| 91. |
- Schmiedek, Florian, et al.
(författare)
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Hundred Days of Cognitive Training Enhance Broad Cognitive Abilities in Adulthood : Findings from the COGITO Study
- 2010
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Ingår i: Frontiers in Aging Neuroscience. - Lausanne : Frontiers Research Foundation. - 1663-4365. ; 2, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- We examined whether positive transfer of cognitive training, which so far has been observed for individual tests only, also generalizes to cognitive abilities, thereby carrying greater promise for improving everyday intellectual competence in adulthood and old age. In the COGITO Study, 101 younger and 103 older adults practiced six tests of perceptual speed (PS), three tests of working memory (WM), and three tests of episodic memory (EM) for over 100 daily 1-h sessions. Transfer assessment included multiple tests of PS, WM, EM, and reasoning. In both age groups, reliable positive transfer was found not only for individual tests but also for cognitive abilities, represented as latent factors. Furthermore, the pattern of correlations between latent change factors of practiced and latent change factors of transfer tasks indicates systematic relations at the level of broad abilities, making the interpretation of effects as resulting from unspecific increases in motivation or self-concept less likely.
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| 92. |
- Schmiedek, Florian, et al.
(författare)
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Keeping It Steady. Older Adults Perform More Consistently on Cognitive Tasks Than Younger Adults
- 2013
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Ingår i: Psychological Science. - : SAGE Publications. - 0956-7976 .- 1467-9280. ; 24:9, s. 1747-1754
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Tidskriftsartikel (refereegranskat)abstract
- People often attribute poor performance to having bad days. Given that cognitive aging leads to lower average levels of performance and more moment-to-moment variability, one might expect that older adults should show greater day-to-day variability and be more likely to experience bad days than younger adults. However, both researchers and ordinary people typically sample only one performance per day for a given activity. Hence, the empirical basis for concluding that cognitive performance does substantially vary from day to day is inadequate. On the basis of data from 101 younger and 103 older adults who completed nine cognitive tasks in 100 daily sessions, we show that the contributions of systematic day-to-day variability to overall observed variability are reliable but small. Thus, the impression of good versus bad days is largely due to performance fluctuations at faster timescales. Despite having lower average levels of performance, older adults showed more consistent levels of performance across days.
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| 93. |
- Schmiedek, Florian, et al.
(författare)
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On the Relation of Mean Reaction Time and Intraindividual Reaction Time Variability
- 2009
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Ingår i: Psychology and Aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 24:4, s. 841-857
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Tidskriftsartikel (refereegranskat)abstract
- Researchers often statistically control for means when examining individual or age-associated differences in variances, assuming that the relation between the 2 is linear and invariant within and across individuals and age groups. We tested this assumption in the domain of working memory by applying variance-heterogeneity multilevel models to reaction times in the n-back task. Data are from the COGITO study, which comprises 101 younger and 103 older adults assessed in over 100 daily sessions. We found that relations between means and variances vary reliably across age groups and individuals, thereby contradicting the invariant linearity assumption. We argue that statistical control approaches need to be replaced by theoretical models that simultaneously estimate central tendency and dispersion of latencies and accuracies and illustrate this claim by applying the diffusion model to the same data. Finally, we note that differences in reliability between estimates for means and variances need to be considered when comparing their unique contributions to developmental outcomes.
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| 94. |
- Schmiedek, Florian, et al.
(författare)
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Practice-Related Changes in Perceptual Evidence Accumulation Correlate With Changes in Working Memory
- 2023
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Ingår i: Journal of Experimental Psychology: General. - : American Psychological Association (APA). - 0096-3445 .- 1939-2222. ; 152:3
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Tidskriftsartikel (refereegranskat)abstract
- It has been proposed that evidence accumulation determines not only the speed and accuracy of simple perceptual decisions but also influences performance on tasks assessing higher-order cognitive abilities, such as working memory (WM). Accordingly, estimates of evidence accumulation based on diffusion decision modeling of perceptual decision-making tasks have been found to correlate with WM performance. Here we use diffusion decision modeling in combination with latent factor modeling to test the stronger prediction that practice-induced changes in evidence accumulation correlate with changes in WM performance. Analyses are based on data from the COGITO Study, in which 101 young adults practiced a battery of cognitive tasks, including three simple two-choice reaction time tasks and three WM tasks, in 100 day-to-day training sessions distributed over 6 months. In initial analyses, drift rates were found to correlate across the three choice tasks, such that latent factors of evidence accumulation could be established. These latent factors of evidence accumulation were positively correlated with latent factors of practiced and unpracticed WM tasks, both before and after practice. As predicted, individual differences in changes of evidence accumulation correlated positively with changes in WM performance. Our findings support the proposition that decision making and WM both rely on the active maintenance of task-relevant internal representations
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| 95. |
- Schmiedek, Florian, et al.
(författare)
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Within-person structures of daily cognitive performance differ from between-person structures of cognitive abilities
- 2020
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Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Over a century of research on between-person differences has resulted in the consensus that human cognitive abilities are hierarchically organized, with a general factor, termed general intelligence or g, uppermost. Surprisingly, it is unknown whether this body of evidence is informative about how cognition is structured within individuals. Using data from 101 young adults performing nine cognitive tasks on 100 occasions distributed over six months, we find that the structures of individuals' cognitive abilities vary among each other, and deviate greatly from the modal between-person structure. Working memory contributes the largest share of common variance to both between- and within-person structures, but the g factor is much less prominent within than between persons. We conclude that between-person structures of cognitive abilities cannot serve as a surrogate for within-person structures. To reveal the development and organization of human intelligence, individuals need to be studied over time.
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| 96. |
- Schmiedek, Florian, et al.
(författare)
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Younger Adults Show Long-Term Effects of Cognitive Training on Broad Cognitive Abilities Over 2 Years
- 2014
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Ingår i: Developmental Psychology. - : American Psychological Association (APA). - 0012-1649 .- 1939-0599. ; 50:9, s. 2304-2310
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Tidskriftsartikel (refereegranskat)abstract
- In the COGITO study (Schmiedek, Lovden, & Lindenberger, 2010), 101 younger adults practiced 12 tests of perceptual speed, working memory, and episodic memory for over 100 daily 1-hr sessions. The intervention resulted in positive transfer to broad cognitive abilities, including reasoning and episodic memory. Here, we examine whether these ability-based transfer effects are maintained over time. Two years after the end of the training, 80 participants returned for follow-up assessments of the comprehensive battery of transfer tasks. We found reliable positive long-term transfer effects for reasoning and episodic memory, controlling for retest effects by including participants from the original control group. This shows, for the first time, that intensive cognitive training interventions can have long-term broad transfer at the level of cognitive abilities.
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| 97. |
- Schroeder, Julia, et al.
(författare)
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MicroRNA-138 is a potential regulator of memory performance in humans
- 2014
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 8, s. 501-
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Tidskriftsartikel (refereegranskat)abstract
- Genetic factors underlie a substantial proportion of individual differences in cognitive functions in humans, including processes related to episodic and working memory. While genetic association studies have proposed several candidate memory genes, these currently explain only a minor fraction of the phenotypic variance. Here, we performed genome-wide screening on 13 episodic and working memory phenotypes in 1318 participants of the Berlin Aging Study II aged 60 years or older. The analyses highlight a number of novel single nucleotide polymorphisms (SNPs) associated with memory performance, including one located in a putative regulatory region of microRNA (miRNA) hsa-mir-138-5p (rs9882688, P-value = 7.8 x 10(-9)). Expression quantitative trait locus analyses on next-generation RNA-sequencing data revealed that rs9882688 genotypes show a significant correlation with the expression levels of this miRNA in 309 human lymphoblastoid cell lines (P-value = 5 x 10(-4)). In silico modeling of other top-ranking GWAS signals identified an additional memory-associated SNP in the 3' untranslated region (3' UTR) of DCP1B, a gene encoding a core component of the mRNA decapping complex in humans, predicted to interfere with hsa-mir-138-5p binding. This prediction was confirmed in vitro by luciferase assays showing differential binding of hsa-mir-138-5p to 3' UTR reporter constructs in two human cell lines (HEK293: P-value = 0.0470; SH-SY5Y: P-value = 0.0866). Finally, expression profiling of hsa-mir-138-5p and DCP1B mRNA in human post-mortem brain tissue revealed that both molecules are expressed simultaneously in frontal cortex and hippocampus, suggesting that the proposed interaction between hsa-mir-138-5p and DCP1B may also take place in vivo. In summary, by combining unbiased genome-wide screening with extensive in silico modeling, in vitro functional assays, and gene expression profiling, our study identified miRNA-138 as a potential molecular regulator of human memory function.
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| 98. |
- Shing, Yee Lee, et al.
(författare)
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Memory Updating Practice Across 100 Days in the COGITO Study
- 2012
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Ingår i: Psychology and Aging. - : American Psychological Association (APA). - 0882-7974 .- 1939-1498. ; 27:2, s. 451-461
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Tidskriftsartikel (refereegranskat)abstract
- We investigated working memory updating performance in younger and older adults before, during. and after 100-day practice. Performance to presentation time (PT) relation was fitted to a negatively accelerated logistic function. Relative to younger adults, older adults showed lower asymptotes at pretest and posttest, and shallower slopes at pretest. Older adults practicing the task with fast PT gained less than older adults practicing the task with slow PT, probably reflecting the persistent use of a selective strategy throughout the 100-day practice period in the fast FT group. These results have implications for designing and evaluating age-comparative working memory training programs.
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| 99. |
- Shing, Yee Lee, et al.
(författare)
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Neural activation patterns of successful episodic encoding : Reorganization during childhood, maintenance in old age
- 2016
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Ingår i: Developmental Cognitive Neuroscience. - : Elsevier BV. - 1878-9293 .- 1878-9307. ; 20, s. 59-69
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Tidskriftsartikel (refereegranskat)abstract
- The two-component framework of episodic memory (EM) development posits that the contributions of medial temporal lobe (MTL) and prefrontal cortex (PFC) to successful encoding differ across the lifespan. To test the framework's hypotheses, we compared subsequent memory effects (SME) of 10-12 year-old children, younger adults, and older adults using functional magnetic resonance imaging (fMRI). Memory was probed by cued recall, and SME were defined as regional activation differences during encoding between subsequently correctly recalled versus omitted items. In MTL areas, children's SME did not differ in magnitude from those of younger and older adults. In contrast, children's SME in PFC were weaker than the corresponding SME in younger and older adults, in line with the hypothesis that PFC contributes less to successful encoding in childhood. Differences in SME between younger and older adults were negligible. The present results suggest that, among individuals with high memory functioning, the neural circuitry contributing to successful episodic encoding is reorganized from middle childhood to adulthood. Successful episodic encoding in later adulthood, however, is characterized by the ability to maintain the activation patterns that emerged in young adulthood.
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| 100. |
- Solé-Padullés, Cristina, et al.
(författare)
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No Association Between Loneliness, Episodic Memory and Hippocampal Volume Change in Young and Healthy Older Adults : A Longitudinal European Multicenter Study
- 2022
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Loneliness is most prevalent during adolescence and late life and has been associated with mental health disorders as well as with cognitive decline during aging. Associations between longitudinal measures of loneliness and verbal episodic memory and brain structure should thus be investigated.Methods: We sought to determine associations between loneliness and verbal episodic memory as well as loneliness and hippocampal volume trajectories across three longitudinal cohorts within the Lifebrain Consortium, including children, adolescents (N = 69, age range 10–15 at baseline examination) and older adults (N = 1468 over 60). We also explored putative loneliness correlates of cortical thinning across the entire cortical mantle.Results: Loneliness was associated with worsening of verbal episodic memory in one cohort of older adults. Specifically, reporting medium to high levels of loneliness over time was related to significantly increased memory loss at follow-up examinations. The significance of the loneliness-memory change association was lost when eight participants were excluded after having developed dementia in any of the subsequent follow-up assessments. No significant structural brain correlates of loneliness were found, neither hippocampal volume change nor cortical thinning.Conclusion: In the present longitudinal European multicenter study, the association between loneliness and episodic memory was mainly driven by individuals exhibiting progressive cognitive decline, which reinforces previous findings associating loneliness with cognitive impairment and dementia.
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