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5. Overcoming bias in representational similarity analysis

Author

Viviani, Roberto

Subjects
Statistics - Methodology, Quantitative Biology - Quantitative Methods, 62H08, 62H35
Abstract

Representational similarity analysis (RSA) is a multivariate technique to investigate cortical representations of objects or constructs. While avoiding ill-posed matrix inversions that plague multivariate approaches in the presence of many outcome variables, it suffers from the confound arising from the non-orthogonality of the design matrix. Here, a partial correlation approach will be explored to adjust for this source of bias by partialling out this confound in the context of the searchlight method for functional imaging datasets. A formal analysis will show the existence of a dependency of this confound on the temporal correlation model of the sequential observations, motivating a data-driven approach that avoids the problem of misspecification of this model. However, where the autocorrelation locally diverges from its volume estimate, bias may be difficult to control for exactly, given the difficulties of estimating the precise form of the confound at each voxel. Application to real data shows the effectiveness of the partial correlation approach, suggesting the impact of local bias to be minor. However, where the control for bias locally fails, possible spurious associations with the similarity matrix of the stimuli may emerge. This limitation may be intrinsic to RSA applied to non-orthogonal designs. The software implementing the approach is made publicly available (https://github.com/roberto-viviani/rsa-rsm.git)., Comment: 17 pages, 6 figures

Published
2021

6. Phenotypic Models of Drug–Drug‐Gene Interactions Mediated by Cytochrome Drug‐Metabolizing Enzymes.

Author

Viviani, Roberto, Berres, Judith, and Stingl, Julia C.

Subjects
RECOMMENDER systems, GENETIC models, GENETIC polymorphisms, PHENOTYPES, PHARMACOKINETICS
Abstract

Genetic polymorphisms in drug metabolizing enzymes and drug–drug interactions are major sources of inadequate drug exposure and ensuing adverse effects or insufficient responses. The current challenge in assessing drug–drug gene interactions (DDGIs) for the development of precise dose adjustment recommendation systems is to take into account both simultaneously. Here, we analyze the static models of DDGI from in vivo data and focus on the concept of phenoconversion to model inhibition and genetic polymorphisms jointly. These models are applicable to datasets where pharmacokinetic information is missing and are being used in clinical support systems and consensus dose adjustment guidelines. We show that all such models can be handled by the same formal framework, and that models that differ at first sight are all versions of the same linear phenoconversion model. This model includes the linear pharmacogenetic and inhibition models as special cases. We highlight present challenges in this endeavor and the open issues for future research in developing DDGI models for recommendation systems. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Examining the association between trauma and antisocial cognitions

Author

Rabl, Luna and Viviani, Roberto

Subjects
FOS: Psychology, Psychology, Social and Behavioral Sciences
Abstract

In literature, the development of the dark personality is associated with the experience of childhood trauma in combination with genetic disposition and environmental factors. In previous studies, we have developed and validated the SST for antisocial cognitions, a task that is able to capture cognitions in the range of antisocial and prosocial schemas. In this study, we therefore want to investigate whether the SST and the choice of antisocial schemas are also related to experienced trauma, as assumed in the literature.

Published
2022
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24. Negative Cognitions in the Personality Domains of the AMPD

Author

Kienhöfer, Valerie, Mirgel, Sarah, Wilhelm, Selina, Fischle, Sonja, Rabl, Luna, Labek, Karin, and Viviani, Roberto

Subjects
Personality Inventory for DSM-5, Scrambled Sentences Task, AMPD, Alternative Model of Personality Disorders, Negative Cognitions
Abstract

Healthy individuals show a tendency towards positive cognitions that is reversed during depression. This tendency is revealed by the Scrambled Sentences Task (SST), an experimental procedure that was also shown to be associated with vulnerability to suffer from depressive episodes. Here, we used the SST to map the prevalence of negative cognitions across the personality domains of criterion B of the Alternative Model of Personality Disorder (AMPD) of the DSM-5 in healthy individuals. The AMPD was developed to characterize personality in a dimensional approach spanning both healthy and pathological individuals. We expected negative cognitions to be more frequent among individuals with high negative affectivity and detachment scores, as these dimensions are thought to be associated with disorders of affect. This association was stable and significant in three separate experiments and persisted for detachment after adjusting for current depression levels. In the Five-Factor Model of Personality (FFM), in contrast, only openness failed to show any association with negative cognitions. Negative affectivity and detachment differed in the preferential association with negative and positive cognitions, respectively. This finding suggests a possible role of motivational factors related to sensitivity to negative and positive incentives in linking personality dimensions and cognitive tendencies, with an anhedonic dimension of negative cognitions being present alongside current depressive symptoms.

Published
2022
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40. Effort-Reward-Imbalance, Burnout, and Depression Among Psychiatrists 2006 and 2016-Changes After a Legislative Intervention

Author

Beschoner, Petra, von Wietersheim, Jörn, Jarczok, Marc N., Braun, Maxi, Schönfeldt-Lecuona, Carlos, Viviani, Roberto, Jerg-Bretzke, Lucia, Kempf, Maximilian, and Brück, Aniela

Subjects
DDC 150 / Psychology, Depression, Psychiater, Burnout-Syndrom, Effort-reward-imbalance, Psychische Gesundheit, Berufskrankheit, ddc:150, Job strain, Physicians, Mental health, ddc:610, Psychiatrists, DDC 610 / Medicine & health, Burnout, Professional
Abstract

Background: Physicians, especially psychiatrists, have a high risk of job-related stress, and mental impairment. In our study we examined changes in private and occupational stress factors and mental health within a decade. The legislative reduction of physicians' working hours in Germany during this period made it possible to investigate the impact of working hours in particular. Methods: Questionnaires were administered at two psychiatrist meetings (2006 and 2016) about job and family situation, depressiveness, burnout and effort-reward imbalance. A total of N = 1,797 datasets were analyzed. Results: Working hours and free weekends were associated with mental health indices. Correlation analyses showed that a reduction in weekly working hours and working days at weekends was related to reduced scores for effort-reward-imbalance, burnout and depression. Conclusions: Our data show changes in workplace stress and mental health in psychiatrists in a decade in which a reduction in working hours has been required by law. These results can provide indications of effective prevention strategies in the professional context of physicians working in psychiatry., publishedVersion

Published
2021
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45. Sad as a matter of evidence: The desire for self-verification motivates the pursuit of sadness in clinical depression

Author

Viviani, Roberto, Arens, Elisabeth A., Stangier, Ulrich, Viviani, Roberto, Arens, Elisabeth A., and Stangier, Ulrich

Abstract

Background: Research on desired emotions revealed that individuals want to feel negative emotions if they expect these emotions to yield certain benefits. In previous studies, the pursuit of sadness (e.g., via pursuing art that evokes sadness) has been attributed to hedonic motives, i.e., to feel pleasure. We propose that in individuals with major depressive disorder (MDD) the pursuit of sadness may be more strongly related to self-verification motives, i.e., to sustain their sense of self through feeling sad. Methods: Participants with MDD (n = 50) were compared to non-depressed controls (n = 50) in their desired emotional states, as indicated by selected music (sad, happy and neutral), and in their motives (hedonic vs. self-verification) for choosing sad music. Groups were also compared in their self-reported general preference for sadness and the perceived functionality of sadness. Results: MDD participants showed a significant higher desire for sadness; more than half of them deliberately chose sad music. Whereas MDD participants had a marked preference for self-verification over hedonic motives, the reverse was true for non-depressed controls. MDD participants also agreed more strongly with self-verifying functions of sadness and expressed a stronger general preference for sadness. Conclusion: Findings indicate that emotion regulation in MDD might be driven by self-verification motives. They point to the relevance of exploring patients’ desired emotional states and associated motives. The systematic integration of positive affect into the self-image of depressed patients might help to deemphasize the self-verifying function of sadness, thereby overcoming the depression.

Published
2020

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