-of-interest analysis of the hippocampus) were observed. Results indicate that moderate dancing activity (1-2 times per week, on average) has no additional effects on gray matter volume and cognitive functioning when a certain lifestyle or physical activity and fitness level are reached.

Previous research has shown that Need for Cognition (NFC), the individual tendency to engage in and enjoy cognitive endeavors, contributes to academic performance. Most studies on NFC and related constructs have thereby focused on grades to capture tertiary academic success. This study aimed at a more comprehensive approach on NFC’s meaning to success in university. We examined not only performance but also rather affective indicators of success. The current sample consisted of 396 students of different subjects with a mean age of 24 years (139 male). All participants took part in an online survey that assessed NFC together with school performance and further personality variables via self-report. Success in university was comprehensively operationalized including performance, satisfaction with one’s studies, and thoughts about quitting/changing one’s major as indicators. The value of NFC in predicting tertiary academic success was examined with correlation analyses and path analysis. NFC significantly correlated with all success variables with the highest correlation for study satisfaction. Path analysis confirmed the importance of NFC for study satisfaction showing that NFC had a significant direct effect on study satisfaction and via this variable also a significant indirect effect on termination thoughts. This study clearly indicates that NFC broadly contributes to the mastery of academic requirements and that it is worthwhile to intensify research on NFC in the context of tertiary education.

Decades of research in quantitative genetics have found substantial heritability for personality traits as well as for mental disorders which formed the basis of the ongoing molecular genetic studies that aim to identify genetic variations that actually contribute to the manifestation of complex traits. With regard to psychological traits, genetic variation impacting neurotransmitter function have been of particular interest. Additionally, the role of environmental factors including gene × environment interactions has been further investigated and the impor-tance of developmental aspects has been stressed. Furthermore, endophenotypes which link complex traits with their respective biological underpinnings and thus bridge the gap between gene and behaviour have begun to be included in research efforts. In accordance with this approach, this thesis aims to further examine the influence of genetic variation impacting serotonergic and dopaminergic functioning on endophenotypes of anxiety-related behaviour. To this end, two well established paradigms – the acoustic startle reflex and the cortisol stress response – were employed. Both show considerable interindividual variation which has been found in quantitative genetic studies to be at least partly based on genetic factors. In addition, the neural circuits underlying these endophenotypes are relatively well understood and thus reveal references for the detection of associated genetic influences. The results of this thesis associate the overall startle magnitude in two independent samples of young adults with a polymorphism in the promoter region of the serotonin transporter (5-HTT) gene (5-HTTLPR): Carriers of the short (S) allele which results in a reduced gene ex-pression showed a stronger startle magnitude which is in line with numerous findings linking the S allele to increased measures of negative emotionality. In addition to 5-HTTLPR, the effects of past stressful life events on the startle response were investigated: Participants who had recently experienced at least one stressful life event exhibited stronger startle responses and reduced habituation of the startle reflex although there was no 5-HTTLPR × environment inter-action effect. A third study revealed independent and joint effects of 5-HTTLPR and a poly-morphism in the dopamine receptor 4 gene (DRD4) in the same sample of young adults with regard to the cortisol stress response with carriers of the DRD4 7R allele which has been associ-ated with higher scores in sensation seeking, showing reduced cortisol responses. In addition, a 5-HTTLPR × DRD4 interaction effect emerged: 5-HTTLPR long (L) allele carriers showed the lowest cortisol response but only when they possessed at least one copy of the DRD4 7R allele. Moreover, in a fourth study a life span approach was taken and the influence of a further important serotonergic polymorphism which impacts the functioning of tryptophan hydroxylase 2 (TPH2), the rate limiting enzyme in the biosynthesis of serotonin, on interindividual differences in the startle response was investigated in three different age samples: children, young adults and older adults. There was a sex × TPH2 genotype interaction effect in a sample of young adults on the overall startle response while there was no effect of TPH2 in children or older adults. The last study of this thesis presents findings regarding the influence of two dopaminergic polymorphisms in genes encoding the enzyme catechol-O-methyltransferase (COMT) and the dopamine transporter (DAT), respectively, which both terminate dopamine signalling and are thus important regulators of dopaminergic neurotransmission, on the startle reflex in older adults. COMT met/met homozygotes showed the strongest and val/val homozygotes displayed the smallest startle magnitude which is in line with findings linking the COMT met allele to increased scores of anxiety related traits and disorders. Regarding DAT, participants homozygous for the 10R allele, which had previously associated with attention-deficit hyperactivity disorder, showed a stronger overall startle response. In sum, this thesis comprises data on interindividual differences in an electrophysiological and a hormonal endophenotype across the life span and their association with serotonergic and dopaminergic function based on genetic variation. One major finding is the clear evidence for the influence of serotonergic polymorphisms on the startle response in young adults while in contrast in older adults genetic variation in the dopaminergic system exerted considerable influence. These differences might be due to developmental processes in the different stages of life although cohort effects and effects of different recruitment strategies can also not be ruled out. Furthermore, there were significant differences regarding the genetic influence on the acoustic startle reflex and cortisol stress response in one and the same sample which might be due to methodological differences of the two paradigms as well as differences in their underlying neuronal circuits. In conclusion, this thesis supports the acoustic startle reflex and the cortisol stress response as valuable endophenotypes and thus indicators for underlying neurobiological circuits although some methodological issues remain. It also highlights the importance of taking developmental factors and changes over the course of life into account. Finally, this thesis emphasizes the necessity to include reliably and validly assessed past experienced events in molecular genetic studies in order to understand the interplay between genetic and environmental factors in shaping (endo)-phenotypes.

Geborgenheit im Schutze der Familie ist eine der grundlegendsten Erfahrungen, auf die sich eine gesunde Lebensbewältigung und lebensbejahende Einstellung gründen kann. Ist die leibliche Familie nicht in der Lage, dauerhaft für ein Kind zu sorgen, kann die Adoption eine Möglichkeit sein, für betreffende Kinder allseitig förderliche Bedingungen des Aufwachsens zu schaffen. Die Sorge fremder Eltern um heimatlose Kinder ist im historischen Rückblick bereits frühzeitig nachweisbar und auch im Tierreich bekannt. Adoption ist ein Lebensphänomen. In der Literatur sind nicht wenige Arbeiten damit befasst, das Phänomen der Adoption als ein Wagnis zu betrachten, gestützt auf Beispiele schwieriger Entwicklungswege betroffener Kinder. Gleichsam umgibt das Adoptionsthema eine Aura des Besonderen, da dieses Zusammenleben von der Normfamilie abweicht. Wenngleich empirische Forschung belegt, dass die meisten Adoptierten gut angepasst sind und vergleichbare Entwicklungsergebnisse wie Nichtadoptierte erzielen, hält sich ein defizitorientierter Blick bis heute und mündet in einer individuellen und gesellschaftlichen Stigmatisierung und Tabuisierung, natürlich nicht ohne Folgen für die Adoptierten selbst. Die vorliegende Studie hat die reale Adoptionserfahrung im Fokus. Es wird untersucht, wie adoptierte Menschen konkret ihren Werdegang begreifen, wie sie den Fakt des Adoptiertseins verarbeiten oder verarbeitet haben und welchen Haltungen sich hieraus ergeben. Das geschieht anhand einer selbst selektierten Stichprobe von 97 adoptierten Jugendlichen und Erwachsenen. Basierend auf Bindungstheorie, Selbstkonzept und Identitätsentwicklung werden weitere adoptionsrelevante Themengebiete beleuchtet und mit empirischen Forschungsdaten in Beziehung gesetzt. Methodisch wurde eine breite Palette adoptionsrelevanter Daten mittels Fragebogen erfasst, mit Freiräumen für persönliche Ergänzungen. Die Auswertung erfolgte mittels deskriptiver Häufigkeitsauszählung und geeigneten bivariaten Analysen, um Einflussfaktoren auf den Verlauf der Adoptionsgeschichte zu eruieren. Eigene Ergänzungen der Teilnehmenden wurden mittels Bildung von Clustern ausgewertet, um Schwerpunktsetzungen herauszustellen. Die Vielgestaltigkeit der Thematik Adoption samt aller Aspekte, die den Entwicklungsverlauf mitbestimmen, zeigt Chancen auf, dass Bindungsabbrüche in frühen Jahren und Ablehnungserfahrung keine zentralen Lebensthemen bleiben müssen – u. a. auch, weil man weiß, wo man hingehört. So lautet die Kernhypothese. Die Ergebnisse zeigen, dass trotz unterschiedlicher Adoptionserfahrungen der Großteil der Befragten ein zufriedenes Leben führt. Zusammenfassend ergeben sich drei Schwerpunkte, mit denen sich die Teilnehmenden dieser Studie vorrangig beschäftigen. Es geht um die Bedingungen im Adoptivelternhaus, um die Notwendigkeit einer offenen Kommunikation über die Adoption und um das Bedürfnis nach Akzeptanz und Gleichberechtigung im alltäglichen Leben und in der Gesellschaft überhaupt. Die Arbeit folgt mit ihrer Veröffentlichung dem Anliegen, Betroffene über Forschungsergebnisse zu informieren und Mut zu machen, sich mit ungelösten Fragestellungen auseinanderzusetzen. Diese Arbeit stützt das Anliegen der modernen Adoptionsforschung, Lebensverläufe adoptierter Menschen zu studieren, um Anpassungsergebnisse zu verstehen und besser einordnen zu können. Ferner wird der Anspruch an die beteiligten Professionen gerichtet, empirische Daten der Adoptionsforschung in die Adoptionspraxis einfließen zu lassen, um Adoptierte und ihre Familien adäquat unterstützen zu können.:Einleitung 5 1. Theoretische Grundlagen 18 1.1 Bindung 18 1.1.1 Das Entstehen von Bindungen 20 1.1.2 Prägung durch frühe Bindungserfahrung – das „Innere Arbeitsmodell“ 22 1.1.3 Die Bindungsqualität 23 1.1.4 Was kann die Bindungsentwicklung beeinflussen? 25 1.1.5 Bindung und Persönlichkeitsentwicklung 31 1.1.6 Zur Stabilität von Bindungen 31 1.1.7 Bindung aus neurobiologischer Sicht 34 1.1.8 Trennung und Verlust aus Sicht der Bindungstheorie 38 1.1.9 Bindungsstörungen 42 1.1.10 Bindung und Adoption 44 1.1.11 Bindungstheorie und Kindeswohl 55 1.2 Das Selbstkonzept 58 1.2.1 Vorläufer der Selbstkonzeptforschung 58 1.2.2 Selbst und Selbstkonzept in der Psychologie der Gegenwart 59 1.2.3 Grundlegende Mechanismen der Selbsterkenntnis 60 1.2.4 Selbstkonzeptentwicklung - Veränderung des Selbst über die Lebensspanne 64 1.2.5 Theorien zum Selbstkonzept 69 1.2.6 Zur Bedeutung des Selbstkonzeptes im Kontext Adoption 74 1.3 Identität – eine andere Form des Selbstverständnisses? 78 1.3.1 Die Aneignung von Identität 83 1.3.2 Der Ausdruck von Identität 86 1.3.3 Identität als Therapieziel 87 1.3.4 Besonderheit der Identitätsarbeit bei Adoptierten 89 2. Adoptionsforschung 100 2.1 Adoption – Risiko oder Schutzfaktor? 103 2.2 Erholungsprozesse im Fokus 111 2.2.1 Wegweisende Studien zum Erholungseffekt 111 2.3 Die Erforschung weiterer Determinanten des Adoptionsprozesses 115 2.3.1 Zur Beziehungsgestaltung in Adoptivfamilien 116 2.3.2 Bindung und Adoption in der Forschung 120 2.3.3 Forschung zur Adoptionsidentität 122 2.3.4 Neurobiologische Erklärungsansätze 123 2.4 Unterstützung für Adoptierte und ihre Familien 128 2.5 Postadoptive Entwicklungsverläufe über die Lebensspanne 131 2.6 Ausblick 134 3. Existenzielle Themen adoptierter Menschen 137 3.1 Mythos und Stigmatisierung 137 3.2 Offenheit 149 3.2.1 Das kindliche Verständnis von Adoption 149 3.2.2 Kontaktsuche und Kontaktgestaltung 153 3.3 Trennung und Verlust 164 3.3.1 Wahrnehmung und Verarbeitung des Verlustes 164 3.3.2 Die dauerhafte Trennung von der Bezugsperson 166 3.3.3 Eine andere Perspektive: Adoptionsbezogener Verlust - sozial konstruiert? 167 3.4 Verwandt sein durch Adoption 175 3.4.1 Verwandtschaftskonzepte 176 3.4.2 Ist Blut dicker als Wasser? 177 3.4.3 Genetische versus psychologische Verwandtschaft 180 3.4.4 Wird Verwandtschaft individuell anders erlebt? 181 3.4.5 Können sich adoptierte Menschen verwandt fühlen? 183 3.5 Versöhnung 185 3.5.1 Was bedeutet Versöhnung? 186 3.5.2 Wie kann sich Versöhnung entwickeln? 186 3.5.3 Versöhnung und Adoption 188 3.6 Adoption als zweitbester Weg? - Das Denken über die Adoption 191 3.6.1 Die Sichtweise der Adoptiveltern 192 3.6.2 Die Sichtweise der Adoptierten 194 3.6.3 Die veränderte Sichtweise der Entwicklungspsychologie 195 3.6.4 Was denken (wissen) die Behandler? 197 3.7 Die reale Adoptionserfahrung aus Sicht der Adoptiveltern 198 3.7.1 Die Adoptionsentscheidung 200 3.7.2 Das Erleben der Adoption 204 4. Auswertung 207 4.1 Gegenstand der Untersuchung 207 4.2 Methode 207 4.3 Statistische Analysen 208 4.3.1 Die Information über den Adoptionsstatus 212 4.3.2 Die Rolle des Umfeldes 217 4.3.3 Die Bedingungen in der Adoptivfamilie 222 4.3.4 Die Umstände der Adoption 229 4.3.5 Der Kontakt mit der Herkunftsfamilie 232 4.3.6 Offene Fragen 239 4.3.7 Identität, Werte und Normen 241 4.3.8 Prägende Erfahrungen im Zusammenhang mit der Adoption 245 4.3.9 Die Auseinandersetzung mit der Adoptionsbiografie 247 4.3.10 Der Rückblick auf die Adoptionsgeschichte 250 4.3.11 Der persönliche Anteil am Verlauf der Adoptionsgeschichte 250 4.3.12 Ergänzung persönlich wichtiger Inhalte der Probanden 252 5. Zusammenfassung 255 5.1 Tendenz der Lebensthemen adoptierter Menschen 258 5.1.1 Wissen und darüber sprechen 258 5.1.2 Was kann das Umfeld tun? 259 5.1.3 Welche Adoptiveltern wünschen sich die Adoptierten? 261 5.1.4 Kontakt zur Herkunftsfamilie - ja oder nein? 263 5.1.5 Der Umgang mit der Adoptionsgeschichte 265 5.2 Der Versuch einer Integration 270 Literaturverzeichnis 274 Tabellenverzeichnis: 328 Anlage 1: Fragebogen 331 Anlage 2: Reformbestrebungen zum Adoptionswesen in Deutschland 357

Transdisciplinary research in general, and stress research in particular, requires an efficient integration of methodological knowledge of all involved academic disciplines, in order to obtain conclusions of incremental value about the investigated constructs. From a psychologist’s point of view, biochemistry and quantitative neuroendocrinology are of particular importance for the investigation of endocrine stress systems (i.e., the HPA axis, and the SNS). Despite of their fundamental role for the adequate assessment of endocrine activity, both topics are rarely covered by conventional psychological curriculae. Consequently, the transfer of the respective knowledge has to rely on other, less efficient channels of scientific exchange. The present thesis sets out to contribute to this exchange, by highlighting methodological issues that are repeatedly encountered in research on stress-related endocrine activity, and providing solutions to these issues. As outlined within this thesis, modern stress research tends to fall short of an adequate quantification of the kinetics and dynamics of bioactive cortisol. Cortisol has gained considerable popularity during the last decades, as its bioactive fraction is supposed to be reliably determinable from saliva and is therefore the most conveniently obtainable marker of HPA activity. However, a substantial fraction of salivary cortisol is metabolized to its inactivated form cortisone by the enzyme 11β-HSD2 in the parotid glands, which is likely to restrict its utility. Although the commonly used antibody-based quantification methods (i.e. immunoassays) might “involuntarily” qualify this issue to some degree (due to their inherent cross-reactivity with matrix components that are structurally-related to cortisol; e.g., cortisone), they also cause differential within-immunoassay measurement bias: Salivary cortisone has (as compared to salivary cortisol) a substantially longer half-life, which leads to an overestimation of cortisol levels the more time has passed since the onset of the prior HPA secretory episode, and thus tends to distort any inference on the kinetics of bioactive cortisol. Furthermore, absolute cortisol levels also depend on the between-immunoassay variation of antibodies. Consequently, raw signal comparisons between laboratories and studies, which are favorable as compared to effect comparisons, can hardly be performed. This finding also highlights the need for the long-sought standardization of biochemical measurement procedures. The presumably only way to circumvent both issues is to rely on quantification of ultrafiltrated blood cortisol by mass-spectrometric methods. Being partly related to biochemical considerations with research on HPA activity, a second topic arises concerning the operationalization of the construct itself: In contrast to the simple outcome measures like averaged reaction times, inclined stress researchers can only indirectly infer on the sub-processes being involved in HPA activity from longitudinally sampled hormone concentrations. HPA activity can be quantified either by (a) discrete-time, or by (b) continuous-time models. Although the former is the most popular and more convenient approach (as indicated by the overly frequent encounter of ANOVAs and trapezoidal AUC calculations in the field of psychobiological stress research), most discrete time models form rather data-driven, descriptive approaches to quantify HPA activity, that assume the existence of some endocrine resting-state (i.e., a baseline) at the first sampling point and disregard any mechanistic hormonal change occurring in between all following sampling points. Even if one ignores the fact, that such properties are unlikely to pertain to endocrine systems in general, many generic discrete time models fail to account for the specific structure of endocrine data that results from biochemical hormone measurement, as well as from the dynamics of the investigated system. More precisely speaking, cortisol time series violate homoscedasticity, residual normality, and sphericity, which need to be present in order to enable (mixed effects) GLM-based analyses. Neglecting these prerequisites may lead to inference bias unless counter-measures are taken. Such counter-measures usually involve alteration of the scale of hormone concentrations via transformation techniques. As such, a fourth-root transformation of salivary cortisol (being determined by a widely used, commercially available immunoassay) is shown to yield the optimal tradeoff for generating homoscedasticity and residual normality simultaneously. Although the violation of sphericity could be partly accounted for by several correction techniques, many modern software packages for structural equation modeling (e.g., Mplus, OpenMX, Lavaan) also offer the opportunity to easily specify more appropriate moment structures via path notation and therefore to relax the modeling assumptions of GLM approaches to the analysis of longitudinal hormone data. Proceeding from this reasoning, this thesis illustrates how one can additionally incorporate hypotheses about HPA functioning, and thus model all relevant sub-processes that give rise to HPA kinetics and dynamics. The ALT modeling framework being advocated within this thesis, is shown to serve well for this purpose: ALT modeling can recover HPA activity parameters, which are directly interpretable within a physiological framework, that is, distinct growth factors representing the amount of secreted cortisol and velocity of cortisol elimination can serve to interpret HPA reactivity and regulation in a more unambiguous way, as compared to GLM effect measures. For illustration of these advantages on a content level, cortisol elimination after stress induction was found to be elevated as compared to its known pharmacokinetics. While the mechanism behind this effect requires further investigation, its detection would obviously have been more difficult upon application of conventional GLM methods. Further extension of the ALT framework allowed to address a methodological question, which had previously been dealt with by a mere rule of thumb; what’s the optimal threshold criterion, that enables a convenient but comparably accurate classification of individuals whose HPA axis is or is not activated upon encountering a stressful situation? While a rather arbitrarily chosen baseline-to-peak threshold of 2.5 nmol/L was commonly used to identify episodes of secretory HPA activity in time series of salivary cortisol concentrations, a reanalysis of a TSST meta- dataset by means of ALT mixture modeling suggested that this 2.5 nmol/L criterion is overly conservative with modern biochemical measurement tools and should be lowered according to the precision of the utilized assay (i.e., 1.5 nmol/L). In sum, parametric ALT modeling of endocrine activity can provide a convenient alternative to the commonly utilized GLM-based approaches that enables the inference on and quantification of distinct HPA components on a theoretical foundation, and thus to bridge the gap between discrete- and continuous-time modeling frameworks. The implementation of the outlined modeling approaches by the respective statistical syntaxes and practical guidelines being derived from the comparison of cortisol assays mentioned above, are provided in the appendix of the present thesis, which will hopefully help stress researchers to directly quantify the construct they actually intend to assess.:1. Introduction 2. The hypothalamus-pituitary-adrenal (HPA) axis 3. Induction and quantification of HPA activity 4. The pitfalls of SCC measurement 5. Creating normality and homoscedasticity: GLM-based analyses 6. Relaxing sphericity: moment structure analyses 7. General conclusion