All posts filed under: Papers

How exploration develops and is linked to impulsivity

Chocolate, hibiscus or spinach ice-cream? Many decisions we make require arbitrating between novelty (e.g., hibiscus) and the benefits of familiar options (e.g., chocolate). This is called the exploration-exploitation trade-off and humans rely on different exploration strategies to make their decision. Exploration strategies vary in performance and computational requirements. The simplest strategy, value-free random exploration, is to ignore prior knowledge and to choose entirely randomly. Such strategy may lead to suboptimal performance (e.g., choosing the disgusting spinach ice-cream), but allows to spare cognitive resources. This is of particular interest when access to cognitive resources is limited and prior knowledge uncertain, such as in development and mental health disorders. In a cross-sectional developmental study, we demonstrate that value-free random exploration is used more at a younger age, in line with the idea that we need to spare more cognitive resources at an earlier age as our brain is still developing. Additionally, in a large-sample online study, we show that value-free random exploration is specifically associated to impulsivity, suggesting an adaptive role for impulsivity, i.e., a way to …

Reliability of web-based affective sounds

Conducting research experiments on web-based platforms have become common in recent years but some designs, especially tasks that involve sounds, have been slow in their online adaptation because of concerns of data quality. In our latest paper, we leveraged recent methods to increase sound presentation quality and tested the reliability of a selected array of commonly used emotional sound stimuli to evoke valence and arousal states online. We found good inter-rater and test-retest reliabilities, with results comparable to in-lab studies which demonstrate that affective sounds can be robustly utilized on web-based platforms. We hope that this will help enable the adaptation and development of new auditory paradigms for online experiments. More information can be found here:Seow TXF & Hauser TU (2021). Reliability of web-based affective auditory stimulus presentation. Behavior Research Methods.

Emerging metacognition allows adolescents to ignore false advice

Adolescents aspire for independence and are often accused of not following the advice of others. Here, we investigated metacognitive development and advice taking across childhood and adolescence. To do this, we created a new space-themed game where participants made simple decisions about the numbers of, for example blue versus yellow, aliens there were on a planet. Participants were also given advice by a helpful ‘space advisor’ and could decide whether to stick with or switch their original decision. We found that adolescents, compared with children, had better metacognitive skills in that they were better able to intuit when they had made a good decision. This metacognitive skill allowed them to better resist misleading advice from others. ‘I know better, and I know I know better!’. More information can be found here:Moses-Payne ME, Habicht J, Bowler A, Steinbeis N & Hauser TU (2021). I know better! Emerging metacognition allows adolescents to ignore false advice. Developmental Science 

Children gather more information when it is not costly

In our recent paper, we are investigating how information gathering changes over childhood and adolescence. We found that children gathered substantially more information before making a decision, but only if it came at no extra costs for sampling information. Using further computational modelling we showed that this effect was driven by a later emergence of subjective sampling costs for gathering information. These findings help us to understand how such cognitive functions develop, and how different information gathering impairments arise in adolescence-related psychiatric disorders.  More information can be found here:Bowler A, Habicht J, Moses-Payne ME, Steinbeis N, Moutoussis M & Hauser TU (2021). Children perform extensive information gathering when it is not costly. Cognition 104535 

Propranolol modulates value-free random exploration

In our recent paper, we are investigating the catecholaminergic bases of different exploration strategies. Previously it was thought that exploration-exploitation trade-off is solved by using computationally demanding exploration algorithms, however, we show that humans also use additional computationally cheaper strategies using a newly developed 3-armed bandit task. Furthermore, we show that one of these heuristics, value-free random exploration (ϵ-greedy), is modulated by noradrenaline. Upon administration of a single dose of propranolol, we found a reduction in value-free random exploration. This could be interesting in the context of disorders of exploration, such as attention-deficit/hyperactivity disorder and how aberrant catecholamine function might contribute to the core behavioural impairments. More information can be found here:Dubois M, Habicht J, Michely J, Moran R, Dolan RJ & Hauser TU (2021). Human complex exploration strategies are enriched by noradrenaline-modulated heuristics eLife 10:e59907

A rise of OCD: OCD symptoms are more affected by the Covid-19 pandemic than other mental health symptoms.

In our new preprint, we present data of our longitudinal study in which we tracked obsessive-compulsive, anxiety and depression symptoms in the general public during the first Covid-19 pandemic wave. We show an elevation across all psychiatric symptoms. However, while depression scores decreased and anxiety symptoms remained stable over time, obsessive-compulsive symptoms rose further even though the peak of the first pandemic wave had passed. These OC symptoms were directly linked to Covid-related information seeking which gave rise to a higher adherence to government Covid-19 guidelines. For more details, see here: Loosen, A. M., Skvortsova, V., & Hauser, T. U. (2020). A Selective Increase in OC Symptoms is Driving Information Seeking and Guideline Adherence During the Covid-19 Pandemic. MedRxiv, 2020.12.08.20245803.

Making a case for a computational psychiatry of juvenile obsessive-compulsive disorder

In a recent paper published in Neuroscience & Biobehavioral Reviews, we review studies relevant to a computational psychiatry of juvenile OCD. Our investigation shows that juvenile OCD is mainly characterised by the disruption of complex reasoning systems. Based on reviewed findings, we suggest a new neurocomputational framework that illustrates how observed alterations may arise with development. Providing testable hypotheses this framework can now guide future research endeavours. More information can be found here: Loosen AM & Hauser TU (2020). Towards a computational psychiatry of juvenile obsessive-compulsive disorder Neuroscience and Biobehavioral Reviews 14;118:631-642 

Myelin-related growth during adolescence related to compulsivity and impulsivity traits

In a recent paper that we recently published in Nature Neuroscience, we present data from a longitudinal cohort study (the NSPN project). We repeatedly acquired MRI scans from over 300 adolescents and followed them over time. Using a specific marked (magentization transfer saturation) that indexes myelination (the insulation of brain connections), we show that adolescence undergoes fundamental reorganisation during adolescence. A wide-spread myelin-related growth is thereby present in both white and gray matter. Looking at traits of impulsivity and compulsivity, we then show that scoring high on these dimensions is related to a reduced growth in prefrontal brain areas. Our study thus links adolescent brain development to prychiatric traits during a periode when many mental health problems emerge. More information can be found here: Ziegler G*, Hauser TU*, Moutoussis M, Bullmore ET, Goodyer IM, Fonagy P, Jones PB, NSPN Consortium, Lindenberger U & Dolan RJ (2019). Compulsivity and impulsivity are linked to distinct developmental trajectories of fronto-striatal myelinatioCompulsivity and impulsivity traits linked to attenuated developmental frontostriatal myelination trajectoriesn. Nature Neuroscience

Papers on exploration and model-free behaviour

I had the pleasure to co-author two papers that provide substantial new insight nto the mechanisms underlying cognition. In a recent paper by Nitzan Shahar, he assesses the reliability of the famous ‘two-step task’ and describes how to improve the reliability of this test. This is critical if we want to adequately capture the functioning of multiple reasoning-systems in health and disorder. In a second paper by Philipp Schwartenbeck, he uses computational modelling to describe to forms of goal-directed exploration. While one of them is to learn environmental contingencies, the other form helps determine in which state an agent is. These forms of goal-directed exploration thus serve different functions and are believed to be important contributors to decision making. Schwartenbeck P, Passecker J, Hauser TU, FitzGerald THB, Kronbichler M & Friston K (2019). Computational mechanisms of curiosity and goal-directed exploration. eLife doi:10.1101/589713 Shahar N, Hauser TU, Moutoussis M, Moran R, Keramati M, NSPN Consortium & Dolan RJ (2019). Improving the reliability of model-based decision-making estimates in the two-stage decision task with reaction-times and drift-diffusion modeling. …

Propranolol modulates Information Gathering

In a recent paper that we have just published in Journal of Neuroscience, we show that Information Gathering can be modulated using the noradrenergic Beta-Receptorblocker Propranolol. Upon a single dose propranolol, we found a reduction in information gathering. Computational modelling revealed that this is due to an earlier rise of an internal urgency signal, which promotes timely decisions. This could be interesting in the context of OCD, because we found a delay in this urgency signal in patients with OCD. Hauser TU, Moutoussis M, Purg N, Dayan P* & Dolan RJ* (2018). Beta-blocker propranolol modulates decision urgency during sequential information gathering. J Neurosci 38 (32) 7170-7178