| 1. |
- 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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| 2. |
- Li, Shu-Chen, et al.
(författare)
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Aging magnifies the effects of dopamine transporter and D2 receptor genes on backward serial memory
- 2013
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 34:1, s. 358.e1-358.e10
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Tidskriftsartikel (refereegranskat)abstract
- Aging compromises dopamine transporter (DAT) and receptor mechanisms in the frontostriatal circuitry. In a sample of 1288 younger and older adults, we investigated (i) whether individual differences in genotypes of the DAT gene (i.e., SLC6A3, the DAT variable number of tandem repeat 9/9, 9/10, and 10/10) and in the D2 receptor (DRD2) gene (i.e., the C957T [rs6277] CC and any T) interactively contribute to phenotype variations in episodic memory performance; and (ii) whether these genetic effects are magnified in older adults, because of considerable declines in the dopamine functions. Our results showed that carrying genotypes associated with higher levels of striatal synaptic dopamine (DAT 9/9) and higher density of extrastriatal D2 receptors (C957T CC) were associated with better backward serial recall, an episodic memory task with high encoding and retrieval demands. Critically, the gene-gene interaction effect was reliably stronger in older than in younger adults. In line with the resource modulation hypothesis, our findings suggest that aging-related decline in brain phenotypes (e.g., dopamine functions) could alter the relations between genotypes and behavioral phenotypes (e.g., episodic memory).
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| 3. |
- Lövdén, Martin, et al.
(författare)
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Does variability in cognitive performance correlate with frontal brain volume?
- 2013
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 64, s. 209-15
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about the neural correlates of within-person variability in cognitive performance. We investigated associations between regional brain volumes and trial-to-trial, block-to-block, and day-to-day variability in choice-reaction time, and episodic and working memory accuracy. Healthy younger (n=25) and older (n=18) adults underwent 101 daily assessments of cognitive performance, and their regional brain volumes were measured manually on magnetic resonance images. Results showed that smaller prefrontal white matter volumes were associated with higher block-to-block variability in choice-reaction time performance, with a stronger association observed among older adults. Smaller volumes of the dorsolateral prefrontal cortex covaried with higher block-to-block variability in episodic memory (number-word pair) performance. This association was stronger for younger adults. The observed associations between variability and brain volume were not due to individual differences in mean performance. Trial-to-trial and day-to-day variability in cognitive performance were unrelated to regional brain volume. We thus report novel findings demonstrating that block-by-block variability in cognitive performance is associated with integrity of the prefrontal regions and that between-person differences in different measures of variability of cognitive performance reflect different age-related constellations of behavioral and neural antecedents.
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| 4. |
- 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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| 5. |
- Lövdén, Martin, 1972, et al.
(författare)
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No moderating influence of education on the association between changes in hippocampus volume and memory performance in aging
- 2023
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Ingår i: Aging Brain. - : Elsevier. - 2589-9589. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Contemporary accounts of factors that may modify the risk for age-related neurocognitive disorders highlight education and its contribution to a cognitive reserve. By this view, individuals with higher educational attainment should show weaker associations between changes in brain and cognition than individuals with lower educational attainment. We tested this prediction in longitudinal data on hippocampus volume and episodic memory from 708 middle-aged and older individuals using local structural equation modeling. This technique does not require categorization of years of education and does not constrain the shape of relationships, thereby maximizing the chances of revealing an effect of education on the hippocampus-memory association. The results showed that the data were plausible under the assumption that there was no influence of education on the association between change in episodic memory and change in hippocampus volume. Restricting the sample to individuals with elevated genetic risk for dementia (APOE ε4 carriers) did not change these results. We conclude that the influence of education on changes in episodic memory and hippocampus volume is inconsistent with predictions by the cognitive reserve theory.
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| 6. |
- 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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| 7. |
- Brose, Annette, et al.
(författare)
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Adult Age Differences in Covariation of Motivation and Working Memory Performance: Contrasting Between-Person and Within-Person Findings
- 2010
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Ingår i: Research in Human Development. - : Informa UK Limited. - 1542-7609 .- 1542-7617. ; 7:1, s. 61-78
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Tidskriftsartikel (refereegranskat)abstract
- Developmental theorists have proposed for a long time that the prevailing focus on stable individual differences has obstructed the discovery of short-term covariations between cognitive performance and contextual influences within individuals that may help to uncover mechanisms underlying long-term change. As an initial step to overcome this imbalance, we observed measures of motivation and working memory (WM) in 101 younger and 103 older adults across 100 occasions. Our main goals were to (1) investigate day-to-day relations between motivation and WM, (2) show that these relations differ between groups of younger and older adults, and (3) test whether the within-person and between-person structures linking motivational variables to WM are equivalent (i.e., the ergodicity assumption). The covariation between motivation and WM was generally positive in younger adults. In contrast, older adults showed reduced variability in motivation, increased variability across trials, and small reliability-adjusted correlations between motivation and WM. Within-person structures differed reliably across individuals, defying the ergodicity assumption. We discuss the implications of our findings for developmental theory and design, stressing the need to explore the effects of between-person differences in short-term covariations on long-term developmental change.
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| 8. |
- 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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| 9. |
- Czernochowski, Daniela, et al.
(författare)
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When binding matters: An ERP analysis of the development of recollection and familiarity in childhood
- 2004
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Ingår i: Bound in Memory: Insights from behavioral and neuropsychological research. - 3832228713 ; , s. 93-128
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Dual process models of recognition memory assume that memory retrieval can be based on two distinct processes: an assessment of a context-free feeling of familiarity or on the reinstatement of specific context attributes that have been bound together to form a representation of the study episode during encoding (recollection). Recent neurophysiological evidence suggests that familiarity and recollection are mediated by different medial temporal lobe circuitries and accomplished by different binding mechanisms. The assessment of familiarity has been associated with intra-item binding mechanisms of the perirhinal cortex, whereas the explicit retrieval of specific details of a study episode depends on inter-item binding mechanisms mediated by the hippocampal formation and the prefrontal cortex. A related line of evidence for the independence of these memory processes comes from the examination of patients with selective lesions: Vargha-Khadem et al. (1997) reported three cases of early bilateral hypoxic lesions restricted to the hippocampus. Although these patients were unable to acquire and to retrieve episodic information, they were unlike most adult amnesics clearly able to acquire semantic knowledge after their injury. We examined the developmental aspects of recollection and familiarity by means of an event-related potential (ERP) study in two groups of children (6–8 years, 10–12 years) and young adults (20–29 years). Topographical differences of ERP components between the age groups were found in the memory task, but not in an auditory discrimination (oddball) task, suggesting that ERP differences between groups can be ascribed to differential memory processes rather than to general age differences. Our findings support the view of a differential development of recollection and familiarity. We discuss these findings in the light of different memory strategies in children as indicated by a generally lower performance level and a more conservative response criterion.
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| 10. |
- de Frias, Cindy, et al.
(författare)
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Revisiting the dedifferebtion hypothesis with longitudinal multi-cohort data
- 2007
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Ingår i: Intelligence. ; 35, s. 381-392
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Tidskriftsartikel (refereegranskat)abstract
- The present longitudinal multi-cohort study examines whether interindividual variability in cognitive performance and change increases in old age, and whether associations among developments of different cognitive functions increase with adult age. Multivariate multiple-group latent growth modeling was applied to data from narrow cohorts separated by five years of age. Tests assessing episodic recall, semantic knowledge, semantic fluency, and visuospatial ability were administered to 1000 non-demented adults (initially aged 35–80 years), participating in the Betula Project at three occasions over a 10-year period. Greater interindividual differences in change were noted in older age groups. Age-related increases in correlations among performance scores were noted for different cognitive measures beginning in old age, but not earlier. Our study supports a dynamic view of dedifferentiation of cognitive aging.
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