| 1. |
- Botvinik-Nezer, Rotem, et al.
(author)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Journal article (peer-reviewed)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. |
- Cabeza, Roberto, et al.
(author)
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Maintenance, reserve and compensation : the cognitive neuroscience of healthy ageing
- 2018
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In: Nature Reviews Neuroscience. - : Nature Publishing Group. - 1471-003X .- 1471-0048. ; 19:11, s. 701-710
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Research review (peer-reviewed)abstract
- Cognitive ageing research examines the cognitive abilities that are preserved and/or those that decline with advanced age. There is great individual variability in cognitive ageing trajectories. Some older adults show little decline in cognitive ability compared with young adults and are thus termed ‘optimally ageing’. By contrast, others exhibit substantial cognitive decline and may develop dementia. Human neuroimaging research has led to a number of important advances in our understanding of the neural mechanisms underlying these two outcomes. However, interpreting the age-related changes and differences in brain structure, activation and functional connectivity that this research reveals is an ongoing challenge. Ambiguous terminology is a major source of difficulty in this venture. Three terms in particular — compensation, maintenance and reserve — have been used in a number of different ways, and researchers continue to disagree about the kinds of evidence or patterns of results that are required to interpret findings related to these concepts. As such inconsistencies can impede progress in both theoretical and empirical research, here, we aim to clarify and propose consensual definitions of these terms.
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| 3. |
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| 4. |
- Nelson, James K., et al.
(author)
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Mapping interference resolution across task domains : A shared control process in left inferior frontal gyrus
- 2009
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In: Brain Research. - Netherlands : Elsevier Science. - 0006-8993 .- 1872-6240. ; 1256, s. 92-100
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Journal article (peer-reviewed)abstract
- Work in functional neuroimaging has mapped interference resolution processing onto left inferior frontal regions for both verbal working memory and a variety of semantic processing tasks. The proximity of the identified regions from these different tasks suggests the existence of a common, domain-general interference resolution mechanism. The current research specifically tests this idea in a within-subject design using fMRI to assess the activation associated with variable selection requirements in a semantic retrieval task (verb generation) and a verbal working memory task with a trial-specific proactive interference manipulation (recent-probes). High interference trials on both tasks were associated with activity in the midventrolateral region of the left inferior frontal gyrus, and the regions activated in each task strongly overlapped. The results indicate that an elemental component of executive control associated with interference resolution during retrieval from working memory and from semantic memory can be mapped to a common portion of the left inferior frontal gyrus.
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| 5. |
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| 6. |
- Persson, Jonas, et al.
(author)
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Cognition and Aging : Typical Development
- 2008
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In: Handbook of Developmental Cognitive Neuroscience. - : The MIT Press, Cambridge, US, and London, UK.. - 9780262141048 ; , s. 591-606
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Book chapter (peer-reviewed)abstract
- Declining cognitive functions are a normal and inevitable part of healthy aging. Some changes may stem from global alterations in brain functions, including metabolic changes; others may result from localized decline of specific neural circuits. Current research on cognitive aging aims not only to identify the mechanisms that underlie cognitive change, but also to understand and harness the genetic, experiential and environmental factors that promote the preservation of cognitive abilities. Recent technological advances are leading to new breakthroughs in cognitive aging research, while also posing new challenges to understand the relation between genetic, anatomical, physiological, and cognitive factors and to integrate these levels of analysis. Moreover, the availability of high-resolution neuroimaging methods is revising our perspective on aging and giving way to new ideas about the aging mind and brain. We now know that the aging brain is not simply a depleted and reduced version of the younger brain. Instead, recent cognitive neuroscience evidence points to patterns of preservation and decline, along with functional reorganization and plasticity.
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| 7. |
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| 8. |
- Persson, Jonas, et al.
(author)
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Gaining Control : Training Executive Function and Far Transfer of the Ability to Resolve Interference [retracted]
- 2008
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In: Psychological Science. - : SAGE Publications. - 0956-7976 .- 1467-9280. ; 19:9, s. 881-888
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Journal article (peer-reviewed)abstract
- Functional brain-imaging data document overlapping sites of activation in prefrontal cortex across memory tasks, suggesting that these tasks may share common executive components. We leveraged this evidence to develop a training regimen and a set of transfer tasks to examine the trainability of a putative executive-control process: interference resolution. Eight days of training on high-interference versions of three different working memory tasks increased the efficiency with which proactive interference was resolved on those particular tasks. Moreover, an improved ability to resolve interference was also transferred to different working memory, semantic memory, and episodic memory tasks, a demonstration of far-transfer effects from process-specific training. Participants trained with noninterference versions of the tasks did not exhibit transfer. We infer that the transfer we demonstrated resulted from increased efficiency of the interference-resolution process. Therefore, this aspect of executive control is plastic and adaptive, and can be improved by training.
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| 9. |
- Persson, Jonas, et al.
(author)
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Imaging Fatigue of Interference Control Reveals the Neural Basis of Executive Resource Depletion
- 2013
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In: Journal of cognitive neuroscience. - : MIT Press - Journals. - 0898-929X .- 1530-8898. ; 25:3, s. 338-351
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Journal article (peer-reviewed)abstract
- Executive control coordinates, prioritizes, and selects task-relevant representations under conditions of conflict. Behavioral evidence has documented that executive resources are separable, finite, and can be temporarily depleted; however, the neural basis for such resource limits are largely unknown. Here, we investigate the neural correlates underlying the fatigue or depletion of interference control, an executive process hypothesized to mediate competition among competing memory representations. Using a pre/post continuous acquisition fMRI design, we demonstrate that, compared with a nondepletion control group, the depletion group showed a fatigue-induced performance deficit that was specific to interference control and accompanied by a left-to-right shift in the network of active regions. Specifically, we observed decreased BOLD signal in the left inferior frontal gyrus (IFG), striatum, and the cerebellum, along with a corresponding increase in right hemisphere regions including the IFG, insular, and temporal cortex. Depletion-related changes in activation magnitude correlated with behavioral changes, suggesting that decreased recruitment of task-relevant regions, including left IFG, contributes to impaired interference control. These results provide new evidence about the brain dynamics of "process-specific" fatigue and suggest that depletion may pose a significant limitation on the cognitive and neural resources available for executive control.
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