Since heterogeneity in depressed patients makes treatment decisions difficult and treatment often unsuccessful, we seek to identify certain subtypes of depression. 30 to 40% of depressed patients... Show moreSince heterogeneity in depressed patients makes treatment decisions difficult and treatment often unsuccessful, we seek to identify certain subtypes of depression. 30 to 40% of depressed patients have anger regulation problems; from irritability to anger attacks. What is the significance of anger in depression? Does it signify a subtype of depression? In the NESDA cohort, we compared a large sample of currently depressed patients with irritability to currently depressed patients without irritability. Irritable depressed patients had more symptoms of depression, more often had comorbid anxiety and had more often attempted suicide than non-irritable depressed patients. In a student sample, we investigated the role of the MAOA genotype and found that women with the high expression variant are possibly more vulnerable to anger or aggression during depression. Using acute tryptophan depletion we temporarily lowered serotonin in remitted depressed patients with and without anger regulation problems during their depression. We found no cognitive differences between the two groups, but the experiment did show us that depressed patients with anger regulation problems may be more serotonergically vulnerable. Further research is needed to elucidate best suited treatment strategies for anger regulation problems in depression Show less
The present thesis concentrates on predictors and outcomes of occupational stress in emergency (ER-) nurses, working in in-hospital emergency wards, ambulance services and fast rescue teams. More... Show moreThe present thesis concentrates on predictors and outcomes of occupational stress in emergency (ER-) nurses, working in in-hospital emergency wards, ambulance services and fast rescue teams. More specifically, this thesis focuses on the relationships between (1) demographic factors, (2) exposure to traumatic events, (3) job characteristics, (4) organizational variables, (5) coping strategies and (5) goal orientation as potential determinants of (a) job satisfaction, (b) turnover intention, (c) burnout, (d) work engagement, (e) post-traumatic stress symptoms (f) fatigue and (g) other somatic complaints. The first part of this chapter gives an overview of the main results of the different studies, followed by an attempt to integrate all these results from a theoretical and methodological point of view, resulting in a set of practical recommendations and directions for future research Show less
Despite the promising findings related to the efficacy of primary health care-based physical activity interventions and recommendations for primary health care professionals to promote physical... Show moreDespite the promising findings related to the efficacy of primary health care-based physical activity interventions and recommendations for primary health care professionals to promote physical activity, the introduction of physical activity interventions in routine daily primary health care practice does not always happen as desired. Specifically, rates of physical activity promotion by primary health care professionals are far from optimal and physical activity interventions are not delivered as intended by the intervention developers. Knowledge of the factors that determine the success or failure of the introduction of innovations in health care is important for the development of strategies to improve the introduction process. As a first step towards the effective introduction of physical activity interventions in primary health care practice, the main aim of this thesis is to investigate what factors influence the introduction of physical activity interventions in primary health care. Show less
In this thesis four studies assessing putative pathways implicated in cognitive models of depression are presented and discussed. In two initial studies the possibility to manipulate attention... Show moreIn this thesis four studies assessing putative pathways implicated in cognitive models of depression are presented and discussed. In two initial studies the possibility to manipulate attention allocation bias using two types of attention bias modification (ABM) procedures was explored. Neither method successfully or consistently modified attention allocation bias in dysphoric individuals. Putative interactions between 5-HTTLPR genotype and life stress were studied in the third study. Adopting an endophenotype approach, effects on measures of biased information processing were assessed. S-allele carriers showed increased recognition of negative mood state as a function of recent negative life events. Hypothesized interactions with childhood emotional abuse or affection attention allocation bias were found non-significant. A main effect of 5-HTTLPR was observed such that s- allele carriers selectively oriented attention towards negative information. In the fourth study the predictive value of cognitive reactivity to sad mood (measured with the LEIDS-r questionnaire) for the first onset of depression was assessed. Among 834 never previously depressed participants, cognitive reactivity predicted first onset of depression over the subsequent two years, even when various other factors, including baseline symptoms and negative life events, were statistically controlled for. Finally, these findings are discussed and related to the existing literature Show less
Much of the previous work investigating the impact of honor on conflict management has focused on how people endorsing honor values respond to possibly offensive interactions. Despite the... Show moreMuch of the previous work investigating the impact of honor on conflict management has focused on how people endorsing honor values respond to possibly offensive interactions. Despite the accumulation of this research, it is yet unclear why people endorsing the ideal of honor respond more fiercely after being offended. Moreover, hardly any systematic attempts have been undertaken to identify ways in which these negative ramifications of offensive encounters can be prevented or reduced. The discoveries made in the context of this dissertation paint a more balanced picture of the effect of honor concern on conflict management and inform us on possible avenues of effective conflict intervention. Show less
By using innovative paradigms, the present thesis provides convincing evidence that action-effect learning, and sensorimotor processes in general play a crucial role in the development of action-... Show moreBy using innovative paradigms, the present thesis provides convincing evidence that action-effect learning, and sensorimotor processes in general play a crucial role in the development of action- perception and production in infancy. This finding was further generalized to sequential action. Furthermore the thesis suggests that means-selection-, ends-selection information, and action-effect knowledge together feed into a unitary concept of goal. Both these findings have the potential to generate interesting new research question Show less
One of the greatest environmental challenges the world is facing today is combating global warming. One of the solutions is the implementation of CO2 capture and storage (CCS). CCS is a... Show moreOne of the greatest environmental challenges the world is facing today is combating global warming. One of the solutions is the implementation of CO2 capture and storage (CCS). CCS is a controversial technology, and attitudes towards it are influenced by public communications. In this dissertation, I identify pitfalls in the communication about CCS. I show that irrelevant details dilute the persuasiveness of a relevant message, that giving more weight to either advantages or disadvantages of CCS is perceived as manipulative-even as illegitimate when people expect informative communications-and that citing pro-environmental motives for corporate involvement with CCS can be perceived as greenwashing. Furthermore, I reveal psychological processes underlying these pitfalls. To avoid long-term negative perceptions, stakeholders with an interest in CCS can best take people's source expectations into account and provide a relevant, balanced and credible message about the technology Show less
Worry and rumination are cognitive processes that have been proposed to constitute a driving force across many psychological disorders, emotional disorders in particular. The two concepts are often... Show moreWorry and rumination are cognitive processes that have been proposed to constitute a driving force across many psychological disorders, emotional disorders in particular. The two concepts are often referred to by the overarching term repetitive negative thinking (RNT), however whether they are indeed representations of the same process is debated. The main aim of the present thesis is to contribute to the ongoing worry-rumination debate by investigating whether worry and rumination are indeed transdiagnostic processes and whether they represent a shared underlying process. In accordance with this aim several studies were designed covering two lines of research; i) epidemiological studies comparing worry and rumination in their relationship with each other and with emotional disorders; ii) experimental studies examining worry at a more functional/process level. Overall the studies presented in this thesis yield support for both accounts: worry and rumination are highly related, are present across emotional disorders and show both similarities and differences at process level. Especially at a general, abstract, level similarities between worry and rumination seem to predominate. However, at a more concrete and specific level both similarities and differences are observed. Such differences can be relevant for research as well as therapeutic interventions. Depending on the questions in a certain research or clinical context emphasis on a more general-abstract or concrete-specific perspective on worry and rumination seems warranted. Show less
In comparison to hearing children, children with hearing loss more often experience social-emotional problems. This thesis aimed to assess whether this was also true for 1-to-5-year-old children... Show moreIn comparison to hearing children, children with hearing loss more often experience social-emotional problems. This thesis aimed to assess whether this was also true for 1-to-5-year-old children who had received a cochlear implant (CI) to remediate their hearing loss. In comparison to hearing peers, children with CI were found to be delayed on some but not all aspects of social-emotional functioning. No delays were found regarding social behavior or empathy. However, children with CI did show delays on theory of mind understanding and on the development of moral emotions. Against expectations, language skills did not have a major influence on children's social-emotional development. Parents in both groups had adopted similar parenting styles. Positive parenting was associated with better social-emotional functioning in children, whereas negative or uninvolved parenting were associated with lower social-emotional functioning. Based on this thesis we can conclude that a CI is beneficial for the social-emotional development of children with a hearing loss. However, these children are still at risk of developing delays in some areas of social-emotional functioning. Furthermore, we should not assume that children with CI who have a strong language development will also show a healthy social-emotional development. Show less
Confidence in a theory increases when it is confirmed by relevant data. Alongside some consistent findings, the data in the prevailing thesis largely detail a lack of confirmation of the... Show moreConfidence in a theory increases when it is confirmed by relevant data. Alongside some consistent findings, the data in the prevailing thesis largely detail a lack of confirmation of the neurotrophin hypothesis. And where expected associations were established (e.g., abnormally low serum BDNF concentrations in the depressed state), the meaning often was not that clear (e.g., reverse causation). I therefore conclude, whilst taking limitations into account and acknowledging that the results are contingent upon imperfect and peripheral measurement, that the most reliable evidence in humans does not corroborate the neurotrophin hypothesis. So, given the data, the final words of this thesis are that solid work over novelty shows that the neurotrophin hypothesis should no longer be credited in its original form. All that glitters is not gold - back to the drawing table Show less
Previous research has revealed that it is important for people to be moral. Nevertheless, they may sometimes commit immoral acts. In this dissertation, I examined when people tend to act in ways... Show morePrevious research has revealed that it is important for people to be moral. Nevertheless, they may sometimes commit immoral acts. In this dissertation, I examined when people tend to act in ways that are considered moral; whether it is important for them to be perceived as moral by others; and how much they care whether or not they succeed in behaving according to their moral values. Additionally, I used neuroscientific (i.e., EEG and fMRI) and psychophysiological (i.e., skin conductance) research methods to gain insight in some of the processes underlying these questions. Extending previous research by examining people's actual moral behavior and shedding light on the cognitive and affective processes underlying their acts, the findings in this dissertation reveal not only that, but also when and how people behave according to their moral values. Show less
Smoking and nicotine dependence are associated with an onset or an increased severity of the symptoms of depression and anxiety disorders, and this association is well-established. However, the... Show moreSmoking and nicotine dependence are associated with an onset or an increased severity of the symptoms of depression and anxiety disorders, and this association is well-established. However, the mechanisms underlying this association are not yet clear. In this thesis, we found that early-onset smokers have an early onset of an anxiety disorder. We also found that nicotine-dependent smokers have more severe symptoms of depression and anxiety than the other three groups, which are comparable in symptom severity. Moreover, the rate of improvement of symptoms in dependent smokers is slower than in the other groups. In a follow-up study with the same sample, we found that only those nicotine-dependent smokers have more severe symptoms of depression and anxiety who carry the Val66Val polymorphism of the BDNF gene. In individuals carrying the Val66Met genotype of the BDNF gene, there was no difference among the four smoking groups in symptoms severity. We further found that the levels of serum BDNF is higher in current smoking groups than in non-smoking groups. No association of nicotine dependence with serum BDNF was found. Finally, we investigated the moderating role of attentional control on smoking-related attentional bias, but no moderating effect was found. Smoking, Nicotine dependence, BDNFVal66Met, severity of depression/ anxiety, attentional control Show less
Growing evidence highlights the importance of visual-spatial processing skills (VSPS) but teaching and training of these skills at early age in schools remain understudied. To this end, we have... Show moreGrowing evidence highlights the importance of visual-spatial processing skills (VSPS) but teaching and training of these skills at early age in schools remain understudied. To this end, we have developed a computerized application called TangSolver that aim to move one step toward assessment and training of VSPS of school age children. First, we compared the effectiveness of an experimental computerized VSPS-enhancing approach, a conventional face-to-face training regime, and a non-training control group in improving performance in a tangram game among typical children. Second, we investigated how training-resistant possible visuospatial processing differences between children with and without ASD are. We studied the effect of computerized vs. face-to-face visuospatial training in a group of normally intelligent children with ASD and typically developing children as control. Findings show that (a) children with and without ASD do not differ much in visuospatial processing (as assessed by a tangram-like task) and the few differences we observed were all eliminated by training; (b) training can improve visuospatial processing (equally) in both children with ASD and normally developing children; and (c) computer-based and face-to-face training was equally effective. Show less
Medically unexplained (physical) symptoms (MUS, or MUPS) are symptoms that cannot be attributed to organic pathology and they represent a common category of complaints in health care. Medically... Show moreMedically unexplained (physical) symptoms (MUS, or MUPS) are symptoms that cannot be attributed to organic pathology and they represent a common category of complaints in health care. Medically unexplained symptoms (MUS) are a humanitarian and economic burden. Among them, pain complaints without organic pathology are the most prevalent. For many years, researchers have tried to answer the question how it is possible that people can have somatic complaints without any medical explanation. The main aim of this thesis was to examine the possible causal role of implicit illness memory or schemata in increased symptom reporting. In this thesis, different techniques were used to manipulate the cognitive schemata related to illness, to examine whether this caused increased symptom reporting. In addition, we examined the cross-sectional and temporal relationships between implicit illness-related memory and symptom reporting among patients with fibromyalgia, irritable bowel syndrome and/or chronic fatigue syndrome. The results offer several promising routes for future studies to examine the role of illness memory in the etiology of somatic complaints. The suffering of many patients with medically unexplained symptoms or subjective health complaints and their impact on our health care costs warrants this kind of research. Show less
Inductive reasoning and more specifically, analogical reasoning, is a basic process involved in a wide range of higher cognitive processes. Therefore, this type of reasoning is often regarded as... Show moreInductive reasoning and more specifically, analogical reasoning, is a basic process involved in a wide range of higher cognitive processes. Therefore, this type of reasoning is often regarded as representing a core component of intelligence. The first few years of primary school represent a particular time period for the rapid development of this ability. Unsurprisingly, children display much variable inter- and intra-individual strategic analogical behavior at this age. To date, conclusions regarding the nature of changes in the ability to reason by analogy have frequently been drawn on the basis of results obtained from cross-sectional training studies. In contrast, the studies presented in this dissertation were designed to microgenetically investigate young children__s inter- and intra-individual variable analogical learning trajectories over time. By providing children with repeated non-guided practice, dynamic-test-type training and transfer tasks, as well as applying specific methods and analyses, detailed accounts of changing strategic analogical performance were revealed. These accounts were interpreted along five dimensions of cognitive change: the source, rate, path, breadth and variability of change, in accordance with the overlapping waves theory of Siegler (1996) Show less
In this thesis we examine how different aspects of emotion regulation are linked to social functioning and psychopathology in children and adolescents with Autism Spectrum Disorder (ASD) compared... Show moreIn this thesis we examine how different aspects of emotion regulation are linked to social functioning and psychopathology in children and adolescents with Autism Spectrum Disorder (ASD) compared to their typically developing (TD) peers. We take a broad perspective on emotion regulation by examining i) Emotion awareness, ii) Coping, and iii) Empathy. Main findings where that children with ASD scored lower on social functioning and higher on internalizing behavior, compared to their TD peers. Furthermore, all three aspects of emotion regulation were related with social functioning and psychopathology in both groups. Although children with ASD appeared to be motivated to engage in peer interactions, cognitive and affective impairments may prevent them from effectively deal with the own and other__s emotions. This thesis showed that internalizing and externalizing behavior in children with ASD mainly stems from impaired emotion regulation. Clinical implications and suggestions for further research are also given. Show less
The Feature Co-occurrence Constraint theory proposed in this dissertation provides a means to capture the development of the language-learning child's segment inventory. It does this by combining a... Show moreThe Feature Co-occurrence Constraint theory proposed in this dissertation provides a means to capture the development of the language-learning child's segment inventory. It does this by combining a growing set of features with constraints that are automatically activated as soon as these features are acquired. Representation and derivation go hand in hand, and develop together during acquisition. The Feature Co-occurrence Constraint theory builds on a minimal view of phonology, where the inventory is seen as epiphenomenal rather than a mentally ‘real’ object, features are few and monovalent, and the constraint set is limited to no more than two types. The theoretical consequences of the proposal for both feature theory and constraint theory are worked out in detail and a thorough discussion of phonological acquisition is provided, making this book of interest to both theoretical phonologists as acquisitionists. Show less
