| 1. |
- Breznau, Nate, et al.
(författare)
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Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:44
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Tidskriftsartikel (refereegranskat)abstract
- This study explores how researchers analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each teams workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings.
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| 2. |
- Persson, Jonas, et al.
(författare)
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Altered deactivation in individuals with genetic risk for Alzheimer's disease
- 2008
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Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 46:6, s. 1679-1687
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Tidskriftsartikel (refereegranskat)abstract
- Regions that show task-induced deactivations may be part of a default-mode network related to processes that are more engaged during passive than active task conditions. Alteration of task-induced deactivations with age and dementia is indicated by atypical engagement of default-mode network regions. Genetic studies show a relation between the apolipoprotein E4 (APOE4) allele and the common form of Alzheimer’s disease (AD), and altered functional brain activation has been observed in non-demented APOE4 carriers compared to non-carriers. Here we investigate the hypothesis of altered default-mode network brain responses in individuals with genetic risk for AD. Functional MRI was used to assess task-induced deactivation in 60 subjects of which 30 carried at least one copy of the APOE4 allele, and 30 non-carriers. Subjects were scanned while performing a semantic categorization task shown to promote episodic memory encoding. The results show patterns of deactivation consistent with the default-mode network. We also found reduced deactivation in non-demented APOE4 carriers compared to non-carriers, suggesting alterations in the default-mode network in the absence of dementia. These results implicate possibilities for investigatin altered properties of task-induced deactivations in individuals with genetic risk for AD, and may prove useful for pre-clinical identification of individuals susceptible to memory problems and AD.
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| 3. |
- Rademakers, R, et al.
(författare)
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Association of cyclin-dependent kinase 5 and neuronal activators p35 and p39 complex in early-onset Alzheimer's disease.
- 2005
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Ingår i: Neurobiology of Aging. - New York : Elsevier BV. - 0197-4580 .- 1558-1497. ; 26:8, s. 1145-1151
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Tidskriftsartikel (refereegranskat)abstract
- Malfunctioning of cyclin-dependent kinase 5 (CDK5) through aberrant proteolytic cleavage of its neuronal activators p35 and p39 is involved in neurodegeneration in Alzheimer's disease (AD) and other neurodegenerative brain diseases. By extensive genetic analysis of the genes encoding CDK5 (CDK5), p35 (CDK5R1) and p39 (CDK5R2), we excluded causal mutations in 70 familial early-onset AD patients. We performed an association study with five informative SNPs in CDK5 in two independent samples of early-onset AD patients and matched control individuals from The Netherlands and northern Sweden. Association was observed with g.149800G>C in intron 5 of CDK5, and a two times increased risk was observed in both patient samples for carriers of the C-allele. Our data are indicative for a role of the CDK5 molecular complex in the genetic etiology of early-onset AD, and suggest that a yet unknown functional variant in CDK5 or in a nearby gene might lead to increased susceptibility for early-onset AD.
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