This thesis summarizes a PhD research project, in which we successfully developed and tested a smartphone-based version of the AAT. We used the mobile AAT to show that approach-avoidance tendencies... Show moreThis thesis summarizes a PhD research project, in which we successfully developed and tested a smartphone-based version of the AAT. We used the mobile AAT to show that approach-avoidance tendencies can undergo substantial state-like changes. We further demonstrate how these changes can be systematically related to other state-variables and how important health-related outcomes such as overweight and obesity, can be explained by disruptions of these dynamics. Our findings have broad implications for approach-avoidance research and task-based research in general, as they reveal how smartphones can be used to get insights into the dynamic nature of task outcomes and how (disruptions of) these dynamics can have important real-life consequences. Show less
This dissertation focused on the neural and behavioral mechanisms underlying adolescent learning and mental health in the context of peers and friends. The neuroimaging findings revealed that... Show moreThis dissertation focused on the neural and behavioral mechanisms underlying adolescent learning and mental health in the context of peers and friends. The neuroimaging findings revealed that reward processing for self and peers rely on common reward-related brain regions, whereas a social brain region (TPJ) showed social specificity to observed outcomes for unfamiliar peers compared to friends. Moreover, typically developing adolescents and adolescents with ADHD show neural sensitivity in reward and salience brain regions towards rewards for themselves, friends and peers compared to losses. There were no group differences in neural processing of (vicarious) outcomes between adolescents with and without ADHD, yet a symptom-level approach showed more neural sensitivity for own compared to friends’ losses in individuals with more inattention symptoms. The behavioral findings indicated that adolescents’ learning performance benefitted from observing the choices and outcomes of peers irrespective of the relationship with this peer. The results did not show effects of friendship (quality) and social status on observational and academic learning, but there was a protective effect of friendship quality on internalizing problems. Taken together, these findings highlight adolescence as a period of observational learning opportunities from different types of peers. Adolescence can also serve as a window of opportunity to improve mental health by fostering high-quality friendships. Show less
Two types of financial incentives can help improve healthy lifestyles: carrots (a reward where one can gain something) and sticks (a deposit contract where one can lose something). In a deposit... Show moreTwo types of financial incentives can help improve healthy lifestyles: carrots (a reward where one can gain something) and sticks (a deposit contract where one can lose something). In a deposit contract, participants deposit own money and can lose or earn it back depending on lifestyle changes. We studied the potential of deposit contracts to stimulate a healthy lifestyle.A smartphone app was developed together with the Swiss university ETH Zurich to conduct experimental research into the effects of deposit contracts. In addition, we collaborated with the American company WayBetter to observe the effects of commercially available deposit contracts. Finally, the opinion of people with cardiovascular disease and healthcare professionals regarding financial incentives and deposit contracts for lifestyle change was investigated.The results show that deposit contracts can have strong effects on exercise behavior (daily step counts) in the short term. The results also show that voluntary participation in deposit contracts is limited, but can be increased by doubling the amount deposited and by allowing participants to determine the amount themselves. Finally, healthcare providers think it is a good idea to use financial incentives, but people with cardiovascular disease themselves are skeptical about the use of deposit contracts. Show less
This thesis generated insights into the neural and affective signatures of connectedness between parents and adolescents and between people in general, which is operationalized by responses to eye... Show moreThis thesis generated insights into the neural and affective signatures of connectedness between parents and adolescents and between people in general, which is operationalized by responses to eye contact and empathy. Overall, our findings show that during adolescence, parents are still highly attuned to their child at the neural and affective level. In addition, adolescents report to feel more connected with their parents than with unknown others, although this was not directly reflected in stronger neural responses. Another interesting finding is that making eye contact for a prolonged period generally enhanced the socio-emotional connection between people, both between parents and adolescents and with unknown others. For individuals with a history of CEM and depressed adolescents eye contact is less socially rewarding, however, and does not seem to foster a stronger connectedness with others. Studying the psychobiological underpinnings of affiliative bonding, including the parent-adolescent bond, brings us a step closer to unraveling how such bonds are established and maintained during adolescence. And even more important: Once we know how these bonds are established, we might be better able to modify and repair these bonds in situations in which they for some reason got disrupted. Show less
Despite decades of research from psychology, anthropology, biology and economics, how social preferences arise and vary across contexts remains an open question. In three empirical chapters, this... Show moreDespite decades of research from psychology, anthropology, biology and economics, how social preferences arise and vary across contexts remains an open question. In three empirical chapters, this dissertation addresses this gap using a variety of economic games and neuroimaging techniques that allow for a tractable modeling of cooperation and competition. Overall, findings suggest that while social preferences are linked to neural structure, they can also adapt to environmental factors as well as beliefs about interaction partners. This doctoral thesis shows that interacting with ingroup or outgroup members, taking decisions publicly or privately, and knowing whether we may interact with others again affect our cooperative behavior. These results highlight the importance of understanding how prosociality may be altered and lay the foundations for policy makers to further those social environments that encourage prosocial behavior. Show less
By monitoring ongoing actions and performance outcomes, we are able to detect errors or mismatches between our intentions or predictions. Disturbances in such performance-monitoring processes may... Show moreBy monitoring ongoing actions and performance outcomes, we are able to detect errors or mismatches between our intentions or predictions. Disturbances in such performance-monitoring processes may importantly contribute to impaired adaptive behavior in clinical disorders, such as excessively impulsive behavior in externalizing disorders or excessively rigid or careful behavior in anxiety- and obsessive-compulsive disorders. In daily life, performance monitoring often takes place in a social context, where our actions have consequences not only for ourselves, but also for others. The investigation of (alterations in) such (pro)social performance-monitoring processes may help explain functional and social impairments across a wide range of clinical disorders. In this dissertation, we used various neuroimaging paradigms to examine subclinical and neurochemical influences on performance monitoring when errors had consequences for oneself or others. The studies in this dissertation indicate that neural performance-monitoring correlates are modulated by social, subclinical, and neurochemical factors, including social (responsibility) context, obsessive-compulsive symptoms, ovarian hormones, and pharmacological manipulations of dopamine and oxytocin. These findings have implications for the potential and utility of error-related brain activity as a clinical biomarker or endophenotype, our insight into social symptoms and impairments in obsessive-compulsive disorder, and for our understanding of the neurochemical mechanisms underlying performance monitoring. Show less
In my study I looked for a plausible cognitive theoretical framework for conforming behavior. The Theory of Event Coding (TEC) was the cognitive theory that offered a good basis for building this... Show moreIn my study I looked for a plausible cognitive theoretical framework for conforming behavior. The Theory of Event Coding (TEC) was the cognitive theory that offered a good basis for building this framework. I conducted an experiment using an existing study design adopted from previous studies of conformity adding a non-social condition where participants were confronted not with what they thought were other students’ choices but with random computer choices. According to TEC, a simple confrontation with an alternative behavior would affect reproduction of your own behavior at a later stage. The study results supported my theory. Unfortunately, the results were possibly influenced by Regression to the Mean. So I changed the study design to eliminate the issue. Also I wanted to see if and how conformity was affected by culture: collectivistic versus individualistic. This study was conducted partially in the lab (in the Netherlands and China) and partially online (in the USA and India). The results confirmed my initial hypothesis: the conformity effect did not differ across all experimental groups irrespective of the country or condition suggesting that people are sensitive to intervening events, but the social nature of these intervening events is irrelevant. Show less
In the realm of cognitive science, the quest to understand cognitive control has persisted for decades. Traditional notions of cognitive control have focused on inhibition through the prefrontal... Show moreIn the realm of cognitive science, the quest to understand cognitive control has persisted for decades. Traditional notions of cognitive control have focused on inhibition through the prefrontal cortex, but this dissertation challenges that perspective with a more comprehensive framework: The Metacontrol State Model (MSM). The MSM proposes that cognitive control emerges from the interplay between two opposing systems – one promoting flexibility and the other promoting persistence. These systems interact to shape our cognitive processing styles, thereby influencing our ability to effectively regulate our actions. This dissertation explores questions such as why individuals exhibit differences in cognitive control capacity and how state-related changes and trait-related predispositions impact cognitive control function. The overarching goal of this dissertation is to empirically test the MSM model and shed light on the factors that influence cognitive control. Through a series of experiments, it seeks to understand how altered states of consciousness, achieved through meditation techniques or serotonergic psychedelics, affect the balance between intentional and habitual processes. Additionally, it examines the extent to which individual trait biases serve as trans-diagnostic markers in various psychopathologies. This work comprises a literature review and six empirical articles. By integrating theory and empirical research, this dissertation takes us on a journey into the intricate world of cognitive control, shaping our understanding of how it influences our lives. Show less
This dissertation focuses on identifying neural mechanisms underlying social evaluations and self-views from a parent-adolescent perspective among adolescents with and without depression, and their... Show moreThis dissertation focuses on identifying neural mechanisms underlying social evaluations and self-views from a parent-adolescent perspective among adolescents with and without depression, and their parents. As part of RE-PAIR, affective and neural responses to praise and criticism about the adolescent child, and neural responses to reliving positive autobiographical memories were assessed, using ecologically valid fMRI-tasks. Particularly criticism seems to be highly salient to parents and adolescents, activating the salience network and decreasing mood. Both praise and reliving positive autobiographical memories activate areas important for self-referential processing in adolescents, which might reflect the ‘positive self’. Aberrant self-related processing when reliving autobiographical memories and increased sensitivity to parental criticism might be key underlying neural mechanisms in adolescent depression. By feeling more negatively, having more negative self-views, interpreting the environment as more negatively, memorizing past experiences in a more negative way, and focusing on negative events more often, adolescents with depression seem to have multiple negativity biases. These negativity biases are likely to negatively impact social relationships, potentially further reinforcing negative feelings and a negative self. Interventions exploring and strengthening the positive self, in particular the positive self aligning with the current self, might be useful for treating, or even preventing adolescent depression. Show less
Gerritsen, R.J.S.; Band, G.P.H.; Lafeber, J.; van den Beukel, N.; van Voskuilen, B.; Hoogland, R. 2023
Social anxiety is anxiety about negative evaluation and rejection by others. Social anxiety has been long related to reduced eye contact, this feature is seen as a casual and a maintaining factor... Show moreSocial anxiety is anxiety about negative evaluation and rejection by others. Social anxiety has been long related to reduced eye contact, this feature is seen as a casual and a maintaining factor of social anxiety disorder. However, related empirical findings were equivocal. The dissertation sought to address three key questions: (1) Whether social anxiety is featured by gaze avoidance. (2) Under which conditions socially anxious individuals display gaze avoidance. (3) To what extent subjective experience of gaze avoidance corresponds with actual gaze behavior. Using the combination of naturalistic social settings and wearable eye-trackers, the dissertation provides evidence for the relationship between social anxiety and gaze avoidance particularly in naturalistic social situation, and further reveals that the relationship depends on severity of social anxiety symptoms, type of social situation and age group. Besides, gaze anxiety is moderately associated with actual gaze avoidance. Altogether, the dissertation sheds light on the nature of gaze behavior adopted by socially anxious individuals in naturalistic social interactions. Show less
For people with chronic kidney disease (CKD), adhering to a range of self-management tasks—such as healthy eating, frequent physical activity, and non-smoking—is crucial. However, changing health... Show moreFor people with chronic kidney disease (CKD), adhering to a range of self-management tasks—such as healthy eating, frequent physical activity, and non-smoking—is crucial. However, changing health behaviors is difficult. To support patients in doing so, an eHealth care pathway was developed and evaluated. The results provide different insights into patients' priorities and care needs. Many individuals with CKD experience problems in self-management, which can be hindered by many different barriers of which a common one is psychological distress. Therefore, personalized interventions are needed with screening and treatment of both psychological distress and suboptimal self-management, tailored to the specific barriers and needs of the individual patient. The E-GOAL eHealth care pathway is an example of such a personalized intervention, combining cognitive behavioral therapy with self-management support. Patients were enthusiastic about the eHealth care pathway. However, in a randomized study, the intervention was not effective in reducing psychological distress compared with regular care only. Patients did experience improvements in areas of functioning and self-management that they prioritized themselves. These mixed results show that interventions could be implemented that are person-tailored, with personalized outcomes that reflect individually meaningful treatment goals and improvements for every patient. Show less
This thesis examines questions related to the prevalence of anxiety symptomatology and disorders in older adults, and compares two brief low-threshold psychological interventions (blended... Show moreThis thesis examines questions related to the prevalence of anxiety symptomatology and disorders in older adults, and compares two brief low-threshold psychological interventions (blended Acceptance and Commitment Therapy versus face-to-face Cognitive Behavioral Therapy) for older adults with anxiety symptoms in primary care. Show less
This thesis describes a dissimilarity-based classification tool, the δ-machine, which gives an alternative way of statistical modeling compared to the conventional ones that directly use predictor... Show moreThis thesis describes a dissimilarity-based classification tool, the δ-machine, which gives an alternative way of statistical modeling compared to the conventional ones that directly use predictor variables. We use the symbol δ, because it is commonly used as a symbol for dissimilarities in multidimensional scaling.In this thesis, we discuss the properties of the δ-machine, and extend the δ-machine from handling continuous predictor variables only to handle different types of predictor variables, including continuous, ordinal, nominal, and binary predictor variables via the two tailored dissimilarity functions. Furthermore, we study the classification performance of the δ-machine in high dimensional data. We propose a Majorization-Minimization algorithm to interpolate new data points coherently into previously constructed classical multidimensional scaling (CMDS) configurations, and use the proposed algorithm in the δ-machine in high dimensional data scenario, where CMDS is applied to reduce the original high dimensional predictor variables. In order to make predictions for new data points, therefore, needs to interpolate them into the constructed CMDS.The δ-machine shows promising predictive performance in general and is able to find informative exemplars/prototypes, which bring extra insights of data. The informative exemplars could be used in the further study. Show less
This thesis investigated the development of emotional functioning in 2-to-6-year-old children with and without autism. Whereas autistic children experienced more challenges in the emotional domain,... Show moreThis thesis investigated the development of emotional functioning in 2-to-6-year-old children with and without autism. Whereas autistic children experienced more challenges in the emotional domain, their emotional abilities improved with age, and developed in similar ways as observed in non-autistic children. On the one hand, this thesis showed that autistic children might deal with emotions in a different way, and they might experience various difficulties when communicating emotions with non-autistic people. One the other hand, it is important to note that the difficulties could be bidirectional. As stated by the “double empathy problem”, non-autistic people may experience the same difficulties when communicating with autistic people. This could be a meaningful direction for future research, investigating emotional communication as a two-way interaction rather than focusing only on how people with autism react to people without autism. Furthermore, this thesis showed that autistic children had the potential to learn and to develop in the emotional domain. Again, this points to the importance of investigating how to create an inclusive social environment, which is not only nurturing for children without autism, but can also benefit the development of children with autism and with other special needs. Show less
This PhD project revealed that the female hormonal status – including OC use – and stress vulnerability – as defined by the MR-haplotype – have practical implications in experimental psychological... Show moreThis PhD project revealed that the female hormonal status – including OC use – and stress vulnerability – as defined by the MR-haplotype – have practical implications in experimental psychological research. Furthermore, incorporation of these variables in models of emotional information processing may be of help in understanding and treating mood disorders in women. Namely, even small biases may affect information processing and may contribute to the resilience or proneness to mood-disorders.Our research was among the first to show that the genetic makeup of healthy women may play a role in the influence of the female hormonal status on emotional information processing. Healthy female MR-haplotype 1/3 carriers may be more prone to distress, and may also be more sensitive to (pharmacological) changes which may counteract or sustain their vulnerability. Consistently, we observed subtle markers of depressogenic side-effects of OC only in MR-haplotype 1/3 carriers. Our findings regarding the MR-haplotypes 2 carriers are generally in line with earlier observations. We observed that MR-haplotype 2 carriers – especially homozygotes – are the less susceptible, more optimistic and more rational individuals, also in ‘unstressed’ conditions. However, stress-related psychopathology is very heterogeneous by nature and proteins from multiple genes are likely to interact in the stress-susceptibility phenotype. Last but not least, we should not ignore that the increased vulnerability of women to mood disorders is the result of a plethora of biological, psychological and sociological factors.OC-users had lower affect variability and reduced sensitivity to interpersonal emotional cues. This may be experienced as either a stabilizing or a blunting effect of OC, perhaps depending on the individual’s appraisal. The lower depression scores of OC-users in our longitudinal study suggests a protective effect of monophasic OC on symptoms of reproductive depression. Future studies should investigate (former) OC-users in larger cohorts including novel users, satisfied users and ‘brand-switchers’ in order to control for the survivor effect. Show less
This dissertation covered several relevant cycles of placebo research with the main aim to optimize placebo effects in medical contexts. Firstly, a literature review described how the immune system... Show moreThis dissertation covered several relevant cycles of placebo research with the main aim to optimize placebo effects in medical contexts. Firstly, a literature review described how the immune system can be impacted by placebo effects and their underlying learning theories. In the following chapter, these learning theories were integrated to form an optimal research design by means of pharmacological conditioning to fit a specific patient group: children with juvenile idiopathic arthritis. Secondly, this dissertation focused on developing placebo information strategies to harness placebo beliefs and educate persons about the relevancy of placebo effects in practice. These insights are valuable because treatment expectations can have a positive or negative effect on treatment outcomes. Finally, insights from placebo learning theories and placebo information strategies were combined in an integrative experimental research design. This research design employed a more ethical form of placebo use because participants were made aware of placebos, called open-label placebos. In this last study we demonstrated that open-label placebo analgesia can be induced by combining learning theories and placebo information strategies. Altogether, this dissertation provided insights in learning mechanisms, communication strategies, and research paradigms that involve the optimization of placebo effects in medical context. Show less
The results described in this thesis support the strong empirical evidence for the effectiveness of CBT-Ef for patients with an eating disorder and a BMI>17.5. When compared to TAU, we found... Show moreThe results described in this thesis support the strong empirical evidence for the effectiveness of CBT-Ef for patients with an eating disorder and a BMI>17.5. When compared to TAU, we found comparable effects on eating disorder psychopathology, however CBT-Ef is superior in enhancing self-esteem with significantly fewer sessions and within a shorter time. We found no support for the hypothesis that more severe self-esteem problems, higher levels of perfectionism, or more interpersonal problems would obstruct long-term improvement and would therefore need extra attention in an extended protocol. A broader use of CBT-Ef in clinical practice could result in more efficient and accessible treatment for patients with an eating disorder. In another study we found COMET to be effective in enhancing self-esteem in patients with an eating disorder. Since we did not find the predictive value of low self-esteem in CBT-E treatment outcome, we suggest to integrate COMET in an eating disorder treatment only when low self-esteem is pronounced and interferes with making progress. Show less
The aim of the current dissertation was to examine the psychological, neurological and behavioral impact of different types of traumatic (A1) and stressful (non-A1) life events, including a focus... Show moreThe aim of the current dissertation was to examine the psychological, neurological and behavioral impact of different types of traumatic (A1) and stressful (non-A1) life events, including a focus on the impact of childhood maltreatment. The role of brain structure (hippocampal volume) and function (neural correlates of emotional face processing and social rejection) in intergenerational transmission of child abuse versus neglect was investigated using a multi-generational family study design. Show less
In this thesis, I investigated the behavioral and neural processes involved in self-concept development in adolescence within the context of future-oriented educational decision-making. The studies... Show moreIn this thesis, I investigated the behavioral and neural processes involved in self-concept development in adolescence within the context of future-oriented educational decision-making. The studies presented in this thesis all highlight that self-concept is a multifaceted and complex construct that not only develops in interaction with the social environment, but can also have an impact on someone’s future environment. For example, results from chapter 2 indicated that the social environment, expressed in the outcomes of social comparisons, can affect the positivity of the self to a different extent across multiple domains and different stages of adolescence. Chapter 3 showed how adolescents’ academic self-concept can influence their motivation to stay committed to goals important for their future educational environment, whereas chapter 4 illustrated differences in self-esteem and self-concept clarity in individuals who differed in their experienced problems with choosing this future educational environment. Finally, chapter 5 demonstrated that in late adolescence, sensitivity to outside influences can be used to stimulate self-concept development through training which can ultimately help adolescents in their educational decision-making and adjustment in higher education. Together, these studies provide a comprehensive view on self-concept development in adolescence that takes place within a broader social, and educational context. Show less
