| 1. |
- 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.
|
|
| 2. |
- 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).
|
|
| 3. |
- 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.
|
|
| 4. |
- Freidle, Malin, et al.
(författare)
-
No evidence for any effect of multiple sessions of frontal transcranial direct stimulation on mood in healthy older adults
- 2020
-
Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 137
-
Tidskriftsartikel (refereegranskat)abstract
- The dorsolateral prefrontal cortex (DLPFC) is part of a network important for emotional regulation and the possibility of modulating activity in this region with transcranial direct current stimulation (TDCS) to change mood has gained great interest, particularly for application in clinical populations. Whilst results in major depressive disorder have been promising, less is known about the effects of TDCS on mood in non-clinical populations. We hypothesized that multiple sessions of anodal TDCS applied over the left DLPFC would enhance mood, primarily as measured by the Profile of Mood States questionnaire, in healthy older adults. In addition, in an exploratory analysis, we examined the potentially moderating role of working memory training. Working memory, just like emotional regulation, taxes the DLPFC, which suggests that engaging in a working memory task whilst receiving TDCS may have a different effect on activity in this region and consequently mood. A total of 123 participants between 65 and 75 years of age were randomly assigned to receive either 20 sessions of TDCS, with or without working memory training, or 20 sessions sham stimulation, with or without working memory training. We found no support for enhancement of mood due to TDCS in healthy older adults, with or without cognitive training and conclude that the TDCS protocol used is unlikely to improve mood in non-depressed older individuals.
|
|
| 5. |
- Lebedev, Alexander V., et al.
(författare)
-
Effects of daily L-dopa administration on learning and brain structure in older adults undergoing cognitive training : a randomised clinical trial
- 2020
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Cognitive aging creates major individual and societal burden, motivating search for treatment and preventive care strategies. Behavioural interventions can improve cognitive performance in older age, but effects are small. Basic research has implicated dopaminergic signalling in plasticity. We investigated whether supplementation with the dopamine-precursor L-dopa improves effects of cognitive training on performance. Sixty-three participants for this randomised, parallel-group, double-blind, placebo-controlled trial were recruited via newspaper advertisements. Inclusion criteria were: age of 65–75 years, Mini-Mental State Examination score >25, absence of serious medical conditions. Eligible subjects were randomly allocated to either receive 100/25 mg L-dopa/benserazide (n = 32) or placebo (n = 31) prior to each of twenty cognitive training sessions administered during a four-week period. Participants and staff were blinded to group assignment. Primary outcomes were latent variables of spatial and verbal fluid intelligence. Compared to the placebo group, subjects receiving L-dopa improved less in spatial intelligence (−0.267 SDs; 95%CI [−0.498, −0.036]; p = 0.024). Change in verbal intelligence did not significantly differ between the groups (−0.081 SDs, 95%CI [−0.242, 0.080]; p = 0.323). Subjects receiving L-dopa also progressed slower through the training and the groups displayed differential volumetric changes in the midbrain. No statistically significant differences were found for the secondary cognitive outcomes. Adverse events occurred for 10 (31%) and 7 (23%) participants in the active and control groups, correspondingly. The results speak against early pharmacological interventions in older healthy adults to improve broader cognitive functions by targeting the dopaminergic system and provide no support for learning-enhancing properties of L-dopa supplements in the healthy elderly. The findings warrant closer investigation about the cognitive effects of early dopamine-replacement therapy in neurological disorders. This trial was preregistered at the European Clinical Trial Registry, EudraCT#2016-000891-54 (2016-10-05).
|
|
| 6. |
- Lebedev, Alexander V., et al.
(författare)
-
LSD-Induced Entropic Brain Activity Predicts Subsequent Personality Change
- 2016
-
Ingår i: Human Brain Mapping. - : Wiley. - 1065-9471 .- 1097-0193. ; 37:9, s. 3203-3213
-
Tidskriftsartikel (refereegranskat)abstract
- Personality is known to be relatively stable throughout adulthood. Nevertheless, it has been shown that major life events with high personal significance, including experiences engendered by psychedelic drugs, can have an enduring impact on some core facets of personality. In the present, balanced-order, placebo-controlled study, we investigated biological predictors of post-lysergic acid diethylamide ( LSD) changes in personality. Nineteen healthy adults underwent resting state functional MRI scans under LSD ( 75 mu g, I. V.) and placebo ( saline I. V.). The Revised NEO Personality Inventory ( NEO-PI-R) was completed at screening and 2 weeks after LSD/placebo. Scanning sessions consisted of three 7.5-min eyes-closed resting-state scans, one of which involved music listening. A standardized preprocessing pipeline was used to extract measures of sample entropy, which characterizes the predictability of an fMRI time-series. Mixed-effects models were used to evaluate drug-induced shifts in brain entropy and their relationship with the observed increases in the personality trait openness at the 2-week follow-up. Overall, LSD had a pronounced global effect on brain entropy, increasing it in both sensory and hierarchically higher networks across multiple time scales. These shifts predicted enduring increases in trait openness. Moreover, the predictive power of the entropy increases was greatest for the music-listening scans and when ego-dissolution was reported during the acute experience. These results shed new light on how LSD-induced shifts in brain dynamics and concomitant subjective experience can be predictive of lasting changes in personality.
|
|
| 7. |
- Lebedev, Alexander V., et al.
(författare)
-
Working Memory and Reasoning Benefit from Different Modes of Large-scale Brain Dynamics in Healthy Older Adults
- 2018
-
Ingår i: Journal of cognitive neuroscience. - : MIT Press. - 0898-929X .- 1530-8898. ; 30:7, s. 1033-1046
-
Tidskriftsartikel (refereegranskat)abstract
- Researchers have proposed that solving complex reasoning problems, a key indicator of fluid intelligence, involves the same cognitive processes as solving working memory tasks. This proposal is supported by an overlap of the functional brain activations associated with the two types of tasks and by high correlations between interindividual differences in performance. We replicated these findings in 53 older participants but also showed that solving reasoning and working memory problems benefits from different configurations of the functional connectome and that this dissimilarity increases with a higher difficulty load. Specifically, superior performance in a typical working memory paradigm (n-back) was associated with upregulation of modularity (increased between-network segregation), whereas performance in the reasoning task was associated with effective downregulation of modularity. We also showed that working memory training promotes task-invariant increases in modularity. Because superior reasoning performance is associated with downregulation of modular dynamics, training may thus have fostered an inefficient way of solving the reasoning tasks. This could help explain why working memory training does little to promote complex reasoning performance. The study concludes that complex reasoning abilities cannot be reduced to working memory and suggests the need to reconsider the feasibility of using working memory training interventions to attempt to achieve effects that transfer to broader cognition.
|
|
| 8. |
- Nilsson, Jonna, et al.
(författare)
-
Acute increases in brain-derived neurotrophic factor in plasma following physical exercise relates to subsequent learning in older adults.
- 2020
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Multidomain lifestyle interventions represents a promising strategy to counteract cognitive decline in older age. Brain-derived neurotrophic factor (BDNF) is essential for experience-dependent plasticity and increases following physical exercise, suggesting that physical exercise may facilitate subsequent learning. In a randomized-controlled trial, healthy older adults (65-75 years) completed a 12-week behavioral intervention that involved either physical exercise immediately before cognitive training (n = 25; 13 females), physical exercise immediately after cognitive training (n = 24; 11 females), physical exercise only (n = 27; 15 females), or cognitive training only (n = 21; 12 females). We hypothesized that cognition would benefit more from cognitive training when preceded as opposed to followed by physical exercise and that the relationship between exercise-induced increases in peripheral BDNF and cognitive training outcome would be greater when cognitive training is preceded by physical exercise. Greater increases of plasma BDNF were associated with greater cognitive training gains on trained task paradigms, but only when such increases preceded cognitive training (ß = 0.14, 95% CI [0.04, 0.25]). Average cognitive training outcome did not differ depending on intervention order (ß = 0.05, 95% CI [-0.10, 0.20]). The study provides the first empirical support for a time-critical but advantageous role for post-exercise increases in peripheral BDNF for learning at an interindividual level in older adults, with implications for future multidomain lifestyle interventions.
|
|
| 9. |
- Nilsson, Jonna, et al.
(författare)
-
Associations of cardiorespiratory fitness and moderate-to-vigorous physical activity with latent cognitive abilities in older adults
- 2022
-
Ingår i: Psychology of Sport And Exercise. - : Elsevier. - 1469-0292 .- 1878-5476. ; 60, s. 102171-102171
-
Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated that physical activity has a small but positive effect on cognition in old age, which suggests that it may be possible to alter the trajectory of age-related cognitive decline. However, our understanding of which aspects of physical activity that are important for modifying cognition remains incomplete. Adopting an exploratory approach in a sample of 115 healthy older adults (65–75 years), the present cross-sectional study used structural equation modelling to investigate the dissociable associations of physical activity (moderate-to-vigorous activity, derived from 7-day accelerometry) and cardiorespiratory fitness (VO2 max, derived from maximal treadmill ergometer test) with multiple latent cognitive abilities (working memory, episodic memory, spatial and verbal reasoning). The results showed a significant positive association between fitness and working memory, when physical activity was statistically controlled for, and a positive association of similar point magnitude between physical activity and episodic memory, when fitness was statistically controlled for, although the latter association did not reach statistical significance. The results add to the foundation for a more careful investigation of the dissociable associations of moderate-to-vigorous physical activity and fitness with cognition in old age, and encourages future research to test the hypothesis that cardiorespiratory fitness benefits working memory via general cerebrovascular effects on grey matter volume, whilst moderate-to-vigorous physical activity benefits episodic memory via effects on neuroplastic processes.
|
|
| 10. |
- Nilsson, Jonna, et al.
(författare)
-
Direct-Current Stimulation Does Little to Improve the Outcome of Working Memory Training in Older Adults
- 2017
-
Ingår i: Psychological Science. - : SAGE Publications. - 0956-7976 .- 1467-9280. ; 28:7, s. 907-920
-
Tidskriftsartikel (refereegranskat)abstract
- The promise of transcranial direct-current stimulation (tDCS) as a modulator of cognition has appealed to researchers, media, and the general public. Researchers have suggested that tDCS may increase effects of cognitive training. In this study of 123 older adults, we examined the interactive effects of 20 sessions of anodal tDCS over the left prefrontal cortex (vs. sham tDCS) and simultaneous working memory training (vs. control training) on change in cognitive abilities. Stimulation did not modulate gains from pre- to posttest on latent factors of either trained or untrained tasks in a statistically significant manner. A supporting meta-analysis (n = 266), including younger as well as older individuals, showed that, when combined with training, tDCS was not much more effective than sham tDCS at changing working memory performance (g = 0.07, 95% confidence interval, or CI = [-0.21, 0.34]) and global cognition performance (g = -0.01, 95% CI = [-0.29, 0.26]) assessed in the absence of stimulation. These results question the general usefulness of current tDCS protocols for enhancing the effects of cognitive training on cognitive ability.
|
|
