An examination of dedifferentiation in cognition among African-American older adults.

Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC, USA.
Journal of Cross-Cultural Gerontology 10/2008; 24(2):193-208. DOI: 10.1007/s10823-008-9080-8
Source: PubMed

ABSTRACT The structure and organization of cognitive abilities has been examined across the life span. The current analysis had three specific aims: (1) test the factor structure of a broad cognitive ability battery across three age groups; (2) examine differences in the pattern of factor covariation across age groups; and (3) examine the pattern of factor mean differences across age groups. A sample of 512 older African Americans (mean age = 66.6 years, 25.4% male) from the Baltimore Study of Black Aging was administered a battery of cognitive tests assessing the domains of perceptual speed, verbal memory, inductive reasoning, vocabulary, and working memory. Factor models were estimated separately in middle-age adults (50-59 years, n = 107), young-old adults (60-69 years, n = 198), and old-old adults (70-79 years, n = 207). There was loading invariance across the three age groups that suggests that the selected tests measured cognition similarly across age. There was no evidence of dedifferentiation across increasingly older age groups. Factor mean differences were observed with the middle-age group having significantly higher factor means than the young-old and old-old groups; however, there was only one factor mean difference between the young-old and the old-old groups. The results suggest that a pattern of dedifferentiation of cognitive abilities does not exist within this sample of older African Americans and that the 60-69 year age range may be a critical period for cognitive decline in this population.

Download full-text


Available from: Jason C Allaire, Jul 28, 2015
  • Source
    • "ies find such differences in cognitive performance between the group of young – old adults and old – old adults , reporting good levels of performance in both cases ( Colcombe and Kramer , 2003 ; Sims et al . , 2009 ) . However , this is probably because these studies usually fix the boundary between young – old adults and old – old adults at 70 ( Sims et al . , 2009 ) , i . e . , at too young an age for such differences to be revealed . One finding which appears systematically throughout the literature is the fact that as age advances , a corresponding increase arises both in levels of dependency and in the probability of developing dementia . The passage of time is thus one of the factors most clo"
    [Show abstract] [Hide abstract]
    ABSTRACT: The main objective of this study was to analyze the similarities and differences in cognitive performance, level of dependency, cognitive plasticity and QoL in a sample of young-old adults and old-old adults, bearing in mind both the age-group (under or over 80 years) and the cognitive status of the participants. The study population consisted of 220 people living in sheltered accommodation for elderly people in the South of Spain, with an average age of 80.75 years. Participants were evaluated by means of cognitive performance tests, a QoL questionnaire, a depression scale and a dependency assessment scale. The results indicate that the main differences in the variables analyzed are due to the cognitive status of the sample and not to the fact that the participants are under or over 80 years of age. The findings show that major inter-individual differences in this stage of life depend not only on age but also on cognitive status, which is thus an important factor to take into account when working with this sector of the population.
    Archives of gerontology and geriatrics 12/2010; 53(3):292-7. DOI:10.1016/j.archger.2010.11.030 · 1.53 Impact Factor
  • Source
    • "Some cross-sectional studies have provided empirical support for cognitive dedifferentiation in older adults (Babcock, Laguna, & Roesch, 1997; Baltes et al., 1980; Hertzog, & Bleckley, 2001). In other cross-sectional studies, contrary findings, i.e., a differentiation of cognitive abilities with age, have been reported (Cunningham, Clayton, & Overton, 1975; Schmidt, & Botwinick, 1989; Tomer, & Cunningham, 1993, Tucker-Drob & Salthouse, 2008), or results supported neither differentiation nor dedifferentiation (Bickley, Keith, & Wolfe, 1995; Cunningham, & Birren, 1980; Juan-Espinosa et al., 2000; Juan-Espinosa et al., 2002; Park et al., 2002; Sims, Allaire, Gamaldo, Edwards & Whitfield, 2009). Thus, the question of dedifferentiation appears to represent an unresolved issue in cross-sectional data. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study examined five aspects of change (or stability) in cognitive abilities in middle adulthood across a 12-year period. Data come from the Interdisciplinary Study on Adult Development. The sample consisted of N=346 adults (43.8years on average, 48.6% female). In total, 11 cognitive tests were administered to assess fluid and crystallized intelligence, memory, and processing speed. In a first series of analyses, strong measurement invariance was established. Subsequently, structural stability, differential stability, stability of divergence, absolute stability, and the generality of changes were examined. Factor covariances were shown to be equal across time, implying structural stability. Stability coefficients were around .90 for fluid and crystallized intelligence, and speed, indicating high, yet not perfect differential stability. The coefficient for memory was .58. Only in processing speed the variance increased across time, indicating heterogeneity in interindividual development. Significant mean-level changes emerged, with an increase in crystallized intelligence and decline in the other three abilities. A number of correlations among changes in cognitive abilities were significant, implying that cognitive changes in middle adulthood share up to 50 percent of variance. KeywordsCognitive change-Middle adulthood-Measurement invariance-Intraindividual change-Interindividual change
    European Journal of Ageing 09/2010; 7(3):135-146. DOI:10.1007/s10433-010-0161-5 · 1.27 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: African Americans are disproportionately affected by hypertension. The goal here was to better understand the relationship between well-being and environmental factors and their influence on hypertension. It was hypothesized that there would be a positive association among perceived stress, depression, and hypertension mediated by social support. Data from 2 sample populations were included: the Carolina African American Study of Aging (N = 395) and the Baltimore Study of Black Aging (N = 602) provided information on demographics, perceived stress, social support, depression, and hypertension. Regression analysis was used to examine the hypothesis. Significant relationships were found between perceived stress/depression and hypertension. The relationship between depression and hypertension was partially mediated by social support (given), while the relationship between depression and hypertension was not. Our findings suggest that the impact of stress and hypertension is mediated by individual coping strategies. Given the excess stress and hypertension experienced by African Americans, coping may be a particularly salient factor in longevity. Future research should provide insight about specific aspects of coping and other personal characteristics that facilitate and limit the effect of coping on hypertension.
    Journal of the National Medical Association 02/2011; 103(2):116-22. · 0.91 Impact Factor
Show more