ABC Talent Grant: April 2022

In English, speakers may use the word ‘elevator’ or ‘lift’ to refer to the same concept, an example of lexical variation (i.e., variation at the word level). In fact, some languages exhibit more lexical variation than others, and it remains unclear why this is the case. This project focuses on (sign) language emergence, and studies how lexical variation is influenced by shared context (the amount of shared social and psychological information between individuals) and population properties.

We will investigate this using an experiment and a computational model. In an experiment in which participants improvise gestures to convey information, participants will be presented with either the same stimuli as their interlocutor (simulating shared context) or with different stimuli. In parallel, we will develop a computational model with Bayesian learners who make inferences about the mental states of their interlocutors, and study the effect of various population properties on lexical variation.

ABC Talent Grant: April 2022

Standard pre-post analysis methods employed in lesion studies make an unnecessarily permissive assumption, namely that some individuals may exhibit improved post-lesion ability. This assumption (1) limits the statistical sensitivity of lesion studies (wasting animal lives) and (2) restricts inference to unspecific population averages when researchers seek universal insights that apply to every individual.

To address these problems, we will develop tailored Bayesian hypothesis tests that assume that successful lesioning impairs every individuals’ ability and that can directly quantify evidence for spared abilities. We will use these tests to reevaluate recent evidence that challenges the widely-held belief that the hippocampus is necessary for memory formation in non-human primates. We believe our methods will be useful for studies using permanent (e.g., surgical, genetic knock-out) and transient lesions (e.g., optogenetics, TMS) in humans and animals. We will, therefore, make these methods available in an R package and JASP module.

ABC Talent Grant: September 2021

Experimental psychology relies on different tasks to study cognitive inhibition. Recently, the reliability of these tasks has been questioned. One major issue is that tasks originally designed to find robust overall effects have limited between-participant variability leading to small and unreliable individual differences. In this project, we aim to investigate whether more resolution to study individual differences can be achieved by combining increasingly richer data sources using sophisticated Bayesian hierarchical modelling techniques.

We first conduct a large-scale simulation study to understand how many trials and participants are needed for different sources of data to successfully assess individual differences. We will then assess how much sensitivity for individual differences can be gained by combining behaviour and neuroimaging in a joint model.

The novel outcomes of this project are two-fold: first, a quantitative assessment of inter-individual and trial-to-trial variability across brain and behaviour, leading to practical guidelines to adjust numbers of subjects, trials, and types of measurements for the investigation of individual differences, and second, a collection of openly accessible joint modelling pipelines optimized for inter-individual differences studies in inhibition and beyond.

ABC Talent Grant: September 2021

Many of us spend a large part of our lives interacting with other people in digital environments. How does social interaction mediated by digital technologies impact on individual well-being? The aim of this project is to offer a theoretical and formal model that draws on Dr Ridderinkhof's work on network analysis of wellbeing and Dr. Hipólito's extensive neurocomputational modelling experience (in collaboration with Prof Karl Friston) of how technological tools and smart environments can positively and negatively affect wellbeing. A theoretical and formal model of interaction with digital technologies will be developed building on Dr. Hipólito's work on Bayesian active inference. This theoretical and modelling work will deliver a conceptual toolbox that policy makers, psychotherapists, modellers and digital designers can use. The planned studies are cross-disciplinary and will involve close collaboration between the Urban Mental Health project based at AMC, the ILLC, the psychology department and the IAS.

ABC Talent Grant: September 2021

People with psychosis have much higher smoking rates than the general population, they smoke up to three times as often and more cigarettes per day. Smoking has been associated with worse clinical outcomes, including psychotic relapse and readmissions. Daily nicotinergic stimulation and oxidative stress induced by toxic compounds in cigarettes probably induces increased neuronal dysfunction and mental stress. Tobacco use has been linked to structural and functional brain alterations in schizophrenia, but has not been studied before in the early stages of psychosis. Given that smoking e risk factor, it is important to understand underlying neurobiological
mechanisms of this profound link. We will triangulate innovative imaging approaches and data from different stages of psychosis. Insights into tobacco use and brain alterations in early psychosis will further inform us on the relevance and potential neurobiological targets for smoking prevention and treatment.

ABC Talent Grant April 2021

Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive form of brain stimulation, in which a magnetic coil is placed on the scalp to modify target brain networks. rTMS is an emerging, evidence based and safe treatment option for major depressive disorder (MDD). 
A recent study showed that when combining rTMS with cognitive behavioural therapy (CBT) during stimulation, this has an additive effect on relieving symptoms. One of the hypotheses behind this catalytic effect is that depressive networks can be coupled by cognitive tasks, after which rTMS induced neuroplasticity and its antidepressant effects may spread over networks throughout the brain during stimulation.
In this proof-of-concept project, we will use state-of-the-art neuronavigated brain stimulation combined with cognitive tasks, to improve rTMS efficacy and gain better insights in depressive circuitry involved in rTMS responses. 

ABC Talent Grant April 2021

To become proficient language users children need to learn how their language is structured at the sound, word, and sentence level. A prominent question in the study of language acquisition is whether children use a domain-general learning mechanism or a language-specific learning mechanism to acquire linguistic structure. The goal of this ABC grant is to further develop an empirical paradigm that addresses this question in an ecologically valid but controlled laboratory setting. Children will be playing interactive games in the linguistic and nonlinguistic domain in which their main task is to convey messages to other children participating in the game. Children can only convey these messages using novel, nonexistent words (linguistic domain) or visual shapes (nonlinguistic domain). We will investigate what types of structure emerge in these games and whether children’s linguistic background (monolinguals versus bilinguals) impacts on the types of structure that emerge.

ABC Talent Grant April 2021

Despite the increasing accessibility of ethical information, consumers underutilize this information, leading to missed societal opportunities to combat forced labour, climate change, and poverty. One potential reason for this under-use may be conflicting information-seeking and avoidance motives surrounding negatively-framed ethical information. Consumers may use ethical information when confronted with it but avoid such information when possible because it is unpleasant to contemplate. With this ABC Talent Grant, we will investigate how positive vs. negative framing of ethical information influences the tension between information-seeking to make informed choices and information-avoidance to reduce unpleasant emotions and the resulting impact on choice. Further, we will bring insights from social psychology to identify potential avenues to increase curiosity for negatively-framed information.  In particular, we will explore three methods of generating curiosity for ethical information—providing social norms about other’s information-seeking, shifting the social distance of ethical information, and enhancing empathic concern.

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, 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 modelling 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 haemorrhage, 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 behavioural 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 2022

Network science has provided numerous insights into brain and behaviour function, albeit mainly in parallel. To enhance our understanding of brain-behaviour interactions, we must integrate brain and behavioural networks. We propose a novel hierarchical approach, in which we (1) bridge the gap between individual-level and group-level networks, and (2) merge brain and behaviour networks. Subsequently, we validate our models in a large ADHD cohort. This new approach can inform future studies using integrated brain-and symptom networks as treatment targets, thereby enabling us to deepen our theoretical understanding of these brain-behaviour links in psychiatric disorders.

ABC Project Grant 2022

Even though the traditional conception of meaning, formulated in terms of logical truth conditions, has been highly fruitful, resulting in a wealth of theoretical insights, it may be too rigid to account for the wealth of actual data. One pressing issue is the relation between meaning and other aspects of cognition, e.g., available cognitive strategies and individual differences.

This project will propose and study a new theory of semantic representations that puts cognitive differences at the center. We will examine the stability of meaning representations over time and across different semantic tasks. We will investigate which aspects of meaning are rigid and which are sensitive to individual differences or task requirements. Finally, we will explore whether individual differences arise from participants employing various cognitive strategies.

ABC Project Grant 2022

The neuronal mechanisms underlying conscious perception are strongly debated. In this project we test contrasting predictions of some of the major theories of consciousness. Specifically, we will investigate whether top-down modulation of visual cortex by feedback projections from prefrontal cortex is causally involved in visual perception, as predicted by some major theory of consciousness (e.g., Global Neuronal Workspace Theory - GNWT) but not others (e.g., Integrated Information Theory - IIT). First, we will develop an inter-species methodology to measure conscious perception during visual backward masking in mice. Then, we will use optogenetics to inactivate top-down projections from prefrontal to visual cortex during a visual detection task in mice. This will reveal whether inactivating these top-down projections impairs conscious perception, as predicted by GNWT but not by IIT.

ABC Project Grant Janury 2021

What is the origin of compulsive behaviour? Compulsivity, understood as the performance of repetitive behaviour without voluntary control, is a prominent factor in several psychiatric disorders, such as obsessive-compulsive disorder (OCD). However, the neurobiological origins of compulsivity are not sufficiently understood, and this prevents researchers and health professionals to improve the clinical outcomes of compulsivity disorders. In this project, our interdisciplinary team will tackle the ambitious goal of identifying biomarkers for compulsivity across different animal species, including humans. We will develop an experimental-computational framework in which preclinical and clinical data on rodents and humans will be used to build and constrain computational models of the brain networks involved in compulsive behaviour. These models will in turn inform the acquisition of animal data and the analysis of human data, allowing us to identify clinically relevant biomarkers for compulsivity, which are not captured by more traditional approaches.

ABC Project Grant January 2021

Faced with a great deal of information on a daily basis, we often employ heuristics to make quick and energy-efficient decisions that can appear suboptimal from an economic perspective. Relatively little is understood about the cognitive, evolutionary, and ecological drivers of these (irrational) decision biases. They are likely rooted in biological predispositions that were once highly adaptive, and may therefore present themselves differently across individuals and environments, but similarly across species. In this project, we study inter-species and inter-individual differences in decision biases, and effects of environmental stressors on these biases. We therefore compare decision biases of humans and chimpanzees in a 3D foraging task, in which participants have to find food. Here, we manipulate the environment (to include e.g., predators or social agents) to study when and how decision biases arise in both species. Our studies will be carried out at ARTIS Zoo in Amsterdam.

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 colour 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 colours 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.