ABC Talent Grant, September 2020

Learning from threat is highly adaptive and can – from a theoretical point of view – be achieved via different reinforcement learning algorithms with very distinct properties. Whereas one kind of learning relies on updating threat-predictions only when the experienced, differs from the expected outcomevalue (i.e. value prediction error), other forms of learning also integrate unexpected changes in sensory properties of the outcome, using so-called sensory prediction errors. With this ABC talent grant, we aim to investigate whether humans acquire and update fear based on prediction errors of one single, or different reinforcement learning systems. Furthermore, we will investigate the neural circuits supporting these different forms of learning from threat in humans. The acquired knowledge can directly be applied to adapt protocols in (pre-)clinical treatments of  anxiety disorders and/or provide an explanation for why fear memories are – under certain conditions – resistant to change.

ABC Talent Grant, September 2020

Deep brain stimulation (DBS) is effective in psychiatric disorders. Several working mechanisms have been proposed, including stimulation of brain white matter tracts to normalize brain activity. If we would better understand the working mechanisms of DBS, we may improve response rates.

An interesting factor involved in the working mechanisms of DBS may be neurometabolic networks. Neurometabolic networks determine the brain’s gray and white matter structure and functioning. Lipids are of special interest, because they constitute about half of brain dry weight, and determine white matter integrity. Surprisingly, there is no earlier research on neurometabolic networks and DBS.

In this project, we investigate how the molecular structure of the brain interacts with DBS. To this end, we assess neurometabolic networks in a transdiagnostic sample of patients with a psychiatric disorder treated with DBS. If we find associations between neurometabolic features and DBS, these features may be used to enhance and predict response.

ABC Talent Grant, April 2020

Why do common psychiatric disorders, such as depression, anxiety and substance abuse, often co-occur? They show partial overlap of genetic, psychosocial risk-factors and biological dysregulations, suggesting both shared and unique etiology. Nawijn is interested in elucidating these shared and specific etiological factors, to better understand heterogeneity and commonalities across psychiatric disorders.

The ABC Talent project will be performed within the HELIUS cohort. State-of-the-art computational modeling will be used across diagnostic boundaries and bridging biological, psychological and social domains to map shared and specific contributing factors across disorders.

With the ABC Talent Grant Nawijn will develop a theoretical and methodological framework, and aims to procure external funding to extend the current project to longitudinal models.

ABC Talent Grant, April 2020

Many young adults spend 3-5 hours daily on social media and some indicate that they feel ‘addicted’, pointing to an emerging public health problem. The idea of a “digital detox” to regain control over social media use has become increasingly popular. However, the effectiveness of detox-interventions remains controversial. The promise of a detox is that it helps to break the habit, but the peril is that it could ultimately lead to intensified use as a consequence of “incubation of craving”. In this ABC Talent project, we aim to elucidate the effects of a digital detox on social media use, and the underlying mechanisms of habit and craving. During and following a detox intervention, we will apply Ecological Momentary Assessment of self-reported craving and automaticity and relate this to duration and frequency of social media use. Additionally, we will conduct an fMRI investigation of the mechanisms underlying a digital detox.

ABC Talent: Susanna Zuurbier, Amsterdam University Medical Center

ABC Talent Grant, September 2019

A cerebral cavernous malformation is a vascular abnormality in the brain and imposes doctors and patients with a dilemma on whether to intervene or not: without intervention, around 4-30% of symptomatic cerebral cavernous malformations lead to sudden bleedings in the brain, causing death or severe handicap in over 20% of patients. Neurosurgery can prevent brain hemorrhage, but may also permanently damage the brain tissue.

Many patients perceive a cerebral cavernous malformation as an abnormality in their brain that they cannot control, which reduces their quality of life. Risk severity perception depends on perceived personal control on that risk, which in turn affects psychological and physical well-being.

In the absence of clear guidelines based on randomized clinical trials, decision-making is mainly opinion- instead of evidence-based. The goal of my research is to develop a decision model to guide interventions based on new predictors of bleeding of cerebral cavernous malformations and quality of life.

The project for managing cavernous malformations in the brain calls for an interdisciplinary collaboration. I will work together with experts in the field of neurology (prof. dr. Y.B.W.E.M. Roos, Amsterdam UMC), social and behavioral sciences (prof. dr. F. van Harreveld (UvA)) and biomedical engineering & physics (assistant prof. dr. M.W.A. Caan).  

ABC Talent: Milica Nikolić, University of Amsterdam, Research Institute of Child Development and Education

ABC Talent Grant, September 2019

Self-conscious emotions, such as embarrassment and shame, are powerful forces that facilitate social affiliation but dysregulation in self-conscious emotions can significantly impair social functioning. In particular, excessive embarrassment and shame and related blushing responses are hallmark features of social anxiety disorder (SAD), a common mental disorder that starts in adolescence. Little is known about how self-conscious emotions, such as embarrassment and its related blushing response, are generated.

Morever, whether feeling oneself blush triggers more embarrassment via biased interoception and mentalizing about what others think of us—the process thought to underlie SAD— has never been explored. The aim of this project is to shed light on the neural underpinnings of embarrassment including blushing, its self-perception, and related mentalizing in adolescents with high and low levels of social anxiety. Two groups of 30 adolescents with high and low levels of SAD symptoms will sing a song on stage while being video-recorded.

Afterwards, we will play the video of their performance vs. that of another participant to them while measuring their brain activity and blushing in the fMRI scanner. By comparing viewing self vs. other across the high vs. low socially anxious groups, we can, for the first time, identify the neural correlates of blushing and thereby establish how the occurrence and duration of blushing is linked to interoceptive and mentalizing processes. Furthermore, we will establish which neural mechanisms characterize enhanced self-conscious emotions in SAD, and whether they map onto localizers for interoception and mentalizing.

The findings will decompose the processes that may render an adaptive but transient embarrassment in healthy individuals into a debilitating vicious circle of heightened self-consciousness in socially anxious individuals.

ABC Talent: Isidoor Bergfeld, Amsterdam UMC, University of Amsterdam, Department of Psychiatry

ABC Talent Grant, April 2019

Autobiographical memories play an important role in forming our identities, imagining ourselves in the future and maintaining long-term goals. The less specific autobiographical memories of patients with major depression, therefore, are hypothesized to result in a failure to maintain long-term goals and, in turn, suicidality. Alternatively, reduced basic cognitive functions of depressed patients could underlie the deficiencies in autobiographical memory as well as future planning. With this ABC talent grant, we aim to see how basic cognitive functions, autobiographical memory, sense of self and future planning interact, and how these relate to psychiatric symptoms.

ABC Talent: Maartje de Jong, Spinoza Centre for Neuroimaging, Amsterdam

ABC Talent Grant, April 2019

Recurrent processing is thought to be crucial for consciousness. We will pharmacologically hamper recurrent processing (using an NMDA-blocker) and investigate the effect of this intervention on functional characteristics of visual cortex and the perception of visual illusions. Since illusions occur without stimulus-driven support, we hypothesize a reduction of illusion-strength. Furthermore, we expect modulations of population receptive fields (measured using laminar fMRI) in the deep/superficial but not the middle layers of visual cortex, considering the known involvement of deep/superficial layers in recurrent processing. By combining pharmacology with state-of-the-art neuroimaging we aim to link biochemical with system-level mechanisms underlying conscious perception.

ABC Project Grant 2020

To optimize processing in our dynamic environment, the brain continuously tries to predict the timing of upcoming events. In musical rhythm, temporal expectations are ubiquitous, and crucial to our ability to synchronize to music, affecting perception, motor behaviour, as well as emotion. Thus, musical rhythm is exceptionally well suited to study temporal expectations. Previously, temporal expectations were often studied in the context of a regular, periodic, beat (“beat-based expectations”). However, humans can also form expectations based on a predictable but irregular pattern (“memory-based expectations”). It is unclear whether beatbased and memory-based expectations rely on shared or separate neural and computational mechanisms. Also, recently it was suggested that individuals may differ in their reliance on beat-based or memory-based expectations.  

In this project, first, we will compare two classes of computational models that have been used to explain temporal expectations: entrainment models, based on coupled oscillators, and probabilistic models. Specifically, we will test whether these models underlie beat-based and memory-based expectations respectively, and whether we can use the models to explain why some people rely more on the beat, and others more on the rhythmic pattern when forming temporal expectations. In the second part of the project, we will use
neuroimaging to study the neural networks underlying temporal expectations, using the same models. 

Together, these studies will provide insight in how our brain forms temporal expectations, and how this is related to the structure in the input and individual differences. This will not only improve our general knowledge of predictive processing and our understanding of the human musical mind, but also has implications for the use of rhythm-based interventions, especially in movement rehabilitation.
 

ABC Project Grant 2020

For survival, it is imperative to learn and remember which cues represent threat, and to generalize such memories to similar situations. However, fear-generalization can turn maladaptive when nonthreatening situations are inappropriately remembered as threatening, a main characteristic of patients with anxiety or stress-related disorders. Recent insight derived from basic animal studies point to physical exercise training as a novel therapeutic avenue to target the neurobiological roots of fear-generalization. But, depending on the timing of such an exercise training intervention, fear-generalization may also aggravate. The key objective of this translational ABC project is to provide a neurobiological account of how exercise training affects fear-generalization, and how this can promote prevention or aggravation of developing anxiety- and stress-related symptoms.

ABC Project Grant 2019

The seemingly-simple question "How are letters represented in the brain?" is complicated by the fact that different languages have different representational systems (e.g., alphabets), and that many different linguistic properties plausibly influence letter representations.

We study grapheme-colour synesthesia, where normal (healthy) individuals have consistent color sensations with letters (“R is sky-blue”). Remarkably, the linguistic properties of each letter (e.g., orthographic, phonetic) act as regulatory factors (RFs): they influence the synesthetic letter-to-colour pairings. These RFs similarly influence non-synesthetes requested to choose colors for letters. In this project, we employ synesthetic colours as a means for cross-language comparisons of letter representations.

We will create a large multi-language letter-to-colour database, a computational model predicting letter-to-colour associations using the (weighted) regulatory factors, and a neurological model explaining how linguistic properties shape letter representations in the brain. Finally, a spinoff project pilots the computational model as innovative approach to second-language learning.

ABC Project Grant 2019

Sleep promotes memory consolidation through specific neural mechanisms. Recent data suggest that memory consolidation can be externally enhanced both by boosting slow oscillations and by presenting memory cues during sleep. While consciousness during sleep – dreaming – has been associated with memory performance, it is unknown whether consciousness is needed to support these memory consolidation processes. Through combined assessment of neural activity, dream reports and memory performance in humans and animals, this project provides an exhaustive account of the role of dreaming in memory consolidation and its underlying neural mechanisms, and paves the way towards targeted (non)clinical interventions.