Why do some children easily find their way in social situations and are satisfied with their social lives, while others experience more difficulties? One key component that may explain this is... Show moreWhy do some children easily find their way in social situations and are satisfied with their social lives, while others experience more difficulties? One key component that may explain this is social competence: the ability to fulfill both own and other’s social goals. This thesis focused on individual differences in social competence from childhood to adolescence by examining contextual, developmental and neurobiological influences on aggressive and prosocial responses to social evaluation. Findings showed robust neural processes related to social feedback and subsequent aggression already in middle childhood. Additionally, this thesis revealed that the period between childhood and adolescence is important for the behavioral and neural development of inhibition of aggression following negative, neutral and positive social feedback. Aggression following social feedback decreased towards adolescence, but aggression following positive feedback decreased earlier in childhood than following negative feedback. Moreover, the involvement of the dorsolateral prefrontal cortex, known for its role in executive functioning, decreased over time. Finally, results indicated that the co-occurrence of aggression following rejection and prosocial behavior following observed rejection may possibly protect against externalizing behaviors and promote wellbeing. This thesis highlights the importance of examining the interplay of developmental processes across social contexts to understand mental health outcomes. Show less
This thesis describes a cross-sectional behavioral and neuroimaging study in a sample of n=85 adolescents with a history of childhood sexual abuse related PTSD (CSA-related PTSD), anxiety and/or... Show moreThis thesis describes a cross-sectional behavioral and neuroimaging study in a sample of n=85 adolescents with a history of childhood sexual abuse related PTSD (CSA-related PTSD), anxiety and/or depressive disorders or no psychiatric symptoms. We assessed attachment representation as well as psychopathological symptoms, attentional bias and emotional face processing among diagnostic groups. We also correlated unresolved-disorganized attachment representation (Ud) and psychopathology using a general psychopathology factor (GPF) to grey matter (volume), white matter (tracts) and resting state functional connectivity (RSFC) of the brain in the entire sample. We found that clinical groups did not significantly differ in psychopathology. The unresolved-disorganized cannot classify category (Ud/CC) was overrepresented in the CSA-related PTSD group. Coherence of mind also differentiated the clinical groups, but Ud did not. The CSA-related PTSD group had a negative attention bias for neutral and fearful faces, the anxiety/depressive disorders group only for fearful faces. No differences were found for emotional face processing among diagnostic groups. We found a differential relationship of Ud and a GPF to grey matter volume, white matter integrity of white matter tracts and RSFC for Ud. Ud was associated with lateralization of the brain to the left with regard to amygdala RSFC and hippocampal volume. Show less
Sensory function is impaired in adults with conservatively treated OBPL. There is widespread motor misrouting together with motor functional impairment in conservatively treated OBPL, not... Show moreSensory function is impaired in adults with conservatively treated OBPL. There is widespread motor misrouting together with motor functional impairment in conservatively treated OBPL, not explained by muscle weakness. There were no differences in the degree of cocontraction between OBPL patients and healthy subjects for either the triceps or deltoid muscles during supramaximal biceps stimulation. However, elbow stiffness was approximately 1.7 times higher in OBPL patients than in control subjects during voluntary levels of contraction, suggesting a significant effect of misrouting in the patients. In children with OBPL the deficit during automatic arm abduction was not observed during voluntary movements and therefore cannot be explained by a peripheral deficit, suggesting a central component. In adults OBPL affected imagined but not actual elbow flexion suggested an impairment of motor planning. Show less
The prevalence of obesity, defined as a body mass index (BMI) > 30 kg/m2, is increasing to epidemic proportions. In 2014, 11% of men and 15% of women worldwide were obese. Thus, more than... Show moreThe prevalence of obesity, defined as a body mass index (BMI) > 30 kg/m2, is increasing to epidemic proportions. In 2014, 11% of men and 15% of women worldwide were obese. Thus, more than half a billion adults worldwide are classed as obese. The fundamental cause of obesity is an imbalance between energy intake (excessive intake of energy-dense foods) and energy expenditure (reduced physical activity). People with obesity are at risk for a range of chronic conditions including cardiovascular disease (CVD) and nonalcoholic fatty liver disease (NAFLD). Furthermore, obesity is a major risk factor for the development of type 2 diabetes, which is one of the most common chronic diseases in nearly all countries. According to the World Health Organization, the global prevalence of diabetes in 2014 was estimated to be 9%, of which 90% was comprised of type 2 diabetes. This thesis focuses on cardiovascular and cerebral dimensions and function in people with obesity and type 2 diabetes. State-of-the-art imaging techniques are used to investigate links between the heart, liver, abdominal fat, and brain to elucidate parts of the complex relationships between these organs. Show less
This thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments... Show moreThis thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments investigating neural correlates of novel grammar learning and of the analytical component of language aptitude, using a variety of neuroimaging methods: functional magnetic resonance imaging, diffusion tensor imaging and electroencephalography. This thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments investigating neural correlates of novel grammar learning and of the analytical component of language aptitude, using a variety of neuroimaging methods: functional magnetic resonance imaging, diffusion tensor imaging and electroencephalography. Show less
When trying to understand texts, readers engage in various cognitive processes. If all goes well, the engagement in these cognitive processes during reading results in the construction of a... Show moreWhen trying to understand texts, readers engage in various cognitive processes. If all goes well, the engagement in these cognitive processes during reading results in the construction of a coherent mental representation of the text, the essence of successful reading comprehension. To construct such a representation, readers need to monitor the coherence of the text and of their emerging mental representation of what the text is about. The central aim of the empirical studies described is to examine coherence-monitoring processes across development by measuring reader’s ability to detect coherence breaks during reading of narratives. The first part of this dissertation consists of three empirical studies (chapter 2-4). The first study examined whether good and poor comprehenders at age 8-9 and 10-11 detected coherence-breaks during and/or after reading. The second study builds on the first study by examining the protracted development of coherence monitoring in an adolescent population (ages 10-22) using the same task under more challenging circumstances. The third study explored the neural correlates of coherence-break detection in young adults in an fMRI study. The second part of this dissertation consists of two conceptual chapters in which the results are summarized and discussed in a broader theoretical perspective (chapter 5-6). Show less
The aim of this set of studies was to provide more insight in individual characteristics that influence care-giving abilities, in particular precursors of harsh and abusive parenting. We examined... Show moreThe aim of this set of studies was to provide more insight in individual characteristics that influence care-giving abilities, in particular precursors of harsh and abusive parenting. We examined how different subtypes of childhood abuse were related to child abuse potential in adulthood. Emotional neglect in childhood was related to child abuse potential, which is in line with earlier research showing the long-lasting effects of emotional maltreatment and neglect in childhood. With regard to the effects of oxytocin on the neural basis of parenting, we used fMRI to examine how oxytocin influenced emotion recognition using pictures of both adult and infant faces, taking experiences of maternal love withdrawal into account as potential moderator. Oxytocin enhanced neural activity in regions involved in emotion processing, such as the IFG, insula and STG. Our findings regarding the moderating role of experiences of maternal love withdrawal are inconsistent for emotion recognition in adult faces and in infant faces. Lastly, a new paradigm (LISSA) to observe sensitivity in response to standardized infant cues was developed and tested. Our results show that sensitivity can be reliably assessed using this procedure, making the LISSA a promising method for future research and clinical practice. Show less
As infants are fully dependent on their parents, correct perception and interpretation of infant signals is crucial for infant survival. It is therefore not surprising that specific brain circuits... Show moreAs infants are fully dependent on their parents, correct perception and interpretation of infant signals is crucial for infant survival. It is therefore not surprising that specific brain circuits and neuroendocrine processes have evolved to perceive infant signals correctly and to respond adequately. However, parents vary in their ability to respond to their infants in a sensitive way and several factors may be involved in parental sensitive responsiveness. One important factor influencing parenting behavior is the neuropeptide oxytocin. Of all the hormones involved in parenting and other social behaviors, oxytocin has received the most interest, as evidenced by the high number of scientific studies over the past decade (Bos, Panksepp, Bluthé, & Honk, 2012; Van IJzendoorn & Bakermans-Kranenburg, 2012). Many studies suggest that oxytocin is related to sensitive parenting (Bakermans-Kranenburg & Van IJzendoorn, 2008; Feldman, Weller, Zagoory-Sharon, & Levine, 2007), although the exact mechanism underlying this positive association is not entirely clear yet. Another factor that influences parenting behavior is adult state of mind with respect to attachment (Van IJzendoorn, 1995). In the current dissertation, the role of oxytocin and adult attachment in parenting is examined with a series of functional magnetic resonance imaging experiments. Show less
The aims of this thesis were to gain insight into specific disease processes in Huntington__s Disease (HD) and to identify biomarkers. To achieve these aims, cognitive functioning, structural brain... Show moreThe aims of this thesis were to gain insight into specific disease processes in Huntington__s Disease (HD) and to identify biomarkers. To achieve these aims, cognitive functioning, structural brain characteristics and intrinstic functional brain connectivity of premanifest and early HD subjects were examined. Cortical, subcortical and the intermediate white matter brain tissue shows evidence of structural and functional decline. We found evidence that disease processes, such as altered metabolism, excessive iron accumulation and cell loss, play a role in the changes. We conclude that changes occur throughout the brain from the earliest disease phase onwards. Hence, both premanifest and manifest HD should not be regarded as a disorder of the basal ganglia, but as a disease affecting the whole brain. Candidate biomarkers that have the potential to objectively reflect the early changes and the progressive nature of the disease are measures of subcortical atrophy, integrity of white matter pathways and of intrinsic functional brain connectivity. Iron, creatine, and N-acetylaspartate concentrations in the caudate nucleus and putamen may prove to be useful as markers of disease state for objectifying transitional disease processes from premanifest to manifest HD. Visuospatial working memory could be applied as a state marker for stage two HD. Show less
This thesis describes the development of a novel alcohol clamp, a new method to obtain stable plasma levels of alcohol and its application in CNS-research. The method might have several advantages... Show moreThis thesis describes the development of a novel alcohol clamp, a new method to obtain stable plasma levels of alcohol and its application in CNS-research. The method might have several advantages that were explored in subsequent studies described in this thesis. The stability of the alcohol clamp was used to examine functional effect profiles and time-dependence of different CNS-effects. The tests to examine these effects were chosen based upon a prior review of the literature, during which the most sensitive CNS-tests were selected. Hereafter, we studied the alcohol clamping method as a tool to compare alcohol disposition capacities between different (ethnic) populations and as a tool to compare their different CNS-responses to multiple stable alcohol levels. We also investigated whether the clamping method could be useful as a future benchmarking entity in CNS-research, based on its fMRI effects on the brain at rest and its efficacy on tremor symptoms. Finally, we employed the method in an interaction study with a compound that is in development for addictive disorders including alcoholism. This thesis has examined several examples of situations where the alcohol clamp has been a useful research instrument during alcohol research and in early drug development. Show less
The research described in this thesis aimed to gain insight in risky behavior in adolescence, by examining the development of decision-making in relation to brain development. Chapter 1 describes... Show moreThe research described in this thesis aimed to gain insight in risky behavior in adolescence, by examining the development of decision-making in relation to brain development. Chapter 1 describes two existing possible explanations for adolescent risky behavior, the first explanation focuses on the development of cognitive control, and states that adolescents’ immature ability to control their impulses may bias them to act risky. The second explanation focuses on emotional/motivational processes, and suggests that adolescents engage in risky behavior because they respond stronger to the possible rewards associated with risks than children and adults do. Chapters 2, 3, and 7 describe studies on developmental changes in the processes that form the building blocks of more complex decision-making under risk; probability estimation, reward processing and working memory. Chapters 4, 5, and 6 explore the relative contributions of reward sensitivity and cognitive control to decision-making across development. This thesis shows knowledge about brain maturation can inform models of adolescent risky behavior. And that adolescent risk-taking can be explained as the consequence of the earlier maturation of reward related relative to cognitive control related brain circuitry. Show less
