Research master thesis | Psychology (research) (MSc)
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The link between anxiety in parents and children is well established, yet the physiological correlates of this intergenerational link in anxiety remain underexplored. This study examines the...Show moreThe link between anxiety in parents and children is well established, yet the physiological correlates of this intergenerational link in anxiety remain underexplored. This study examines the physiological correlates of emotion processing between parents and children. The primary aim of the current study was to explore the link between parents' and children's pupil responses to negative versus positive expressions. The secondary aim was to study the links of parental anxiety to the child’s pupil responses to emotional expressions. A community sample of 90 children (8–12 years old, M = 10.13, SD = 1.32, 47 girls) and their parents (47 mothers) viewed positive and negative dynamic facial expressions while an eye-tracker recorded their pupil dilation. Parents were asked to fill out a questionnaire about their anxiety. Both parents and children exhibited stronger physiological responses to fearful and sad faces compared to happy faces, suggesting heightened arousal to these negative emotions. In contrast only parents, but not children exhibited a significantly stronger physiological reaction to anger. The link of parental anxiety to children's pupil responses varied by emotion type. The strength of the link between parental anxiety and pupil responses was the strongest for fearful expressions, followed by happy and sad expressions, and weakest for angry expressions. The study is the first to show a link between the physiological correlates of emotion processing between parents and children and support the idea that parental anxiety explains variance in child emotion processing.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Objective: The Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) is the gold standard to assess post-traumatic stress disorder (PTSD). Although the CAPS-5 was developed and validated in Western...Show moreObjective: The Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) is the gold standard to assess post-traumatic stress disorder (PTSD). Although the CAPS-5 was developed and validated in Western populations, many clinicians and researchers also use it to assess PTSD in non-Western refugee populations. In this study we investigated whether PTSD as assessed with the CAPS-5 has the same structure and meaning across trauma-exposed, treatment-seeking individuals with either a Dutch (i.e. Western) background or a non-Western refugee background. Method: We evaluated commonly accepted DSM-5 PTSD factor models and tested different levels of measurement invariance (configural and scalar invariance) in a clinical sample of non-Western refugee patients (N = 710) and Dutch patients (N = 1162) suffering from prolonged complaints of psychotrauma, using confirmatory factor analyses (CFA). Results: CFAs showed that the Hybrid model of PTSD fit the data best in the Dutch and non-Western refugee subsample, as well as in the combined sample, indicating that configural invariance was met. The model representing scalar invariance showed a worse fit compared to the model representing configural invariance, indicating that factor loadings and/or symptom severity differed between the subsamples. Further investigation showed that this result could mainly be attributed to non-Western refugee patients often manifesting higher scores on the CAPS-5 items than Dutch patients. Conclusions: Non-Western refugee patients showed a similar structure of DSM-5 PTSD symptoms as Dutch patients. Furthermore, the relative contribution of the majority of symptoms to its belonging symptom cluster was similar between non-Western refugee patients and Dutch patients. This meant that both groups understood these symptoms in the same way. However, non-Western refugee patients often manifested a higher symptom severity than Dutch patients.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Humans have the unique ability to process and organize sensory input into meaningful concepts, a capacity that is compromised in clinical populations, such as semantic dementia (SD). Our study...Show moreHumans have the unique ability to process and organize sensory input into meaningful concepts, a capacity that is compromised in clinical populations, such as semantic dementia (SD). Our study proposes that these concepts are shaped by the interaction between internal neural networks and external environmental interactions, and understanding this process in the healthy brain will inform our knowledge of degenerative disorders like SD. Therefore, our study aimed to examine changes in neural activation patterns in healthy individuals by utilizing functional magnetic resonance imaging (fMRI) during a conceptual decision task before and after concept generation training. The primary analyses did not reveal significant changes in neural activation patterns in the anterior temporal lobes (ATL) or inferior frontal gyrus (IFG). A slight increase in behavioral accuracy suggests that some conceptual learning has occurred, however, this effect was not robust enough to induce detectable neural changes in the targeted brain regions. Exploratory analyses revealed expanded neural engagement following the conceptualization task in early visual cortices (V2). This revealed that while traditional regions, such as the ATL and IFG did not show significant decoding accuracy patterns, early visual areas process task-dependent information independently, constituting a possible shift of visual processing strategies towards a more dynamic and integrative role after conceptual learning. These findings challenge the traditional view of concepts as fixed internal representations and highlight the need for expanded research including larger sample sizes and advanced methodologies to deepen our understanding of these underlying neural and cognitive mechanisms. Such research could provide important implications for clinical populations, such as those with SD, where these mechanisms may be disrupted.Show less
Research master thesis | Psychology (research) (MSc)
open access
Within depression research, there is an abundance of measures to assess various aspects of the disorder. However, research has rarely taken into account whether different instruments are capable of...Show moreWithin depression research, there is an abundance of measures to assess various aspects of the disorder. However, research has rarely taken into account whether different instruments are capable of measuring the same components of depression. The present study compared whether three self-report methods led to the same conclusions regarding shifts in depressive symptom severity. For this study, 238 participants of the WARN-D study completed a pre-post measure, an EMA measure and a single-item measure. The pre-post and EMA measures both contained the Patient Health Questionnaire 9 (PHQ-9). To assess the convergence between the methods, Kendall’s Tau correlations were run. Additionally, to assess the robustness of the results, multiverse analyses were conducted for different depressive symptom severity categorizations and for different thresholds of compliance with EMA measurements (50% and 75%). Results indicated negligible to weak convergence between the self-report methods (rτ ranged between .06 and .22, depending on the comparison). The findings were robust across the different multiverse analyses, save for one comparison. Overall, the present study indicated that different self-report measures might lead to different categorizations of changes in depressive symptom severity for the same participant. This means that future studies should consider which self-report method would be best suited to answer their research question or whether it might be more appropriate to use multiple methods to be able to draw more informative conclusions.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Adolescent’s prosocial behaviour is likely related to their social context and relationships. This social context drastically changes during adolescence, with peers becoming more important relative...Show moreAdolescent’s prosocial behaviour is likely related to their social context and relationships. This social context drastically changes during adolescence, with peers becoming more important relative to parents. This pilot study therefore investigated the relative contribution and interaction of adolescents’ quality of parental and peer attachment in predicting their prosocial behaviour towards unknown peers. Forty-two adolescents aged 9-12 completed the brief Inventory of Parent and Peer Attachment and an adapted version of the Prosocial Effort Task. In this task, participants choose whether to earn rewards for themselves and others by exerting physical effort. Computational modelling was used to quantify the rate at which rewards lose subjective value to adolescents when effort increases, both when earning rewards for others and for themselves. The difference in this effort discounting rate for others and for themselves was used as measure of prosocial behaviour, as well as the difference between the number of times participants chose to exert high effort for others and for themselves. We show that adolescents are generally less willing to exert effort for others than for themselves, and that their willingness to exert effort for a reward is more strongly affected by the effort needed to obtain it when someone else will receive this reward. These findings support the cost-benefit framework of prosocial motivation. Linear models fitted using nonparametric bootstrapping show nonsignificant trends in the expected directions, namely higher quality parental and peer attachment being related to more prosocial behaviour and peer attachment generally being a stronger predictor than parental attachment. We found some evidence that girls show significantly more prosocial behaviour than boys. Future research should further investigate these potential effects using larger samples with a broader age range across adolescence, to also study developmental effects.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Childhood maltreatment (CM) is a public health issue affecting mental and physical well-being of individuals across the lifespan. The literature so far suggests that CM is a risk factor for the...Show moreChildhood maltreatment (CM) is a public health issue affecting mental and physical well-being of individuals across the lifespan. The literature so far suggests that CM is a risk factor for the development and severity of EDs in adulthood. This study aims to build upon and update the findings of Molendijk et al. (2017) by integrating both pre-2016 and post-2016 literature on the relationship between all types of CM (physical, sexual, and emotional) and all types of EDs. A random-effects meta-analysis with moderator analyses was performed to assess the associations between all types of CM and all types of ED, focusing on their prevalence, severity, and related comorbid conditions. The prevalence of CM was consistently and significantly higher in ED patients (18.4- 57.7%) than in healthy controls (7.2-29.2%) and mostly higher compared to psychiatric controls (21.2 - 31.1%). The odds of developing EDs were significantly elevated in individuals exposed to CM, with ORs ranging from 2.81 to 4.60. CM exposure was associated with greater severity of EDs (r = .21, 95% CI [0.10, 0.32], p < .001) and was also associated with higher levels of depression and anxiety (r = .19, 95% CI [0.11, 0.26], p < .001). Additionally, we found that CM exposure significantly increased the likelihood of comorbid mental health disorders in patients with EDs compared to non-exposed counterparts (ORs 1.15 to 3.96), with the strongest associations observed for Axis I disorders, especially depression and anxiety. Moderator analyses revealed that recent studies reported slightly higher CM prevalence in AN samples. Sample size influenced the sexual CM-BED relationship (R2 =0.42, p =.04), and higher study quality was linked to lower prevalence rates (R2 = 0.07, p < .001), though these factors explained only a small part of the heterogeneity. Our findings highlight that all types of childhood maltreatment (physical, sexual, and emotional) are associated with a range of EDs in adulthood and influence both the severity and course of EDs.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Objective: This study aimed to clarify the relationship between the course of core depressive symptoms and the course of insomnia symptoms in older adults with a depressive disorder, and to...Show moreObjective: This study aimed to clarify the relationship between the course of core depressive symptoms and the course of insomnia symptoms in older adults with a depressive disorder, and to identify predictors of an unfavorable versus a favorable course of core depressive symptoms and insomnia symptoms. Method: We examined 329 older adults (median age 69 (IQR 65-75), 66.9% women) with a depressive disorder within the Netherlands Study of Depression in Older persons (NESDO), a naturalistic cohort study with a six-year follow-up and assessments every six months in between. Core depressive symptoms and insomnia symptoms were assessed with 14 and 3 items, respectively, from the Inventory of Depressive Symptomatology (IDS). We applied growth mixture modelling to identify classes of participants with similar trajectories of core depressive symptoms and insomnia symptoms. The association between core depressive and insomnia symptom trajectories was examined with a chi-squared test. Finally, we investigated predictors of class membership for core depressive symptoms and for insomnia symptoms using multinomial logistic regression. Results: We identified three trajectories of core depressive symptoms: high and stable (22.2% of participants were assigned to this class), moderate and declining (37.4%), and low and declining (40.4%). We identified four trajectories of insomnia symptoms: high and stable (23.1%), moderate and stable (55.6%), low and increasing (7.6%), and moderate and declining (13.7%). There was a significant association between core depressive and insomnia symptom trajectories, in particular for the most and least favorable trajectories. Number of chronic diseases, a comorbid anxiety disorder, and functional limitations predicted less favorable core depressive symptom trajectories. We found no predictors for insomnia symptom trajectories. Conclusion: Persistent insomnia symptoms are highly prevalent in older adults with depression, even in those with improving core depressive symptoms. This highlights the need for separate treatment of insomnia symptoms in addition to depression interventions.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Adolescents’ future expectations (FE) regarding the attainability of desired life goals are variable, and, compared to allistic peers (i.e., non-autistics), are often more pessimistic. One reason...Show moreAdolescents’ future expectations (FE) regarding the attainability of desired life goals are variable, and, compared to allistic peers (i.e., non-autistics), are often more pessimistic. One reason may be that autistic adolescents have more difficulties on the social domain, and therefore perceive their own social competence as poorer than allistic peers. Importantly, FE may inform adolescents goal-directed actions, such that expectations for the future influence actual future outcomes. Thus, the importance of assessing which factors influence future expectations is evident. This study assessed the extent to which autistic and allistic adolescents differ on self-perceived social competence (SPSC), and FE (on the romantic and self-development domains); and the extent to which autistic adolescents’ SPSC was related to their FE compared to allistic peers, controlled for global self-esteem. Autistic adolescents’ were expected to have lower FE than allistic peers’, related to lower SPSC. Preliminarily, the uni-dimensionality and reliability of constructs was tested with factor analyses. Mediation analyses on a total of 142 adolescents, 88 allistic and 54 autistic (Mrange 12-21; Mage = 16.31, SD = 1.94), revealed that, though autism was not directly related to having less optimistic FE for either romantic or self-development goals, SPSC mediated the relationship between autism and FE for self-development (i.e., having a job/career, or continuing their education). That is, autistic adolescents’ lower SPSC was related to poorer FE for self-development compared to allistic peers, when controlled for global self-esteem. Clinical implications and future directions for research are discussed.Show less
Research master thesis | Psychology (research) (MSc)
open access
Bullying victimization is a major public health concern, because victims often experience long-term negative mental health outcomes. Longitudinal brain structure research in children is needed to...Show moreBullying victimization is a major public health concern, because victims often experience long-term negative mental health outcomes. Longitudinal brain structure research in children is needed to understand the possible mechanisms underlying the relation between bullying victimization and negative mental health outcomes. Previous research has shown that the fusiform gyrus, amygdala and vmPFC are impaired in victims. Therefore, this thesis examined the relation between victimization and fusiform gyrus, amygdala and vmPFC volume over time. We hypothesized that victims of bullying, compared to children uninvolved in bullying, would have a larger fusiform gyrus volume and a steeper volume increase. Furthermore, we hypothesized that victims of bullying, compared to children uninvolved in bullying, would have a smaller amygdala and vmPFC volume and a steeper volume decrease. The sample consisted of 156 children (62% female), aged between 7 and 9 years old at baseline, from the Leiden Consortium on Individual Development. At the beginning of the study, the Revised Olweus Bully/Victim Questionnaire was administered to measure bullying victimization and high-resolution structural MRI scans were taken. This was done again two years later. Children were classified as victims if they had been bullied regularly in the past two months. We did not find an effect of victimization on fusiform gyrus, amygdala and vmPFC volume. Future research examining the influence of victimization on both structural and functional brain development is needed to provide further insights, which can help inform the design of interventions to reduce the negative consequences of bullying victimization. The current findings emphasize the importance of protective factors that make a victim’s brain development resilient against victimization. This indicates a need for interventions targeting the development of social-emotional skills or the increase of family support.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Transcutaneous vagus nerve stimulation (tVNS) together with mindful acceptance hold promise for pain management, yet their combined efficacy remains largely unstudied. This study investigates...Show moreTranscutaneous vagus nerve stimulation (tVNS) together with mindful acceptance hold promise for pain management, yet their combined efficacy remains largely unstudied. This study investigates whether this combination can effectively reduce pain perception in healthy participants. We exposed 52 participants to two types of heat stimuli by using a Medoc pain device: Warm temperature of 47 °C and hot temperature of 51 °C. Subsequently, participants were divided into receiving either active tVNS (n = 26), or sham tVNS (n = 26). During the experiment, on alternating blocks, we asked participants to exercise mindful acceptance or to react naturally towards the experimentally induced heat pain. Participants rated their subjective pain by using a visual analogue slider and underwent EEG recordings to assess Contact-Heat Evoked Potentials (CHEPs). After performing several rmANOVAs, the results indicated that tVNS combined with mindful acceptance did not significantly reduce reported pain perception and neurophysiological responses, compared to the control group. However, mindful acceptance alone was associated with reduced subjective pain ratings, both for the affective (p < .001, np2 = .45) and sensory (p < .001, np2 = .39) aspects of pain, though it did not significantly reduce CHEPs (p = .82, np2 = .001). Lastly, tVNS alone did not significantly influence subjective pain ratings, both affective (p = .13, ηp² = .045) and sensory (p = .42, ηp² = .013), nor CHEPs (p = .31, np2 = .021). Overall, these findings suggest a positive effect of mindful acceptance on subjective pain perception, but future studies assessing objective measures of neurophysiological correlates during tVNS with mindful acceptance are warranted.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Many situations in daily life require the simultaneous performance of motor and cognitive tasks, such as reaching for items in the supermarket while recalling a shopping list. For patients with...Show moreMany situations in daily life require the simultaneous performance of motor and cognitive tasks, such as reaching for items in the supermarket while recalling a shopping list. For patients with Parkinson’s Disease (PwPD), who already suffer from distinct motor and cognitive symptoms, these situations can be even more challenging. While deep brain stimulation (DBS) provides a promising option for symptom management in the advanced stages of the disease, its effect on everyday life situations has not been explored as much. Thus, using a dual-task paradigm, this study aimed to address this gap by investigating the effects of varying levels of cognitive load and DBS on motor and cognitive performance in PwPD. Eight PwPD with DBS were tested twice: once with DBS turned on and once off. Motor performance was assessed with a custom-designed motor task that required the patients to perform consecutive goal-directed reaching movements. These movements were recorded with a markerless hand-tracking module to capture broad motor performance measures and detailed kinematic data. Cognitive performance was assessed with a serial subtraction task, including high and low levels of cognitive load (subtracting by seven and one, respectively). Finally, linear mixed-effect models were used to statistically compare the effects of DBS, high, and low cognitive load on overall motor and cognitive performance and relevant kinematic features. The results show that high cognitive load negatively affected overall motor and cognitive performance, while low cognitive load only affected cognitive performance. On the other hand, DBS improved overall motor performance while not affecting cognitive performance. Furthermore, high cognitive load and DBS had a significant, yet opposite, effect on the same kinematic features: deceleration time, movement time, reaction time, peak velocity, and coefficient of variation of trajectory error. In conclusion, this study highlights the feasibility of administering more naturalistic experimental designs with a dual-task paradigm and detailed kinematic analyses in PwPD. We show that the dual-task effect is dependent on the amount of cognitive load and that Deep Brain Stimulation can significantly improve motor performance in dual-tasking scenarios. Finally, our detailed kinematic analyses reveal specific components of a reaching movement responsible for changes in motor performance, providing valuable insights for future research and clinical practice.Show less
Research master thesis | Psychology (research) (MSc)
under embargo until 2025-07-31
2025-07-31T00:00:00Z
We tested the effects of audit probability (high, low, ambiguous) and audit probability change (increase, decrease) on compliance in a simplified tax return task. Participants were asked to report...Show moreWe tested the effects of audit probability (high, low, ambiguous) and audit probability change (increase, decrease) on compliance in a simplified tax return task. Participants were asked to report correct returns, faced with either a high (40%), low (10%) or ambiguous (10-40%) audit probability. In addition, audit probabilities of each participant were either increased or decreased by five percentage points after half of all trials were completed. Results showed that, in line with our predictions, high audit probability yielded significantly higher compliance than low audit probability and that high and ambiguous audit probability yielded similar compliance. Contrary to our expectations, audit probability change in the form of increases or decreases did not yield significant effects on compliance. The present study indicates that an ambiguous audit probability can yield increased compliance akin to a high audit probability. Our findings provide a starting point for further investigation into the effects of information about audit probability on tax compliance. Suggestions for replication studies and further research are provided.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Adolescence is characterized by the onset of puberty. Puberty, in turn is shown to be a driver of brain development and has been related to the onset and increase of internalizing symptoms. However...Show moreAdolescence is characterized by the onset of puberty. Puberty, in turn is shown to be a driver of brain development and has been related to the onset and increase of internalizing symptoms. However, the relationship between puberty, brain development, and internalizing symptoms has not been studied using multiple pubertal measures in both sexes. Here we examine the mediating role of brain development on the relationship between puberty and internalizing symptoms. Pubertal status, timing, age at menarche, and internalizing symptoms were assessed based on self-reports in 160 adolescents between 10 and 25 using a three-wave accelerated longitudinal design. Structural MRI scans were only obtained in the first wave. Subsequently, the relations between the pubertal measures (status, timing, age at menarche) and internalizing symptoms were tested as well as their relations with grey matter thickness and volume in frontal, cingulate, and subcortical areas. Only age at menarche as a timing variable had a significant effect on internalizing symptoms at T1 in girls (ß = -.36, p = .002, 95% CI [-.68, -.17]). Mediation models revealed no significant mediation of grey matter thickness and volume in our ROIs. Other effects did not reach significance or became non-significant after Bonferroni corrections. These findings indicate that menstruating before one’s peers is a risk factor for developing internalizing symptoms. This highlights the importance of supporting early menstruating girls to possibly prevent them from developing internalizing symptoms. Replication studies are needed to assess the accuracy of our results.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Building on evidence that minority representation increases minorities’ political participation, in my preregistered study, I investigated whether increased racial representation within the climate...Show moreBuilding on evidence that minority representation increases minorities’ political participation, in my preregistered study, I investigated whether increased racial representation within the climate movement causes Americans of color (N = 226) to evaluate the climate movement more positively and to encourage them to partake in climate activism. I tested this by using a 2 x 2 between-subjects design in which representation was manipulated both descriptively (i.e., the presence of people of color) and substantively (i.e., a focus on issues specifically affecting people of color) in a short video about climate activism. The results showed that descriptive representation had a positive, significant effect on evaluation of the movement, but no effects were found for substantive representation nor on climate action behavior. These findings enrich the scientific literature and provide insights on how social movements can become more inclusive, potentially increasing their effectiveness.Show less
