| 1. |
- Bellander, Martin, et al.
(författare)
-
Behavioral correlates of changes in hippocampal gray matter structure during acquisition of foreign vocabulary
- 2016
-
Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 131, s. 205-213
-
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.
|
|
| 2. |
- Berggren, Rasmus
(författare)
-
Cognitive development and educational attainment across the life span
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis I explore two strands of research: in the first half I explore the effects of language learning on brain structure and cognitive function. In the second half I study to what extent educational attainment alter the rate of cognitive decline in old age. These different strands of research are united through the concept of brain plasticity, which is the brain’s ability to change its structural configuration in response to new experiences. In Study I we charted the neural underpinning of foreign language learning in a sample of younger adults. A total of 56 younger adults were randomized to either a 10-week beginner’s course in Italian or a control condition. For those studying Italian we found that grey-matter change in the right hippocampus was associated with how much time they spent practicing, rather than with how good they became suggesting that effort, rather than achieved proficiency, is what drives neuroplastic change. Study II presents the largest (to date) randomized trial looking into the causal effects of language learning as cognitive engagement in older age, specifically foreign language learning. 160 people between ages 65 and 75 were randomized to either an 11-week beginner’s course in Italian, or an 11-week relaxation training course. While we predicted that language learning would improve cognitive function, specifically associative memory, we found no evidence to support this hypothesis. Study III and IV address the question of whether or not educational attainment affects the rate of cognitive decline in old age. While it is clear that educational attainment is associated with level of cognitive function, we find no evidence that it alters the rate of decline in old age. Study III address this question using a novel statistical approach while Study IV presents a meta-analysis on the subject, arriving at similar conclusions.
|
|
| 3. |
- Berggren, Rasmus, et al.
(författare)
-
Education Does Not Affect Cognitive Decline in Aging : A Bayesian Assessment of the Association Between Education and Change in Cognitive Performance.
- 2018
-
Ingår i: Frontiers in psychology. - : Frontiers Media SA. - 1664-1078. ; 9, s. 1138-
-
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.
|
|
| 4. |
- Berggren, Rasmus, et al.
(författare)
-
Foreign language learning in older age does not improve memory or intelligence : Evidence from a randomized controlled study.
- 2020
-
Ingår i: Psychology and Aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 35:2, s. 212-219
-
Tidskriftsartikel (refereegranskat)abstract
- Foreign language learning in older age has been proposed as a promising avenue for combatting age-related cognitive decline. We tested this hypothesis in a randomized controlled study in a sample of 160 healthy older participants (aged 65-75 years) who were randomized to 11 weeks of either language learning or relaxation training. Participants in the language learning condition obtained some basic knowledge in the new language (Italian), but between-groups differences in improvements on latent factors of verbal intelligence, spatial intelligence, working memory, item memory, or associative memory were negligible. We argue that this is not due to either poor measurement, low course intensity, or low statistical power, but that basic studies in foreign languages in older age are likely to have no or trivially small effects on cognitive abilities. We place this in the context of the cognitive training and engagement literature and conclude that while foreign language learning may expand the behavioral repertoire, it does little to improve cognitive processing abilities. (PsycINFO Database Record (c) 2020 APA, all rights reserved).
|
|
| 5. |
- Brehmer, Yvonne, et al.
(författare)
-
The importance of the ventromedial prefrontal cortex for associative memory in older adults : A latent structural equation analysis
- 2020
-
Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 209
-
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.
|
|
| 6. |
- Chew, Michelle, et al.
(författare)
-
National outcomes and characteristics of patients admitted to Swedish intensive care units for COVID-19 A registry-based cohort study
- 2021
-
Ingår i: European Journal of Anaesthesiology. - : LIPPINCOTT WILLIAMS & WILKINS. - 0265-0215 .- 1365-2346. ; 38:4, s. 335-343
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Mortality among patients admitted to intensive care units (ICUs) with COVID-19 is unclear due to variable follow-up periods. Few nationwide data are available to compare risk factors, treatment and outcomes of COVID-19 patients after ICU admission. OBJECTIVE To evaluate baseline characteristics, treatments and 30-day outcomes of patients admitted to Swedish ICUs with COVID-19. DESIGN Registry-based cohort study with prospective data collection. SETTING Admissions to Swedish ICUs from 6 March to 6 May 2020 with laboratory confirmed COVID-19 disease. PARTICIPANTS Adult patients admitted to Swedish ICUs. EXPOSURES Baseline characteristics, intensive care treatments and organ failures. MAIN OUTCOMES AND MEASURES The primary outcome was 30-day all-cause mortality. A multivariable model was used to determine the independent association between potential predictor variables and death. RESULTS We identified 1563 patients with complete 30-day follow-up. The 30-day all-cause mortality was 26.7%. Median age was 61 [52 to 69], Simplified Acute Physiology Score III (SAPS III) was 53 [46 to 59] and 62.5% had at least one comorbidity. Median PaO2/FiO(2) on admission was 97.5 [75.0 to 140.6] mmHg, 74.7% suffered from moderate-to-severe acute respiratory failure. Age, male sex [adjusted odds ratio (aOR) 1.5 (1.1 to 2.2)], SAPS III score [aOR 1.3 (1.2 to 1.4)], severe respiratory failure [aOR 3.0 (2.0 to 4.7)], specific COVID-19 pharmacotherapy [aOR 1.4 (1.0 to 1.9)] and continuous renal replacement therapy [aOR 2.1 (1.5 to 3.0)] were associated with increased mortality. Except for chronic lung disease, the presence of comorbidities was not independently associated with mortality. CONCLUSIONS Thirty-day mortality rate in COVID-19 patients admitted to Swedish ICUs is generally lower than previously reported despite a severe degree of hypoxaemia on admission. Mortality was driven by age, baseline disease severity, the presence and degree of organ failure, rather than pre-existing comorbidities.
|
|
| 7. |
- Seblova, D., et al.
(författare)
-
Education and age-related decline in cognitive performance : Systematic review and meta-analysis of longitudinal cohort studies
- 2020
-
Ingår i: Ageing Research Reviews. - : Elsevier BV. - 1568-1637 .- 1872-9649. ; 58
-
Forskningsöversikt (refereegranskat)abstract
- Central theories of cognitive aging propose that education is an important protective factor for decline in cognitive performance in older age. We conducted a systematic review and meta-analysis of reported estimates of an association between educational attainment and change in performance in six cognitive domains (episodic memory, processing speed, verbal fluency, crystallized intelligence, fluid intelligence, and global ability) in the general population of older individuals. The systematic search (11th of October 2019) identified 92 eligible articles. The episodic memory domain had the highest number of estimates (37 estimates from 18 articles, n =109,281) included in the meta-analysis. The fewest estimates (6 estimates from 6 articles, n = 5263) were included for fluid intelligence. Pooled mean estimates from an inverse-variance weighted random effects analysis were not statistically significant and indicated that any association between education and change in cognitive performance is likely of a negligible magnitude. The estimates for education's role (one additional year) for change in cognitive performance ranged from -0.019 (95 % confidence interval, CI = -0.047, 0.010) to 0.004SD (CI = -0.003, 0.012) per decade. Even if the larger positive point estimates (i.e., protective effects) are selectively considered, the influence of education on change is still at least 12 times less important for the cognitive functioning of an older individual than the association between education and level of cognitive performance. Sensitivity analyses did not substantially alter these results. However, heterogeneity was substantial, and remained largely unexplained by mean age, mean educational attainment, Gini coefficient, GDP per capita, maximum follow-up period, and publication year. Overall, education is an important factor in aging due to its robust association with level of performance, but the current base of empirical evidence is not revealing a consistent and substantial association between educational attainment and changes in cognitive performance in the general population. Theories of cognitive aging must be updated to incorporate this pattern of findings.
|
|
