Removing the effects of the site in brain imaging machine-learning Measurement and extendable benchmark

Multisite machine-learning neuroimaging studies, such as those conducted by the ENIGMA Consortium, need to remove the differences between sites to avoid effects of the site (EoS) that may prevent or fraudulently help the creation of prediction models, leading to impoverished or inflated prediction accuracy. Unfortunately, we have shown earlier that current Methods Aiming to Remove the EoS (MAREoS, e.g., ComBat) cannot remove complex EoS (e.g., including interactions between regions). And complex EoS may bias the accuracy. To overcome this hurdle, groups worldwide are developing novel MAREoS. However, we cannot assess their effectiveness because EoS may either inflate or shrink the accuracy, and MAREoS may both remove the EoS and degrade the data. In this work, we propose a strategy to measure the effectiveness of a MAREoS in removing different types of EoS. FOR MAREOS DEVELOPERS, we provide two multisite MRI datasets with only simple true effects (i.e., detectable by most machine-learning algorithms) and two with only simple EoS (i.e., removable by most MAREoS). First, they should use these datasets to fit machine-learning algorithms after applying the MAREoS. Second, they should use the formulas we provide to calculate the relative accuracy change associated with the MAREoS in each dataset and derive an EoS-removal effectiveness statistic. We also offer similar datasets and formulas for complex true effects and EoS that include first-order interactions. FOR MACHINE-LEARNING RESEARCHERS, we provide an extendable benchmark website to show: a) the types of EoS they should remove for each given machine-learning algorithm and b) the effectiveness of each MAREoS for removing each type of EoS. Relevantly, a MAREoS only able to remove the simple EoS may suffice for simple machine-learning algorithms, whereas more complex algorithms need a MAREoS that can remove more complex EoS. For instance, ComBat removes all simple EoS as needed for predictions based on simple lasso algorithms, but it leaves residual complex EoS that may bias the predictions based on standard support vector machine algorithms

Emotional and cognitive processes underlying decision-making : study of children, adolescents and adults with typical development or with autism spectrum disorders

L'objectif général de cette thèse était de mieux caractériser les processus cognitifs et émotionnels guidant la prise de décision à risque. En adoptant une perspective intégrative, regroupant les approches de la psychologie du développement, de la psychologie cognitive et de la psychopathologie, nous avons successivement examiné (i) les mécanismes cognitifs et émotionnels conduisant des adultes à être susceptibles à l'un des principaux biais décisionnels, l'effet du cadre, (ii) la relation entre la prise de risque et la capacité de régulation émotionnelle au cours du développement, (iii) l'influence de l'aversion au risque des individus ayant un Trouble du Spectre de l'Autisme (TSA) sur leur rationalité dans une tâche expérimentale de prise de décision. Notre première étude, réalisée auprès d'adultes typiques, a confirmé expérimentalement que les processus émotionnels d'attraction aux gains sûrs et d'aversion aux pertes sûres hypothétisés par Daniel Kahneman étaient bien au cœur de la susceptibilité à l'effet du cadre. De plus, le contraste de plusieurs conditions expérimentales a confirmé la robustesse de ces processus émotionnels et a permis d'identifier qu'un facteur méthodologique variant entre les deux principales tâches d'effet du cadre modérait la susceptibilité à l'effet du cadre. Notre seconde étude, réalisée auprès d'enfants, d'adolescents et d'adultes typiques, a exploré la relation entre le développement d'une stratégie de régulation émotionnelle (la réévaluation cognitive) et le développement de la prise de décision à risque et de la susceptibilité à l'effet du cadre. Nos résultats ont montré que les adolescents prenaient plus de risques que les enfants ou les adultes mais révélaient que cette hausse de prise de risque était limitée aux situations comportant de faibles chances de succès. De plus, nous n'avons trouvé aucune différence intergroupe quant à l'utilisation de la réévaluation cognitive ou la susceptibilité à l'effet du cadre. Dans une troisième étude, nous avons exploré les capacités de prise de décision de personnes ayant un TSA. Afin d'explorer la relation entre aversion au risque et rationalité chez les personnes ayant un TSA, nous avons adapté un paradigme d'effet du cadre afin de créer des situations où l'aversion au risque pouvait alternativement être une stratégie plus avantageuse, aussi avantageuse ou moins avantageuse que la prise de risque. Nos résultats ont montré que les participants ayant un TSA prenaient systématiquement moins de risques que les participants contrôle lorsque l'aversion au risque était plus avantageuse, ou aussi avantageuse que la prise de risque. En revanche, lorsque l'aversion au risque était moins avantageuse que la prise de risque, les deux groupes manifestaient un pattern de décision similaire. En conclusion, ces différentes études permettent d'enrichir la connaissance des processus émotionnels et cognitifs guidant la prise de décision à risque et la susceptibilité au principal biais décisionnel au cours du développement typique et chez les personnes ayant un TSA.This thesis aimed to provide a better understanding of cognitive and emotional processes underlying the decision under risk. Adopting an integrative perspective that includes approaches of developmental psychology, cognitive psychology and psychopathology, we have successively examined (i) cognitive and emotional processes underlying one of the major decisional bias, the framing effect, (ii) the relationship between risk-taking, framing susceptibility and emotion regulation during development, (iii) the role of risk-aversion in rationality of individuals with Autism Spectrum Disorders (ASD) in experimental situations. Our first study, analyzing decisions of adults with typical development, has experimentally confirmed that emotional processes of attraction to sure gains and aversion to sure losses hypothesized by Daniel Kahneman are at the core of framing susceptibility. Moreover, the contrast of several conditions has confirmed the robustness of these emotional processes and allowed to identify that one methodological factor varying between the two main framing tasks moderates framing susceptibility. Our second study, analyzing decisions of children, adolescents and adults with typical development, has explored the relationship between the development of an emotion regulation strategy (cognitive reappraisal) and the development of risk-taking and framing susceptibility. Our results showed that adolescents took more risks than children or adults but this increase in risk-taking was limited to situations with a high level of risk. We found no group differences on the frequency and the efficacy of using cognitive reappraisal and on framing susceptibility. Our third study assessed decision-making of adults with ASD. In order to explore the role of risk-aversion in rationality in individuals with ASD, we have adapted a framing paradigm to create situations in which risk-aversion was alternatively more rational, less rational, or neither more nor less rational than risk-taking. Results showed that participants with ASD took fewer risks than control participants when risk-aversion was more, or as advantageous as risk-taking. In contrast, when risk-aversion was less advantageous than risk-taking, both groups adopted a similar decision pattern. In conclusion, these studies expand knowledge on cognitive and emotional processes underlying the decision under risk and framing susceptibility during typical development and in individuals with ASD

Reliability of moral decision-making: Evidence from the trolley dilemma

International audienceThe application of framing effects in the field of moral judgement has offered a golden opportunity to assess the reliability of people’s moral judgements and decisions. To date, however, these studies are still scarce and they suffer from multiple methodological issues. Therefore, this study aims to provide further insights into the reliability of moral judgements while fixing these methodological shortcomings. In this study, we employed the classic trolley dilemma moral decision-making paradigm to determine the extent to which moral decisions are susceptible to framing effects. A total of 1,040 participants were included in the study. The data revealed that choices of participants did not significantly differ between the two frames. Equivalence tests confirmed that the associated effect size was very small. Further exploratory analyses revealed an unplanned interaction between the framing effect and the target of the framing manipulation. This result became from marginally statistically significant to insignificant following different sensitivity analyses. The implications and limitations of these findings and directions for future research are discussed

Association of sleep with moral severity to accidental harm transgressions: A cross‐sectional study

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The interplay between the importance of a decision and emotion in decision-making

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