| 1. |
- Vestergren, Peter, 1974-, et al.
(författare)
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Development of the cognitive dysfunction questionnaire (CDQ) in a population based sample
- 2011
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Ingår i: Scandinavian Journal of Psychology. - Stockholm : Almqvist & Wiksell. - 0036-5564 .- 1467-9450. ; 52:3, s. 218-228
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Tidskriftsartikel (refereegranskat)abstract
- The study reports on the development of a questionnaire for assessment of adult cognitive dysfunction (CDQ). Participants in a population-based sample(65 ± 15 years, N = 370) responded to a 90-item pilot version covering multiple aspects of memory/cognition. Based on exploratory principal components analyses and correlations with criterion measures of cognitive functioning (MMSE, Block Design, semantic/episodic memory), 20 items loading on 6 components were selected for the final version of the questionnaire. Cronbach’s a for the total score was 0.90. There was evidence of construct validity as judged by correlations between CDQ scores, objective cognitive measures, and a subjective memory measure (PRMQ). Discriminant validity was demonstrated by a low and non-significant correlation with depressive symptoms. Further evidence of construct validity was provided by correlations with age and educational attainment. In conclusion, the CDQ is promising as a self-rating screening tool for cognitive dysfunction, and will be the subject of further development and validation.
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| 2. |
- Josefsson, Maria, 1979-, et al.
(författare)
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Genetic and Lifestyle Predictors of 15-Year Longitudinal Change in Episodic Memory
- 2012
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Ingår i: Journal of The American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 60:12, s. 2308-2312
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To reveal distinct longitudinal trajectories in episodic memory over 15 years and to identify demographic, lifestyle, health-related, and genetic predictors of stability or decline. Design: Prospective cohort study. Setting: The Betula Project, Umeå, Sweden. Participants: One thousand nine hundred fifty-four healthy participants aged 35 to 85 at baseline. Measurements: Memory was assessed according to validated episodic memory tasks in participants from a large population-based sample. Data were analyzed using a random-effects pattern-mixture model that considered the effect of attrition over two to four longitudinal sessions. Logistic regression was used to determine significant predictors of stability or decline relative to average change in episodic memory. Results: Of 1,558 participants with two or more test sessions, 18% were classified as maintainers and 13% as decliners, and 68% showed age-typical average change. More educated and more physically active participants, women, and those living with someone were more likely to be classified as maintainers, as were carriers of the met allele of the catechol-O-methyltransferase gene. Less educated participants, those not active in the labor force, and men were more likely to be classified as decliners, and the apolipoprotein E ɛ4 allele was more frequent in decliners. Conclusion: Quantitative, attrition-corrected assessment of longitudinal changes in memory can reveal substantial heterogeneity in aging trajectories, and genetic and lifestyle factors predict such heterogeneity.
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| 3. |
- Pudas, Sara, et al.
(författare)
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Maintenance and Manipulation in Working Memory : Differential Ventral and Dorsal Frontal Cortex fMRI Activity
- 2009
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Ingår i: Acta Psychologica Sinica. - : Science Press. - 0439-755X. ; 41:11, s. 1054-1062
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Tidskriftsartikel (refereegranskat)abstract
- A verbal working memory protocol was designed and evaluated on a group of healthy younger adults in preparation for a large-scale functional magnetic resonance (fMRI) study on aging and memory. Letters were presented in two critical conditions: (i) maintenance, in which letters were to be memorized and kept in mind over a four second interval, and (ii) manipulation, in which letters were shifted forward in alphabetical order, and the new order was kept in mind. Analyses of fMRI data showed that the protocol elicited reliable activation in the frontal cortex, with manipulation producing more extensive activation patterns, both in whole-brain analyses and in predefined regions of interest (ROIs). There was also a distinction between dorsal and ventral lateral prefrontal regions, such that manipulation elicited more dorsolateral prefrontal activation. The protocol also elicited activation in various subcortical areas, previously associated with working-memory tasks. It was concluded that this working memory protocol is appropriate for investigating age-related changes in frontal-cortex functioning.
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| 4. |
- Wikgren, Mikael, 1981-, et al.
(författare)
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APOE ε4 is associated with longer telomeres, and longer telomeres among ε4 carriers predicts worse episodic memory
- 2012
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 33:2, s. 335-344
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Tidskriftsartikel (refereegranskat)abstract
- Both leukocyte telomere length and the apolipoprotein ε4 allele have been associated with mortality, cardiovascular disease, cognition, and dementia. The authors investigated whether leukocyte telomere length was associated with APOE genotype or cognitive abilities in the context of APOE genotype. The setting for this cross-sectional study was 427 nondemented individuals aged 41–81 yr. The authors found that ε4 carriers overall exhibited significantly longer telomeres compared with non-carriers (difference of 268 bp, p = 0.001). This difference was greatest at the lower limit of the age span and nonsignificant at the upper limit, which translated into a significantly higher telomere attrition rate (p = 0.049) among ε4 carriers (37 bp/years) compared with non-carriers (21 bp/year). Further, longer telomeres among ε4 carriers significantly predicted worse performance on episodic memory tasks. No significant associations were found on tasks tapping semantic and visuospatial ability, or among ε3/ε3 carriers. In conclusion, APOE ε4 carriers had longer telomeres compared with non-carriers, but higher rate of attrition. Among them, longer telomeres predicted worse performance on episodic memory tasks. These observations suggest that the ε4 allele is associated with abnormal cell turnover of functional and possibly clinical significance.
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| 5. |
- Vestergren, Peter, 1974-, et al.
(författare)
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Multigroup confirmatory factor analysis of the cognitive dysfunction questionnaire : instrument refinement and measurement invariance across age and sex
- 2012
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Ingår i: Scandinavian Journal of Psychology. - : Wiley-Blackwell. - 0036-5564 .- 1467-9450. ; 53:5, s. 390-400
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Tidskriftsartikel (refereegranskat)abstract
- The study adopted CFA to investigate the factorial structure and reduce the number of items of the Cognitive Dysfunction Questionnaire (CDQ; Vestergren, Rönnlund, Nyberg, & Nilsson, 2011). The analyses were based on data for a total of 1115 participants from population based samples (mean age: 63.0 ± 14.5 years, range: 25 - 95) randomly split into a refinement (n = 569) and a cross-validation (n = 546) sample. Equivalence of the measurement and structural portions of the refined model was demonstrated across the refinement and cross-validation samples. Among competing models the best fitting and parsimonious model had a hierarchical factor structure with five first-order and one second-order general factor. The final version of the CDQ consisted of 20 items in five domains (Procedural actions, Semantic word knowledge, Face recognition, Temporal orientation and Spatial navigation). Internal consistency reliabilities were adequate for the total scale and for the subscales. Multigroup CFAs were performed and the results indicate measurement invariance across age and sex up to the scalar level. Finally, higher levels of cognitive dysfunction as reflected by CDQ scores were observed with advancing age and with deficits in general cognitive functioning as reflected by scores on the Mini-Mental State Examination. In conclusion, adoption of the final version of the CDQ appears to be a way of measuring cognitive dysfunction without administering formal cognitive tests. Future studies should apply it among clinical groups to further test its usefulness.
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| 6. |
- Backeström, A., et al.
(författare)
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Glucose metabolism and cognitive dysfunction
- 2010
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Ingår i: Abstracts of the EASD, Stockholm 2010. - : Springer Science and Business Media LLC. ; , s. S292-S292
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Konferensbidrag (refereegranskat)abstract
- Background and aims: The association between type 2 diabetes and different forms of cognitive impairment is well established. The mechanism behind the association is however still unrevealed. We have recently reported that raised blood glucose levels were associated to impairment in episodic memory, the memory function first affected in the progress to dementia. However, patients with type 2 diabetes have not only elevated levels of blood glucose, but also increased levels of insulin because of insulin resistance. It has been suggested that insulin itself might have a negative effect on cognitive function and memory. Diabetes is associated with a long standing hyperglycaemia but also with hypertension and hyperlipideima, leading to micro and macro vascular disease. Thus, our aim was to study whether insulin affects episodic memory independently of glucose in a nondiabetic adult population. Materials and methods: We linked and matched two large population based data sets in Sweden, the Betula study and the Västerbotten Intervention Program. We identified 364 (F/M 207/157, mean age 50.5 ±8.0 years) nondiabetic subjects, free from dementia, who had participated in the two surveys within six months. The memory test included testing of episodic memory. We transformed the results using the mean values and standard deviation from the youngest age group to compute a composite z-score (subjects’ value minus mean score in the 40-year-old group divided by SD). Fasting plasma insulin (FPI) and glucose (FPG) were analyzed with standard methods. Results: Women had higher levels of episodic memory (mean z-score -0.06, SD 0.54) compared to men (mean z-score -0.36, SD 0.51, p<0.001). Given the sex difference in the outcome variable we stratified for sex. In a univariate linear regression both FPG (B -0.274, SE 0.068, Beta -0.271, p<0.001) and FPI (B -0.389, SE 0.131, Beta -0.204, p=0.003) were significantly associated with episodic memory in women but not in men. FPG, but not FPI, remained significantly associated with episodic memory after adjustment for hypertension, total P-cholesterol, bodymass index, educational level, depression, smoking and cardiovascular disease ( FPG: B -0.218, SE 0.070, Beta -0.220, p=0.002; FPI: B -0.232, SE 0.149, Beta -0.127, p=n.s.), when FPG and FPI were analyzed separately. Entering both FPG and FPI into the regression model did not attenuate the association between FPG and episodic memory (FPG: B -0.204, SE 0.071, Beta -0.206, p=0.005). Conclusion: We conclude that an increase in plasma glucose, but not plasma insulin, is associated with impairment in episodic memory in women. This could be explained by a negative effect on the hippocampus caused by raised plasma glucose levels.
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| 7. |
- Bergdahl, Maud, et al.
(författare)
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Natural teeth and cognitive function in humans
- 2007
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Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 48:6, s. 557-565
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Tidskriftsartikel (refereegranskat)abstract
- A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50–85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age.
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| 8. |
- Bäckman, Lars, et al.
(författare)
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Effects of working-memory training on striatal dopamine release
- 2011
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 333:6043, s. 718-
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Tidskriftsartikel (refereegranskat)abstract
- Updating of working memory has been associated with striato-frontal brain regions and phasic dopaminergic neurotransmission. We assessed raclopride binding to striatal dopamine (DA) D2 receptors during a letter-updating task and a control condition before and after 5 weeks of updating training. Results showed that updating affected DA activity before training and that training further increased striatal DA release during updating. These findings highlight the pivotal role of transient neural processes associated with D2 receptor activity in working memory.
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| 9. |
- Dahlin, Erika, 1981-, et al.
(författare)
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Training of the executive component of working memory : subcortial areas mediate transfer effects
- 2009
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Ingår i: Restorative Neurology and Neuroscience. - : IOS Press. - 0922-6028 .- 1878-3627. ; 27:5, s. 405-419
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Several recent studies show that training can improve working memory (WM) performance. In this review, many issues related to WM training, such as neural basis, transfer effects, and age-related changes are addressed. Method: We focus on our own studies investigating training on tasks taxing the executive updating function and discuss our findings in relation to results from other studies investigating training of the executive component of WM. Results: The review confirms positive behavioral effects of training on working memory. The most common neural pattern following training is fronto-parietal activity decreases. Increases in sub-cortical areas are also frequently reported after training, and we suggest that such increases indicate changes in the underlying skill following training. Transfer effects are in general difficult to demonstrate. Some studies show that older adults increase their performance after WM training. However, transfer effects are small or nonexistent in old age. Conclusions: The main finding in this review is that sub-cortical areas seem to have a critical role in mediating transfer effects to untrained tasks after at least some forms of working memory training (such as updating).
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| 10. |
- Dahlin, Erika, 1981-, et al.
(författare)
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Transfer of learning after updating training mediated by the striatum
- 2008
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 320:5882, s. 1510-1512
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Tidskriftsartikel (refereegranskat)abstract
- Process-specific training can improve performance on untrained tasks, but the magnitude of gain is variable and often there is no transfer at all. We demonstrate transfer to a 3-back test of working memory after 5 weeks of training in updating. The transfer effect was based on a joint training-related activity increase for the criterion (letter memory) and transfer tasks in a striatal region that also was recruited pretraining. No transfer was observed to a task that did not engage updating and striatal regions, and age-related striatal changes imposed constraints on transfer. These findings indicate that transfer can occur if the criterion and transfer tasks engage specific overlapping processing components and brain regions.
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