| 1. |
- Bäckman, Lars, et al.
(författare)
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Linking cognitive aging to alterations in dopamine neurotransmitter functioning : Recent data and future avenues
- 2010
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Ingår i: Neuroscience and Biobehavioral Reviews. - : Elsevier BV. - 0149-7634 .- 1873-7528. ; 34:5, s. 670-677
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Forskningsöversikt (refereegranskat)abstract
- Molecular-imaging studies of dopaminergic neurotransmission measure biomarkers of dopamine (DA), such as the DA transporter and D(1) and D(2) receptor densities in the living brain. These studies indicate that individual differences in DA functions are linked to cognitive performance irrespective of age, and serve as powerful mediators of age-related decline in executive functioning, episodic memory, and perceptual speed. This focused review targets several recent findings pertaining to these relationships. Specifically, we discuss novel evidence concerning (a) the role of DA in within-person cognitive variability; (b) age-related differences in DA release during cognitive processing; (c) DA release following cognitive training in younger and older adults; and (d) the relationship between DA and task-induced functional brain activity. Based on these lines of empirical inquiry, we outline a series of avenues for future research on aging, DA, and cognition.
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| 2. |
- Cabeza, Roberto, et al.
(författare)
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Maintenance, reserve and compensation : the cognitive neuroscience of healthy ageing
- 2018
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Ingår i: Nature Reviews Neuroscience. - : Nature Publishing Group. - 1471-003X .- 1471-0048. ; 19:11, s. 701-710
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Forskningsöversikt (refereegranskat)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. |
- Li, Shu Chen, et al.
(författare)
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Aging cognition : From neuromodulation to representation
- 2001
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Ingår i: Trends in Cognitive Sciences. - 1364-6613. ; 5:11, s. 479-486
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Forskningsöversikt (refereegranskat)abstract
- Basic cognitive functions, such as the abilities to activate, represent, maintain, focus and process information, decline with age. A paradigm shift towards cross-level conceptions is needed in order to obtain an integrative understanding of cognitive aging phenomena that cuts across neural, information-processing, and behavioral levels. We review empirical data at these different levels, and computational theories proposed to enable their integration. A theoretical link is highlighted, relating deficient neuromodulation with noisy information processing, which might result in less distinctive cortical representations. These less distinctive representations might be implicated in working memory and attentional functions that underlie the behavioral manifestations of cognitive aging deficits.
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| 4. |
- Lövdén, Martin, 1972, et al.
(författare)
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Education and Cognitive Functioning Across the Life Span
- 2020
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Ingår i: Psychological Science in the Public Interest. - : SAGE Publications. - 1529-1006 .- 2160-0031 .- 1539-6053. ; 21:1, s. 6-41
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Forskningsöversikt (refereegranskat)abstract
- © The Author(s) 2020. Cognitive abilities are important predictors of educational and occupational performance, socioeconomic attainment, health, and longevity. Declines in cognitive abilities are linked to impairments in older adults’ everyday functions, but people differ from one another in their rates of cognitive decline over the course of adulthood and old age. Hence, identifying factors that protect against compromised late-life cognition is of great societal interest. The number of years of formal education completed by individuals is positively correlated with their cognitive function throughout adulthood and predicts lower risk of dementia late in life. These observations have led to the propositions that prolonging education might (a) affect cognitive ability and (b) attenuate aging-associated declines in cognition. We evaluate these propositions by reviewing the literature on educational attainment and cognitive aging, including recent analyses of data harmonized across multiple longitudinal cohort studies and related meta-analyses. In line with the first proposition, the evidence indicates that educational attainment has positive effects on cognitive function. We also find evidence that cognitive abilities are associated with selection into longer durations of education and that there are common factors (e.g., parental socioeconomic resources) that affect both educational attainment and cognitive development. There is likely reciprocal interplay among these factors, and among cognitive abilities, during development. Education–cognitive ability associations are apparent across the entire adult life span and across the full range of education levels, including (to some degree) tertiary education. However, contrary to the second proposition, we find that associations between education and aging-associated cognitive declines are negligible and that a threshold model of dementia can account for the association between educational attainment and late-life dementia risk. We conclude that educational attainment exerts its influences on late-life cognitive function primarily by contributing to individual differences in cognitive skills that emerge in early adulthood but persist into older age. We also note that the widespread absence of educational influences on rates of cognitive decline puts constraints on theoretical notions of cognitive aging, such as the concepts of cognitive reserve and brain maintenance. Improving the conditions that shape development during the first decades of life carries great potential for improving cognitive ability in early adulthood and for reducing public-health burdens related to cognitive aging and dementia.
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| 5. |
- Lövdén, Martin, 1972, et al.
(författare)
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Human Skill Learning: Expansion, Exploration, Selection, and Refinement
- 2020
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Ingår i: Current Opinion in Behavioral Sciences. - : Elsevier BV. - 2352-1546. ; 36, s. 163-168
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Forskningsöversikt (refereegranskat)abstract
- © 2020 The Authors Learning, or the process of acquiring knowledge and skill, allows humans to shape and adapt to their environments during development. Researchers have long theorized that the principal brain processes behind learning resemble a recruitment process. The brain initially explores an expanded pool of candidate neural circuits. Based on outcomes, the most promising candidate circuit is selected for refinement. Partly fuelled by new methods, the last decade of research on learning-related functional and structural changes in rodents has supported this theory, and, more recently, related evidence has started to emerge from human studies. We emphasize the need for formal theories and neurocomputational modelling of cortical plasticity to guide work on open issues, such as the link between functional and structural changes.
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| 6. |
- Lövdén, Martin, et al.
(författare)
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Structural brain plasticity in adult learning and development
- 2013
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Ingår i: Neuroscience and Biobehavioral Reviews. - : Elsevier BV. - 0149-7634 .- 1873-7528. ; 37:9, s. 2296-2310
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Forskningsöversikt (refereegranskat)abstract
- Recent research using magnetic resonance imaging has documented changes in the adult human brain's grey matter structure induced by alterations in experiential demands. We review this research and relate it to models of brain plasticity from related strands of research, such as work on animal models. This allows us to generate recommendations and predictions for future research that may advance the understanding of the function, sequential progression, and microstructural nature of experience-dependent changes in regional brain volumes. Informed by recent evidence on adult age differences in structural brain plasticity, we show how understanding learning-related changes in human brain structure can expand our knowledge about adult development and aging. We hope that this review will promote research on the mechanisms regulating experience-dependent structural plasticity of the adult human brain.
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| 7. |
- Noack, Hannes, et al.
(författare)
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Cognitive plasticity in adulthood and old age: Gauging the generality of cognitive intervention effects
- 2009
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Ingår i: Restorative Neurology and Neuroscience. - 1878-3627. ; 27:5, s. 435-453
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Forskningsöversikt (refereegranskat)abstract
- Interventions enabling aging individuals to fulfill their plastic potential promise to postpone, attenuate, or even reverse the adverse effects of senescent brain changes on cognitive abilities and everyday competence in old age. Based on an overview of the concept of plasticity in lifespan development, we selectively review evidence from cognitive intervention studies and conclude that most of them have failed to observe generalizable performance improvements, as documented by the small size and scope of positive transfer to untrained tasks. We further note that generally accepted criteria for defining transfer distance are lacking, rendering the relevant evidence difficult to interpret. Hence, we propose a taxonomy of transfer distance based on the structure of human intellectual abilities.
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| 8. |
- Papenberg, Goran, et al.
(författare)
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Aging-related magnification of genetic effects on cognitive and brain integrity
- 2015
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Ingår i: Trends in cognitive sciences. - : Elsevier BV. - 1364-6613 .- 1879-307X. ; 19:9, s. 506-514
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Forskningsöversikt (refereegranskat)abstract
- Heritability studies document substantial genetic influences on cognitive performance and decline in old age. Increasing evidence shows that effects of genetic variations on cognition, brain structure, and brain function become stronger as people age. Disproportionate impairments are typically observed for older individuals carrying disadvantageous genotypes of different candidate genes. These data support the resource-modulation hypothesis, which states that genetic effects are magnified in persons with constrained neural resources, such as older adults.,However, given that findings are not unequivocal, we discuss the need to address several factors that may resolve inconsistencies in the extant literature (gene-gene and gene-environment interactions, study populations, gene-environment correlations, and epigenetic mechanisms).
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| 9. |
- Papenberg, Goran, et al.
(författare)
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Genetics and Functional Imaging : Effects of APOE, BDNF, COMT, and KIBRA in Aging
- 2015
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Ingår i: Neuropsychology Review. - : Springer. - 1040-7308 .- 1573-6660. ; 25:1, s. 47-62
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Forskningsöversikt (refereegranskat)abstract
- Increasing evidence from cross-sectional and longitudinal molecular-genetic studies suggests that effects of common genetic variations on cognitive functioning increase with aging. We review the influence of candidate genes on brain functioning in old age, focusing on four genetic variations that have been extensively investigated: APOE, BDNF, COMT, and KIBRA. Similar to the behavioral evidence, there are reports from age-comparative studies documenting stronger genetic effects on measures of brain functioning in older adults compared to younger adults. This pattern suggests disproportionate impairments of neural processing among older individuals carrying disadvantageous genotypes. We discuss various factors, including gene-gene interactions, study population characteristics, lifestyle factors, and diseases, that need to be considered in future studies and may help understand inconsistent findings in the extant literature.
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| 10. |
- Wenger, Elisabeth, et al.
(författare)
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Expansion and Renormalization of Human Brain Structure During Skill Acquisition
- 2017
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Ingår i: Trends in cognitive sciences. - : Elsevier BV. - 1364-6613 .- 1879-307X. ; 21:12, s. 930-939
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Forskningsöversikt (refereegranskat)abstract
- Research on human brain changes during skill acquisition has revealed brain volume expansion in task-relevant areas. However, the large number of skills that humans acquire during ontogeny militates against plasticity as a perpetual process of volume growth. Building on animal models and available theories, we promote the expansion-renormalization model for plastic changes in humans. The model predicts an initial increase of gray matter structure, potentially reflecting growth of neural resources like neurons, synapses, and glial cells, which is followed by a selection process operating on this new tissue leading to a complete or partial return to baseline of the overall volume after selection has ended. The model sheds new light on available evidence and current debates and fosters the search for mechanistic explanations.
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