| 1. |
- Josefsson, Maria, 1979-, et al.
(author)
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Genetic and Lifestyle Predictors of 15-Year Longitudinal Change in Episodic Memory
- 2012
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In: Journal of The American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 60:12, s. 2308-2312
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Journal article (peer-reviewed)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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| 2. |
- Pudas, Sara, et al.
(author)
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Maintenance and Manipulation in Working Memory : Differential Ventral and Dorsal Frontal Cortex fMRI Activity
- 2009
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In: Acta Psychologica Sinica. - : Science Press. - 0439-755X. ; 41:11, s. 1054-1062
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Journal article (peer-reviewed)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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| 3. |
- Olofsson, Jonas K., et al.
(author)
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Long-term episodic memory decline is associated with olfactory deficits only in carriers of ApoE-є4
- 2016
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In: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 85, s. 1-9
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Journal article (peer-reviewed)abstract
- The ɛ4 allele of the Apolipoprotein E gene is a genetic risk factor for late-onset dementia of the Alzheimers' type (DAT), which is characterized by loss of both episodic memoryand olfactory functions. Little is known about the possible role of ɛ4 in the association between ongoing episodic memory decline and olfactory deficits in the general population, but such information is relevant in determining the relevance of olfaction as a marker of DAT risk. The present study was based on a large, population-based sample (n=1087, aged 45–90 years, of which 324 were ɛ4-carriers). Episodic memory change rates were established using data collected every 5 years for a 10–20 year interval leading up to an olfactory assessment using the Scandinavian Odor Identification Test at the last wave of data collection. Participants were classified according to whether or not their episodic memory ability declined more rapidly than the age-typical norm (by >1SD). Our main result is that only in ɛ4-carriers was episodic memory decline associated with odor identification impairment. In individuals without ɛ4, odor identification was unrelated to episodic memory decline status. Follow-up analyses indicated that this moderation by ɛ4 was due to the olfactory nature of the identification test, and that the effect was not caused by 63 individuals with dementia. Our results suggest that the ɛ4 determines the functional association between ongoing episodic memory decline and olfaction. These findings are consistent with the notion that ɛ4-carriers with DAT, compared to non-carriers, display a cortical atrophy pattern that is more focused on mediotemporal lobe regions supporting olfactory and episodic memory functions. Olfactory and memory assessments might provide complementary information on mediotemporal atrophy prior to clinical dementia onset, but the ɛ4 should be considered when using olfactory assessment as an early-stage indicator.
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| 4. |
- Nilsson, Lars-Göran, 1944-, et al.
(author)
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Challenging the notion of an early-onset of cognitive decline.
- 2009
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In: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 30:4, s. 521-524; discussion 530
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Journal article (other academic/artistic)abstract
- Salthouse claims that cognitive aging starts around 20 years of age. The basis for this claim is cross-sectional data. He dismisses longitudinal data, which typically show the cognitive decline to start much later, around 60 years of age. He states that longitudinal data cannot be trusted because they are flawed. There is a confounding between the effects of maturation and retest effects. We challenge Salthouse's strong claim on four accounts.
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| 5. |
- Vestergren, Peter, 1974-, et al.
(author)
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Development of the cognitive dysfunction questionnaire (CDQ) in a population based sample
- 2011
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In: Scandinavian Journal of Psychology. - Stockholm : Almqvist & Wiksell. - 0036-5564 .- 1467-9450. ; 52:3, s. 218-228
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Journal article (peer-reviewed)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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| 6. |
- Vestergren, Peter, 1974-, et al.
(author)
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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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In: Scandinavian Journal of Psychology. - : Wiley-Blackwell. - 0036-5564 .- 1467-9450. ; 53:5, s. 390-400
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Journal article (peer-reviewed)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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| 7. |
- Wikgren, Mikael, 1981-, et al.
(author)
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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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In: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 33:2, s. 335-344
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Journal article (peer-reviewed)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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| 8. |
- Backeström, A., et al.
(author)
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Glucose metabolism and cognitive dysfunction
- 2010
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In: Abstracts of the EASD, Stockholm 2010. - : Springer Science and Business Media LLC. ; , s. S292-S292
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Conference paper (peer-reviewed)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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| 9. |
- Bergdahl, Jan, et al.
(author)
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Treatment of chronic stress in employees: Subjective, cognitive, and neural correlates.
- 2005
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In: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 46:5, s. 395-402
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Journal article (peer-reviewed)abstract
- This study reports the effect of an affect-focused intervention program, the Affect School (AS), on stress, psychological symptoms, cognitive functioning and neural activity. Fifty employees in social service and education, with high levels of chronic stress, were randomly divided into a treatment (N=27) and control (N=23) group. Complete sets of data were available in 20 participants in the treatment group and in 17 in the control group. The Percieved Stress Questionnaire assessed stress and the Symptom Chech List-90 psychological symptoms before and after the treatment. Episodic-memory functioning under focussed and divided attention conditions was also assessed. Prior and after the AS, seven participants in the treatment group were studied with fMRI during episodic memory processing. After the AS there was a reduction in stress and psychological symptoms for the treatment group but not in the control group. The controls showed a reduction in episodic memory functioning whereas the performance of the treatment group remained intact. The fMRI scanning indicated a qualitative change in the neural network subserving episodic memory. These preliminary results suggest that the AS is effective on individuals with high stress.
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| 10. |
- Bergdahl, Maud, et al.
(author)
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Difference in apolipoprotein E type 4 allele (APOE ɛ4) among dentate and edentulous subjects
- 2008
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In: Gerodontology. - : Wiley. - 0734-0664 .- 1741-2358. ; 25:3, s. 179-186
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Journal article (peer-reviewed)abstract
- Objectives: To evaluate the frequency of apolipoprotein (APOE) alleles and determine whether APOE type 4 allele (ɛ4) was associated with edentulousness even when certain factors were controlled.Background: The APOE are important in lipid homeostasis, and APOE ɛ4 has been found in many diseases and to have a negative impact on longevity. Tooth loss is more common in ill aged subjects with low income and education.Materials and methods: In a population-based study involving 1860 subjects between 35 and 85 years 1321 dentate (mean age = 54; 54% women, 46% men) and 539 edentulous (mean age = 72; 62% women, 38% men) subjects were studied. Logistic regression was performed with dentate/edentulous as dependent variables and years of education, socio-economic status, social network, stress level, handicap from birth, 23 various diseases and APOE ɛ4 as covariates. Thereafter, APOE ɛ4 frequencies were studied in 342 dentate and 336 edentulous subjects 50–85 years of age. The subjects were matched with regard to age, gender, years of education, living condition, stress level, handicap from birth and 23 various diseases.Results: APOE allele frequency in the total group was ɛ2 = 7.8%, ɛ3 = 76.4% and ɛ4 = 15.8%. Age, living condition, years of education and APOE ɛ4 were significant covariates in edentulous subjects (p ≤ 0.001). APOE ɛ4 in the matched groups revealed significant differences between the dentate group and the edentulous group (χ2 = 5.68; p = 0.017). There was no group effect (F(29,648) = 0.849; p < 0.696; Wilks' lambda = 0.963). In the dentate group, the frequencies of APOE were: ɛ2 = 8.8%, ɛ3 = 77.9% and ɛ4 = 13.3%. Corresponding frequencies of APOE in the edentulous group were: ɛ2 = 6.6%, ɛ3 = 75.4% and ɛ4 = 18.0%.Conclusion: Despite matching both groups with regard to different background factors, the edentulous group had a higher frequency of APOE ɛ4 than the dentate group. Thus, genetic factors might contribute to greater risk in developing complex oral diseases leading to tooth loss or just be an indication that the subjects in our study carrying APOE ɛ4 are more fragile.
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