This thesis sought to investigate the relationships between treatment delays in bipolar disorder (BD) and cognitive impairments which characterize the disorder, measured both objectively and...Show moreThis thesis sought to investigate the relationships between treatment delays in bipolar disorder (BD) and cognitive impairments which characterize the disorder, measured both objectively and subjectively. Previous studies have established that a long delay occurs between the onset of mood symptoms in BD and the first form of treatment received, estimates ranging between 6 and 11 years. Cognitive impairments in the domains of executive functions, processing speed and memory were found to persist in BD patients even during euthymia. Such cognitive impairments burden BD patients, prevent them from regaining an appropriate level of general functioning and diminish their quality of life. Thus, in order to determine whether treatment delay impacts the cognitive impairments present in BD, 69 participants were followed over the course of one year, at three different time points. The participants took part in clinical interviews, and then were asked to complete multiple measures, such as the YMRS, the QIDS, four WAIS subscales (Block Design, Arithmetic, Information and Digit symbol), and the Cognition subscale of the WHODAS. The average treatment delay found in the current sample was 14.53 years. The results of the current study suggest that longer treatment delays did not significantly predict worse cognitive functioning in BD patients, either when measured subjectively, or when measured objectively.Show less
In the Netherlands, children are interrogated using the Dutch child interrogation method ‘the scenariomodel’. Surprisingly, this method does not consider the impact of children's personality traits...Show moreIn the Netherlands, children are interrogated using the Dutch child interrogation method ‘the scenariomodel’. Surprisingly, this method does not consider the impact of children's personality traits, despite literature indicating that these traits play a central role in their perspectives and can therefore influence the course of the interrogation and their testimony. This correlational study investigated the extent to which the personality trait 'shyness' plays a role in the course of the child interrogation according to the scenariomodel and in the quality of the witness statement. The research target group are children under the age of 12 who are victims of online sexual abuse. Participants (N = 23) underwent an ethically responsible simulation of online sexual abuse and a simulation of a child interrogation according to the scenariomodel. The transcripts of the interrogations were coded to first examine the quality of the testimony based on three indicators: accuracy of the statement, completeness of the statement and the amount of forensic information. And second to investigate the course of the interrogation based on the resistance that children show. Shyness was measured with a questionnaire. The study anticipated that shy children exhibit more resistance and provide lower quality testimonials due to their susceptibility to suggestiveness and social discomfort during interrogations. However, the results showed no significant correlations between shyness and the quality indicators of the testimony, nor between shyness and resistance. A mediating effect of resistance on the quality of the testimony was therefore also excluded. This suggests that the scenariomodel may be resistant to the negative influences of this personality trait and can be used without concern for interrogating shy children who have been victims of online sexual abuse. However, due to important limitations of the study, firm conclusions cannot be drawn and follow-up research is necessary.Show less
Bachelor thesis | Cultural Anthropology and Development Sociology (BSc)
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This thesis explores the continuum of East African knowledge production with a particular focus on the dialogue between endogenous East African and Western colonial knowledge production through...Show moreThis thesis explores the continuum of East African knowledge production with a particular focus on the dialogue between endogenous East African and Western colonial knowledge production through colonialism. This dialogue is approached through an investigation of the colonial classifications of tribe and ethnicity, depicting how these classifications were created and enforced, and their interaction with and effect on endogenous East African knowledge production.Show less
Suicidal ideation is more prevalent in people with Borderline Personality Disorder. Negative self-conscious emotions, such as shame and guilt, may be related to this relationship. In this study the...Show moreSuicidal ideation is more prevalent in people with Borderline Personality Disorder. Negative self-conscious emotions, such as shame and guilt, may be related to this relationship. In this study the relationship between suicidal ideation and borderline personality traits was explored. Shame and guilt were analysed as possible mediators. The Personality Assessment Inventory – Borderline Scale was used to assess borderline personality traits, and Ecological Momentary Assessment was used to gather data on suicidal ideation, guilt and shame four times a day, over the course of three weeks via an app. The sample consisted of (N = 82) adults with a history of a suicide attempt or moderate-to-severe suicidal ideation in the past year. The relationships were analysed using a parallel mediation model consisting of multiple multilevel regression analyses. All steps of the model showed significant relationships. The last step showed that instead of typical mediation, the model indicated suppression, because of an increase in the association between borderline personality traits and suicidal ideation when accounting for shame and guilt. More research is necessary to explore the possible cause of these findings.Show less
This research aims to investigate the topology of the brain during reward processing and the influence of dopamine and norepinephrine on this network. So far, most research about reward processing...Show moreThis research aims to investigate the topology of the brain during reward processing and the influence of dopamine and norepinephrine on this network. So far, most research about reward processing has concentrated on specific brain areas and connections between particular regions, rather than the brain's organization and architecture. By investigating this organisation, gaps in our understanding of the brain architecture can be addressed, which could in turn lead to a better understanding of pathologies that disrupt the brain’s architecture. It is hypothesized that the brain will be more integrated during reward processing, and that increased dopamine and norepinephrine activity will result in a more integrated brain organisation. To test this prediction, the Global Efficiency (GE) of a total of 132 Regions of Interest (ROIs) and BOLD- activity of the Substantia Nigra/Ventral Tegmental Area (SN/VTA) and the Locus Coeruleus (LC) were obtained during a reward processing task, which 38 participants completed. During a functional magnetic resonance imaging (fMRI) scan, participants completed a reward- emotion recognition test. As predicted, in the reward condition, the paired t-test showed a higher GE in comparison to the no-reward condition in several nodes, mostly in the default mode network. These findings imply that the brain is more integrated when processing reward than when it is not processing reward. However, the catecholamines showed no significant correlation with this integration. Future research is needed to investigate the topology and influence of different catecholamines in more detail. The implications of these findings will be discussed.Show less
In recent years, classical psychedelics have become increasingly popular as a possible treatment method for mental health disorders. Optimizing set and setting during psychedelic use leads to the...Show moreIn recent years, classical psychedelics have become increasingly popular as a possible treatment method for mental health disorders. Optimizing set and setting during psychedelic use leads to the most beneficial outcomes. Trait mindfulness, which is the general tendency to experience mindfulness in daily life, could be seen as part of the set. Earlier research suggested that psychedelic drug intake could lead to increases in practicing mindfulness, trait mindfulness, and cognitive flexibility (CF), all factors associated with positive mental health outcomes. Moreover, these factors seem to be interconnected, as, for instance, trait mindfulness can predict higher CF. Since there has currently been no research yet on the influence of psychedelic drug intake on CF with trait mindfulness as a mediator, as well as on the impact of psychedelic drug intake on trait mindfulness controlling for current meditation practice, this paper aimed at filling this explanatory gap. The findings suggested that psychedelic-experienced individuals are more likely to currently be a meditator than psychedelic naives and that the positive association between psychedelic use and trait mindfulness remains after correcting for current meditation practice. Further, a significant indirect relationship between psychedelic drug intake and CF with trait mindfulness as a mediator has been found, though the direct effect is non-significant. Lastly, psychedelic use-related variables were investigated, showing that the dose could positively predict CF but other variables, including frequency, recency, and likelihood of next intake could not. Implications of these findings for current practice, future research, and psychedelic-based treatment were considered.Show less
Background Alzheimer's dementia (AD) and mild cognitive impairment (MCI) are neurodegenerative conditions associated with cognitive decline. Previous research suggests that motor impairments are...Show moreBackground Alzheimer's dementia (AD) and mild cognitive impairment (MCI) are neurodegenerative conditions associated with cognitive decline. Previous research suggests that motor impairments are also present in individuals with MCI and AD. This thesis study aims to evaluate motor sequence learning abilities in patients with amnestic MCI (aMCI) and AD compared to healthy controls. This thesis study also explores the relationship between amyloid-β burden, a known biomarker for MCI and AD, and motor sequence learning to study whether such motor learning could also be a behavioral biomarker. This is because measuring amyloid-β is very costly and invasive, and thus the search for other biomarkers is important. Methods A cross-sectional design was employed, and participants included 28 AD patients, 33 aMCI patients, and 53 healthy controls. Motor sequence learning was assessed using a computerized task measuring reaction time and accuracy per trial, and with this information the rate and final amount of learning was calculated, i.e. how fast and how much information the participants are able to learn, respectively. Amyloid-β burden was measured using PET imaging, with higher burden reflecting more severity of the symptoms of aMCI and AD. Results The final amount of learning was not different amongst the groups, and the rate of learning was only significantly different between the AD and aMCI groups, with the AD groups showing a faster rate of learning. The AD and healthy control group did not, however, differ significantly in terms of rate of learning. The amount of amyloid-β in the brain was not associated with motor sequence learning abilities. Conclusion The findings suggest that motor sequence learning abilities are preserved in individuals with aMCI and AD, both in terms of how fast and how much they learn. In fact, patients with AD showed a faster rate of learning than patients with aMCI, although this was not found when comparing the AD patients with the healthy individuals. It is possible that this finding is because patients had more to learn by the end of the task than the aMCI group given that their memory is worse, and displayed a faster rate of learning due to this. This thesis study also suggests that motor sequence learning is not a behavioral biomarker for aMCI and AD. The search for less invasive and more easily measurable biomarkers continues to be imperative.Show less
The current study examined to what extent the quality of the sibling relationship and the quality of the parent-child relationship is linked to aggressive behavior between siblings during conflicts...Show moreThe current study examined to what extent the quality of the sibling relationship and the quality of the parent-child relationship is linked to aggressive behavior between siblings during conflicts. In addition, it was examined whether the quality of the parent-child relationship would moderate the relation between the quality of the sibling relationship and aggressive behavior between siblings during conflict. These relations were examined with a sample of 26 families, of which two siblings aged 8-15 years old and one parent participated. The amount of aggressive behavior during conflicts between siblings, quality of the sibling relationship and the quality of the parent-child relationship were measured by questionnaires. The results of this study showed a negative relation between the sibling relationship quality and aggressive behavior during conflicts between siblings, a positive relation between the quality of the sibling relationship and the quality of the parent-child relationship and a negative relation between the quality of the parent-child relationship and aggressive behavior during conflicts between siblings. The quality of the parent-child relationship did not act as a moderator for the relationship between the quality of the sibling relationship and the degree of aggressive behavior in conflicts between siblings. These results indicate a possible indirect role of the parent-child relationship quality in the degree of aggressive behavior in conflicts between siblings.Show less
In a world of rising economic inequality, exploring factors that contribute to a more equal society is vital. The extent to which people are generous towards those around them can help reduce local...Show moreIn a world of rising economic inequality, exploring factors that contribute to a more equal society is vital. The extent to which people are generous towards those around them can help reduce local inequalities. While previous literature has established a link between economic mobility and preferences for redistribution, the impact on individual giving remains unclear. Therefore, this study examined the influence of economic mobility on giving behavior and whether meritocratic beliefs mediate this effect. The sample included 301 participants, predominantly from Global South countries. Participants were randomly assigned to ranks on a 5-rank ladder resembling socioeconomic classes and to conditions of low or high economic mobility. First, participants played a game in which they estimated the number of dots in a picture. Those with high economic mobility could earn 3 points, and those with low economic mobility could earn 1 point per round. In a dictator game, they could indicate how many points they want to give to reach rank. Results showed that the high economic mobility condition had significantly stronger meritocratic beliefs about the estimation game, aligning with the first hypothesis. However, contrary to the second hypothesis, participants in the high economic mobility condition gave significantly more to the ranks below them. Meritocratic beliefs about the estimation game did not mediate the effect. This suggests that inducing high economic mobility seems to increase generosity, particularly towards those with fewer resources. Policymakers and non-governmental organizations should promote high economic mobility to foster generosity in society.Show less
Autism spectrum disorder (ASD) is a developmental disorder that still holds many uncertainties regarding the etiology. In order to provide the most effective assistance to children with ASD,...Show moreAutism spectrum disorder (ASD) is a developmental disorder that still holds many uncertainties regarding the etiology. In order to provide the most effective assistance to children with ASD, understanding the cognitive foundation of this disorder is crucial. There are several theories on this subject, yet there is limited research delving deeper into the potential connections between these theories. This research focused on the Central Coherence Theory and the Executive Dysfunction Theory and investigated whether there is a relation between these factors in explaining ASD. For this purpose, the Rey-Osterrieth Complex Figure Task, Tower of Hanoi, Picture Span and Autism Spectrum Questionnaire were administered to 89 children aged between 8 and 11 from six different primary schools in the Netherlands. Correlation analyzes were conducted to examine whether performance on central coherence, planning, and working memory correlated with the level of ASD traits. Using the PROCESS Macro, a mediation analysis was conducted to investigate whether executive functions could mediate the relationship between central coherence and ASD characteristics. The results of this study indicated that neither central coherence nor planning nor working memory were associated with the number of ASD characteristics. Moreover, no mediating effect of planning or working memory could be found. The fact that the results were not in line with the expectations could possibly be related to the non-clinical sample used in the current study, among other things. Future research should continue to focus on further investigation into the relationship between central coherence and executive functions, carefully taking into account the heterogeneity of ASD.Show less
Social media has become a platform for sharing alcohol and other drug (AOD) recovery journeys, with #selflove as a prominent theme. This study explores the association of self- views, positive...Show moreSocial media has become a platform for sharing alcohol and other drug (AOD) recovery journeys, with #selflove as a prominent theme. This study explores the association of self- views, positive emotions, and social connections in the context of social media, particularly regarding #selflove and in AOD recovery. Specifically, social connections are examined as they are considered to be a relevant point of support during the recovery process. Positive emotions are examined, as employing a more positive outlook towards oneself is associated with a more positive self-view and a more sustained recovery process. The dataset comprises 902 posts from Instagram and Twitter in 2019 collected by Ziemer (2022). The present study addresses two research questions: (1) What is the association between positive and negative self-views in social media posts using chi-square analysis to identify a balanced self-view (discussing negative and positive self-views) during the recovery journey, (2) to what extent can positive self-view mentions be predicted through logistic regression, based on expressed connectedness with family/friends, the AOD recovery community, and positive emotions in the posts. Surprisingly, the results challenge the initial hypothesis of predominantly balanced self-views in these posts, as no association was found between mentioning positive and negative self-views within a single post. Contrary to expectations, mentioning positive self- views was not linked to references to connecting with others or positive emotions. Future research should employ more nuanced coding for emotions and social connections. Qualitative measures can help capture potential differences between sharing one's recovery journey online and the actual offline experience.Show less
