| 1. |
- Botvinik-Nezer, Rotem, et al.
(författare)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Tidskriftsartikel (refereegranskat)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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| 2. |
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| 3. |
- Aczel, Balazs, et al.
(författare)
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Consensus-based guidance for conducting and reporting multi-analyst studies
- 2021
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Ingår i: eLIFE. - : eLife Sciences Publications. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Any large dataset can be analyzed in a number of ways, and it is possible that the use of different analysis strategies will lead to different results and conclusions. One way to assess whether the results obtained depend on the analysis strategy chosen is to employ multiple analysts and leave each of them free to follow their own approach. Here, we present consensus-based guidance for conducting and reporting such multi-analyst studies, and we discuss how broader adoption of the multi-analyst approach has the potential to strengthen the robustness of results and conclusions obtained from analyses of datasets in basic and applied research.
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| 4. |
- Anderson, Christopher J., et al.
(författare)
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Response to Comment on "Estimating the reproducibility of psychological science"
- 2016
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 351:6277
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Gilbert et al. conclude that evidence from the Open Science Collaboration's Reproducibility Project: Psychology indicates high reproducibility, given the study methodology. Their very optimistic assessment is limited by statistical misconceptions and by causal inferences from selectively interpreted, correlational data. Using the Reproducibility Project: Psychology data, both optimistic and pessimistic conclusions about reproducibility are possible, and neither are yet warranted.
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| 5. |
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| 6. |
- Bourget, M. H., et al.
(författare)
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Microscopy-BIDS: An Extension to the Brain Imaging Data Structure for Microscopy Data
- 2022
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- The Brain Imaging Data Structure (BIDS) is a specification for organizing, sharing, and archiving neuroimaging data and metadata in a reusable way. First developed for magnetic resonance imaging (MRI) datasets, the community-led specification evolved rapidly to include other modalities such as magnetoencephalography, positron emission tomography, and quantitative MRI (qMRI). In this work, we present an extension to BIDS for microscopy imaging data, along with example datasets. Microscopy-BIDS supports common imaging methods, including 2D/3D, ex/in vivo, micro-CT, and optical and electron microscopy. Microscopy-BIDS also includes comprehensible metadata definitions for hardware, image acquisition, and sample properties. This extension will facilitate future harmonization efforts in the context of multi-modal, multi-scale imaging such as the characterization of tissue microstructure with qMRI.
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| 7. |
- Buchanan, E. M., et al.
(författare)
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The Psychological Science Accelerator's COVID-19 rapid-response dataset
- 2023
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data.
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| 8. |
- Czeszumski, Artur, et al.
(författare)
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#EEGManyLabs: Investigating the Replicability of Influential EEG Experiments
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- There is growing awareness across the neuroscience community that the replicability of findings on the relationship between brain activity and cognitive phenomena can be improved by conducting studies with high statistical power that adhere to well-defined and standardized analysis pipelines. Inspired by efforts from the psychological sciences, and with the desire to examine some of the foundational findings using electroencephalography (EEG), we have launched #EEGManyLabs, a large-scale international collaborative replication effort. Since its discovery in the early 20th century, EEG has had a profound influence on our understanding of human cognition, but there is limited evidence on the replicability of some of the most highly cited discoveries. After a systematic search and selection process, we have identified 27 of the most influential and continually cited studies in the field. We plan to directly test the replicability of key findings from 20 of these studies in teams of at least three independent laboratories. The design and protocol of each replication effort will be submitted as a Registered Report and peer-reviewed prior to data collection. Prediction markets, open to all EEG researchers, will be used as a forecasting tool to examine which findings the community expects to replicate. This project will update our confidence in some of the most influential EEG findings and generate a large open access database that can be used to inform future research practices. Finally, through this international effort, we hope to create a cultural shift towards inclusive, high-powered multi-laboratory collaborations.
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| 9. |
- Darai-Ramqvist, Eva, et al.
(författare)
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Microenvironment-dependent phenotypic changes in a SCID mouse model for malignant mesothelioma
- 2013
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Malignant mesothelioma is an aggressive, therapy-resistant tumor. Mesothelioma cells may assume an epithelioid or a sarcomatoid phenotype, and presence of sarcomatoid cells predicts poor prognosis. In this study, we investigated differentiation of mesothelioma cells in a xenograft model, where mesothelioma cells of both phenotypes were induced to form tumors in severe combined immunodeficiency mice.Methods: Xenografts were established and thoroughly characterized using a comprehensive immunohistochemical panel, array comparative genomic hybridization (aCGH) of chromosome 3, fluorescent in situ hybridization, and electron microscopy.Results: Epithelioid and sarcomatoid cells gave rise to xenografts of similar epithelioid morphology. While sarcomatoid-derived xenografts had higher growth rates, the morphology and expression of differentiation-related markers was similar between xenografts derived from both phenotypes. aCGH showed a convergent genotype for both xenografts, resembling the original aggressive sarcomatoid cell sub-line.Conclusion: Human mesothelioma xenografts from sarcomatoid and epithelioid phenotypes converged to a similar differentiation state, and genetic analyses suggested that clonal selection in the mouse microenvironment was a major contributing factor. This thoroughly characterized animal model can be used for further studies of molecular events underlying tumor cell differentiation.
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| 10. |
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| 11. |
- Dreber, Anna, et al.
(författare)
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Olika slutsatser från samma data : Den analytiska flexibiliteten i medicinsk forskning är ofta stor
- 2023
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Ingår i: Läkartidningen. - : Läkartidningen Förlag AB. - 1652-7518 .- 0023-7205. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of research data entails many choices. As a result, a space of different analytical strategies is open to researchers. Different justifiable analyses may not give similar results. The method of multiple analysts is a way to study the analytical flexibility and behaviour of researchers under naturalistic conditions, as part of the field known as metascience. Analytical flexibility and risks of bias can be counteracted by open data sharing, pre-registration of analysis plans, and registration of clinical trials in trial registers. These measures are particularly important for retrospective studies where analytical flexibility can be greatest, although pre-registration is less useful in this context. Synthetic datasets can be an alternative to pre-registration when used to decide what analyses should be conducted on real datasets by independent parties. All these strategies help build trustworthiness in scientific reports, and improve the reliability of research findings.
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| 12. |
- Drude, Natascha Ingrid, et al.
(författare)
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Planning preclinical confirmatory multicenter trials to strengthen translation from basic to clinical research : a multi-stakeholder workshop report
- 2022
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Ingår i: Translational Medicine Communications. - : Springer Nature. - 2396-832X. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Clinical translation from bench to bedside often remains challenging even despite promising preclinical evidence. Among many drivers like biological complexity or poorly understood disease pathology, preclinical evidence often lacks desired robustness. Reasons include low sample sizes, selective reporting, publication bias, and consequently inflated effect sizes. In this context, there is growing consensus that confirmatory multicenter studies -by weeding out false positives- represent an important step in strengthening and generating preclinical evidence before moving on to clinical research. However, there is little guidance on what such a preclinical confirmatory study entails and when it should be conducted in the research trajectory. To close this gap, we organized a workshop to bring together statisticians, clinicians, preclinical scientists, and meta-researcher to discuss and develop recommendations that are solution-oriented and feasible for practitioners. Herein, we summarize and review current approaches and outline strategies that provide decision-critical guidance on when to start and subsequently how to plan a confirmatory study. We define a set of minimum criteria and strategies to strengthen validity before engaging in a confirmatory preclinical trial, including sample size considerations that take the inherent uncertainty of initial (exploratory) studies into account. Beyond this specific guidance, we highlight knowledge gaps that require further research and discuss the role of confirmatory studies in translational biomedical research. In conclusion, this workshop report highlights the need for close interaction and open and honest debate between statisticians, preclinical scientists, meta-researchers (that conduct research on research), and clinicians already at an early stage of a given preclinical research trajectory.
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| 13. |
- Gau, Rémi, et al.
(författare)
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Brainhack : Developing a culture of open, inclusive, community-driven neuroscience
- 2021
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Ingår i: Neuron. - : Elsevier. - 0896-6273 .- 1097-4199. ; 109:11, s. 1769-1775
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Tidskriftsartikel (refereegranskat)abstract
- Brainhack is an innovative meeting format that promotes scientific collaboration and education in an open, inclusive environment. This NeuroView describes the myriad benefits for participants and the research community and how Brainhacks complement conventional formats to augment scientific progress.
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| 14. |
- Hallinan, D., et al.
(författare)
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International transfers of personal data for health research following Schrems II: a problem in need of a solution
- 2021
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 29, s. 1502-1509
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Tidskriftsartikel (refereegranskat)abstract
- On 16 July 2020, the Court of Justice of the European Union issued their decision in the Schrems II case concerning Facebook’s transfers of personal data from the EU to the US. The decision may have significant effects on the legitimate transfer of personal data for health research purposes from the EU. This article aims: (i) to outline the consequences of the Schrems II decision for the sharing of personal data for health research between the EU and third countries, particularly in the context of the COVID-19 pandemic; and, (ii) to consider certain options available to address the consequences of the decision and to facilitate international data exchange for health research moving forward. © 2021, The Author(s).
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| 15. |
- Hardwicke, Tom E., et al.
(författare)
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Data availability, reusability, and analytic reproducibility : evaluating the impact of a mandatory open data policy at the journal Cognition
- 2018
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 5:8
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Tidskriftsartikel (refereegranskat)abstract
- Access to data is a critical feature of an efficient, progressive and ultimately self-correcting scientific ecosystem. But the extent to which in-principle benefits of data sharing are realized in practice is unclear. Crucially, it is largely unknown whether published findings can be reproduced by repeating reported analyses upon shared data ('analytic reproducibility'). To investigate this, we conducted an observational evaluation of a mandatory open data policy introduced at the journal Cognition. Interrupted time-series analyses indicated a substantial post-policy increase in data available statements (104/417, 25% pre-policy to 136/ 174, 78% post-policy), although not all data appeared reusable (23/ 104, 22% pre-policy to 85/136, 62%, post-policy). For 35 of the articles determined to have reusable data, we attempted to reproduce 1324 target values. Ultimately, 64 values could not be reproduced within a 10% margin of error. For 22 articles all target values were reproduced, but 11 of these required author assistance. For 13 articles at least one value could not be reproduced despite author assistance. Importantly, there were no clear indications that original conclusions were seriously impacted. Mandatory open data policies can increase the frequency and quality of data sharing. However, suboptimal data curation, unclear analysis specification and reporting errors can impede analytic reproducibility, undermining the utility of data sharing and the credibility of scientific findings.
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| 16. |
- Helgesson, Gert, et al.
(författare)
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Editors publishing in their own journals : A systematic review of prevalence and a discussion of normative aspects
- 2022
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Ingår i: Learned Publishing. - : Wiley. - 0953-1513 .- 1741-4857. ; 35:2, s. 229-240
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Forskningsöversikt (refereegranskat)abstract
- Journal editors are the main gatekeepers in scientific publishing. Yet there is a concern that they may receive preferential treatment when submitting manuscripts to their own journals. The prevalence of such self-publishing is not known, nor the consequences for reliability and trustworthiness of published research. This study aimed to systematically review the literature on the prevalence of editors publishing in their own journals and to conduct a normative ethical analysis of this practice. A systematic review was performed using the following databases: Medline, PsycInfo, Scopus and Web of Science. Articles that provided primary data about editors publishing in own journals were included. We identified 15 studies meeting inclusion criteria. There was large variability of self-publishing across fields, journals and editors, ranging from those who never published in their own journal to those publishing extensively in their own journal. Many studies suffered from serious methodological limitations. Nevertheless, our results show that there are settings where levels of self-publication are very high. We recommend that editors-in-chief and associate editors who have considerable power in journals refrain from publishing research articles in their own journals. Journals should have clear processes in place about the treatment of articles submitted by editorial board members.
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| 17. |
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| 18. |
- Ingre, Michael, et al.
(författare)
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Estimating statistical power, posterior probability and publication bias of psychological research using the observed replication rate
- 2018
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 5:9
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we show how Bayes' theorem can be used to better understand the implications of the 36% reproducibility rate of published psychological findings reported by the Open Science Collaboration. We demonstrate a method to assess publication bias and show that the observed reproducibility rate was not consistent with an unbiased literature. We estimate a plausible range for the prior probability of this body of research, suggesting expected statistical power in the original studies of 48-75%, producing (positive) findings that were expected to be true 41-62% of the time. Publication bias was large, assuming a literature with 90% positive findings, indicating that negative evidence was expected to have been observed 55-98 times before one negative result was published. These findings imply that even when studied associations are truly NULL, we expect the literature to be dominated by statistically significant findings.
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| 19. |
- Ingre, Michael, 1965-
(författare)
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P-hacking in academic research : a critical review of the job strain model and of the association between night work and breast cancer in women
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- P-hacking can be described as a more or less deliberate, explorative approach to data analysis with a flexible/opportunistic search space and the reporting of primarily statistically significant findings. This leads to inflated type-1 error rates and to bias in reported estimates in the scientific literature.This thesis aims to describe how p-hacking can be manifested in academic research and to illustrate how bias due to p-hacking is expected to affect the veracity of published findings using two specific examples from the literature. This thesis also argues that when evaluating published findings in the current academic environment, we should assume a priori that biases due to p-hacking and publication bias are present.The thesis used Monte Carlo simulations and systematic reviews of the literature in two specific fields: the proposed associations between exposure to night work and breast cancer in women, and between job strain and coronary heart disease.A general model and mathematical framework to predict expected bias from p-hacking was developed, and can be used for a priori defined protected inferences of any published finding, under explicit assumptions of various levels of p-hacking. The model indicated a close to 100% chance of demonstrating a false positive association in larger studies, but also showed that even minimal p-hacking results in substantial bias in estimates.The literature review identified large flexibility in the analytical process, allowing for the final model to be picked from a large pool of available models, with an implied search space of thousands of estimates. Some of the specific observations made here could be used to argue evidence for high risk of p-hacking and publication bias in the reviewed literature:None of the 17 reviewed studies on job strain and coronary heart disease reported the proper estimate of the job strain interaction (chapter 6) and our analysis showed that the proper estimate would not have been statistically significant in any of the studies (chapter 7).One study described a data driven approach with an implied search space of at least 502 models, where adjusting for confounding did not reduce the strength of the association, as would be expected, but instead increased its strength so it fell above the threshold for statistical significance (chapter 5).One study was based on a speculative and marginally significant estimate after arbitrarily restricting the analysis to a subgroup, when estimates on the full group were available and indicated a non-significant association (chapter 5).Statistical power analyses on research into night work and breast cancer indicated that statistically significant findings were over-represented in the literature (p≈.001) suggesting the presence of bias from p-hacking or selective publishing of significant findings (chapter 5).The findings also suggest that previously reported estimates in meta-analyses was likely to represent prevailing bias in the two fields reviewed here. A bias-adjusted meta-analysis on the job strain model and coronary heart disease with a total of 462,220 subjects and 6,836 CHD events indicated no support for the job strain interaction (RR=1.00; 95% CI: 0.88--1.14). In addition, it did not show an increased risk due to high job demand (RR=1.03; 95% CI: 0.97--1.11) but it did confirm previously reported risks due to low job control (RR=1.11; 95% CI: 1.03--1.20).
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| 20. |
- Klein, Olivier, et al.
(författare)
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A Practical Guide for Transparency in Psychological Science
- 2018
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Ingår i: Collabra: Psychology. - : University of California Press. - 2474-7394. ; 4:1
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Forskningsöversikt (refereegranskat)abstract
- The credibility of scientific claims depends upon the transparency of the research products upon which they are based (e.g., study protocols, data, materials, and analysis scripts). As psychology navigates a period of unprecedented introspection, user-friendly tools and services that support open science have flourished. However, the plethora of decisions and choices involved can be bewildering. Here we provide a practical guide to help researchers navigate the process of preparing and sharing the products of their research (e.g., choosing a repository, preparing their research products for sharing, structuring folders, etc.). Being an open scientist means adopting a few straightforward research management practices, which lead to less error prone, reproducible research workflows. Further, this adoption can be piecemeal – each incremental step towards complete transparency adds positive value. Transparent research practices not only improve the efficiency of individual researchers, they enhance the credibility of the knowledge generated by the scientific community.
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| 21. |
- Koba, Cemal, et al.
(författare)
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Spontaneous eye movements during eyes-open rest reduce resting-state-network modularity by increasing visual-sensorimotor connectivity
- 2021
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Ingår i: Network Neuroscience. - : MIT Press - Journals. - 2472-1751. ; 5:2, s. 451-476
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Tidskriftsartikel (refereegranskat)abstract
- During wakeful rest, individuals make small eye movements during fixation. We examined how these endogenously driven oculomotor patterns impact topography and topology of functional brain networks. We used a dataset consisting of eyes-open resting-state (RS) fMRI data with simultaneous eye tracking. The eye-tracking data indicated minor movements during rest, which correlated modestly with RS BOLD data. However, eye-tracking data correlated well with echo-planar imaging time series sampled from the area of the eye-orbit (EO-EPI), which is a signal previously used to identify eye movements during exogenous saccades and movie viewing. Further analyses showed that EO-EPI data were correlated with activity in an extensive motor and sensorimotor network, including components of the dorsal attention network and the frontal eye fields. Partialling out variance related to EO-EPI from RS data reduced connectivity, primarily between sensorimotor and visual areas. It also produced networks with higher modularity, lower mean connectivity strength, and lower mean clustering coefficient. Our results highlight new aspects of endogenous eye movement control during wakeful rest. They show that oculomotor-related contributions form an important component of RS network topology, and that those should be considered in interpreting differences in network structure between populations or as a function of different experimental conditions.
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| 22. |
- Koenig, Julian, et al.
(författare)
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Cortical thickness and resting-state cardiac function across the lifespan : A cross-sectional pooled mega-analysis
- 2021
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Ingår i: Psychophysiology. - : Wiley. - 0048-5772 .- 1469-8986 .- 1540-5958. ; 58:7
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12–87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS—or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
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| 23. |
- Lakens, Daniel, et al.
(författare)
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Justify your alpha
- 2018
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Ingår i: Nature Human Behaviour. - : Nature Publishing Group. - 2397-3374. ; 2:3, s. 168-171
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Tidskriftsartikel (refereegranskat)abstract
- In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.
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| 24. |
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| 25. |
- Lekander, Mats, et al.
(författare)
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Intrinsic functional connectivity of insular cortex and symptoms of sickness during acute experimental inflammation
- 2016
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 56, s. 34-41
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Tidskriftsartikel (refereegranskat)abstract
- Task-based fMRI has been used to study the effects of experimental inflammation on the human brain, but it remains unknown whether intrinsic connectivity in the brain at rest changes during a sickness response. Here, we investigated the effect of experimental inflammation on connectivity between areas relevant for monitoring of bodily states, motivation, and subjective symptoms of sickness. In a double blind randomized controlled trial, 52 healthy volunteers were injected with 0.6 ng/kg LPS (lipopolysaccharide) or placebo, and participated in a resting state fMRI experiment after approximately 2h 45 minutes. Resting state fMRI data were available from 48 participants, of which 28 received LPS and 20 received placebo. Bilateral anterior and bilateral posterior insula sections were used as seed regions and connectivity with bilateral orbitofrontal and cingulate (anterior and middle) cortices was investigated. Back pain, headache and global sickness increased significantly after as compared to before LPS, while a non-significant trend was shown for increased nausea. Compared to placebo, LPS was followed by increased connectivity between left anterior insula and left midcingulate cortex. This connectivity was significantly correlated to increase in back pain after LPS and tended to be related to increased global sickness, but was not related to increased headache or nausea. LPS did not affect the connectivity from other insular seeds. In conclusion, the finding of increased functional connectivity between left anterior insula and middle cingulate cortex suggests a potential neurophysiological mechanism that can be further tested to understand the subjective feeling of malaise and discomfort during a sickness response.
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| 26. |
- Lindsäter, Elin, et al.
(författare)
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Exhaustion disorder : scoping review of research on a recently introduced stress-related diagnosis
- 2022
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Ingår i: BJPsych Open. - : Cambridge University Press. - 2056-4724. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSymptoms related to chronic stress are prevalent and entail high societal costs, yet there is a lack of international consensus regarding diagnostics and treatment. A new stress-related diagnosis, exhaustion disorder, was introduced into the Swedish version of ICD-10 in 2005. Since then, use of the diagnosis has increased rapidly.AimsTo create the first comprehensive synthesis of research on exhaustion disorder to report on the current state of knowledge. Preregistration: Open Science Framework (osf.io), doi 10.17605/OSF.IO/VFDKW.MethodA PRISMA-guided scoping review of all empirical studies of exhaustion disorder was conducted. Searches were run in the MEDLINE, PsycInfo and Web of Science databases. Data were systematically charted and thematically categorised based on primary area of investigation.ResultsEighty-nine included studies were sorted into six themes relating to lived experience of exhaustion disorder (n = 9), symptom presentation and course (n = 13), cognitive functioning (n = 10), biological measures (n = 24), symptom measurement scales (n = 4) and treatment (n = 29). Several studies indicated that individuals with exhaustion disorder experience a range of psychiatric and somatic symptoms beyond fatigue, but robust findings within most thematic categories were scarce. The limited number of studies, lack of replication of findings and methodological limitations (e.g. small samples and scarcity of specified primary outcomes) preclude firm conclusions about the diagnostic construct.ConclusionsMore research is needed to build a solid knowledge base for exhaustion disorder. International collaboration regarding the conceptualisation of chronic stress and fatigue is warranted to accelerate the growth of evidence.
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| 27. |
- Lodin, Karin, et al.
(författare)
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Cross-sectional associations between inflammation, sickness behaviour, health anxiety and self-rated health in a Swedish primary care population
- 2019
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Ingår i: European journal of inflammation. - : SAGE Publications. - 2058-7392 .- 1721-727X. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated associations between inflammatory markers, sickness behaviour, health anxiety and self-rated health in 311 consecutive primary care patients. Poor self-rated health was associated with high sickness behaviour (rho = 0.28, P < 0.001; rho = 0.42, P = 0.003) and high health anxiety (rho = 0.31, P < 0.001; rho = -0.32, P = 0.003). High levels of interleukin 6 were associated with poor self-rated health in men (rho = 0.26, P = 0.009). Low levels of interleukin-6 were associated with poor self-rated health in women (rho = -0.15, P = 0.04), but this association was non-significant when adjusted for health anxiety (rho = -0.08, P = 0.31). These results are consistent with the theory that interoceptive processes draw on both inflammatory mediators and the state of sickness behaviour in inferring health state.
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| 28. |
- McGrath, Cormac, et al.
(författare)
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Data sharing in qualitative research : opportunities and concerns
- 2018
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Ingår i: MedEdPublish. - : F1000 Research Ltd. - 2312-7996. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Data sharing is increasingly practiced by researchers and mandated by research funders as well as scientific journals. However, data sharing within qualitative research paradigms is less common, and sharing interview data has particular challenges. Earlier debate has pointed to the value of data sharing for discouraging research fraud and permitting critical scrutiny. We elaborate on this discussion by highlighting the value of data sharing for cumulative science, for re-use, and to maximise the value of the participants’ contribution. We review methods and possibilities for sharing interview data, and give concrete recommendations for mitigating risks to the participants. In conclusion, we find that sharing of interview data is possible, valuable, and ethical, and serves a purpose for both journals and researchers.
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| 29. |
- Mundt, Filip, et al.
(författare)
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Diagnostic and Prognostic Value of Soluble Syndecan-1 in Pleural Malignancies
- 2014
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Ingår i: BioMed Research International. - : Hindawi Limited. - 2314-6133 .- 2314-6141. ; , s. 419853-
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Tidskriftsartikel (refereegranskat)abstract
- Background. The distinction between malignant and benign pleural effusions is a diagnostic challenge today and measuring soluble biomarkers could add to the diagnostic accuracy. Syndecan-1 is a proteoglycan involved in various cellular functions and is cleaved from the cell surface in a regulated manner. The shed fragment, which can be recovered in effusion supernatant and in serum, retains its binding capacities, but often with different functions and signalling properties than the cell-bound form. Aim. This study aimed to investigate the diagnostic and prognostic value of soluble syndecan-1 in pleural effusions and sera from patients with pleural malignancies. Study Design. Using two cohorts of patients, we assessed the diagnostic and prognostic value of soluble syndecan-1 in pleural effusions and sera, using enzyme-linked immunosorbent assays. Results. In pleural effusions, syndecan-1 distinguished malignant and benign diseases, with an odds ratio of 8.59 (95% CI 3.67 to 20.09). Furthermore, syndecan-1 in pleural effusions predicted a survival difference for patients with pleural metastatic disease and malignant mesothelioma of 11.2 and 9.2 months, respectively. However, no such effects were seen when syndecan-1 was measured in serum. Conclusion. Soluble syndecan-1 is a promising candidate biomarker for the cytopathological diagnosis and prognostication of malignant pleural effusions.
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| 30. |
- Mundt, Filip, et al.
(författare)
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Hyaluronan and N-ERC/Mesothelin as Key Biomarkers in a Specific Two-Step Model to Predict Pleural Malignant Mesothelioma
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Diagnosis of malignant mesothelioma is challenging. The first available diagnostic material is often an effusion and biochemical analysis of soluble markers may provide additional diagnostic information. This study aimed to establish a predictive model using biomarkers from pleural effusions, to allow early and accurate diagnosis. Patients and Methods: Effusions were collected prospectively from 190 consecutive patients at a regional referral centre. Hyaluronan, N-ERC/mesothelin, C-ERC/mesothelin, osteopontin, syndecan-1, syndecan-2, and thioredoxin were measured using ELISA and HPLC. A predictive model was generated and validated using a second prospective set of 375 effusions collected consecutively at a different referral centre. Results: Biochemical markers significantly associated with mesothelioma were hyaluronan (odds ratio, 95% CI: 8.82, 4.82-20.39), N-ERC/mesothelin (4.81, 3.19-7.93), CERC/mesothelin (3.58, 2.43-5.59) and syndecan-1 (1.34, 1.03-1.77). A two-step model using hyaluronan and N-ERC/mesothelin, and combining a threshold decision rule with logistic regression, yielded good discrimination with an area under the ROC curve of 0.99 (95% CI: 0.97-1.00) in the model generation dataset and 0.83 (0.74-0.91) in the validation dataset, respectively. Conclusions: A two-step model using hyaluronan and N-ERC/mesothelin predicts mesothelioma with high specificity. This method can be performed on the first available effusion and could be a useful adjunct to the morphological diagnosis of mesothelioma.
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| 31. |
- Månsson, Kristoffer, et al.
(författare)
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Can Psychological Treatment Slow Down Cellular Aging in Social Anxiety Disorder? : An Intervention Study Evaluating Changes in Telomere Length and Telomerase Activity
- 2018
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Ingår i: Biological Psychiatry. - : Elsevier BV. - 0006-3223 .- 1873-2402. ; 83:9, s. S351-S352
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Mental illness, including anxiety disorders, is linked to accelerated cell aging. This is evidenced by shorter leukocyte telomere length. Cells with critically short telomeres may undergo apoptosis. In dividing cells, telomere shortening is counteracted by the telomeraseenzyme. Telomerase is reportedly low following chronic psychological stress. We hypothesized that a psychological treatment may increase telomerase activity, less telomere attritionand greater symptom improvement.Methods: Forty-six patients (91% SSRI naïve) with social anxiety disorder(SAD; mean age 31, 63% females) underwent a 9-week waiting period, and 9 weeks of Internet-delivered cognitive behavior therapy(CBT). During treatment, symptoms were assessed weekly using the Liebowitz Social Anxiety Scale (LSAS-SR). Fasting blood samples were collected twice before treatment, and at post-treatment. Genomic DNA was extracted using DNeasy® Blood & Tissue Kit (Qiagene) to assess leukocyte telomere length. Telomerase activity was detected by real-time telomeric repeat amplification protocol (RT-TRAP).Results: Patients improved significantly on the LSAS-SR (p<.001; Cohen’s d=1.5). Pre-post changes in telomerase and telomere length correlated positively (Pearson’s r=.31, p=.05). Reduced telomerase activity (<33th percentile) was associated with less improvement and increased activity (>66th percentile) with more improvement on the LSAS-SR (Z=-2.4, p=.02).Conclusions: We demonstrate, to our knowledge for the first time, that altered telomerase activity is associated with clinical response to a psychological treatment in a psychiatric population. The observed CBT effect on telomerase in patients with SAD is consistent with results from animal trials and a small previous study of antidepressants in humans. Thus, telomerase activation may play an important role in clinical recovery.
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| 32. |
- Månsson, Kristoffer N. T., et al.
(författare)
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Improvement in indices of cellular protection after psychological treatment for social anxiety disorder
- 2019
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Telomere attrition is a hallmark of cellular aging and shorter telomeres have been reported in mood and anxiety disorders. Telomere shortening is counteracted by the enzyme telomerase and cellular protection is also provided by the antioxidant enzyme glutathione peroxidase (GPx). Here, telomerase, GPx, and telomeres were investigated in 46 social anxiety disorder (SAD) patients in a within-subject design with repeated measures before and after cognitive behavioral therapy. Treatment outcome was assessed by the Liebowitz Social Anxiety Scale (self-report), administered three times before treatment to control for time and regression artifacts, and posttreatment. Venipunctures were performed twice before treatment, separated by 9 weeks, and once posttreatment. Telomerase activity and telomere length were measured in peripheral blood mononuclear cells and GPx activity in plasma. All patients contributed with complete data. Results showed that social anxiety symptom severity was significantly reduced from pretreatment to posttreatment (Cohen’s d = 1.46). There were no significant alterations in telomeres or cellular protection markers before treatment onset. Telomere length and telomerase activity did not change significantly after treatment, but an increase in telomerase over treatment was associated with reduced social anxiety. Also, lower pretreatment telomerase activity predicted subsequent symptom improvement. GPx activity increased significantly during treatment, and increases were significantly associated with symptom improvement. The relationships between symptom improvement and putative protective enzymes remained significant also after controlling for body mass index, sex, duration of SAD, smoking, concurrent psychotropic medication, and the proportion of lymphocytes to monocytes. Thus, indices of cellular protection may be involved in the therapeutic mechanisms of psychological treatment for anxiety.
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| 33. |
- Nilsonne, Gustav, et al.
(författare)
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A multimodal brain imaging dataset on sleep deprivation in young and old humans
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Stockholm Sleepy Brain Study I is a functional brain imaging study of 48 younger (20-30 years) and 36 older (65-75 years) healthy participants, with magnetic resonance imaging after normal sleep and partial sleep deprivation in a crossover design. We performed experiments investigating emotional mimicry, empathy for pain, and cognitive reappraisal, as well as resting state functional magnetic resonance imaging (fMRI). We also acquired T1- and T2-weighted structural images and diffusion tensor images (DTI). On the night before imaging, participants were monitored with ambulatory polysomnography and were instructed to sleep either as usual or only three hours. Participants came to the scanner the following evening. Besides MRI scanning, participants underwent behavioral tests and contributed blood samples, which have been stored in a biobank and used for DNA analyses. Participants also completed a variety of self-report measures. The resulting multimodal dataset may be useful for hypothesis generation or independent validation of effects of sleep deprivation and aging, as well as investigation of cross-sectional associations between the different outcomes. V. 2 of this manuscript published 2017-10-12. Changes: new co-author (Claus Lamm), changed affiliations for Kristoffer Månsson, minor changes in the abstract, and revisions of the main text and figures.
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| 34. |
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| 35. |
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| 36. |
- Nilsonne, Gustav, et al.
(författare)
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Circulating Interleukin 6 in Parkinson Disease
- 2017
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Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 74:5, s. 607-608
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 37. |
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| 38. |
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| 39. |
- Nilsonne, Gustav, et al.
(författare)
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Diurnal Variation of Circulating Interleukin-6 in Humans : A Meta-Analysis
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- The pleiotropic cytokine interleukin-6 (IL-6) has been proposed to contribute to circadian regulation of sleepiness by increasing in the blood at night. Earlier studies have reported diurnal variation of IL-6, but phase estimates are conflicting. We have therefore performed a meta-analysis on the diurnal variation of circulating IL-6. Studies were included if they reported IL-6 in plasma or serum recorded at least twice within 24 hours in the same individual. A systematic search resulted in the inclusion of 43 studies with 56 datasets, for a total of 1100 participants. Individual participant data were available from 4 datasets with a total of 56 participants. Mixed-effects meta-regression modelling confirmed that IL-6 varied across the day, the most conspicuous effect being a trough in the morning. These results stand in contrast to earlier findings of a peak in the evening or night, and suggest that diurnal variation should be taken into account in order to avoid confounding by time of day in studies of IL-6 in plasma or serum.
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| 40. |
- Nilsonne, Gustav, 1982-
(författare)
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Dyrköpt avtal med Elsevier
- 2019
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Annan publikation (populärvet., debatt m.m.)abstract
- Nyligen meddelade Bibsam-konsortiet, som för svenska lärosätens räkning förhandlar om vetenskapliga tidskriftsprenumerationer, att man nått ett nytt avtal med Elsevier. Därmed slutar det avtalslösa tillstånd som rått i bortåt ett och ett halvt år, då svenska forskare inte fått tillgång till aktuella artiklar i Elseviertidskrifter. Det nya avtalet är transformativt. Detta innebär att det innehåller publicering med öppen tillgång för svenska forskare utan att forskaren eller lärosätet behöver betala en avgift för varje artikel. Fler artiklar kommer därmed att bli omedelbart öppet tillgängliga.Det gamla avtalet med Elsevier kostade 14 miljoner euro 2017, samtidigt som tidskrifterna också tog betalt per artikel för publicering med öppen tillgång. Det var helt nödvändigt att bryta den skenande kostnadsökningen, och Bibsamkonsortiet ska ha all heder av sitt beslut att inte fortsätta med samma typ av avtal som förut.Men det transformativa avtalet med Elsevier är en pyrrhusseger. Problemet med det nya avtalet är att det cementerar låsningen till en föråldrad publiceringskultur. Förlaget tillåts fortfarande ta dubbelt betalt: både för att vi ska få läsa andra länders artiklar, och för att publicera svenska artiklar med öppen tillgång – fastän båda kostnaderna är inbakade i samma avtal. Vi får alltså betala först för att de reser en brandvägg framför vetenskapens landvinningar, och sedan igen för att få spika upp våra egna alster på väggens utsida.Öppna arkiv på internet gör att vetenskapliga resultat kan publiceras till mycket låg kostnad, och utan den fördröjning som tidskrifternas granskning innebär. Systematiska metoder för att granska kvaliteten efter publicering har potential att ersätta den traditionella referentgranskningen, som ofta åberopas som kvalitetshöjande, men som i allmänhet försiggår i det fördolda och inte i sig kan granskas. Tidskrifternas roll som förvaltare av ett prestigekapital som snedvrider forskningsprocessen behöver brytas.Experimentet med ett avtalslöst tillstånd visade att svensk forskning klarade sig bra. Kostnaden för det nya avtalet är ännu inte offentliggjord, men den kvardröjande låsningen till Elsevier medför en risk för fortsatta kostnadsökningar. Det går inte att motivera att svensk forskning årligen ska dräneras på hundratals miljoner kronor för att köpa tillbaka forskningsresultat som borde varit öppet tillgängliga från början. Bibsamkonsortiet borde experimentera med att säga upp fler avtal. Inbesparade medel skulle kunna användas exempelvis till stöd för att publicera forskningsdata och andra forskningsprodukter öppet och FAIR.
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| 41. |
- Nilsonne, Gustav, et al.
(författare)
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EEG-based model and antidepressant response
- 2021
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 39
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Tidskriftsartikel (refereegranskat)abstract
- In a recent article, Wu et al.1 presented an electroencephalogram (EEG)-based prediction model for antidepressant treatment response1. Here, we point to limitations in the methods used to define response and to validate the prediction model—specifically, that change from baseline Hamilton depression rating scale (HAMD) scores needs to take into account the nonlinearity of response, and that the validation analysis transposed the predictor and the outcome.1. ARISING FROM W. Wu et al. Nature Biotechnology. https://doi.org/10.1038/s41587-019-0397-3 (2020)
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| 42. |
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| 43. |
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| 44. |
- Nilsonne, Gustav, et al.
(författare)
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Effects of 25 mg oxazepam on emotional mimicry and empathy for pain : a randomized controlled experiment
- 2017
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- Emotional mimicry and empathy are mechanisms underlying social interaction. Benzodiazepines have been proposed to inhibit empathy and promote antisocial behaviour. First, we aimed to investigate the effects of oxazepam on emotional mimicry and empathy for pain, and second, we aimed to investigate the association of personality traits to emotional mimicry and empathy. Participants (n= 76) were randomized to 25mg oxazepam or placebo. Emotional mimicry was examined using video clips with emotional expressions. Empathy was investigated by pain stimulating the participant and a confederate. We recorded self-rated experience, activity in major zygomatic and superciliary corrugator muscles, skin conductance, and heart rate. In the mimicry experiment, oxazepam inhibited corrugator activity. In the empathy experiment, oxazepam caused increased self-rated unpleasantness and skin conductance. However, oxazepam specifically inhibited neither emotional mimicry nor empathy for pain. Responses in both experiments were associated with self-rated empathic, psychopathic and alexithymic traits. The present results do not support a specific effect of 25mg oxazepam on emotional mimicry or empathy.
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| 45. |
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| 46. |
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| 47. |
- Nilsonne, Gustav
(författare)
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Experimental therapeutics against malignant mesothelioma : investigations in vitro
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Malignant mesothelioma is a tumour of the mesothelium, a specialized tissue found in the pleura, pericardium, peritoneum, and tunica vaginalis testis. The tumour has strong etiological links to asbestos, with a latency period ranging up to several decades between asbestos exposure and tumour diagnosis. Treatment is mostly ineffective and the median survival is around 12 months. The tumour exhibits an interesting and peculiar heterogeneity; tumour cells may assume either an epithelioid or a sarcomatoid phenotype. Presence of the sarcomatoid phenotype is a predictor for therapy resistance and a worse prognosis. In this work, we have investigated the anticancer effects of selenite, a small ion formed by the oxidation of selenium. We show that selenite can induce cell death and apoptosis in malignant mesothelioma cells. The specific signalling pathways have been delineated. Furthermore, we have shown that selenite sensitizes mesothelioma cells to NK-cell mediated recognition and killing. Specifically, we have shown that selenite exerts its anticancer effects in cells of both phenotypes through the induction of oxidative stress. Apoptosis is induced through the mitochondrial pathway. Differences in the activation pattern of Bcl-family proteins could be observed between cells of the two phenotypes. Interestingly, p53 protein was enriched in the nuclei of selenite-treated cells, but in a form bereft of its DNA-binding ability. We hypothesise that this is explained by redox inactivation due to the prooxidant effects of selenite. Perturbation of the apoptosis signalling network by inhibition of key mediators had very little effect, suggesting that the network is robust through functional redundancy. A systematic testing of selenite in a panel of six cell lines of varying differentiation alone and together with conventional drugs showed that the cells were resistant in general, but all cell lines were sensitive to at least one of the tested drugs. Synergistic effects between selenite and other drugs were limited. Phenotype was a poor predictor of response. These results highlight the need for improved personalisation of mesothelioma treatment. In the last sub-project, we have showed that selenite sensitizes mesothelioma cells to NK-cell mediated killing. A search for alterations in NK-cell receptor ligand expression revealed that the inhibitory ligand HLA-E was down-regulated on tumour cells in response to selenite. Further analyses showed that the mRNA expression for HLA-E remained constant during selenite treatment, while the intracellular and surface protein levels decreased, and that increased recognition by NK cells was dependent on HLA-E downregulation rather that on modulation of other NK cell ligands. These results indicate that selenite is a potential new drug against malignant mesothelioma. Further trials are warranted to determine the safety and efficacy of selenite in a clinical setting.
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| 48. |
- Nilsonne, Gustav, et al.
(författare)
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Health at the ballot box : disease threat does not predict attractiveness preference in British politicians
- 2016
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- According to disease avoidance theory, selective pressures have shaped adaptive behaviours to avoid people who might transmit infections. Such behavioural immune defence strategies may have social and societal consequences. Attractiveness is perceived as a heuristic cue of good health, and the relative importance of attractiveness is predicted to increase during high disease threat. Here, we investigated whether politicians' attractiveness is more important for electoral success when disease threat is high, in an effort to replicate earlier findings from the USA. We performed a cross-sectional study of 484 members of the House of Commons from England and Wales. Publicly available sexiness ratings (median 5883 ratings/politician) were regressed on measures of disease burden, operationalized as infant mortality, life expectancy and self-rated health. Infant mortality in parliamentary constituencies did not significantly predict sexiness of elected members of parliament (p = 0.08), nor did life expectancy (p = 0.06), nor self-rated health (p = 0.55). Subsample analyses failed to provide further support for the hypothesis. In conclusion, an attractive leader effect was not amplified by disease threat in the UK and these results did not replicate those of earlier studies from the USA concerning the relationship between attractiveness, disease threat and voting preference.
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| 49. |
- Nilsonne, Gustav, et al.
(författare)
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Intrinsic brain connectivity after partial sleep deprivation in young and older adults
- 2017
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Konferensbidrag (refereegranskat)abstract
- Introduction: Sleep deprivation has been reported to affect intrinsic brain connectivity, notably in the default mode network, but studies to date have shown inconsistent effects and have largely included young participants. We therefore aimed to investigate effects of partial sleep deprivation on intrinsic brain connectivity in young and older participants. Methods: Participants aged 20-30 (n = 30) and 65-75 (n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Participants were monitored with eye-tracking to ensure they did not fall asleep during scanning. Results: Sleep deprivation caused increased global signal variability, defined as log-transformed standard deviation of average gray matter signal (0.16 [0.07, 0.24], p = 0.0004). In contrast to previous studies, sleep deprivation did not cause major changes in investigated resting state networks, nor did it cause changes in regional homogeneity. Younger participants had higher functional connectivity in most examined resting state networks, as well as higher regional homogeneity in brain areas including anterior and posterior cingulate cortex. Conclusions: We show for the first time that partial sleep deprivation caused increased global signal variability. This outcome should be examined as a potential biomarker for sleepiness using independent data. Unlike a few earlier studies, we did not find less default mode connectivity in the sleep deprived state, possibly because of stricter monitoring of participants' wakefulness.
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| 50. |
- Nilsonne, Gustav, et al.
(författare)
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Intrinsic brain connectivity after partial sleep deprivation in young and older adults : results from the Stockholm Sleepy Brain study
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Sleep deprivation has been reported to affect intrinsic brain connectivity, notably reducing connectivity in the default mode network. Studies to date have however shown inconsistent effects, in many cases lacked monitoring of wakefulness, and largely included young participants. We investigated effects of sleep deprivation on intrinsic brain connectivity in young and older participants. Participants aged 20–30 (final n = 30) and 65–75 (final n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two 8-minutes eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session, monitored by eye-tracking. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Sleep deprivation caused increased global signal variability. Changes in investigated resting state networks and in regional homogeneity were not statistically significant. Younger participants had higher connectivity in most examined networks, as well as higher regional homogeneity in areas including anterior and posterior cingulate cortex. In conclusion, we found that sleep deprivation caused increased global signal variability, and we speculate that this may be caused by wake-state instability.
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