Disa Sauter (FMG)
Henkjan Honing (FGW)

An ABC guest colloquium in September 2023 will feature Dr Sam Mehr, School of Psychology, University of
Auckland and Child Study Center, Yale University. Dr Mehr received his PhD from Harvard in 2017 on the
topic of the psychology of music. His work combines approaches from the psychological, anthropological, and
computational sciences to ask fundamental questions around what music is, how music works, and why music
exists. Dr Mehr is also one of the pioneers of the citizen science movement, which has important implications
for the ways in which researchers from a wide range of disciplines can connect with the broader public. 

ABC Colloquium Samuel Mehr

[granted July 2023]

Jorien Treur (AUMC)
Margot van de Weijer (AUMC)

There are many research groups in Amsterdam that are in some way integrating genetics in their research, but with very different specializations, ranging from gene-environment interplay to imaging and to clinical and developmental psychology. Using the ABC Themes & Transversal Perspectives Grant, we will bring together all genetics researchers in Amsterdam during a Genetics Network Amsterdam meeting. With this meeting, we aim to stimulate collaborations between diverse research groups and discuss science communication about genetics research to the general public. In addition, we want to use this opportunity to actively connect Amsterdam genetics researchers with ABC, by presenting the different ABC themes and transversal perspectives (and the research that takes place in these domains). In doing so, we can find out where ABC’s research intersects with the research of the researchers present at the meeting, and in this way find out where there are still missed opportunities for collaboration.

[granted July 2023]

Steven Scholte (FMG)
Iris Groen (FNWI, Informatics)

This event was dedicated to the exploration of Neuro-AI.

[granted May 2024]

Anja Lok (AMC)
Stanley Brul (FNWI)

Microbiome research has reshaped our understanding of health, particularly the gut-brain connection, linking microbial imbalances to conditions like depression. The microbiome's role in mood and behavior is influenced by diet, with modern, processed foods potentially disrupting gut bacteria. This growing field promises to transform medical and nutritional practices by rethinking humans as "holobionts," organisms that are part human and part microbe.

The interdisciplinary project INSIDE OUT combines microbiome science with Art through immersive experiences designed by Polymorf to engage the public. Using virtual reality (VR), sensory devices, and interactive dining, the project highlights how gut bacteria impact mental health. Experiences like Dinner for Two, Haute Cuisine, and Drinkable Memories offer unique ways to explore this relationship, creating deeper public awareness.

Supported by experts from microbiology and psychiatry, INSIDE OUT aims to make complex research tangible, fostering dialogue on the microbiome’s crucial role in well-being. The project will be showcased at museums, festivals, and public places, including Amsterdam UMC.

Anja Lok & Stanley Brul

Faculty of Medicine and Faculty of Science
Amsterdam Microbiome Expertise Center
Polymorf

[granted October 2024]

Romke Rouw (FMG)
Cyriel Pennartz (FNWI)
Nicholas Root (FMG)

For a synesthete, stimulation in one domain leads to involuntary conscious sensory experiences in another domain.  Remarkably, when non-synesthetes are forced to report cross-modal associations (e.g., a color with a tactile experience), they show surprisingly similar patterns^1,2 as synesthetes, yet consciously believe that they are answering randomly.  We recently revealed³  that the test-retest gold standard, long thought to accurately 'diagnose'  synesthesia, is neither a necessary nor a sufficient instrument to distinguish synesthetes from non-synesthetes. Instead, self-report alone reliably distinguishes synesthetes: conscious awareness of cross-modal correspondences (CMCs) is the necessary and sufficient criterion. This reveals how synesthesia offers unique 'cases' to study interrelationships between individual differences, consciousness, and multisensory integration; research areas in which ABC members hold strong expertise.  We present a multidisciplinary symposium and workshop on Synesthesia, Multisensory Processes and Consciousness within the conference of the International Association of Synesthetes, Artists, and Scientists, which will be held in Amsterdam on May 28-29, 2026⁴, with the aim to bring together international researchers, ABC members, and MBCS/ABC students. In the symposium we present a theoretical and computational framework of consciousness^5,6, in which multimodal richness, as well as sensory unity and integration, are essential hallmarks of conscious experience. A proposed essential hallmark of consciousness, multimodal richness, can now be considered an operationalizable construct, as it differentiates synesthetic from non-synesthetic cross-modal representations.

We invite all ABC members to participate in the symposium, lectures and discussions, as well as informal discussions during a social event.

<sub>1. Rouw, R., Case, L., Gosavi, R., & Ramachandran, V. (2014). Color associations for days and letters across different languages. Frontiers in psychology, 5, 369.
2.  Simner, J., Ward, J., Lanz, M., Jansari, A., Noonan, K., Glover, L., et al. (2005). Non-random associations of graphemes to colours in synaesthetic and non-synaesthetic populations. Cogn. Neuropsychol. 22, 1069–1085. doi: 10.1080/026432905002001223. Root, N., Chkhaidze, A., Melero, H., Sidoroff-Dorso, A., Volberg, G., Zhang, Y., & Rouw, R. (2025). How “diagnostic” criteria interact to shape synesthetic behavior: The role of self-report and test–retest consistency in synesthesia research. Consciousness and Cognition, 129, 103819.
4. https://iasasevents.com/leadership/
5. Pennartz, C. M. (2022). What is neurorepresentationalism? From neural activity and predictive processing to multi-level representations and consciousness. Behavioural brain research, 432, 113969.
6. Pennartz CMA (2015) The Brain’s Representational Power – on consciousness and the integration of modalities. MIT press (382 pp.). ISBN: 9780262029315.</sub>

[granted May 2025]

Linguistic and non-linguistic top-down influences on perception captured through oscillatory activity.

Monique Flecken (FGW)
Conrado Bosman (FNWI)

The way we see the world around us is very much influenced by what we know and what we expect; for example, we are more likely to see an (ambiguous) image as left- or right-oriented when beforehand a very brief flash of light is presented on the respective side of the screen. Prior information thus biases our perception. Does this also hold for linguistic information? What about words cueing the orientation just before an image is presented? Do these cues bias the perceptual system in similar, or different ways? Psycholinguistic research suggests that words are ‘special’, in that they cue a category, rather than a specific exemplar of a concept: the word ‘dog’ can refer to a chihuahua or a bulldog. When we see a dog of any kind we are perfectly ‘prepared’ for it because of the linguistic label. In perception research, little attention is paid to language as a source of prior knowledge. We address, using neuroimaging, whether there is something special about language for our perceptual system.

[granted July 2023]

Umberto Olcese (FNWI) 
Lucia Talamini (FMG)

The sleeping brain, while less receptive to external stimuli compare to wakefulness, still processes sensory inputs. Recently, we have shown that we can manipulate individual memories during sleep using a technique called closed-loop neurostimulation (CLNS). This method targets auditory stimuli to specific phases of brain oscillations during sleep, allowing for precise memory enhancement or suppression. By focusing on REM sleep's theta oscillations, vital for emotional memory processing, we will further explore to what extent this technique can be used to modulate memory. To address this question, we will compare human EEG recordings to high-density recordings in rats, thus revealing how auditory stimulation affects theta oscillations at the circuit level and, at the same time, in a translational approach. Our goal is to understand emotional memory consolidation at the neural level, enabling  immediate repercussion for clinical research and clinical practice, with implications for treatments  to disorders such as post-traumatic stress disorder (PTSD).

[granted July 2023]

Disa Sauter (FMG)
Floris Roelofsen (FNWI) 
Roza Kamiloğlu (FMG)

Nonverbal vocalisations, such as laughter, sighs, moans, and grunts, are fundamental elements of human behaviour. Yet despite their significance, scientific exploration of human vocalisations has been limited, particularly in terms of understanding what leads us to produce vocalisations.
In the current project, we will leverage the extensive ethnographic dataset of the Electronic Human Relations Area Files, a comprehensive collection of digitized high-quality ethnographies from 315 world cultures. We will produce a nonverbal vocalisations ethnography, which will be analyzed using computational methods, including both clustering analysis and supervised machine learning.
This project will establish whether different kinds of nonverbal vocalisations occur universally, what triggers them, and what primary functions they serve.

[granted July 2023]

Lindy-Lou Boyette (FMG, Clinical Psychology)
Jentien Vermeulen (AUMC, Psychiatry, Dep. Early Psychosis)
Lieuwe De Haan (AUMC, Psychiatry, Dep. Early Psychosis)

Cannabis can exacerbate psychotic symptoms due to its psychoactive compound THC  (tetrahydrocannabinol). Nevertheless, there is a high prevalence of cannabis use in individuals with psychotic disorders. Interventions effectively targeting this comorbidity are currently lacking.  However, CBD (cannabidiol), a second, non-psychoactive cannabis compound, has emerged as a  potential therapeutic agent due to its antipsychotic properties. Additionally, evidence suggests  that CBD reduces craving and withdrawal in cannabis use disorder. Therefore we propose CBD as  an adjacent therapy for cannabis use in psychosis, targeting both aspects of the dual diagnosis  simultaneously.

This support grant will be utilized in hiring research assistance to apply for funding 
for conducting a placebo-controlled CBD trial in dual diagnosis. It would be a new collaboration between the UvA Clinical Psychology and the UMC Amsterdam and UMC Utrecht Early Psychosis  departments. Ultimately, our aim to create a cross-disciplinary expert group on comorbid  psychosis and substance use research and care. 

[granted May 2024]

Romke Rouw (FMG, PSY, Brain and Cognition)
Jelle Zuidema (FNWI, ILLC)
Nicholas Root (FMG, PSY, Brain and Cognition)

In grapheme-color synesthesia, letters evoke specific, automatic, and consistent color sensations (e.g., “F is burgundy-red”). Our ABC-Project (2019-2023) measured synesthetic letter-to-color associations in 15 languages, and revealed that linguistic properties (e.g., orthographic, semantic, phonetic) influence the letter-to-color pairings.

These findings highlight how grapheme-color synesthesia is not only interesting in its own right; it offers a unique way to examine letter representations. Currently, we employ Representational Similarity Analysis (RSA) to measure synesthetes’ neural activity to (achromatic) letters. We hypothesize that similarities in a synesthetes' colors (behavioral measure) reflect similarities in their neural letter representations (LFA region) (neuroimaging measure).

Moreover, our ABC Project revealed that non-synesthetes (asked to pick colors with letters) will show similar letter-color patterns as synesthetes. Therefore, we extend our study to include more extensive behavioral/neuroimaging measurements in non-synesthetes. Can letter-color associations prove a non-invasive and cheap manner to reveal properties of (neural) letter representations?

[granted May 2024]

Sonia Ramotowska (FGW)
Maria Aloni (FGW) 
Ingmar Visser (FMG)

Negative quantifiers (e.g., fewer than n) can be verified by an empty set. For example, the sentence “Fewer than 3 dots are blue” is true when there are 2 or 1 blue dots (non-empty set scenarios) and when there are 0 blue dots (empty set). This last scenario is typically more difficult to conceive and neglected by language users (the neglect zero effect).

This project aims to contribute to the debate about the processing of negative quantifiers, particularly testing the empty set scenario. Its first novel contribution is to test the neglect zero effect by measuring the online processing of the empty set scenario with ERPs. The second contribution involves the combination of neurophysiological measures with eye-tracking. For example, we will test if the empty set scenarios lead to a different visual exploration of the pictures (for which sentence verification needs to be carried out) than other scenarios.

[granted October 2024)

Jan Willem de Gee (FNWI | SILS)
Romke Rouw (FMG, PSY, Brain and Cognition)

Misophonia is characterized by intense and involuntary stress responses to certain, often human-made, sounds (e.g., chewing). Research has highlighted the autonomic nervous system's (ANS) role in differentiating misophonic reactions from typical annoyance experienced with generally unpleasant sounds (e.g., nails on chalkboard). However, assessment of the (intensity of) the misophonic response currently relies almost entirely on subjective self-reports, which are prone to response bias. Thus, the field needs a reliable, valid, and easy-to-use objective measurement tool of the involuntary ANS response. Here, we will develop and validate a sensitive, affordable, and objective online pupil-based measurement tool of the misophonic ANS response. During the online experiment, participants (N=230) will hear 10 misophonic triggers and 10 generally unpleasant sounds and rate their aversiveness, while we measure their pupil size. All participants will additionally fill out several questionnaires, including the Amsterdam Misophonia Scale. We will perform multiple linear regression and, across participants, model questionnaire scores as a function of subjective ratings and pupil response magnitudes (both quantified as the participant-wise contrast between misophonia trigger and generally unpleasant sounds). The individual difference approach addresses the question of why one individual develops misophonia while another does not, but also what explains these range of symptom severity. Should all sufferers be regarded different manifestations of the same underlying anomality? Or is severe misophonia qualitatively different? How to address questions related to heterogeneity within a condition, defining the boundaries of a condition, and the role of individual differences in explaining symptom severity are important questions not only in misophonia research, but also in for example autism, psychiatric genetics and dyslexia.

[granted May 2025]