The human-canine bond exists for over 15,00 years ago, when humans began to socialize the European wolf-dogs. The influence of humans on the appearance of dogs created the extraordinary variety of...Show moreThe human-canine bond exists for over 15,00 years ago, when humans began to socialize the European wolf-dogs. The influence of humans on the appearance of dogs created the extraordinary variety of phenotypic diversity among the modern dog. Humans seem to be particularly interested in certain paedomorphic features in animals, such as a round face and large pupils, which is related to the Kindchenschema. Remarkably, one of the characteristics in dogs is an extra dark colouring around the pupil which seems to create an enlarging effect of the existing pupil. This so-called ring might be part of the human influence within the domestication of the modern dog. As well as a higher contrast between the iris and the ring, which creates a more visible ring and therefore strengthens the influence of the ring. The current study hypothesized and expected that 1) the ring is a predictor of the level of perceived cuteness in humans, 2) contrast is a moderator of this relationship and 3) attitude is correlated with the level of perceived cuteness. The 1100 participants were asked to rate 36 pictures of dogs on cuteness via an online questionnaire. The results showed that the larger the ring, the higher the level of perceived cuteness, as well as a positive correlation between attitude and the level of perceived cuteness. However, the contrast between the ring and the iris did not influence the relationship between the ratio ring/iris and the level of perceived cuteness. These results carefully confirm the influence of humans on a dog’s appearance. Future research could focus on gazing as a predictor of perceived cuteness, including isolating the eyes as presented stimuli.Show less
Children with sex chromosome trisomy’s (SCT) are more vulnerable to developing behavioral, neurocognitive and social-emotional functioning problems and have an increased risk of psychopathology....Show moreChildren with sex chromosome trisomy’s (SCT) are more vulnerable to developing behavioral, neurocognitive and social-emotional functioning problems and have an increased risk of psychopathology. This study investigates through group comparisons to what extent the timing of diagnosis (prenatal/postnatal) influences the type and degree of problem behavior of children aged 1-7 years. In total, 93 children (71 prenatal and 22 postnatal) with an extra X or Y chromosome and 102 non-clinical controls and their parents participated in the study. Types of problem behavior were assessed using the Child Behavior Checklist (CBCL) and a medical history questionnaire. The results indicate that children with SCT generally show more total and internalizing problem behavior than typically developing children, but not significantly more externalizing problem behavior. When it comes to specific problem behaviors, SCT children generally have a shorter attention span, are more easily distracted, tend to be more withdrawn and isolated, worry and experience anxieties and are more sensitive to stimuli and moodiness. The results show that no differences are found in total, internalizing and externalizing problem behavior between children with a prenatal and postnatal diagnosis. However, children with a postnatal diagnosis generally worry more excessively, experience anxiety and are often more irritable compared to children with a prenatal diagnosis of SCT. Finally, the results show that temper tantrums/oppositional behavior, short span of attention/distractibility and excessive worry and fear within the clinical group increases with age. In conclusion, this suggests that it is important to bring the possible consequences of SCT to the attention of medical care providers and parents, so that these children do not worry excessively, experience anxiety and are more irritable (anymore). This proves that there is a need for early interventions in children with SCT, to ensure the quality of life and to reduce the risk of mental health problems.Show less
Introduction. The course of PTSD is heterogenous and four common symptom trajectories have been established: resilience, recovery, chronic and delayed-onset. Social support is a predictor of PTSD...Show moreIntroduction. The course of PTSD is heterogenous and four common symptom trajectories have been established: resilience, recovery, chronic and delayed-onset. Social support is a predictor of PTSD following traumatic events, however little is known about the predictive value of perceived lack social support on PTSD symptom trajectory membership. There are significant differences between men and women in the emergence of PTSD symptoms, but the potential effect of gender in the predictive value of social support on PTSD trajectories has never been investigated. Aims. We aimed to examine (1) to what extent perceived lack of social support measured shortly after acute traumatic injury predicts PTSD symptom trajectory classification, and (2) to investigate whether gender moderates this association. Method. The sample consisted of N = 377 individuals with suspected serious injury subsequent to a potential traumatic event. Perceived lack of social support (SSL-d) was measured at baseline and PTSD symptoms (CAPS-IV clinical interview) were assessed at baseline, 1, 3 6 and 12 months post-trauma. Participants were previously classified into trajectories based on their initial PTSD symptom severity and change in symptoms over time by utilizing Bayesian latent growth mixture modeling. The predictive value of perceived lack of social support was tested by logistic regression analyses on three sets of contrasting trajectories with gender as a moderator: resilience vs. recovery, resilience vs. chronic, and recovery vs. chronic. Results. – Perceived lack of social support significantly predicted trajectory classification in the following sets of contrasting trajectories: chronicity vs. resilience and recovery vs. resilience, but after adjustment for multiple testing the effect was no longer significant. No significant effect of social support was found for the analysis predicting recovery vs. chronicity. Further, gender did not moderate the relation between social support and PTSD trajectories. Discussion. There may be a non-significant trend predicting membership of trajectories with initial PTSD symptoms (recovery and chronic) instead of a non-symptomatic trajectory (resilience) for individuals with a high-level perceived lack of support. A high perceived lack of support did not predict the maintenance of symptoms in individuals with elevated PTSD symptom levels. The predictive value of social support on PTSD symptom trajectories may be stronger for negative interactions and in high-betrayal trauma populations.Show less
Deze bachelor scriptie onderzocht of het mogelijk was om een model met een kleiner aantal voorspellers te maken voor het classificeren van Alzheimer aan de hand van atrofiematen berekend met behulp...Show moreDeze bachelor scriptie onderzocht of het mogelijk was om een model met een kleiner aantal voorspellers te maken voor het classificeren van Alzheimer aan de hand van atrofiematen berekend met behulp van MRI-scans. Er is gebruikgemaakt van voorspellers uit drie datasets en er werd gekeken naar welke voorspellers daarvan in het model zouden komen. De gestelde hypothesen waren als volgt: 1) het is mogelijk om een simpeler model te maken met dezelfde of zelfs hogere accuratesse en 2) de hippocampus is een van de voorspellers in beide modellen. Er werd gewerkt met een LASSO logistische regressie met een strengere en een minder strenge penalty. Door de penalty’s werden minder relevante voorspellers buiten het model gehouden. Uit de resultaten bleek dat het model met 21 voorspellers een accuratesse had van AUC=0.92. Het simpelere model met slechts 8 voorspellers had een accuratesse van AUC=0.91. Hiermee kon de eerste hypothese niet bevestigd worden. De tweede hypothese werd wel bevestigd, aangezien bij beide modellen de hippocampus deel uitmaakte van de voorspellers. Ondanks dat het simpelere model minder accuraat bleek te zijn dan het complexere model, was het verschil tussen beide accuratessewaardes erg klein. Daarbij telde het simpelere model slechts 8 voorspellers in tegenstelling tot 21. Dit simpelere model zou voordelig kunnen zijn voor verder onderzoek naar classificatie van Alzheimer, omdat er hiermee minder atrofiematen berekend hoeven worden. Dit is gunstig omdat de diagnose van Alzheimer sneller kan worden gesteld, de benodigde hulp sneller kan worden verleend en overbodige kosten zo worden vermeden.Show less
Background: Despite being a common disease with a complexity of symptoms, irritable bowel syndrome is often under-recognized and under-treated by GPs. Improving the early identification of symptoms...Show moreBackground: Despite being a common disease with a complexity of symptoms, irritable bowel syndrome is often under-recognized and under-treated by GPs. Improving the early identification of symptoms is in order to be provide an early, adequate IBS diagnosis and maybe even treatment. The aim was to create a model to predict IBS-diagnosis two years before onset with the use of routine primary healthcare data. Methods: A cohort study was caried out based on the available routine primary healthcare data from GPs in Leiden and the Hague. From this data patients have been extracted with first onset IBS between January 2017 to December 2018, the IBS-cohort. Patients were also randomly selected (1:10) without the IBS-diagnosis, the non-IBS cohort. The data included demographic, enrolment information, clinical coding of symptoms and diagnosis according to the International Classification of Primary Cara (ICPC), and medical administrative data. Stepwise backward selection was used to select certain potential predictors out of the 104 available variables. With the use of logistic regression, these selected predictors were used to generate an effective prediction model. Model performance was assessed with the use of stepwise backward selection and area under the ROC curve (AUC). Findings: Data from approximately 300,000 patients were available. The study population included 3586 patients, in which the IBS diagnosis was recorded in 326 patients (9.1%). The baseline model, the full model with all available non-selected predictors and the selected prediction model all showed a good performance, of 0.63, 0.73 and 0.71. Conclusions: To improve the under-recognition and under-treatment of IBS this study has demonstrated the potential of prediction models in identifying IBS-diagnosis in patients. Further research is needed to externally validate the generalizability of this study. Also, improvement can be found in implementing the social, psychological and emotional symptoms in the model.Show less
While the bystander effect is a common phenomenon, the effects of this non-intervention during critical moments to the victims is not clear. The current retrospective study investigated whether non...Show moreWhile the bystander effect is a common phenomenon, the effects of this non-intervention during critical moments to the victims is not clear. The current retrospective study investigated whether non-intervention of bystanders had an effect on victims who experienced undesired behavior in the workplace. We hypothesized the fulfilment of victims’ four fundamental needs would go down, their self-blame would be higher, their perpetrator blame would be lower, and their negative emotions would be higher because of the non-intervention of bystanders. The data from 150 participants were analyzed and results showed main effects of intervention of bystanders, the need to belong, the need for meaningful existence, and self-blame. Here, passive bystanders affected these needs more negatively than active bystanders. Additional analyses also showed main effects for the need to belong, bystander blame, and positive emotions. However, no main effects were found of the need for control and self-esteem, perpetrator blame, and negative emotions. Practical implications regarding the work environment and awareness are discussed.Show less
Placebos are a substance that do not have the qualities to create an effect on its own. Placebo effects are a well-known phenomenon in science and healthcare. However the positive effects of...Show morePlacebos are a substance that do not have the qualities to create an effect on its own. Placebo effects are a well-known phenomenon in science and healthcare. However the positive effects of placebo are not that well applied in healthcare. A reason for this may be that placebos are seen as a deception of a patient. When placebo is used to replace the actual medicine, then the acceptance to use this is very low with healthcare professionals (HP). However if the placebo is not a replacement but an addition to a working medicine the acceptability of HP’s is higher. The studies about the placebouse that have been done before are mostly focused on one type of placebo-use and do not make comparisons between different types of placebo-use. Another problem in placebo research is that the research of the placebo-effects are focused on one specialization, such as Cardiology. In this research the acceptability of eight types of placebo use within a specialization will be compared with each other, with the following research question: “To what extent does the acceptability of healthcare professionals for eight different types of placebo-use differ within their specializations in medical pediatrics?” The specializations in this research are, General pediatrics (HP’s work in a general healthcare department, or in four or more specializations), Cardiology and Neonatology. There are three RMA’s executed for answering this question. The results show that treatment-strengthening placebo music scores the highest acceptability, within all three specializations. Between the specializations there is no significant difference on acceptability (p = 0.984). This research has shown that HP’s have a high acceptability towards treatment-strengthening placebo-use.Show less
Placebos are a substance that do not have the qualities to create an effect on its own. Placebo effects are a well-known phenomenon in science and healthcare. However the positive effects of...Show morePlacebos are a substance that do not have the qualities to create an effect on its own. Placebo effects are a well-known phenomenon in science and healthcare. However the positive effects of placebo are not that well applied in healthcare. A reason for this may be that placebos are seen as a deception of a patient. When placebo is used to replace the actual medicine, then the acceptance to use this is very low with healthcare professionals (HP). However if the placebo is not a replacement but an addition to a working medicine the acceptability of HP’s is higher. The studies about the placebouse that have been done before are mostly focused on one type of placebo-use and do not make comparisons between different types of placebo-use. Another problem in placebo research is that the research of the placebo-effects are focused on one specialization, such as Cardiology. In this research the acceptability of eight types of placebo use within a specialization will be compared with each other, with the following research question: “To what extent does the acceptability of healthcare professionals for eight different types of placebo-use differ within their specializations in medical pediatrics?” The specializations in this research are, General pediatrics (HP’s work in a general healthcare department, or in four or more specializations), Cardiology and Neonatology. There are three RMA’s executed for answering this question. The results show that treatment-strengthening placebo music scores the highest acceptability, within all three specializations. Between the specializations there is no significant difference on acceptability (p = 0.984). This research has shown that HP’s have a high acceptability towards treatment-strengthening placebo-use.Show less
Peer victimization is defined as physically, verbally, or psychologically abusing the victim with the purpose of causing them harm. Research suggests that peer victimization is linked to a variety...Show morePeer victimization is defined as physically, verbally, or psychologically abusing the victim with the purpose of causing them harm. Research suggests that peer victimization is linked to a variety of different cognitive outcomes, such as fear of negative evaluation, rumination, low self-esteem, and self-blaming. However, not much research has been done on whether peer victimization impacts how people learn from feedback. The goal of this study was to reveal whether participants’ level of peer victimization influenced their affective updating (i.g. changes in feelings of the self over time) in response to negative versus positive feedback. For this, a social evaluative paradigm using an impromptu speech task was employed on 97 participants with a mean age of 20.27 years. Participants had to evaluate themselves, receive feedback from judges, and then rate how they felt about themselves. Results indicated that the level of peer victimization did not predict positivity or negativity biases in adapting self-views in response to feedback mismatch. With the aim of unraveling the neurophysiological correlates of learning from feedback, the role of midfrontal theta power was investigated, since theta activity has been found to be stronger during social rejection, and it has been linked to learning and prediction errors. More specifically, theta activity was expected to strengthen the relationship between peer victimization and negative learning rates. Results revealed that theta activity did not moderate this relationship. This thesis offers a first attempt to unravel the connection between social feedback, peer victimization, and high-frequency parietal delta power.Show less
Recent research has highlighted the importance of the ability to enjoy oneself and successfully pursue hedonic goals for subjective well-being. Research identified that individual differences in...Show moreRecent research has highlighted the importance of the ability to enjoy oneself and successfully pursue hedonic goals for subjective well-being. Research identified that individual differences in the ability to enjoy hedonic experiences are explained by the experience of intrusive thoughts. Hypothesizing that individuals with financial stress have more reason to ruminate, it is relevant to investigate financially stressed individuals are being disadvantaged or whether a high ability to enjoy oneself can help to disregard intrusive thoughts about their financial situation. Therefore, current study investigated individual differences in the experience of enjoyable activities and how price, one’s ability to enjoy and financial scarcity can predict hedonic consumer choices. An scenario-study describing a restaurant visit (€25 vs. €60) was performed on a section of the Dutch population (n = 129). Results of the study show that individuals prefer a cheaper restaurant visit when the goal is to maximize pleasure, but prefer a more expensive restaurant when the goal is to maximize quality. Furthermore, having a good ability to enjoy oneself can predict the amount of experienced enjoyment in a expensive restaurant visit. The study did not find a relationship between subjective financial stress and experienced enjoyment. Lastly, contradicting expectations, Trait Hedonic Capacity predicts enjoyment for people without financial stress, but not for individuals with financial stress. Results of current research should be interpreted with care since the used sample did not contain enough participants with financial stress.Show less
The Implicit Memory Method for Criminal Investigation (IMMCI) is a method that exploits the implicit knowledge guilty suspects have about a crime scene. When this method can be implemented in...Show moreThe Implicit Memory Method for Criminal Investigation (IMMCI) is a method that exploits the implicit knowledge guilty suspects have about a crime scene. When this method can be implemented in practice, it may support crime investigation. The method is mainly based on using source confusion to elicit implicit memory about the crime scene. At the police station, suspects are shown pictures of manipulated objects from the crime scene (a green chair replaces a red chair, e.g.). Sometime later, suspects carry out a recognition memory test with pictures featuring both actual objects from the crime scene and manipulated ones. Individuals having seen the original objects are expected to be confused about when and where the original and the manipulated ones were presented, revealing their memory for the crime scene. The aim of this study is to evaluate the validity of the IMMCI method in a lab experiment simulating guilty and innocent suspects: individuals who did and individuals who did not see the crime scene. Moreover, we test the influence of attention and remember instruction, in this process. The main hypothesis is that the ‘guilty’ participants have lower scores on source memory than the ‘innocent’ participants. Additionally, attention is expected to improve source memory accuracy. The results show that source memory for innocent participants improves with attention, while the opposite effect is visible for guilty participants. Overall, the IMMCI is able to discriminate between guilty and innocent suspects based on their source memory on score to a certain extent. With some improvements, the IMMCI could contribute to cybercrime investigation. Further research on improving the ecological validity of the method is needed.Show less
