A Life-Course Study of Cognitive Reserve in Dementia--From Childhood to Old Age.

OBJECTIVE: To test a life-course model of cognitive reserve in dementia and examine if school grades around age 10 years, formal educational attainment, and lifetime occupational complexity affect the risk of dementia in old age. METHODS: 7,574 men and women from the Uppsala Birth Cohort Multigenerational Study were followed for 21 years. Information on school performance, formal education, and occupational attainment was collected prospectively from elementary school archives and population censuses. Dementia diagnosis was extracted from the two Swedish registers. Discrete-time Cox proportional hazard models were estimated. RESULTS: Dementia was diagnosed in 950 individuals (12.5%). Dementia risk was lower among individuals with higher childhood school grades (hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.68 to 0.93) and was lower among individuals in data-complex occupations (HR: 0.77; 95% CI: 0.64 to 0.92). Professional/university education predicted lower risk of dementia in minimally adjusted models (HR: 0.74; 95% CI: 0.60 to 0.91), although the effect faded with adjustment for occupational complexity. Lowest risk was found in the group with both higher childhood school performance and high occupational complexity with data (HR: 0.61; 95% CI: 0.50 to 0.75). Importantly, high occupational complexity could not compensate for the effect of low childhood grades. In contrast, dementia risk was reduced in those with higher school grades, irrespective of occupational complexity. CONCLUSION: Higher childhood school performance is protective of dementia risk, particularly when preserved through complex work environments in adulthood, although it will remain protective even in the absence of later-life educational or occupational stimulation

The magnitude of sex differences in verbal episodic memory increases with social progress: Data from 54 countries across 40 years.

Sex differences in episodic memory have been reported. We investigate (1) the existence of sex differences in verbal and other episodic memory tasks in 54 countries, and (2) the association between the time- and country-specific social progress indicators (a) female to male ratio in education and labor force participation, (b) population education and employment, and (c) GDP per capita, and magnitude of sex differences in verbal episodic memory tasks. Data were retrieved from 612 studies, published 1973-2013. Results showed that females outperformed (Cohen's d > 0) males in verbal (42 out of 45 countries) and other (28 out of 45 countries) episodic memory tasks. Although all three social progress indicators were, separately, positively associated with the female advantage in verbal episodic memory performance, only population education and employment remained significant when considering the social indicators together. Results suggest that women's verbal episodic memory performance benefits more than men's from education and employment

Associations of head circumference at birth with early life school performance and later-life occupational prestige

Head circumference at birth has been suggested as a marker of foetal brain development. New-borns with small head size have been shown to have lower intelligence scores in childhood. It is, however, unclear whether this relationship extends into adult life, and more importantly, whether adult status attainment and lifetime success is affected as a result. Furthermore it is unclear how social origin at birth attenuates the relationship between foetal brain development, childhood cognitive outcomes, and lifetime status attainment. Using the Uppsala Birth Cohort Multigenerational Study, a unique population-based database of 14,192 individuals followed from birth into advanced old age, we demonstrate that those born with small head circumference experience reductions in both early-life school performance and lifetime occupational prestige. These effects are not subject to modification by parental social class: small head size at birth is associated with lower grades and lower occupational prestige among individuals born into both advantaged and disadvantaged social classes. Employing causal mediation analysis, we also demonstrate that the link between head circumference at birth and adult occupational prestige is mainly the result of a direct effect, although a portion of this effect is also mediated by early-life school performance which also contributes to occupational attainment trajectories. These findings demonstrate the importance of early-life environments for cognitive development as well as lifetime status attainment

A life-course study of cognitive reserve in dementia: Dementia incidence in inpatient registers and mmse test scores in a clinical study in sweden

Cognitive reserve helps mitigate the impact of pathology on the clinical expression of dementia. Education and occupational complexity are considered as contributors to reserve, although it has been argued that cognitive reserve is likely formed over the life-course. A life-course model of cognitive reserve in dementia risk has not yet been tested. We apply a life-course model and examine if school grades around age 10, formal educational attainment, and lifetime occupational complexity affect dementia incidence in inpatient registers

Sex-di¡erential brain activation during exposure to female and male faces

Sex-discriminating facial features are examples of visual information involved in guiding social behavior. We used functional magnetic resonance imaging (fMRI) to assess brain responses in face-relevant brain areas in men and women during exposure to neutral male and female faces. An increased fMRI signal was found in the left amygdala and adjacent anterior temporal regions in men, but not in women, during exposure to faces of the opposite versus the same sex. These data indicate that the relationship between the sex of the subject and the sex of the face a¡ects activity in the inferior temporal lobe. The sex-di¡erential nature of this activation pattern may re£ect sex di¡erences in cognitive style and attentional processes when confronting faces of the opposite sex

Impact of stuttering as a function of sex and age (Samson et al., 2022)

Purpose: We aimed to cross-sectionally describe the impact of stuttering on persons who stutter (PWS): children, adolescents, and young adults. Based on previous research on PWS and psychosocial health in the general population, we hypothesized that (a) the adverse impact of stuttering in PWS would be larger among adolescents than children and young adults and that (b) females, especially adolescent females, would report being more adversely impacted by their stuttering than males. Method: We pooled samples of Swedish PWS, obtaining 162 individuals (75 females and 87 males), aged 7–30 years. We measured the impact of stuttering using age-relevant versions of the Overall Assessment of the Speaker’s Experience of Stuttering (OASES). The relationship between OASES score, age, and sex was described using a polynomial model with an interaction term between age and sex to allow for potential differences between females and males’ age-related curves. Results: The average trends were that (a) the impact of stuttering was greater for the adolescents than for the children and young adults, and (b) females, especially adolescent females, were on average more impacted by their stuttering than males. Taking self-reported speech fluency into account did not change this pattern. Conclusions: In line with findings on psychosocial health, communication attitude, and self-esteem in the general population, the impact of stuttering seems to be particularly adverse among adolescents, especially female adolescents. Thus, clinicians need to be aware of the risk that young girls who stutter may develop a negative attitude to speech and communication, and this should also be communicated to caregivers and teachers. Supplemental Material S1. Specifications, comparisons, and diagnostics for the regression models used. Samson, I., Schalling, E., Herlitz, A., Lindström, E., & Sand, A. (2022). A cross-sectional investigation of the impact of stuttering on Swedish females and males in childhood, adolescence, and young adulthood. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2022_JSLHR-22-00043</p

Genetic Effects on Old-Age Cognitive Functioning: A Population-Based Study

Associations between genotypes and cognitive outcomes may provide clues as to which mechanisms cause individual differences in old-age cognitive performance. We investigated the effects of five polymorphisms on cognitive functioning in a population-based sample of 2,694 persons without dementia (60-102 years). A structural equation model (SEM) was fit to the cognitive data, yielding five specific latent factors (perceptual speed, episodic memory, semantic memory, category fluency, and letter fluency), as well as a global cognitive factor. These factors showed the expected associations with chronological age. Genotyping was performed for five single-nucleotide polymorphisms that have been associated with cognitive performance: APOE (rs429358), COMT (rs4680), BDNF (rs6265), KIBRA (rs17070145), and CLSTN2 (rs6439886). After controlling for age, gender, and education, as well as correcting for multiple comparisons, we observed negative effects of being an APOE epsilon 4 carrier on episodic memory and perceptual speed. Furthermore, being a CLSTN2 TT carrier was associated with poorer semantic memory. For the global factor, the same pattern of results was observed. In addition, being a BDNF any A carrier was associated with better cognitive performance. Also, older age was associated with stronger genetic effects of APOE on global cognition. However, this interaction effect was partly driven by the presence of preclinical dementia cases in our sample. Similarly, excluding future dementia cases attenuated the effects of APOE on episodic memory and global cognition, suggesting that part of the effects of APOE on old-age cognitive performance may be driven by dementia-related processes