Objective: To explore the relationship between peak melatonin levels and depression scores in patients with rheumatoid arthritis and whether this relationship is mediated by pain, fatigue or...Show moreObjective: To explore the relationship between peak melatonin levels and depression scores in patients with rheumatoid arthritis and whether this relationship is mediated by pain, fatigue or disease activity. Methods: This study was of a cross-sectional, analytical and retrospective design using baseline data of an intervention study. Participants with rheumatoid arthritis were recruited and a total of 30 participants (7 males (23%) and 23 females (77%)) between the ages of 26 and 74 years (M=55.2 and SD=10.74) were analysed in this study. The measures of the study included peak melatonin levels, the IRGL (pain), HADS (depression), DAS-28 (disease activity) and CIS-8 (fatigue). Spearman’s correlations were used to analyse the relationships between all the variables and PROCESS.spss was used to conduct mediation analyses. Results: There was a significant negative relationship between peak melatonin levels and depression scores (p=.039), a significant positive relationship was found between depression and fatigue (p<.001) and a significant positive relationship was found between pain and disease activity (p=.018). The mediation analyses did not reveal any potential mediators. Conclusion: Melatonin is linked to depression; however, this link cannot be explained by the mediators listed in this study and further examination of this link is needed. While there were no potential mediators between melatonin and depression, the relationships found between depression and fatigue as well as between pain and disease activity could be explained by the overlap in the items in the various measurements.Show less
While reading a text, the reader makes a mental representation of this text to understand it. Reading comprehension is one of the most important tasks in primary school. It is important for success...Show moreWhile reading a text, the reader makes a mental representation of this text to understand it. Reading comprehension is one of the most important tasks in primary school. It is important for success in all subjects in school, but it is also important in daily life. The aim of this study is to investigate if readers a text understand better if they are interested in the subject of the text than when they are less interested. In addition, it is investigated whether the difference is different for low-motivated readers than for highly-motivated readers. The following research question has been formulated: ‘Do readers understand a text better when they are very interested in the subject of a text than when they are uninterested in the subject of the text? And is the difference non-identical for highly intrinsically motivated readers and low intrinsically motivated readers?’ To answer the research question, the reader has completed a reading task and a questionnaire about reading motivation. The reader has chosen three interesting topics and three uninteresting topics to read. After reading the text, the reader was asked to answer three literal questions and three inference questions about the text. In this way, it could be investigated whether interest in a specific text plays a role in text comprehension. The reader also completed a questionnaire about reading motivation to investigate whether the difference is different for highly motivated readers than for low-motivated readers. In this research, attention is only paid to intrinsic motivation. The research has shown that interest has no influence on text comprehension and there is no difference for highly motivated readers and low-motivated readers. Despite these results, it is still recommended to look for texts that arouse the interest of children. According to the literature, interest and motivation are effective factors for text comprehension.Show less
General abstract Background: Unhealthy lifestyle increases the change of early mortality of patients with or at risk of Cardiometabolic Diseases (CMDs). Positive effects of eHealth physical...Show moreGeneral abstract Background: Unhealthy lifestyle increases the change of early mortality of patients with or at risk of Cardiometabolic Diseases (CMDs). Positive effects of eHealth physical activity interventions have been recently found. In human supported eHealth interventions feedback and support is primarily provided by a healthcare professional, and in self-help eHealth interventions feedback is primarily automated and displayed via text or graphical form. Incorporating human contact by healthcare professionals showed its first improvements on physical activity. However, influential differences between human supported eHealth interventions and self-help eHealth interventions on physical activity remain unclear. Objective: In this meta-analysis we first evaluated the overall effectiveness of eHealth physical activity intervention in patients with or at risk of Cardiometabolic Diseases (CMD). Second, we analyzed the influence of human support and self-help on the effectiveness of different type(s) of eHealth physical activity intervention. Methods: Our meta-analysis was based on the PICO and PRISMA statements. We searched for English and Dutch studies between 1995 and 2020. We included randomized controlled trials focused on interactive web- mobile based physical activity interventions, and with the goal to modify healthy physical activity in patients of 18 years and older. Baseline and post measures of outcome measurement ‘BMI’ and ‘step count’ were collected. Risk of bias assessment was performed by Cochrane Risk of Bias Tool. We estimated the pooled effect sizes with a random-effects model meta-analysis. Results: A total of 36 studies (N=6,919) fulfilled the eligibility criteria and were included in our meta-analysis, including seven self-help interventions and 29 human supported interventions. We found a significant increase in BMI (Hedges’G 0.29, 95% CI. 0.45 - 0.12) and daily step count (Hedges’G 0.79, 95% CI. 1.37 - 0.22) in the eHealth physical activity intervention group. The subgroup analysis showed that both human-supported and self-help interventions significantly reduced BMI (Hedges’G 0.29; 95% CI 0.45 - 0.12). We found a significant increase in daily step count in the human-supported interventions (0.71; 95% CI 1.34 - 0.09; p = < 0.01), but no significant increase was found in the (group) with self-help interventions (0.11; 95% CI 2.34 - 0.32; p = 0.13). We found no significant difference in effectiveness between human-supported and self-help interventions on BMI (Q(1) = 0.35; 95% CI -0.47 - -0.18; p = 0.552) and daily step count (Q(1) = 1.06 CI -0.32 - 2.44). Discussion: eHealth physical interventions are effective on BMI and daily step count, but there is no significant variety in physical activity outcomes between human supported interventions and self-help interventions. Our results support that physical activity is one of the greatest modifiable behaviors for eHealth physical activity interventions. Future meta-analysis should continue with a multimorbid approach by adapting the shared underlying risk factors.Show less
In the domain of interpersonal communication, the eye region has a vital role. Specifically, the pupil has an essential signalling function, reflecting different cognitive and affective states. The...Show moreIn the domain of interpersonal communication, the eye region has a vital role. Specifically, the pupil has an essential signalling function, reflecting different cognitive and affective states. The colours of the iris, surrounding the pupil, varies largely among human beings. Although studies are conducted on how the colour of the iris influences gaze perception, none have yet investigated the role of iris brightness on the perception of pupil size changes. It is furthermore known that pupil size changes affect interpersonal trust: while dilating pupils lead to a signal of trust, constricting pupils convey untrustworthiness. Nonetheless, the role of iris brightness within this process remains unknown. Moreover, there is evidence for the role of empathy within the processing of pupil size changes. Therefore, the current study explored whether iris brightness affects the perception of pupil size changes. Also, the study examined whether the brightness of the iris in dilating and constricting pupils affected the reported trustworthiness of virtual partners while controlling for the participants’ level of empathy. Fifty-one participants were included in the analysis. These participants were shown animations of a virtual partner with either dark or light irises and dilating, static or constricting pupils. In the Perception of Pupil Movement-task, they were asked: ‘Do you see movement?’. In the Trust-Game Task, they were asked: ‘Would you trust this person to donate money to a charity on behalf of you?’. The results showed that iris brightness affected the perception of pupil size changes. In stimuli with brighter irises, it was easier for participants to detect changes in the size of the pupil. Participants showed less trust when exposed to stimuli representing dilating pupils than static pupils in both light and dark irises while controlling for the individual’s level of empathy. The decreased trust in the constricting stimuli compared to the static stimuli in light and dark irises was in line with expectations. In the dark irises, there was no difference in trust scores between dilating and constricting pupils. In the stimuli representing light irises, on the other hand, there was an effect. This research found no evidence that more empathetic people perceive these subtle cues in eye contact better than less empathetic people. Our results underline the interplay of iris brightness and pupil size changes in monetary decision making and interpersonal communication, specifically regarding perceived trustworthiness.Show less
Previous research has shown that parental verbal expressions of positive and negative information contribute to the development of fear responses in their child using a variety of indices, but...Show morePrevious research has shown that parental verbal expressions of positive and negative information contribute to the development of fear responses in their child using a variety of indices, but research on the effect of parental verbal expressions on physiological indices of fear is limited. The current study aims to investigate whether threat or safety information presented by parents about a stranger affects the heart rate of the children when interacting with those strangers. Additionally, in the light of earlier evidence that has shown a moderating effect on the influence of verbal threat information on physiological changes, the role of child trait social anxiety has been explored as a possible moderator. A sample of 38 10-to-14-year-old children and their primary caregivers have participated in the current study. Parents gave their child verbal threat or safety information about two strangers that the child had to interact with during social tasks: social performance, watching back their performance, and social interaction. Heart rate was continuously recorded during these social tasks. Child trait social anxiety was measured through the child's report on the social anxiety subscale of the SCARED questionnaire. Results showed that parental verbal expressions of threat versus safety did not have a significant effect on the heart rate of the child. Furthermore, no significant moderation of this effect by child trait social anxiety was found. Conclusively, the results of the current experimental design are not in line with the expected outcome and, therefore, possible explanations and the need for further research have been highlighted.Show less
Our current findings add to the literature into the effects of childhood scarcity and current scarcity on cognitive performance. We show that participants who experienced childhood scarcity...Show moreOur current findings add to the literature into the effects of childhood scarcity and current scarcity on cognitive performance. We show that participants who experienced childhood scarcity generally perform worse on executive functioning, as measured by the Hearts and Flowers task. This is in line with the general trend that childhood scarcity seems to impede cognitive functioning (Cermakova et al., 2018; Everson-Rose, 2003). For current scarcity we found no significant main effect of on cognitive performance. However, a interaction effect between childhood scarcity and current scarcity on cognitive performance was present. While childhood scarcity generally impedes cognitive functioning; our research shows that under conditions of high current scarcity people who experienced high levels of childhood scarcity show heightened performance on the HF-task compared to those who experienced lower levels of childhood scarcity. These findings imply that cognitive performance in people who experienced childhood scarcity might not simply be impeded, but rather adopted to specific environments of uncertainty.Show less
In this project, we aimed to examine the effects of cognitive load and semantic instructions on walking parameters. The study may help further our understanding on how walking patterns and motor...Show moreIn this project, we aimed to examine the effects of cognitive load and semantic instructions on walking parameters. The study may help further our understanding on how walking patterns and motor actions can be improved, specifically in older healthy adults. This study’s findings may be valuable in developing rehabilitation programmes as post-stroke patients often show changes in walking patterns. A total of 16 healthy adults aged 55-67 years old walked along a 10-m straight runway under various conditions, while walking speed, step length, and step width were measured. The study used a 2x3 repeated measures design resulting in a total of 6 conditions. The first independent variable was cognitive load which contained two levels; single and dual task. The second independent variable was semantic instructions which contained three levels: no instructions, analytical instruction, and metaphoric instruction. The conditions consisted of each type of instruction being paired with each cognitive load level. There was also a baseline condition, in which participants walked with no instructions. This study hypothesised that a higher cognitive load will result in slower walking speeds, shorter steps and wider steps. Moreover, it hypothesised that compared to analytical instruction, metaphorical instruction will lead to walking parameters closer to baseline performance. Additionally, it was hypothesised that an interaction will occur; as cognitive load increases, metaphoric instruction will result in walking parameters closer to baseline performance. Whereas analytical instruction will result in performance closer to baseline with a lower cognitive load. The measures MANOVA showed that the main effects of cognitive load (p < .001) and semantic instruction (p < .001) on walking speed and step length were significant. A significant interaction was found (p < .001) between our two independent variables on walking speed. Specifically, there was an interaction between baseline performance and type of semantic instruction used. When compared to baseline performance, participants walked faster in the single task condition under metaphorical instruction as compared to under analytical instruction. In conclusion these findings suggest that semantic instruction is important to consider when instructing movement as it can result in deterioration or improvement of performance.Show less
Despite the fact that girls are increasingly choosing technical subjects in high school, the vast majority who practices a technical profession is men. Current research examined the relation...Show moreDespite the fact that girls are increasingly choosing technical subjects in high school, the vast majority who practices a technical profession is men. Current research examined the relation between fathers’ gendered expectations on their sons’ and daughters’ feminine and masculine occupational aspirations, and the role of the children’s gender-stereotypical beliefs in this relation. The resulting research question concerned: To what extent are the father’s genderstereotypical expectations of professions related to his children’s gender-stereotypicaloccupational aspirations, and to what extent do his children’s gender-stereotypical beliefsabout sciences mediate this relation? This question was expected to be answered by examining a sample of 100 Dutch families. Two children from each family, one aged 15 and one aged 17, participated and were asked to complete the OAT-PM and the IAT. The OATAM was administered to their fathers. The results showed no relations between either the father’s gender-stereotypical expectations of professions and his children’s gender-stereotypical beliefs about sciences, nor between the children’s gender-stereotypical beliefsabout sciences and their own gender-stereotypical occupational aspirations. However, it was found that the adolescent daughter’s masculine occupational aspirations were higher when their father had less gender-stereotypical ideas about professions. It was concluded that future research should explore the relation between the father’s implicit gender stereotypes and his children’s gender-stereotypical occupational aspirations further in other social-cultural contexts, and examine the role of explicit gender stereotypes of the child as a mediator in this relation.Show less
Many non-profit organisations employ not only volunteers, but also paid workers, to achieve their organisational objectives. This research examines whether the volunteers of a non-profit...Show moreMany non-profit organisations employ not only volunteers, but also paid workers, to achieve their organisational objectives. This research examines whether the volunteers of a non-profit organisation report appraisal and autonomous respect, job satisfaction and intent to remain a volunteer with the organisation, when they perceive that the paid workers of the organisation display self-sacrifice on behalf of the organisation and interactional justice. The research had a cross sectional survey design and the participants were volunteers working with paid workers in a non-profit organisation (a hospice; N = 52 hospice volunteers). Multiple regression analyses were conducted to test the hypotheses about direct effects. Among volunteers, autonomous and appraisal respect were found positively and directly related to job satisfaction. Additionally, among volunteers, interactional justice received from the paid workers of the organisation was found positively and directly related to autonomous respect, appraisal respect, and job satisfaction. Furthermore, among volunteers, perceived self-sacrifice on behalf of the organisation by the paid workers of the organisation was found directly and positively related to appraisal respect. Thereafter, a mediation regression analysis was conducted to test the hypothesis about the indirect effect. The mediation regression analysis showed that among volunteers, interactional justice received from the paid workers of the organisation relates positively and indirectly to job satisfaction through appraisal respect as a mediator. The theoretical and practical implications, as well as the limitations and suggestions for further research, are discussed.Show less
Urban centres are among the most vulnerable geographical locations for the impacts of climate change. Strengthening the green infrastructures of these urban areas is therefore increasingly...Show moreUrban centres are among the most vulnerable geographical locations for the impacts of climate change. Strengthening the green infrastructures of these urban areas is therefore increasingly important, as this contributes to their climate resilience. For the city of Leiden, as of many other Dutch cities, public space that can be used for greening initiatives is scarce due to urbanisation processes. The private urban gardens of Leiden can provide a solution for this. Many gardens in this cities are currently ‘grey’. Understanding why would provide valuable information for its policy makers. Therefore this study explored the behavioural motives behind the gardens of Leiden and answered the question: ‘why does a garden in Leiden looks like it does’. Next to that this study also researched the relationship between perceived impact and adaptation behaviour. The data for this study was collected through an online survey in which 67 garden owners of Leiden participated. The data gave insight on the behaviour and motives of these garden owners. It showed that green in a garden is often considered important, yet most garden owners had or wanted their garden (partially) tilled. A frequent motive given for this was the functionality of tilling for the use of a garden. Furthermore the data showed a moderately positive correlation between perceived impact of a garden on climate adaptation and the amount of green in a garden. Further research should examine the predictor in this relationship.Show less
Research master thesis | Psychology (research) (MSc)
closed access
Rules regulate society as they help to predict social interactions. Groups, however, do not always abide by rules. Instead, they break them when the conditions are right. Here we hypothesized that...Show moreRules regulate society as they help to predict social interactions. Groups, however, do not always abide by rules. Instead, they break them when the conditions are right. Here we hypothesized that rule abidance behavior is determined by a) an individual choosing another for mutual benefit based on their reputation and b) the social-environmental incentives like fairness and dishonesty. We had three participants building a reputation for their willingness to abide by or break rules. A fourth participant used that information to choose one to three participants, then played several rounds of a dictator game and a die-roll task. Participants were chosen more often when their reputation was in line with environmental incentives, where merely transitioning from one environment to another strengthened that effect. Regulators should therefore ensure the consistency and kinds of environmental incentives that individuals in power positions face across environments for controlling resulting rule abidance behavior.Show less
Background. Stigmatization frequently occurs in individuals with a skin condition such as psoriasis, which can negatively influence their mental health and disease status. While stigma is known to...Show moreBackground. Stigmatization frequently occurs in individuals with a skin condition such as psoriasis, which can negatively influence their mental health and disease status. While stigma is known to be the leading cause of disability for these individuals, little is known about stigmatizing attitudes among the general population and its correlates. This study aimed to examine stigmatizing attitudes towards psoriasis among the Dutch population and investigated possible predictors. Methods. An online survey was administered to 124 participants, which were recruited based on convenience sampling. A 3 x 1 within-subject cross-sectional design was used, investigating the difference in stigmatizing attitudes towards the health conditions psoriasis and common cold (included due to COVID-19), and a healthy control condition. To describe the different conditions, vignettes were used. A one-way repeated measure Manova examined differences between the three conditions on stigmatizing attitudes (assessed by a social distance scale, a direct and indirect version of the impact of skin condition in daily life scale, stereotype endorsement scale, and emotion ratings). In addition, zero-order correlations and multiple regression analyses investigated possible predictors of stigmatizing attitudes towards psoriasis, including sociodemographic variables, familiarity and knowledge about psoriasis, indicators of the behavioral immune system and fear of corona. Results. Manova analysis displayed higher stigmatizing attitudes towards individuals with psoriasis as compared to the control group (p<.001). Besides, overall higher stigmatizing attitudes towards a common cold as compared to the psoriasis group were found. Higher stigmatizing attitudes towards psoriasis were correlated with lower knowledge, higher pathogen disgust, higher perceived infectability, male gender, and familiarity with psoriasis. No correlations were found regarding age, education, fear of corona, or gem aversion. Multiple regression displayed male gender, higher levels of pathogen disgust, and lower levels of knowledge about psoriasis to be predictors of stigmatizing attitudes (p<.05). Conclusion. Stigmatizing attitudes towards psoriasis is shown to be prevalent in Dutch society. As stigmatizing attitudes were shown to be related to reduced knowledge and male gender, future interventions might focus on these factors. Besides, different age groups and professions could be investigated in future studies. Further research is needed, as stigma towards psoriasis is rarely been investigated among the public.Show less
This study examined the relationship between work-time pressure during the workday and recovery at the beginning of the following workday and the role of segmentation supplies and psychological...Show moreThis study examined the relationship between work-time pressure during the workday and recovery at the beginning of the following workday and the role of segmentation supplies and psychological detachment. The research question was as follows: ‘’What is the relationship between work-time pressure and recovery at the beginning of the following workday and what is the role of work-home segmentation supplies and psychological detachment from work as moderators of this relationship?’’. Recovery was measured through questionnaires, as a state, by levels of fatigue and vigor. Five hypotheses were tested by the data of one day from a diary study, which was conducted online. Work-time pressure and psychological detachment were measured in the evening and recovery the next morning. Segmentation supplies was measured at the start of the diary study through a questionnaire. The final number of respondents was N= 45 (26.7 percent male and 73.3 percent female). The findings indicate no significant relationship between daily work-time pressure and recovery. Segmentation supplies and psychological detachment were examined as possible moderators of this relationship but showed no significant relationships. However, segmentation supplies positively predicted vigor significantly. Finally, the relationship between segmentation supplies and psychological detachment was examined, but also showed no significant relationship. Concluding, more research is necessary to increase the reliability of the results. Furthermore, organizations and employers need to be aware of working conditions and how this relates to recovery of their employees to be able to prevent poor employee health in the long run.Show less
Being diagnosed with a cluster B or C personality disorder (PD) is frequently comorbid with a Post-Traumatic Stress Disorder (PTSD) diagnosis and associated with a lower quality of life in...Show moreBeing diagnosed with a cluster B or C personality disorder (PD) is frequently comorbid with a Post-Traumatic Stress Disorder (PTSD) diagnosis and associated with a lower quality of life in comparison to healthy individuals. The aims of this study are to examine if there is a difference in comorbidity rate between PD clusters and how people with a PD, PTSD or both would score their quality of life. In this study, 11 outpatients, who were diagnosed with a cluster B or C PD with the aid of the SCID-5-P, were assessed with the CAPS-5 to examine if they also got PTSD. Additionally, the patients filled out the MHQoL to determine their quality of life. Analyses showed no significant effect between cluster B or C PD with comorbid PTSD. Additionally, analyses showed no significant alteration between cluster B and C PD on quality of life of patients. Lastly, there was not a significant effect between patients with a cluster B or C PD and comorbid PTSD on quality of life. During all analyses, no effect was found between the PD and PTSD diagnoses and the quality of life of patients in outpatient clinics. However, not finding significant effects throughout the whole study could be due to the small sample size which resulted in a lack of power of the analyses. Yet, this does not undermine the importance of exploring this topic. Cluster B and C PD and PTSD are common (comorbid) diagnoses and their impact on daily life are still tremendous.Show less
Financial shame can lead people to avoid seeking or accepting help with their financial problems. We expect that attenuating feelings of shame motivates people to seek help. To test this...Show moreFinancial shame can lead people to avoid seeking or accepting help with their financial problems. We expect that attenuating feelings of shame motivates people to seek help. To test this expectation, we conduct an experiment in which we present participants with an alleged website of an organisation that provides financial advice. They are presented with one of two versions. In one version the communication of the organisation is geared toward attenuating feelings of shame, whereas in the other it is not. As hypothesized, participants who experienced less shame perceived the organisation as more positive and were more likely to contact or recommend the organisation to friends or family, and these people dealt with the financial situation more constructively (hypothesis 1a-1c). Contrary to our hypothesis, only people with higher shame perceived the organisation as less positive and people with higher shame and stigma would contact or recommend the organisation less often to friends or family and handled their financial situation less constructively (hypothesis 2a-2c).Show less
