Gender and education impact on brain aging: a general cognitive factor approach

In cognitive aging research, the study of a general cognitive factor has been shown to have a substantial explanatory power over the study of isolated tests. The authors aimed at differentiating the impact of gender and education on global cognitive change with age from their differential impact on 4 psychometric tests using a new latent process approach, which intermediates between a single-factor longitudinal model for sum scores and an item-response theory approach for longitudinal data. The analysis was conducted on a sample of 2,228 subjects from PAQUID, a population-based cohort of older adults followed for 13 years with repeated measures of cognition. Adjusted for vascular factors, the analysis confirmed that women performed better in tests involving verbal components, while men performed better in tests involving visuospatial skills. In addition, the model suggested that women had a slightly steeper global cognitive decline with oldest age than men, even after excluding incident dementia or death. Subjects with higher education exhibited a better mean score for the 4 tests, but this difference tended to attenuate with age for tests involving a speed component.     

Recycling,evolution and the structure of human personality

Lower childhood cognitive ability may be a risk factor for greater cognitive decline in late life and progression to dementia. To assess variation in age-related cognitive change, it is helpful to have valid measures of cognitive ability from early life. Here, we examine the relation between childhood intelligence and cognitive change in later life in two samples, one born in 1921 and the other in 1936. All participants completed the same test of mental ability (one of the Moray House Test series) at age about 11 years, and were re-examined on Raven’s Progressive Matrices at age 77 (1921-born) or age 64 (1936-born). Where possible, the 1921 sample was re-tested at the age of about 80 years old and the 1936 sample re-tested at about 66 years. After taking into account various covariates, including sex, education and occupation, childhood intelligence was a significant predictor of cognitive change in later life. Results were in the direction that participants with lower childhood mental ability experienced relatively greater cognitive decline, whereas those of higher childhood mental ability showed improved performance. This result suggests that higher premorbid cognitive ability is protective of decline in later life.     

Is age kinder to the initially more able?: differential ageing of a verbal ability in the Healthy Old People in Edinburgh study

Studies that examine whether there is differential age-related decline in intelligence test scores according to initial cognitive status, social class and education are reviewed. We tested the differential ageing hypothesis which states that decline in ability scores over time will be lower in those with superior mental ability, more education and higher social class at the time of original testing. 387 healthy old people were tested at baseline and followed up 4 years later. The National Adult Reading Test (NART) was administered on both occasions. NART-estimated IQ fell by a mean of 2.1 points over 4 years (p<0.001). Subjects in higher social class categories had higher NART scores overall (p<0.001), and had smaller NART decrements over 4 years. Ex-professional and -secretarial groups fell by a mean of 1.4 points in this period, versus 3.2 points for skilled manual, semi-skilled and unskilled groups. In addition, those who fell more in NART were older (p=0.001), were less educated (p<0.001), and had lower NART (p<0.001) scores at baseline. In summary, those with higher baseline ability, in higher social class groups, with more education and who are younger are relatively protected from decline in this verbal ability with age. Possible mechanisms of differential decline in this verbal intelligence with age are discussed.     

Studying individual aging in an interindividual context: typical paths of age-related, dementia-related, and mortality-related cognitive development in old age

This study has 2 objectives: (a) to explore typical paths of cognitive development associated with aging, terminal decline, and dementia and (b) to promote and illustrate an individual-oriented approach to the study of cognitive aging based on longitudinal panel data from a population-based sample (N = 500; age range-sub(T1)= 60-80, where T refers to time) tested at 3 occasions 5 years apart. Results document interindividual differences in multivariate patterns of change. Although cognitive changes generally covary, the present study indicates that subgroups of individuals develop along different paths characterized by selective changes in subsets of cognitive functions. Typical progression of dementia followed a developmental cascade from low declarative memory, via low functioning across all observed cognitive measures, to dementia diagnosis, and finally, death.     

Cross-sectional and longitudinal relationships among age, cognition, and processing speed

Cross-sectional and longitudinal age effects on cognitive function were examined in 302 older adults followed longitudinally. Processing speed was related to cognitive performance at cross-section, and change in speed predicted within-person longitudinal cognitive decline. Statistical control of processing speed greatly reduced cross-sectional age effects but did not attenuate longitudinal aging effects. This difference in processing speed's ability to account for cross-sectional and longitudinal age effects is discussed in the context of theories of cognitive aging and methodological and statistical issues pertaining to the cross-sectional and longitudinal study of cognitive aging.     

Relationships Among Education,Age, and Cognitive Functioning in Older African Americans: The Impact of Desegregation

The current study sought to examine whether there were differences in the structure of specific cognitive abilities and their association with age and education in a sample of African American elders with two different early educational experiences. The study was conducted with a sample of 197 community dwelling older adults ranging in age from 50 to 79 years (mean age = 61.50 years, SD = 7.30 years). The sample included 79 individuals who attended a desegregated school at anytime during their formal education, while 118 participants completed their schooling without ever attending a desegregated school. Major results included: (1) typical patterns among cognitive abilities and age as well as years of education were found in the full sample of participants; (2) the pattern of age differences in cognition differed between the two groups. Regarding the latter, the desegregated sample exhibited significant negative age differences for some cognitive abilities, while the segregated group did not. Discussion focuses on the importance of considering the nature of the educational experience when examining cognitive aging in African American elders.     

Modeling memory decline in older adults: the importance of preclinical dementia, attrition, and chronological age

This longitudinal study examined memory loss in a sample of 391 initially nondemented older adults. Analyses decomposed observed memory loss into decline associated with preclinical dementia, study attrition, terminal decline, and chronological age. Measuring memory as a function of only chronological age failed to provide an adequate representation of cognitive change. Disease progression accounted for virtually all of the memory loss in the 25% of the sample that developed diagnosable dementia. In the remainder of the sample, both chronological age and study attrition contributed to observed memory loss. These results suggest that much of memory loss in aging adults may be attributable to the progression of preclinical dementia and other nonnormative aging processes that are not captured by chronological age.     

Performance variability is related to change in cognition: evidence from the Victoria Longitudinal Study

Performance variability across repeated task administrations may be an important indicator of age-related cognitive functioning. In the present investigation, the authors examined whether age differences and change in inconsistency were related to 6-year (3 occasion) cognitive change. Inconsistency scores were computed from 4 reaction time tasks performed by 446 older adults (54-89 years). Replicating previous cross-sectional results, greater inconsistency was observed for older participants even after controlling for differences in response speed. New longitudinal results demonstrated (a) associations between inconsistency at baseline measurement and 6-year change in cognitive performance; (b) longitudinal change in inconsistency; and (c) intraindividual covariation between 6-year change in inconsistency and 6-year change in level of cognitive function. These findings support the view that performance variability serves as a marker of cognitive aging.     

Characteristics of the Florida cognitive activities scale in older African Americans

Substantial research effort has recently focused on the potential protective effect of cognitively demanding activities on cognitive decline in late life. A significant methodological issue in this effort has been the lack of consistency in approaches to the operational measurement of cognitive activity. In this study, data in support of the reliability and construct validity of the recently developed Florida Cognitive Activities Scale (FCAS) in a sample of 223 African American older adults are provided. Consistent with the findings of the Schinka et al. study using a sample of Whites, the FCAS full scale showed a reasonably high level of internal consistency, small negative correlations with age and a measure of depressive symptomatology, and moderate positive correlations with years of education and neuropsychological measures of overall cognitive functioning, memory, and executive functioning. Even after controlling for the effects of age, education, and gender, the full scale score contributed significantly to the prediction of global cognitive functioning. The results of this study suggest that the FCAS is a reliable and valid measure of cognitive activities in older African Americans and provides additional, although not causative, evidence in support of the hypothesis of a protective effect of cognitive activity against cognitive decline regardless of ethnicity or race.     

教育水平在认知老化中的作用

为考察教育水平在认知老化中的作用,分别使用横断数据和干预数据分析教育水平对认知老化的影响模式。对51名58～83岁的城市社区老年人实施加工速度测验和基本心理能力测验。随机选取25名被试作为干预组接受加工速度训练。被试在前测后第8周接受与前测内容相同的后测。横断分析的结果显示,在特定的认知测验中,教育水平对认知能力的年龄差异有调节作用。干预数据的分析结果显示,加工速度干预效果显著,且对词汇流畅性有迁移作用。但相关分析和回归分析的结果则表明,教育水平在促进老年人干预收益和迁移方面的作用不显著。在获取和应用新知识方面,教育水平的作用并不显著,其在认知老化中的作用可能更多地表现为对固有认知功能的保护。     

Influences of preclinical dementia and impending death on the magnitude of age-related cognitive deficits

The authors examined the influence of preclinical dementia and impending death on the cross-sectional relationship between age and performance in tasks assessing episodic memory, visuospatial skill, and verbal fluency. Increasing age was associated with a general decrease in cognitive performance. In addition, those who were to be diagnosed with dementia or had died by a 3-year follow-up, were older, and performed at a lower level than the remaining sample across all cognitive tasks at baseline. Nevertheless, removal of the preclinical dementia and impending death groups from the original sample affected the cross-sectional age-cognition relations relatively little. This pattern of findings suggests that the biological aging process exerts negative influences on cognitive functioning beyond those resulting from disease and mortality.     

认知老化模型的研究

以２３２名２０－７９岁成人为被试和５项认知能力测验为指标,应用结构方程建模方法建立了认知老化模型。     

Basic forms of cognitive plasticity extended into the oldest-old: retest learning, age, and cognitive functioning

To address the question of whether cognitive plasticity varies by age and level of cognitive functioning in the older population, the authors used a self-guided retest paradigm to assess the basic forms of plasticity of 34 young-olds (M=74.4 years, range=70-79) and 34 oldest-olds (M=84.0 years, range=80-91), with half in each age group screened for high or low (midrange) level of cognitive functioning. As a whole, members of the sample represent about the upper two thirds of their age cohorts. Results show persistent, though age-reduced, learning in all samples and across all tests. However, age is not differentially "kinder" to the more able with respect to the age-graded decline in learning.     

An analysis of diversity in the cognitive performance of elderly community dwellers: individual differences in change scores as a function of age.

This longitudinal study investigated whether age is associated with increases in interindividual variability across 4 ability domains using a sample of 426 elderly community dwellers followed over 3.5 years. Interindividual variability in change scores increased with age for memory, spatial functioning, and speed but not for crystallized intelligence for the full sample and in a subsample that excluded dementia or probable dementia cases. Hierarchical regression analyses indicated that being female, having weaker muscle strength, and having greater symptoms of illness and greater depression were associated with overall greater variability in cognitive scores. Having a higher level of education was associated with reduced variability. These findings are consistent with the view that there is a greater range of responses at older ages, that certain domains of intelligence are less susceptible to variation than others and that variables other than age affect cognitive performance in later life.     

Aging of theory of mind: The influence of educational level and cognitive processing

Previous studies of theory of mind (ToM) in old age have provided mixed results. We predicted that educational level and cognitive processing are two factors influencing the pattern of the aging of ToM. To test this hypothesis, a younger group who received higher education (mean age 20.46 years), an older group with an education level equal to that of the young group (mean age 76.29 years), and an older group with less education (mean age 73.52 years) were recruited. ToM tasks included the following tests: the second‐order false‐belief task, the faux‐pas task, the eyes test, and tests of fundamental aspects of cognitive function that included two background tests (memory span and processing speed) and three subcomponents of executive function (inhibition, updating, and shifting). We found that the younger group and the older group with equally high education outperformed the older group with less education in false‐belief and faux‐pas tasks. However, there was no significant difference between the two former groups. The three groups of participants performed equivalently in the eyes test as well as in control tasks (false‐belief control question, faux‐pas control question, faux‐pas control story, and Eyes Test control task). The younger group outperformed the other two groups in the cognitive processing tasks. Mediation analyses showed that difficulties in inhibition, memory span, and processing speed mediated the age differences in false‐belief reasoning. Also, the variables of inhibition, updating, memory span, and processing speed mediated age‐related variance in faux‐pas. Discussion focused on the links between ToM aging, educational level, and cognitive processing.     

Depressive symptoms predict decline in perceptual speed in older adulthood

Depressive symptoms and cognitive decline are associated in older age, but research is inconsistent about whether one condition influences the development of the other. We examined the directionality of relations between depressive symptoms and perceptual speed using bivariate dual change score models. Assessments of depressive symptoms and perceptual speed were completed by 1,206 nondemented older adults at baseline, and after 2, 8, 11, and 15 years. After controlling for age, education, baseline general cognitive ability, and self-reported health, allowing depressive symptoms to predict subsequent change in perceptual speed provided the best fit. More depressive symptoms predicted subsequently stronger declines in perceptual speed over time lags of 1 year.     

Multilingualism and cognitive state in the oldest old

In this study, the authors examined whether the number of languages a person speaks predicts performance on 2 cognitive-screening tests. Data were drawn from a representative sample of the oldest Israeli Jewish population (N = 814, M age = 83.0 years; SD = 5.4) that was interviewed first in 1989 and then twice more within the following 12 years. Cognitive state differed significantly among groups of self-reported bilingual, trilingual, and multilingual individuals at each of the 3 interview waves. Regression analyses showed that the number of languages spoken contributed to the prediction of cognitive test scores beyond the effect of other demographic variables, such as age, gender, place of birth, age at immigration, or education. Multilingualism was also found to be a significant predictor of cognitive state in a group of individuals who acquired no formal education at all. Those who reported being most fluent in a language other than their mother tongue scored higher on average than did those whose mother tongue was their best language, but the effect of number of languages on cognitive state was significant in both groups, with no significant interaction. Results are discussed in the context of theories of cognitive reserve.     

The effect of education on the onset and rate of terminal decline

Differences in the time of onset and magnitude of terminal decline were examined in three cognitive domains: processing speed, episodic memory, and global function. In addition, cognitive reserve was investigated by testing whether education affected the onset or rate of decline across these domains. Eight hundred ninety-six community-dwelling Australian adults aged ≥ 70 years were assessed up to four times over 12 years, with vital status followed for 17 years. For each of the cognitive measures, a series of change point models were fitted across the 20 years before death to find the optimal point at which terminal decline was distinguished from preterminal decline. Change points were then assessed separately for high- and low-education groups. The change points were 8.5 years for processing speed (95% CI: 6.0-11.2 years), 7.1 years for global function (6.2-9.3), and 6.6 years for episodic memory (5.3-7.1). The rate of decline was two to four times greater in the terminal phase relative to the preterminal phase, depending on the domain. Increased education changed the terminal decline effect differently for each of the three tests, either by significantly hastening the onset of terminal decline and decreasing the rate of decline, or by increasing the rate of either preterminal or terminal decline. Analyses were repeated excluding participants diagnosed with dementia, with no substantive change to the outcomes. In conclusion, the rate and onset of terminal decline varied somewhat across cognitive domains. Education affected terminal decline differently across the domains, but this modification was not consistent with the predictions of cognitive reserve theory.     

The association of neighborhood poverty with personality change in childhood

The child sample of the National Longitudinal Survey of Youth (n.d.) was analyzed to examine the relation of undesirable personality change in early childhood to neighborhood economic deprivation. Participants in the survey who had complete data at Time 1 (3-4 years of age) and Time 2 (5-6 years of age) and who remained in the same neighborhood during both time periods were included in the analyses. The results indicated that neighborhood economic disadvantage was associated with undesirable personality change even after controlling for family-level variables such as maternal education, family income, and cognitive and emotional support in the home environment for children. The association of personality change with neighborhood economic deprivation was not mediated by maternal depression, Head Start participation, cognitive and emotional support in the home, or maternal trust in the neighborhood. The authors discuss recommendations for future investigations.