| 1. |
- Melke, Jonas, 1971, et al.
(author)
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A polymorphism in the serotonin receptor 3A (HTR3A) gene and its association with harm avoidance in women.
- 2003
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In: Archives of general psychiatry. - : American Medical Association (AMA). - 0003-990X. ; 60:10, s. 1017-23
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Journal article (peer-reviewed)abstract
- BACKGROUND: The brain neurotransmitter serotonin is known to affect various aspects of human behavior, including personality traits. Serotonin receptor type 3 is a ligand-gated channel encoded by 2 different subunit genes, HTR3A and HTR3B. A polymorphism (C178T) in the 5' region of the HTR3A gene has recently been identified and suggested to be of functional importance. OBJECTIVE: To elucidate the possible association between the C178T polymorphism in the HTR3A gene and personality traits in women. DESIGN: Two independent samples of 35- to 45-year-old Swedish women were recruited using the population register. Sample 1 (n = 195) was assessed via the Karolinska Scales of Personality and the Temperament and Character Inventory; sample 2 (n = 175) was assessed using the latter only. Both samples were genotyped with respect to the C178T polymorphism in the HTR3A gene. The A1596G polymorphism in the same gene was also investigated. RESULTS: A significant association between C178T genotype and the Temperament and Character Inventory factor harm avoidance was observed in sample 1 (corrected for multiple comparisons P =.04); this finding was subsequently replicated in sample 2 (P =.004) (pooled populations: P<.001). In the pooled sample, all harm avoidance subscales were found to be significantly associated with the C178T polymorphism: anticipatory worry (P =.001), fear of uncertainty (P<.001), shyness (P<.001), and fatigability and asthenia (P =.008). In addition, a significant association was found in sample 1 between the C178T polymorphism and the Karolinska Scales of Personality nonconformity factor (corrected P =.002), including the subscales of social desirability (P<.001), indirect aggression (P =.002), verbal aggression (P =.05), and irritability (P<.001). Participants homozygous for the less common T allele (<4%) differed from the remaining women by displaying lower ratings on harm avoidance and nonconformity. CONCLUSION: The C178T polymorphism in the HTR3A gene may affect the personality trait of harm avoidance in women.
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| 2. |
- Lövdén, Martin, et al.
(author)
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The extent of stability and change in episodic and semantic memory in old age : Demographic predictors of level and change
- 2004
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In: The journals of gerontology. Series B, Psychological sciences and social sciences. - Washington, DC : Gerontological Society of America. - 1079-5014 .- 1758-5368. ; 59:3, s. 130-134
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Journal article (peer-reviewed)abstract
- Structural stability and change in semantic and episodic memory performance as well as interindividual differences in 5-year changes in these constructs are examined within a sample of older adults (age rangeT1 = 60–80; n = 361). Interindividual differences in change were limited but significant. Stability coefficients were higher for semantic memory (.95) than for episodic memory (.87). Changes in episodic and semantic memory performance were strongly associated (r =.68). Across time, variances and covariances increased, and a tendency toward dedifferentiation in terms of increasing correlations was found. Chronological age was related to both level and change, but gender and education were only related to level of memory performance. Collectively, these results depict relatively high degrees of structural stability and stability of interindividual differences in declarative memory in old age.
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| 3. |
- Maitland, Scott B, et al.
(author)
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Selective sex differences in declarative memory.
- 2004
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In: Mem Cognit. - : Springer Science and Business Media LLC. - 0090-502X .- 1532-5946. ; 32:7, s. 1160-9
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Journal article (peer-reviewed)abstract
- Sex invariance of a six-factor, higher order model of declarative memory (two second-order factors: episodic and semantic memory; and four first-order factors: recall, recognition, fluency, and knowledge) was established for 1,796 participants (35-85 years). Metric invariance of first- and second-order factor loadings across sex was demonstrated. At the second-order level, a female advantage was observed for both episodic and semantic memory. At the first-order level, sex differences in episodic memory were apparent for both recall and recognition, whereas the differences in semantic memory were driven by a female superiority in fluency. Additional tests of sex differences in three age groups (35-50, 55-65, and 70-85 years of age) indicated that the female superiority in declarative memory diminished with advancing age. The factor-specific sex differences are discussed in relation to sex differences in hippocampal function.
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| 4. |
- Nilsson, Lars-Göran, et al.
(author)
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Betula : a prospective cohort study on memory, health and aging
- 2004
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In: Aging, Neuropsychology and Cognition. - Hove : Psychology Press. - 1382-5585 .- 1744-4128. ; 11:2-3, s. 134-148
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Journal article (peer-reviewed)abstract
- This article describes the Betula Study with respect to objectives, design, participants, and assessment instruments for health and cognition. Three waves of data collection have been completed in 5-year intervals since 1988-1990. A fourth wave started in 2003 and will be completed in 2005. An overview of Betula research is presented under the headings of memory and cognition and cognitive neuroscience. Health-related issues and sex differences as well as comparisons between cross-sectional and longitudinal studies are discussed in the first section. The influence of different genes and of some brain abnormalities for memory functioning in adulthood and old age constitute main topics in the second section. New data are presented on the association between blood pressure and dementia. We demonstrated that a demented group of participants had higher levels of systolic blood pressure and pulse pressure than non-dementia controls 10 years before diagnosis. The new fourth wave of data collection will, in addition to enriching the Betula database, permit revisiting and reanalyzing the existing data from new perspectives.
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| 5. |
- de Frias, Cindy M, et al.
(author)
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COMT gene polymorphism is associated with declarative memory in adulthood and old age.
- 2004
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In: Behavior genetics. - New York : Kluwer Academic Publishers. - 0001-8244 .- 1573-3297. ; 34:5, s. 533-9
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Journal article (peer-reviewed)abstract
- Variation in memory performance is to a large extent explained by genes. In the prefrontal cortex, the catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine, a neurotransmitter implicated in cognitive functions. The present study examined the effect of a polymorphism in the COMT gene on individual differences and changes in memory in adulthood and old age. Tests assessing episodic and semantic memory were administered to 286 men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula prospective cohort study) at two occasions followed over a 5-year period. Carriers of the Met/Met genotype (with low enzyme activity) performed better on episodic and semantic memory, as compared to carriers of the Val allele (with higher enzyme activity). Division of episodic memory into its recall and recognition components showed that the difference was specific to episodic recall, not recognition tasks; an effect that was observed across three age groups (middle-age, young-old, and old-old adults) and over a 5-year period. The COMT gene is a plausible candidate gene for memory functioning in adulthood and old age.
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| 8. |
- Persson, Jonas, 1971-, et al.
(author)
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The memory-enhancing effects of Ginseng and Ginkgo biloba in healthy volunteers
- 2004
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In: Psychopharmacology. - Berlin : Springer-Verlag. - 0033-3158 .- 1432-2072. ; 172:4, s. 430-434
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Journal article (peer-reviewed)abstract
- Rationale: The use of herbal remedies, such as Ginkgo biloba and Ginseng, for improving cognitive performance has become increasingly popular during recent years. Several previous studies have indicated that administration of Ginkgo biloba and Ginseng may improve aspects of learning and memory in healthy volunteers. These results, however, are generally not supported by well-controlled clinical studies. Also, positive results have often been reported from studies investigating effects related to short-term, chronic administration of the extract. Nonetheless, both Ginkgo biloba and Ginseng are marketed as having the capacity to enhance cognitive functions, such as memory and learning, in the long term. Objective: This study aimed at investigating whether the use of Ginkgo biloba and Ginseng for a long period of time has positive effects on performance on learning and memory. Methods: Community-dwelling volunteers ( n=3500) from The Betula prospective cohort study: memory, health, and aging were included in the study. Results: It was found that the use of neither Ginkgo biloba ( n=40) nor Ginseng ( n=86) was associated with enhanced memory performance in any of the eight memory tests examined, relative to control groups either using or not using nutritional supplements. Conclusions: These findings indicate that use of Ginkgo biloba or Ginseng does not provide any quantifiable beneficial effects on memory performance in the long-term in healthy adult volunteers.
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| 9. |
- Sundström, Anna, 1969-, et al.
(author)
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APOE influences on neurosychological function after mild head injury : within-person comparisons
- 2004
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In: Neurology. - Minneapolis, Minn : Lancet Publications Inc.. - 0028-3878 .- 1526-632X. ; 62:11, s. 1963-1966
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Journal article (peer-reviewed)abstract
- Objective: To examine the relationship between neuropsychological outcome following mild head injury (MHI) and APOE genotype. Methods: Data from a population-based longitudinal study (n = 3,500) were used to identify 34 adults who experienced MHI during the course of the study. Their pre- and postinjury performances on a battery of nine neuropsychological tests were compared within person, and the postinjury performance was compared with that of age- and gender-matched control subjects. Results: The within-person comparisons showed that participants with at least oneAPOE ε4 allele (n = 11) had a significantly decreased postinjury performance on three of the tests, whereas the postinjury performance for APOE ε4-negative participants (n = 23) was unchanged. There was no significant difference in postinjury performance between participants with/without the ε4 allele, and neither group was impaired relative to controls. Conclusions: APOE genotype may influence the outcome following an MHI. Pre/postinjury within-person comparisons seem more sensitive than control group comparisons for detecting injury-related effects.
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