Minimum spanning tree analysis of the human connectome. van Dellen Edwin,Sommer Iris E,Bohlken Marc M,Tewarie Prejaas,Draaisma Laurijn,Zalesky Andrew,Di Biase Maria,Brown Jesse A,Douw Linda,Otte Willem M,Mandl René C W,Stam Cornelis J Human brain mapping One of the challenges of brain network analysis is to directly compare network organization between subjects, irrespective of the number or strength of connections. In this study, we used minimum spanning tree (MST; a unique, acyclic subnetwork with a fixed number of connections) analysis to characterize the human brain network to create an empirical reference network. Such a reference network could be used as a null model of connections that form the backbone structure of the human brain. We analyzed the MST in three diffusion-weighted imaging datasets of healthy adults. The MST of the group mean connectivity matrix was used as the empirical null-model. The MST of individual subjects matched this reference MST for a mean 58%-88% of connections, depending on the analysis pipeline. Hub nodes in the MST matched with previously reported locations of hub regions, including the so-called rich club nodes (a subset of high-degree, highly interconnected nodes). Although most brain network studies have focused primarily on cortical connections, cortical-subcortical connections were consistently present in the MST across subjects. Brain network efficiency was higher when these connections were included in the analysis, suggesting that these tracts may be utilized as the major neural communication routes. Finally, we confirmed that MST characteristics index the effects of brain aging. We conclude that the MST provides an elegant and straightforward approach to analyze structural brain networks, and to test network topological features of individual subjects in comparison to empirical null models. 10.1002/hbm.24014

Dark Nudges and Sludge in Big Alcohol: Behavioral Economics, Cognitive Biases, and Alcohol Industry Corporate Social Responsibility. Petticrew Mark,Maani Nason,Pettigrew Luisa,Rutter Harry,VAN Schalkwyk May Ci The Milbank quarterly Policy Points Nudges steer people toward certain options but also allow them to go their own way. "Dark nudges" aim to change consumer behavior against their best interests. "Sludge" uses cognitive biases to make behavior change more difficult. We have identified dark nudges and sludge in alcohol industry corporate social responsibility (CSR) materials. These undermine the information on alcohol harms that they disseminate, and may normalize or encourage alcohol consumption. Policymakers and practitioners should be aware of how dark nudges and sludge are used by the alcohol industry to promote misinformation about alcohol harms to the public. CONTEXT:"Nudges" and other behavioral economic approaches exploit common cognitive biases (systematic errors in thought processes) in order to influence behavior and decision-making. Nudges that encourage the consumption of harmful products (for example, by exploiting gamblers' cognitive biases) have been termed "dark nudges." The term "sludge" has also been used to describe strategies that utilize cognitive biases to make behavior change harder. This study aimed to identify whether dark nudges and sludge are used by alcohol industry (AI)-funded corporate social responsibility (CSR) organizations, and, if so, to determine how they align with existing nudge conceptual frameworks. This information would aid their identification and mitigation by policymakers, researchers, and civil society. METHODS:We systematically searched websites and materials of AI CSR organizations (e.g., IARD, Drinkaware, Drinkwise, Éduc'alcool); examples were coded by independent raters and categorized for further analysis. FINDINGS:Dark nudges appear to be used in AI communications about "responsible drinking." The approaches include social norming (telling consumers that "most people" are drinking) and priming drinkers by offering verbal and pictorial cues to drink, while simultaneously appearing to warn about alcohol harms. Sludge, such as the use of particular fonts, colors, and design layouts, appears to use cognitive biases to make health-related information about the harms of alcohol difficult to access, and enhances exposure to misinformation. Nudge-type mechanisms also underlie AI mixed messages, in particular alternative causation arguments, which propose nonalcohol causes of alcohol harms. CONCLUSIONS:Alcohol industry CSR bodies use dark nudges and sludge, which utilize consumers' cognitive biases to promote mixed messages about alcohol harms and to undermine scientific evidence. Policymakers, practitioners, and the public need to be aware of how such techniques are used to nudge consumers toward industry misinformation. The revised typology presented in this article may help with the identification and further analysis of dark nudges and sludge. 10.1111/1468-0009.12475

Developing evidence-based patient-focused learning materials to support health behaviour change for people living with psoriatic arthritis. RMD open OBJECTIVES:In psoriatic arthritis (PsA), self-management is important for patient function and quality of life. Behaviour change can be difficult, patients could benefit from high-quality support to initiate change. Our aim was to codesign the project as theory-informed, evidence-based, patient-focused, materials supporting healthy lifestyle changes for patients diagnosed with PsA. METHODS:Development of the materials was overseen by a steering group of patients with PsA, psychologists, rheumatologists, a design team and researchers. First, a literature review was performed to establish the evidence base for behaviours and potential interventions in PsA, including diet, weight, alcohol, smoking, exercise, anxiety, depression and stress. An initial roundtable of patients with PsA prioritised areas and content ideas. Draft materials including a website and downloadable materials were produced. A second roundtable of patients with PsA collected feedback on the draft content and design. A third roundtable was held with patients with PsA and a fourth with clinicians to refine the materials and ensuring that they were evidence based, accessible, interesting, and helpful to initiate and maintain change. A final evaluation survey was performed to review the draft website before launching the final materials. RESULTS:15 candidate topics were prioritised. A website and set of postcards summarising the topics were developed by the design team and refined following feedback from the roundtable groups. CONCLUSION:This project created patient-focused resources to support behaviour change. It addresses common concerns of patients with PsA about how they may optimise their health by providing practical and brief interventions to challenge and support them to make changes. 10.1136/rmdopen-2023-003190