| 1. |
- Bellander, Martin, et al.
(författare)
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No Evidence for Improved Associative Memory Performance Following Process-Based Associative Memory Training in Older Adults
- 2017
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Studies attempting to improve episodic memory performance with strategy instructions and training have had limited success in older adults: their training gains are limited in comparison to those of younger adults and do not generalize to untrained tasks and contexts. This limited success has been partly attributed to age-related impairments in associative binding of information into coherent episodes. We therefore investigated potential training and transfer effects of process-based associative memory training (i.e., repeated practice). Thirty-nine older adults (M-age = 68.8) underwent 6 weeks of either adaptive associative memory training or item recognition training. Both groups improved performance in item memory, spatial memory (object-context binding) and reasoning. A disproportionate effect of associative memory training was only observed for item memory, whereas no training-related performance changes were observed for associative memory. Self-reported strategies showed no signs of spontaneous development of memory-enhancing associative memory strategies. Hence, the results do not support the hypothesis that process-based associative memory training leads to higher associative memory performance in older adults.
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| 2. |
- Bellander, Martin, et al.
(författare)
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Behavioral correlates of changes in hippocampal gray matter structure during acquisition of foreign vocabulary
- 2016
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 131, s. 205-213
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Tidskriftsartikel (refereegranskat)abstract
- Experience can affect human gray matter volume. The behavioral correlates of individual differences in such brain changes are not well understood. In a group of Swedish individuals studying Italian as a foreign language, we investigated associations among time spent studying, acquired vocabulary, baseline performance on memory tasks, and gray matter changes. As a way of studying episodic memory training, the language learning focused on acquiring foreign vocabulary and lasted for 10 weeks. T-1-weighted structural magnetic resonance imaging and cognitive testing were performed before and after the studies. Learning behavior was monitored via participants' use of a smartphone application dedicated to the study of vocabulary. A whole-brain analysis showed larger changes in gray matter structure of the right hippocampus in the experimental group (N = 33) compared to an active control group (N = 23). A first path analyses revealed that time spent studying rather than acquired knowledge significantly predicted change in gray matter structure. However, this association was not significant when adding performance on baseline memory measures into the model, instead only the participants' performance on a short-term memory task with highly similar distractors predicted the change. This measure may tap similar individual difference factors as those involved in gray matter plasticity of the hippocampus.
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| 3. |
- Bellander, Martin, et al.
(författare)
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Lower baseline performance but greater plasticity of working memory for carriers of the val allele of the comt val158met polymorphism
- 2015
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Ingår i: Neuropsychology. - : American Psychological Association (APA). - 0894-4105 .- 1931-1559. ; 29:2, s. 247-254
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Little is known about genetic contributions to individual differences in cognitive plasticity. Given that the neurotransmitter dopamine is critical for cognition and associated with cognitive plasticity, we investigated the effects of 3 polymorphisms of dopamine-related genes (LMX1A, DRD2, COMT) on baseline performance and plasticity of working memory (WM), perceptual speed, and reasoning. Method: One hundred one younger and 103 older adults underwent approximately 100 days of cognitive training, and extensive testing before and after training. We analyzed the baseline and posttest data using latent change score models. Results: For working memory, carriers of the val allele of the COMT polymorphism had lower baseline performance and larger performance gains from training than carriers of the met allele. There was no significant effect of the other genes or on other cognitive domains. Conclusions: We relate this result to available evidence indicating that met carriers perform better than val carriers in WM tasks taxing maintenance, whereas val carriers perform better at updating tasks. We suggest that val carriers may show larger training gains because updating operations carry greater potential for plasticity than maintenance operations.
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| 4. |
- Franzén, Erika, et al.
(författare)
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The EXPANd trial : effects of exercise and exploring neuroplastic changes in people with Parkinson's disease
- 2019
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Ingår i: BMC Neurology. - : Springer Science and Business Media LLC. - 1471-2377. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Parkinson's disease (PD) affects many physiological systems essential for balance control. Recent studies suggest that intensive and cognitively demanding physical exercise programs are capable of inducing plastic brain changes in PD. We have developed a highly challenging balance training (the HiBalance) program that emphasizes critical aspects of balance control through progressively introducing more challenging exercises which incorporates dual-tasking. Earlier studies have shown it to be effective in improving balance, gait and dual-tasking. The study design has thereafter been adjusted to link intervention-induced behavioral changes to brain morphology and function. Specifically, in this randomized controlled trial, we will determine the effects of the HiBalance program on balance, gait and cognition and relate this to task-evoked functional MRI (fMRI), as well as brain-derived neurotrophic factor (BDNF) in participants with mild-moderate PD.Methods: One hundred participants with idiopathic PD, Hoehn & Yahr stage 2 or 3, >= 60 years of age, >= 21 on Montreal Cognitive Assessment will be recruited in successive waves and randomized into either the HiBalance program or to an active control group (the HiCommunication program, targeting speech and communication). Both interventions will be performed in small groups, twice a week with 1 h sessions for 10 weeks. In addition, a 1 h, once a week, home exercise program will also be performed. A double-blinded design will be used. At the pre- and post-assessments, participants will be assessed on balance (main outcome), gait, cognitive functions, physical activity, voice/speech function, BDNF in serum and fMRI (3 T Philips) during performance of motor-cognitive tasks.Discussion: Since there is currently no cure for PD, findings of neuroplastic brain changes in response to exercise would revolutionize the way we treat PD, and, in turn, provide new hope to patients for a life with better health, greater independence and improved quality of life.
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| 5. |
- Lövdén, Martin, et al.
(författare)
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Performance-Related Increases in Hippocampal N-acetylaspartate (NAA) Induced by Spatial Navigation Training Are Restricted to BDNF Val Homozygotes
- 2011
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Ingår i: Cerebral Cortex. - : Oxford University Press (OUP). - 1460-2199 .- 1047-3211. ; 21:6, s. 1435-1442
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence indicates experience-dependent brain volume changes in humans, but the functional and histological nature of such changes is unknown. Here, we report that adult men performing a cognitively demanding spatial navigation task every other day over 4 months display increases in hippocampal N-acetylaspartate (NAA) as measured with magnetic resonance spectroscopy. Unlike measures of brain volume, changes in NAA are sensitive to metabolic and functional aspects of neural and glia tissue and unlikely to reflect changes in microvasculature. Training-induced changes in NAA were, however, absent in carriers of the Met substitution in the brain-derived neurotrophic factor (BDNF) gene, which is known to reduce activity-dependent secretion of BDNF. Among BDNF Val homozygotes, increases in NAA were strongly related to the degree of practice-related improvement in navigation performance and normalized to pretraining levels 4 months after the last training session. We conclude that changes in demands on spatial navigation can alter hippocampal NAA concentrations, confirming epidemiological studies suggesting that mental experience may have direct effects on neural integrity and cognitive performance. BDNF genotype moderates these plastic changes, in line with the contention that gene-context interactions shape the ontogeny of complex phenotypes.
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| 6. |
- Berggren, Rasmus, et al.
(författare)
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Education Does Not Affect Cognitive Decline in Aging : A Bayesian Assessment of the Association Between Education and Change in Cognitive Performance.
- 2018
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Ingår i: Frontiers in psychology. - : Frontiers Media SA. - 1664-1078. ; 9, s. 1138-
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Tidskriftsartikel (refereegranskat)abstract
- Education is positively associated with level of cognitive function but the association between education and rate of cognitive decline remains unresolved, partly for methodological reasons. In this article, we address this issue using linear mixed models and Bayesian hypothesis testing, using data from the Betula cohort-sequential longitudinal study. Our results support the null hypothesis that education does not alter the rate of cognitive decline for visuospatial ability, semantic knowledge, and episodic memory. We propose that education is only a relevant variable for understanding cognitive performance in older age because of the association between performance and education that is formed in early development.
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| 7. |
- Brehmer, Yvonne, et al.
(författare)
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Plasticity of brain and cognition in older adults
- 2014
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Ingår i: Psychological Research. - : Springer Science and Business Media LLC. - 0340-0727 .- 1430-2772. ; 78:6, s. 790-802
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Forskningsöversikt (refereegranskat)abstract
- Aging is typically related to changes in brain and cognition, but the aging process is heterogeneous and differs between individuals. Recent research has started investigating the influence of cognitive and physical training on cognitive performance, functional brain activity, and brain structure in old age. The functional relevance of neural changes and the interactions among these changes following interventions is still a matter of debate. Here we selectively review research on structural and functional brain correlates of training-induced performance changes in healthy older adults and present exemplary longitudinal intervention studies sorted by the type of training applied (i.e., strategy-based training, process-specific training, and physical exercise). Although many training studies have been conducted recently, within each task domain, the number of studies that used comparable methods and techniques to assess behavioral and neural changes is limited. We suggest that future studies should include a multimodal approach to enhance the understanding of the relation between different levels of brain changes in aging and those changes that result from training. Investigating inter-individual differences in intervention-induced behavioral and neuronal changes would provide more information about who would benefit from a specific intervention and why. In addition, a more systematic examination of the time course of training-related structural and functional changes would improve the current level of knowledge about how learning is implemented in the brain and facilitate our understanding of contradictory results.
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| 8. |
- Brehmer, Yvonne, et al.
(författare)
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The importance of the ventromedial prefrontal cortex for associative memory in older adults : A latent structural equation analysis
- 2020
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- Older adults show relatively minor age-related decline in memory for single items, while their memory for associations is markedly reduced. Inter-individual differences in memory function in older adults are substantial but the neurobiological underpinnings of such differences are not well understood. In particular, the relative importance of inter-individual differences in the medio-temporal lobe (MTL) and the lateral prefrontal cortex (PFC) for associative and item recognition in older adults is still ambiguous. We therefore aimed to first establish the distinction between inter-individual differences in associative memory (recollection-based) performance and item memory (familiarity-based) performance in older adults and subsequently link these two constructs to differences in cortical thickness in the MTL and lateral PFC regions, in a latent structural equation modelling framework. To this end, a sample of 160 older adults (65-75 years old) performed three intentional itemassociative memory tasks, of which a subsample (n = 72) additionally had cortical thickness measures in MTL and PFC regions of interest available. The results provided support for a distinction between familiarity-based item memory and recollection-based associative memory performance in older adults. Cortical thickness in the ventro-medial prefrontal cortex was positively correlated with associative recognition performance, above and beyond any relationship between item recognition performance and cortical thickness in the same region and between associative recognition performance and brain structure in the MTL (parahippocampus). The findings highlight the relative importance of the ventromedial prefrontal cortex in allowing for intentional recollection-based associative memory functioning in older adults.
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| 9. |
- Brose, Annette, et al.
(författare)
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Daily variability in working memory is coupled with negative affect : the role of attention and motivation
- 2012
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Ingår i: Emotion. - : American Psychological Association (APA). - 1528-3542 .- 1931-1516. ; 12:3, s. 605-617
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Tidskriftsartikel (refereegranskat)abstract
- Across days, individuals experience varying levels of negative affect, control of attention, and motivation. We investigated whether this intraindividual variability was coupled with daily fluctuations in working memory (WM) performance. In 100 days, 101 younger individuals worked on a spatial N-back task and rated negative affect, control of attention, and motivation. Results showed that individuals differed in how reliably WM performance fluctuated across days, and that subjective experiences were primarily linked to performance accuracy. WM performance was lower on days with higher levels of negative affect, reduced control of attention, and reduced task-related motivation. Thus, variables that were found to predict WM in between-subjects designs showed important relationships to WM at the within-person level. In addition, there was shared predictive variance among predictors of WM. Days with increased negative affect and reduced performance were also days with reduced control of attention and reduced motivation to work on tasks. These findings are in line with proposed mechanisms linking negative affect and cognitive performance.
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| 10. |
- Brose, Annette, et al.
(författare)
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Differences in the Between-Person and Within-Person Structures of Affect Are a Matter of Degree
- 2015
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Ingår i: European Journal of Personality. - : SAGE Publications. - 0890-2070 .- 1099-0984. ; 29:1, s. 55-71
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Tidskriftsartikel (refereegranskat)abstract
- This study tested whether the structure of affect observed on the basis of between-person (BP) differences is equivalent to the affect structures that organize the variability of affective states within persons (WP) over time. Further aims were to identify individual differences in the degree of divergence between the WP and BP structure and examine its association to dispositional and contextual variables (neuroticism, extraversion, well-being and stress). In 100 daily sessions, 101 younger adults rated their mood on the Positive and Negative Affect Schedule. Variability of five negative affect items across time was so low that they were excluded from the analyses. We thus worked with a modified negative affect subscale. WP affect structures diverged reliably from the BP structure, with individual differences in the degree of divergence. Differences in the WP structural characteristics and the degree of divergence could be predicted by well-being and stress. We conclude that BP and WP structures of affect are not equivalent and that BP and WP variation should be considered as distinct phenomena. It would be wrong, for example, to conceive of positive and negative affect as independent at the WP level, as suggested by BP findings. Yet, individual differences in WP structural characteristics are related to stable BP differences, and the degree to which individuals' affect structures diverge from the BP structure can provide important insights into intraindividual functioning.
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