In dit verslag is er onderzoek gedaan naar de robuustheid van de bevinding van het onderzoek van Blake et al. (2019) dat hersenschade aan de basolaterale amygdala (BLA) leidt tot meer positief...Show moreIn dit verslag is er onderzoek gedaan naar de robuustheid van de bevinding van het onderzoek van Blake et al. (2019) dat hersenschade aan de basolaterale amygdala (BLA) leidt tot meer positief affect in dromen, maar niet tot minder negatief affect. Binnen dit onderzoek zijn droomverslagen gescoord op de variabelen positief en negatief affect en vergeleken tussen neuro-typische controles en patiënten die lijden aan de ziekte van Urbach-Wiethe, waarbij bilaterale calcificatie van de BLA optreedt. Deze robuustheid is onderzocht middels een Multiverse Analyse, waarbij er wordt gekeken naar de invloed van alternatieve keuzes op gevonden resultaten. De resultaten van deze analyse suggereren dat het effect van verhoogd positief affect robuust lijkt te zijn voor het excluderen van patiënten met schade buiten de BLA en het toepassen van correcties voor afhankelijkheid tussen droomverslagen van dezelfde participant. Het effect lijkt in mindere mate robuust voor het toevoegen van het aantal woorden per droom als covariaat en lijkt het minst robuust te zijn voor het gebruiken van dichotome classificaties om de scores van positief en negatief affect te bepalen in plaats van de originele 3-punts Likertschaal. Ook het gevonden nul effect dat schade aan de basolaterale amygdala niet leidt tot verminderd negatief affect van dromen lijkt voor elk van de verschillende keuzes robuust te zijn. Hoewel de meeste alternatieve paden in de Multiverse gelijkwaardige resultaten opleverden, zorgde het gebrek aan ruwe data ervoor dat niet alle mogelijkheden onderzocht konden worden. Verder (replicerend) onderzoek zal daarom nodig zijn om de resultaten van Blake et al. (2019) te kunnen verifiëren en in het kader van de huidige literatuur te kunnen plaatsen.Show less
The leader-member exchange (LMX) theory emphasises the relationship between leaders and subordinates at the workplace, suggesting that leaders quickly create in and out-groups with certain...Show moreThe leader-member exchange (LMX) theory emphasises the relationship between leaders and subordinates at the workplace, suggesting that leaders quickly create in and out-groups with certain subordinates which can lead to in-group bias, the act of favouritism of members of your in-group compared to members of an out group. An in-group is a social group which an individual identifies with, whilst an out-group is consequently the dissimilarity to an in-group. It has also been found that people who score highly on the Dark Triad are likely to hold leadership positions. The Dark Triad is a psychological theory of personality illustrating three dark personality types consisting of malicious qualities: Machiavellianism, sub-clinical narcissism and sub-clinical psychopathy. With leaders scoring highly on the Dark Triad and the plausibility of in-group bias occurring in organisations, it is important to investigate whether the Dark Triad influences in-group bias to remove in-group bias from a leader and organisation and cease LMX from forming. Therefore, this paper examines whether in-group bias is present using the dictator game and whether the Dark Triad (both traits individually and as a whole) accentuates in-group bias. First-year psychology students from Leiden University (n = 75) participated in a dictator game to measure in-group bias, before completing the SD3 questionnaire to measure levels of the Dark Triad. Three hypotheses were made: firstly, dictators will allocate a higher endowment to in-group recipients compared to out-group recipients. Secondly, participants scoring highly on either Machiavellianism, narcissism, or both will have a higher in-group bias. Thirdly, participants scoring highly on the Dark Triad as a whole will demonstrate higher in-group bias. Results indicate in-group bias, however, no significant results were found in the relationship between the Dark Triad and in-group bias. This is the first paper to directly investigate the relationship between the Dark Triad and in-group bias with many limitations obstructing the accuracy and generalisability of the results. Therefore, this study lays the groundwork for future research in investigating this relationship.Show less
The quality of the therapeutic relationship is an influential predictor of favourable therapeutic outcomes. Given the ever-increasing cultural diversity within the Netherlands, research should...Show moreThe quality of the therapeutic relationship is an influential predictor of favourable therapeutic outcomes. Given the ever-increasing cultural diversity within the Netherlands, research should consider the unique challenges of building an intercultural therapeutic relationship. Researching specific questions in this area will inform psychotherapy on accommodating the growing culturally diverse population. Hence, this research aimed to investigate the influence of Hofstede’s (1980) individualism cultural dimension on the intercultural therapeutic relationship. This influence was quantified by observing scores (N=122) on the Manual of California Psychotherapy Alliance Scales (CALPAS) relational outcome variables: Working Strategy Consensus (WSC) and Patient Commitment (PC). The patient version (CALPAS-P) was integrated with a questionnaire on background information. Client and therapist's country of origin was used for categorising responses into groups: those where the client and therapist shared an individualistic or collectivist culture of origin (an intracultural therapeutic relationship) (N=103); or those who differed with their therapist on this dimension (an intercultural relationship) (N=19). Two one-way ANOVAs tested the hypotheses. Hypothesis one tested if mean scores for WSC would be lower for clients in an intercultural therapeutic relationship compared to clients in an intracultural therapeutic relationship. Hypothesis two tested if mean scores for PC would be lower for clients in an intercultural therapeutic relationship compared to clients in an intracultural therapeutic relationship. Both analyses were insignificant, suggesting that building WSC and PC in an intercultural relationship is not significantly different to intracultural therapy. Alternative interpretations and limitations in methodology are discussed, facilitating suggestions for future research.Show less
Dit onderzoek richt zich op het verkennen van de rol van sekseverschillen en genderidentiteit op de onderlinge relaties tussen prosociaal gedrag, het vermogen om ‘awe’ te ervaren en de ‘dark triad’...Show moreDit onderzoek richt zich op het verkennen van de rol van sekseverschillen en genderidentiteit op de onderlinge relaties tussen prosociaal gedrag, het vermogen om ‘awe’ te ervaren en de ‘dark triad’-persoonlijkheidskenmerken onder 18 tot 30-jarigen universitaire studenten. Om het verband tussen deze begrippen te onderzoeken is gebruik gemaakt van een samengestelde vragenlijst, waarbij gebruik werd gemaakt van de ‘Traditional Masculinity-Femininity Scale’ (TMF Scale), de ‘Prosociality Scale’, de ‘Dispostional Positive Emotion Scale (DPES) Awe Subscale’ en de ‘Short Dark Triad’ (SD3). Uit de resultaten is naar voren gekomen dat het verschil in gemiddelde score op prosociaal gedrag voor mannen en vrouwen niet significant is en dus als gelijk kan worden beschouwd. Verder werd er een negatieve zwakke correlatie gevonden tussen de TMF score en de ‘dark triad’ score. Er werden geen sterke verbanden gevonden tussen de ‘dark triad’, prosociaal gedrag en ‘awe’. Wel werd gevonden dat er een zwakke tot matige positieve correlatie is tussen ervaren vrouwelijkheid en prosociaal gedrag, wat niet werd gevonden voor ‘awe’. Er kan worden geconcludeerd dat er daadwerkelijk verbanden lijken te zijn tussen deze begrippen en dat deze afhankelijk zijn van hoe mannelijk of vrouwelijk mensen zich voelen, maar dat verder onderzoek van belang is om deze verbanden duidelijk te krijgen.Show less
This study investigated whether there is a relationship between Pyrrhonism and anxiety and stress with gender identity as a moderator. According to ancient Greek philosophy, a Pyrrhonist attitude...Show moreThis study investigated whether there is a relationship between Pyrrhonism and anxiety and stress with gender identity as a moderator. According to ancient Greek philosophy, a Pyrrhonist attitude ensures the presence of Ataraxia (or peace of mind). This study examined whether Pyrrhonism is associated with stress and anxiety. The Non Evident Questionnaire was developed to measure the independent variable. This was administered in a test battery together with the Generalized Anxiety Disorder-7 (GAD-7) and the Perceived Stress Scale (PSS). The test battery was completed online by 176 people. The first hypothesis stated that a Pyrrhonistic attitude and anxiety and stress would be negatively correlated. The second hypothesis was that identifying as transgender would weaken the effect. The main analysis was found to be insignificant for both GAD-7 and PSS. In the moderation analysis, the second hypothesis was found to be significant for both GAD-7 and PSS. On closer examination of the data, the effect turned out to be significantly positive in cisgender people, while it was insignificant and negative in transgender people. The conclusion of this study is that gender identity changes the effect of Pyrrhonism on anxiety and that Pyrrhonism does not reduce anxiety.Show less
Itch is one of the most common conditions worldwide and can lead to higher anxiety and depression symptoms. There is ambiguity on whether anxiety and depression also affect it. This study...Show moreItch is one of the most common conditions worldwide and can lead to higher anxiety and depression symptoms. There is ambiguity on whether anxiety and depression also affect it. This study investigated whether gender affects itch ratings and if this is mediated by anxiety and/or depression. 11 healthy controls, 18 to 35 years old, participated in this study, whereby the DASS-21 and an additional four questionnaires were implemented to investigate the associations between the variables. A dynamometer measured itch avoidance and itch was evoked through cowhage spicules. Nocebo and verbal suggestions were also part of this study. Males scored higher on depression (M = 5, SD = 4.24), while females scored higher on anxiety (M = 6.67, SD = 5.74). The mediation analysis yielded no significant results, except for the indirect effect of depression and itch ratings at baseline, t(9) = 3.313, p = .011, and partial mediation: t(9) = 2.519, p = .036. The control condition of the expectation phase yielded a significant result regarding depression, t(9) = 3.453, p = .009. Overall, there were no significant relationships found between gender, anxiety, depression, and itch ratings, contradicting to previous literature. Due to the current small sample size, further research is needed to investigate the relationship between gender, psychological traits and itch ratings to improve treatment in clinical settings. This could be achieved through larger and more demographically varied samples.Show less
Every day we come across situations that require our attention, and our ability to stay focused on a task or get distracted depends on our levels of cognitive stability and flexibility. A disorder...Show moreEvery day we come across situations that require our attention, and our ability to stay focused on a task or get distracted depends on our levels of cognitive stability and flexibility. A disorder which has been associated with particularly stable attention is autism spectrum disorder (ASD). Traits of ASD are distributed along a continuum and can be found at subthreshold levels in the general population. One of these traits of autism specifically represent the inability to efficiently handle everyday situations that require switching attention between different tasks. It is of interest to assess whether these attentional difficulties in daily life related to non-clinical levels of ASD might be connected to different functioning of cognitive flexibility and stability. A link between these concepts might help to further understand the mechanisms behind ASD and how to cope with the resulting deficits in attention. This study investigated whether the “switching” trait of the short-form AutismSpectrum Quotient questionnaire could predict cognitive flexibility and stability as measured by performance on a task switching paradigm in the general population. While the expected switch cost and incongruence cost were found for both reaction times and error rates, they were not significantly predicted by the scores on the “switching” autism trait subscale. This suggests that attentional difficulties of ASD at the subthreshold level do not predict the functioning of cognitive flexibility or stability. Future research should further investigate the connection between ASD, the different subthreshold traits of it, and cognitive flexibility and stability, possibly with varied measurement instruments.Show less
The overarching aim of this study was to examine the relationship between pretreatment catastrophizing and its subdimensions in patients with chronic low back pain (CLBP) on the effect of a...Show moreThe overarching aim of this study was to examine the relationship between pretreatment catastrophizing and its subdimensions in patients with chronic low back pain (CLBP) on the effect of a multidisciplinary treatment with a specific physical approach. Based on the literature research it was hypothesized that more pretreatment catastrophizing leads to poorer treatment outcomes. This is a retrospective quasi-experimental study of 80 rehabilitation patients with CLBP by administration of self-report questionnaires and several physical measures. Measurements were taken at start and end of the treatment. The outcome measures were pain, disability, quality of life and lumbopelvic stability. Patients followed an eight-week rehabilitation treatment at the Spine and Joint Centre in Rotterdam. The goal of the treatment is to restore function and control movement of the spine and pelvis by focusing on quality of movement. Results show that treatment has significant effects on improved outcome measures. However, the amount of pretreatment catastrophizing and its subdimensions have no significant relationship with effects of treatment on changes in treatment outcomes, except for the subdimension helplessness and pain. Patients with higher pretreatment helplessness tend to benefit more from treatment on pain outcomes. It was concluded that no patients can be declined treatment based on pretreatment catastrophizing scores. Further research can investigate if pretreatment catastrophizing has a relationship with solely the outcome measures at the end of the treatment or if a decline in catastrophizing during treatment has a relationship with treatment outcomes.Show less
Reinforcement learning has emerged as a powerful framework useful in explaining learning and reward maximization within both the computational and cognitive neuroscience fields. In highly...Show moreReinforcement learning has emerged as a powerful framework useful in explaining learning and reward maximization within both the computational and cognitive neuroscience fields. In highly dimensional naturalistic environments, reinforcement principles are naïve in explaining high-level decision-making assuming that the underlying environmental structure is prespecified to the learner. Theories suggest that reinforcement learning methods exploit a complementary neural process, termed structure learning, that can detect and make inferences on the causal structure within high-dimensional environments. This study aims to investigate the shared cognitive capacities between structure learning and reinforcement learning by employing three decision-making tasks, the two-stage Markov Decision task (MDT) and the Weather Prediction Task (WPT), which derive metrics on reinforcement learning, and the Credit Assignment Task (CAT), which derives metrics on structure learning. The central hypotheses expects that performance measures across all tasks are significantly correlated and was investigated by means of behavioral data from the three tasks performed by 48 individuals. Pearson correlations were performed between overall performance and reaction times on the three tasks revealing significant correlations between performance on the CAT and both the MDT and the WPT. Furthermore, confidence in correct cue-outcome assignment, which was a measure for explicit credit assignment was found to be significantly correlated with performance on the MDT. These findings support the central hypotheses that reinforcement learning and structure learning share similar cognitive mechanisms. Recommendations for future research include exploring the various forms of learning through a more comprehensive study on the various types of decision-making tasks and fitting well adapted computational models to the data for better comparison.Show less
In order to achieve integrity and trustworthiness of research, uncertainty of information needs to be communicated with the public. However, it is not always clear what types of data representation...Show moreIn order to achieve integrity and trustworthiness of research, uncertainty of information needs to be communicated with the public. However, it is not always clear what types of data representation induce the most trust and which individual variables influence this. Previous studies have shown that there are trust differences between numerical and verbal representations as well as different uncertainty levels. Other research suggests that education level may be related to trust while research on numeracy and graphical literacy (GL) implies a potential relationship. Numeracy and GL have been reported to have a moderate correlation. Furthermore, trust is theorized to subsist of the related but distinct concepts of trust in number (TN) and trust in source (TS). To investigate these topics, participants were invited to a questionnaire study presenting an uncertainty scenario and assessing their trust as well as individual variables of numeracy, GL and education. Factors of different uncertainty levels, formats and education levels were used to create nine conditions that assessed whether the factors influenced trust. Results showed a small positive correlation between GL and numeracy. A positive moderate relationship was found between TN and TS. Moreover, results displayed a significant difference in TN between verbal and graphical uncertainty communication. Lastly, education was highlighted as a possible predictor of TN. Findings highlight education as a variable related to TN and strengthen the position that trust should be subdivided into TN and TS. Because of theoretical inconsistencies in our findings, more research has to be done on the effect of uncertainty level, format and education level in uncertainty communication.Show less
Angstproblemen bij kinderen is een wereldwijd veelvoorkomend probleem met grote gevolgen op de korte en de lange termijn. Uit de wetenschappelijke literatuur blijkt dat de prevalentie van...Show moreAngstproblemen bij kinderen is een wereldwijd veelvoorkomend probleem met grote gevolgen op de korte en de lange termijn. Uit de wetenschappelijke literatuur blijkt dat de prevalentie van angststoornissen hoger is voor meisjes dan voor jongens. In dit onderzoek wordt onderzocht in hoeverre er significante verschillen bestaan tussen jongens en meisjes in de mate van angst voorafgaand en na afloop van de Cool Little Kids (CLK) interventie. Op basis van wetenschappelijke literatuur zijn een drietal hypotheses opgesteld. De eerste hypothese luidt dat de angstrapportages van ouders van meisjes hoger zijn dan angstrapportages van ouders van jongens vóór de CLK-interventie. De tweede hypothese stelt dat de angstrapportages van ouders van meisjes lager zijn dan angstrapportages van de ouders van jongens na de CLK-interventie. Beide hypotheses zijn op basis van twee independent samples t-toetsen niet significant bevonden. Op basis van de resultaten uit dit onderzoek wordt daarom geconcludeerd dat er geen significant verschillen zijn gevonden tussen jongens en meisjes in de mate van angst vóór en na de CLK-interventie. De derde hypothese stelt dat de angstrapportages van de ouders van kinderen lager zijn na de CLK-interventie dan vóór de CLK-interventie. Deze hypothese, getoetst met een paired samples t-toets, is eveneens niet significant bevonden. De resultaten uit dit onderzoek zijn niet in verwachting met de wetenschappelijke literatuur. Mogelijke verklaringen hiervoor zijn onder andere het gebruik van andere leeftijdscategorieën en te vroege evaluaties van het CLK-project. Suggesties voor vervolgonderzoek zijn onder andere het uitvoeren van exploratief onderzoek en het onderzoeken van de langetermijneffecten.Show less
