Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
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Support of EU Climate Policies in Germany
No full textNo, no data have been collected for this study yet. The data will be collected by a German market research company (Respondi) which also provides the respondent panel. Data collection starts at the 15th of July 2022 and ends when the sample size of 4,800 participants is reached (presumably August 2022)
A mega-analysis of cortical structure and subcortical volumes in conduct disorder in youth: Influence of sex, age-of-onset and callous-unemotional traits
No full textConduct disorder (CD) is one of the most common childhood psychiatric disorders and is characterised by a repetitive and pervasive pattern of aggressive or antisocial behaviours, such as physical aggression towards other humans or animals, theft, property damage and rule violations (APA, 2013). The worldwide prevalence of CD is estimated to be 2-2.5%, with a prevalence of 3-4% in boys and 1-2% in girls (Maughan et al., 2004). Overall, CD is a leading cause of referral to child and adolescent mental health services and places an enormous burden on the affected individuals, their families and society (Erksine et al., 2014; Rivenbark et al., 2018).
Although neuroimaging studies have reported alterations in brain structure in CD and supported the view that CD is a neurodevelopmental disorder, a major concern of the diagnostic criteria for CD (e.g., initiating physical fights) is that they are entirely based on behavioural symptoms, and can be shared with other disorders (e.g., ADHD, Substance Use Disorder, Tourette's disorder or Bipolar Disorder), and are therefore less informative about the underlying psychological states/cognitions or neural substrates which drive the symptoms (Blair et al., 2005; Fairchild et al., 2019). A comprehensive and thorough understanding of the underlying pathophysiology of CD may help address this question and help refine diagnostic approaches. Neuroimaging studies on CD have shown altered neural responses in tasks involving emotional processing and executive function (Alegria et al., 2016; Noordermeer et al., 2016; Raschle et al., 2015) and reductions in grey matter volume (Noordermeer et al., 2016; Raschle et al., 2015; Rogers & De Brito, 2016) across a number of cortical (e.g., ventromedial prefrontal and insular cortices) and subcortical (e.g., amygdala and basal ganglia) regions critical for emotion processing and regulation, reinforcement-based decision-making, executive function and empathic responding (Fairchild et al., 2019).
Although these discoveries marked pivotal advances in our understanding of CD, the evidence base suffers from two important limitations. First, inconsistent findings and a lack of replication are common; demographic and clinical features of the samples, as well as methodological factors, have likely contributed to this. For example, CD is a heterogeneous disorder with subtypes based on the age-of-onset of symptoms (childhood-onset versus adolescence-onset, which is defined by whether severe antisocial behaviours emerge before or after 10 years of age), and the presence or absence of callous-unemotional (CU) traits (encompassed by the ‘with limited prosocial emotions’ specifier in the DSM-5; APA, 2013). However, most primary magnetic resonance imaging (MRI) studies of CD have not examined the influence of these subtypes on their findings. Potential sex differences in the relationship between CD and brain structure might also have contributed to the inconsistent findings (Smaragdi et al., 2017). Most studies of CD have focused only on males and hence it is currently understudied/unclear whether females with CD show similar alterations. Relatedly, studies that have investigated mixed-sex samples were largely underpowered to test for sex-by-diagnosis interactions and may hence have contributed to the inconsistencies observed in the literature. Second, most of the neuroimaging studies had small sample sizes, increasing the risk for false positives and false negatives (Button et al., 2013), as well as resulting in limited power to test differences between CD subtypes or explore heterogeneity. In this context, our understanding of CD-related brain structural alterations could be improved through a large-scale coordinated and harmonised analysis of the vast amounts of existing data to map brain differences in heterogeneous CD patients worldwide.
In 2009, the Enhancing NeuroImaging Genetics through Meta-Analyses (ENIGMA) consortium (http://enigma.ini.usc.edu) was established to pool brain imaging data from existing cohorts across the world in order to better understand brain structure, function, and disease, based on meta- and mega-analyses of brain imaging and genetic data (Bearden & Thompson, 2017; Thompson et al., 2020). The ENIGMA-Antisocial Behavior (ASB) working group aims to clarify associations between CD, conduct problems (CPs), psychopathy, or antisocial personality disorder and alterations in brain structure and function by using ENIGMA’s highly powered consortium approach to overcome the limitations of small studies with low power and uncertain reproducibility. Therefore, the proposed study will focus on examining the cortical and subcortical correlates of CD using a mega-analysis (i.e., individual participant data meta-analysis) of structural MRI (sMRI) data, considering the influence of subtypes and testing for possible sex-specific effects.
In addition to those with a CD diagnosis, there is a considerable amount of youths demonstrating elevated CP (Ghandour et al., 2019; Deighton et al., 2019), but who have not been assessed with diagnostic instruments and/or have not received a clinical diagnosis of CD. It is of interest if the findings from case-control comparisons of brain structure can be generalised to undiagnosed youths with elevated CP. As youths with a CD diagnosis are often recruited from specialised settings (e.g., clinics, mental health services or youth offending services), studying youths with elevated CP recruited through non-specialised settings would reduce selection bias and increase the generalisability of findings to a broader population (Horga et al., 2014). Neuroimaging studies have demonstrated structural brain alterations in youths with elevated CP, including decreased grey matter volume in the insula, amygdala, frontal and temporal regions (Raschle et al., 2015; Rogers & De Brito, 2016). A longitudinal study also reported altered trajectories of cortical thickness development in the dorsolateral prefrontal cortex and the anterior cingulate cortex (ACC), and volume of the hippocampus in youths showing elevated CP (Oostermeijer et al., 2016). Hence, both CP and CD appear to be related to similar and overlapping MRI findings of lower volume in the prefrontal cortex and limbic system. However, to date, no study has directly investigated if and how the cortical and subcortical alterations in youths with elevated CP overlap with the findings in youths with CD. Comparing youths with CD, elevated CP and TD will help clarify the neural mechanisms underlying antisocial behaviours in the clinical population, and extend the results to a more heterogeneous group of undiagnosed individuals showing elevated CP. Based on the ENIGMA-ASB datasets and using large-scale mega-analytical methods, the proposed study will also include an elevated CP group to identify the shared brain alterations underlying elevated antisocial behaviours as well as the specific alterations limited to youths with CD through the large-scale mega-analysis.
Research Questions:
(1) Do youths with CD show differences in cortical thickness, surface area and/or subcortical volume compared to TD youths?
(2) How are sex, age-of-onset and CU traits related to brain alterations in CD?
(3) Can alterations detected in youths with CD be generalised to youths with elevated CP
Phenomenological control as a predictor for mystical experience and persisting effects
No full textAltered states of consciousness can occur in various contexts, and may produce mystical experiences (Hitchcott et al., 2019; Vlisides et al., 2018). There is emerging evidence that such states can predict positive outcomes following psychedelic experiences (Griffiths et al., 2011), but the persisting effects of other altered states are unknown. Another underexplored area is the potential for individual difference characteristics to influence the ways people experience altered states. A new measure, the phenomenological control scale (Dienes et al., 2020), quantifies the capacity of individuals to shape their perceptual experience. As altered states are characterised by considerable changes in perception and cognition, understanding the role that phenomenological control might have in shaping these experience will help to understand the mechanisms that govern any lasting effects from these states. Therefore, this project will examine the influence of phenomenological control across a range of altered states of consciousness, and the potential of these states for mystical experience and persisting effect
Measures of Treatment Burden in Dialysis: A Scoping Review
No full textA pre-registration of the protocol for a scoping review on measures of treatment burden in dialysis
Not a Pipe: Local Assignments between Symbols and Discourse Referents
No full textHuman communication often involves local assignments between perceptually available objects and entities that are currently under discussion (discourse referent). This structure is exploited in many communicative media such as pretend play, puppet shows, diagrams, and animations. In a looking-while-listening eyetracking paradigm we investigate whether 14-to-16-month-old infants can map a conceptual description (e.g., “a car”) to an arbitrary visual object (e.g., a triangle) following linguistic stipulation (e.g., after the triangle is pointed to and labeled as such)
Paper 3 - Ghazal, Cokely, and Garcia-Retamero 2014
No full textPre-registration of the multiverse specification before results are know
Error Related Impairment of Active working Memory (Wessel et al., 2022) Replication study
No full textThis registration folder includes description of all materials and procedure used to replicate experiment#2 of ERIAM (Wessel et al., 2022)
To this date: Data collection is not started yet (add: on 07/03/25, manuscript is under revision and all data are made available as code analysis in the files folder)
This project will be done in Toulouse Jean Jaurès University (France) and passation of the task will take place in CLLE laboratory (CNRS-University Toulouse2)
My professor, Madame Céline Lemercier, and Pierre-Vincent Paubel, take part in this project and will be cited in this work
Exploring usability characteristics in computer-based digital health technologies for family caregivers of people with chronic progressive conditions: a scoping review protocol
No full textA scoping revie
Modulation of visual contrast sensitivity with transcranial random noise stimulation
No full textTranscranial random noise stimulation (tRNS) has been shown to significantly improve visual perception. These performance improvements manifested as both (i) after-effects of visual training combined with tRNS (Fertonani et al., 2011; Pirulli et al., 2013; Contemori et al., 2019; Herpich et al., 2019) and (ii) acute effects during tRNS (van der Groen and Wenderoth, 2016; Ghin et al., 2018; van der Groen et al., 2018, 2019; Battaglini et al., 2019, 2020; Pavan et al., 2019). It has been postulated that the Stochastic resonance (SR) phenomenon underlie noise-induced signal enhancement in studies investigating the acute effect of tRNS on visual processing (van der Groen and Wenderoth, 2016; van der Groen et al., 2018, 2019; Battaglini et al., 2019, 2020; Pavan et al., 2019). SR describes the phenomenon that the response of nonlinear systems to weak, subthreshold signals can be enhanced by adding an optimal level of random noise (Moss et al., 2004; McDonnell and Abbott, 2009). One important feature indicative of the SR phenomenon is that noise benefits are a function of noise intensity and exhibit an inverted U-shape relationship. Thus, while the optimal level of noise benefits performance, excessive noise is detrimental (van der Groen and Wenderoth 2016; van der Groen et al. 2018; Pavan et al. 2019).
Previous studies investigating the acute effect of tRNS on visual detection performance have shown that noise stimulation was particularly beneficial when the visual stimuli were presented with near-threshold intensity (van der Groen and Wenderoth, 2016; van der Groen et al., 2018; Battaglini et al., 2019).
Currently, it is unknown whether signal enhancement via SR could be achieved separately within different neural substrates along the retino-cortical pathway. Inducing SR via tRNS offers a unique opportunity to investigate this question.
Here we plan a series of three experiments which will be executed in three separate sessions.
Experiment 1: TRNS over primary visual cortex (V1) has been shown previously to improve visual contrast detection (van der Groen and Wenderoth, 2016). Here we aim to replicate these results in a new cohort and to determine the optimal tRNS intensity for each individual participant.
Experiment 2: Previous research has suggested that the retina and the optical nerve are highly susceptible to alternating currents (Schutter and Hortensius, 2010). Improvement in vision was reported after repetitive transorbital alternating current stimulation over the retina, in studies involving patients with optic neuropathy or after optic nerve lesions (Gall et al., 2010; Fedorov et al., 2011). The retina and the optic nerve are an interesting target because they can be reliably reached even with low transcranial electrical stimulation intensities since the eyeball is an excellent conductor. Here we will test whether tRNS applied to the retina and the optic nerve improves visual contrast detection in accordance with the SR mechanism. We will apply different tRNS intensities to determine the optimal intensity for each individual participant.
Experiment 3: It is currently unknown whether SR effects are additive when noise is applied to connected yet anatomically remote neural populations. Here we will investigate whether simultaneous application of tRNS to the retina and V1 causes additive effects
A módosult tudatállapotok és intenzív érzelmek hasonlóságai és különbségei daganatos betegek élményvilágában
No full textMind az érzelmek, mind a különböző tudatállapotok definiálása korunk pszichológiájának egyik legnagyobb kihívása. Ahogy a módosult tudatállapotok, úgy az érzelmek is képesek befolyásolni az egyén tér-, idő-, és önészlelését, megváltoztatni gondolatait és viselkedését, és mindkét jelenségkör alkalmazkodássegítő és közösségszervező ereje jelentős. Jelen tanulmány szerzői amellett érvelnek, hogy a két jelenségkört el lehet képzelni egy egységes elméleti keretrendszeren belül, ahol a módosult tudatállapotok leírhatók intenzív, ’medrükből kiáradt’ érzelmekként. Ebben a vizsgálatban 10 magyarul beszélő, daganattal küzdő budapesti felnőttel fogunk majd félig strukturált interjúkat készíteni intenzív érzelmi élményeikről (pl: diagnózis megtudása), illetve módosult tudatállapotokkal (pl: hipnózis) kapcsolatos élményeikről, majd tartalomelemzéssel megpróbáljuk beazonosítani, hogy az intenzív érzelmi élményeik során torzult-e az ön- és valóságészlelésük annyira, hogy az már teljesítse a módosult tudatállapot kritériumait. Amennyiben igen, vagyis az intenzív érzelmi átélés résztvevőink esetében módosult tudatállapothoz vezetett, az további kutatások számára készítheti elő terepet (pl: kognitív képességek vizsgálata intenzív érzelmek laboratóriumi indukciója után)