| 11. |
- 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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| 12. |
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| 13. |
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| 14. |
- Nyberg, Lars, 1966-
(författare)
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Functional imaging studies of intentional and incidental reactivation : implications for the binding problem
- 2012
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Ingår i: Handbook of binding and memory. - : Oxford University Press. - 9780191689680 - 0198529678 - 9780198529675 ; , s. 516-526
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Bokkapitel (refereegranskat)abstract
- A remarkable feature of memory is its ability to group related experiences and differentiate them from the wealth of other, often similar, experiences that are also stored. In effect, when we see the face of a person we know we may recall his or her profession, we may recollect events that occurred when we last met the person, and certain feelings and bodily states which relate to how we feel about the person may be induced. The issue of how information that belongs to the same experience is bound in memory has attracted substantial interest. This chapter reviews studies which support the view that the way the brain is activated during the initial perception-encoding of an event is in part reproduced when episodic information is subsequently retrieved. In other words, the activity pattern at encoding is reactivated in test conditions. These observations of reactivation, in particular incidental reactivation, have potential implications for our understanding of the binding problem.
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| 15. |
- Sandberg, Petra, 1979-, et al.
(författare)
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Executive process training in young and old adults
- 2014
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Ingår i: Aging, Neuropsychology and Cognition. - : Taylor & Francis. - 1382-5585 .- 1744-4128. ; 21:5, s. 577-605
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Tidskriftsartikel (refereegranskat)abstract
- There is a growing body of research on the modifiability of executive functions in different stages of life. Previous studies demonstrate robust training effects but limited transfer in younger and particularly in older adults. The aim of the present study was to investigate whether a theoretically derived intervention for executive functioning, addressing several basic processes (updating, shifting, and inhibition), can induce transfer effects in early and late adulthood. Fifty-nine healthy adults, 29 young and 30 older adults, were randomly assigned to either training or no-contact control groups. The training groups received 15 sessions of executive process training for about 45 min/session during 5 weeks. A test battery including a criterion task and near, intermediate, and far transfer tasks was administered before and after training. Results showed pronounced age-equivalent gains on the criterion task. Near transfer was seen to non-trained updating and inhibition tasks for the young and older trained participants. However, only the young adults showed intermediate transfer to two complex working memory tasks. No far transfer effects were seen for either age group. These findings provide additional evidence for age-related constraints in the ability to generalize acquired executive skills, and specifically show that training of multiple executive processes is not sufficient to foster transfer beyond the very near in older adults.
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| 16. |
- Sandström, Agneta, 1959-, et al.
(författare)
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Cognitive deficits in relation to personality type and hypothalamic-pituitary-adrenal (HPA) axis dysfunction in women with stress-related exhaustion
- 2011
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Ingår i: Scandinavian Journal of Psychology. - Oxford : Wiley-Blackwell. - 0036-5564 .- 1467-9450. ; 52:1, s. 71-82
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Tidskriftsartikel (refereegranskat)abstract
- Exhaustion caused by long-term work-related stress may cause cognitive dysfunction. We explored factors that may link chronic stress and cognitive impairment. Personality, psychiatric screening, and behavior were assessed by self-reporting measures in 20 female patients (mean age 39.3 years; range 26–53) with a preliminary diagnosis of stress-related exhaustion and in 16 healthy matched controls. Cognitive performance was investigated with a detailed neuropsychological test battery. Cortisol axis function was assessed by urinary and saliva collections of cortisol, dexamethasone suppression, Synacthen response, and corticotropin-releasing hormone (CRH) tests. Proinflammatory cytokines were measured. Hippocampal volumes were estimated by magnetic resonance imaging. Multivariate and univariate statistical methods were used to explore putative differences between groups and factors linked to cognitive impairment. Cognitive function clearly differed between groups, with decreased attention and visuospatial memory in the patient group, suggesting frontal cortex/medial temporal cortex-network dysfunction. Increased harm avoidance and persistence was present among patients, with lowered self-directedness linked to lower quality of life, increased anxious and depressive tendencies, and experiences of psychosocial stress. Attention was decreased with concomitantly impaired visuospatial memory. The pituitary (adrenocorticotropic hormone, ACTH) response to CRH was decreased in patients, with an increased cortisol/ACTH response to CRH. However, cortisol production rates, diurnal or dexamethasone-suppressed saliva cortisol levels, and the cortisol response to Synacthen were unaltered. Hippocampal volumes did not differ between groups. These findings suggest that cognitive dysfunction in stress-related exhaustion is linked to distinct personality traits, low quality of life, and a decreased ACTH response to CRH.
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| 17. |
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| 18. |
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| 19. |
- Vestergren, Peter, 1974-, et al.
(författare)
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Testing alters brain activity during subsequent restudy : Evidence for test-potentiated encoding
- 2014
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Ingår i: Trends in Neuroscience and Education. - : Elsevier. - 2211-9493. ; 3:2, s. 69-80
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Tidskriftsartikel (refereegranskat)abstract
- Mixed testing/studying lead to better memory retention compared to repeated study only. A potentiating influence of tests on encoding, particularly during restudy of non-retrieved items, may contribute to this effect. This study investigated whether and how testing affects brain activity during subsequent restudy of Swahili–Swedish word pairs after a cued-recall test. Item-events during fMRI were categorized according to history (tested/studied only) and recall outcome at prescan and postscan tests. Activity was higher for tested compared to studied-only items in anterior insula, orbital parts of inferior frontal gyrus and hippocampus, and lower in regions implicated in the default network, such as precuneus, supramarginal gyrus and the posterior middle cingulate. Findings are discussed in terms of top-down biasing of attention to tested items with concomitant deactivation of regions in the default network. Increased/focused attention to tested items during restudy may lead to test-potentiated encoding via deeper semantic processing and increased associative binding.
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