| 1. |
- Herlitz, Agneta, et al.
(författare)
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Cognitive Sex Differences Are Not Magnified as a Function of Age, Sex Hormones, or Puberty Development During Early Adolescence
- 2013
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Ingår i: Developmental Neuropsychology. - : Informa UK Limited. - 8756-5641 .- 1532-6942. ; 38:3, s. 167-179
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Tidskriftsartikel (refereegranskat)abstract
- Are cognitive sex differences magnified by individual differences in age, sex hormones, or puberty development? Cross-sectional samples of 12- to 14-year-old boys (n = 85) and girls (n = 102) completed tasks assessing episodic memory, face recognition, verbal fluency, and mental rotations. Blood estradiol, free testosterone, and self-rated puberty scores were obtained. Sex differences were found on all cognitive measures. However, the magnitude was not larger for older children, hormones and cognitive performance were not associated, and early maturers did not perform better than late maturers. Thus, cognitive sex differences were not associated with age, levels of sex hormones, or puberty development.
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| 2. |
- Karlsson, Sari, et al.
(författare)
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Modulation of striatal dopamine D1 binding by cognitive processing
- 2009
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Ingår i: NeuroImage. - : Elsevier. - 1053-8119 .- 1095-9572. ; 48:2, s. 398-404
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Tidskriftsartikel (refereegranskat)abstract
- There is strong evidence that dopamine (DA) is implicated in higher-order cognitive functioning, but it remains controversial whether D1 receptor binding can be modified by cognitive activity. We examined striatal D1 binding potential (BP) in 20 younger (22-30 years) and 20 older (65-75 years) persons who underwent two [(11)C] SCH 23390 PET measurements, one while resting and one while performing a cognitive task taxing inhibitory functioning. The younger persons showed significant task-related BP reductions in sensorimotor, limbic, and associative striatum during cognitive activity compared to rest. Older persons showed no reliable BP reductions in any striatal subregion. These findings demonstrate that D1 receptor binding can be modified by cognitive activity in younger persons, but also provide novel evidence for the notion that human aging is associated not only with lower DA receptor density but also with altered modifiability of the DA system.
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| 3. |
- Thilers, Petra P., et al.
(författare)
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Accelerated postmenopausal cognitive decline is restricted to women with normal BMI : Longitudinal evidence from the Betula project
- 2010
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 35:4, s. 516-524
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Tidskriftsartikel (refereegranskat)abstract
- In order to determine whether cognitive performance is influenced by the menopausal transition, we tested cognitive performance at three time points, sampled women in earlier as well as later stages of the menopausal transition (40-65 years of age), and assessed the moderating influence of body mass index (BMI) on rate of change. Multilevel analyses were used to model change in cognitive performance as a function of number of years post menopause over and above chronological age. We investigated change in the menopausal transition for 10 cognitive outcomes in 193 women who were postmenopausal during the last test wave. The model, controlling for age and education, showed that postmenopausal women within the normal range of BMI (BMI 18.5-25) displayed more rapid decline than women with BMI above 25 for measures of visuospatial ability and episodic memory. In addition, there was an accelerated rate of change post menopause for all women on verbal fluency. The results support the notion that the diminished postmenopausal production of endogenous estrogen may have a slight negative influence on cognitive abilities, but mainly for women within a normal BMI range.
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| 4. |
- Thilers, Petra
(författare)
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The association between steroid hormones and cognitive performance in adulthood
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis was to investigate whether endogenous estrogen and testosterone were associated with cognitive performance in adulthood and whether hand preference affected the pattern of sex differences in cognitive performance. The analyses in Studies I-IV were based on data from the Betula project in Umeå, Sweden; a population-based longitudinal study on aging and memory. At the second follow-up, there were 3011 participants between 35 and 90 years of age, some entering the project for the first time and others visiting the second or third time. In Study I, the association between endogenous testosterone and cognitive performance was investigated in men and women. We used (a) a reliable hormone assay, (b) a wide range of cognitive measures to discern regular trends in the data, and (c) participants of a wide age range to explore the hypothesized age-testosterone interaction. The results showed a positive association between testosterone and performance on episodic and spatial tasks for men that increased with age. In contrast, there was a negative trend between testosterone and cognitive performance in women. The results show that testosterone has a sex specific effect on cognition, with opposite directional effects observed for men and women. The aim of Study II was to investigate whether there were sex differences in cognitive performance in non-right-handed individuals. Given that the bulk of individuals are righthanded, reports of sex differences are based on the majorities cognitive profile. Earlier studies have found an interaction between sex and hand preference in cognitive performance. Results from Study II revealed that there were sex differences in episodic memory, verbal fluency, and spatial ability among right-handed, but not among non-right-handed individuals. Non-right-handed men tended to perform better on verbal tasks and lower on the spatial task in contrast to right-handed men. Furthermore, non-right-handed women showed the reverse pattern, with lower verbal and higher spatial performance as compared to right-handed women. Tentatively, these data suggest atypical lateralization pattern for right-handed and non-right-handed individuals. In Studies III and IV, the aim was to investigate whether the diminishing levels of estrogen in menopause were associated with cognitive decline. When cross-sectional data was investigated in Study III, no association between menopause phase and cognitive performance was found. In Study IV, longitudinal data was explored to investigate whether cognitive performance changed systematically for women passing through menopause, independent of age-related change in cognition. Results indicate that post-menopausal women show accelerated decline, or less gain, on tasks that measure spatial ability, verbal fluency, and episodic memory. The association between estrogen and accelerated rate of change was most pronounced in normal weight women. This association may reflect the fact that estrogen is largely produced in fat tissue post menopause, with women with higher body mass index (BMI) values having higher levels of estrogen. This thesis shows that (a) there is a positive association between testosterone and cognitive performance in men, a relationship that increases with increasing age, (b) there are no sex differences in cognition in groups of non-right-handed individuals, (c) cognitive performance does not differ between groups of pre-, peri-, and postmenopausal women, but (d) following menopause, women reveal a higher rate of change for some cognitive measures independent of age-related cognitive change, an effect that is chiefly observed for women with normal BMI.
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