Objective Clinic-based studies suggest that dementia is diagnosed at older ages in bilinguals compared to monolinguals. The current study sought to test this hypothesis in a large, prospective, community-based study of initially non-demented Hispanic immigrants living in a Spanish-speaking enclave of Northern Manhattan. Method Participants included 1,067 participants in the Washington/Hamilton Heights Inwood Columbia Aging Project (WHICAP) who were tested in Spanish and followed at 18–24 month intervals for up to 23 years. Spanish-English bilingualism was estimated via both self-report and an objective measure of English reading level. Multilevel models for change estimated the independent effects of bilingualism on cognitive decline in four domains: episodic memory, language, executive function, and speed. Over the course of the study, 282 participants developed dementia. Cox regression was used to estimate the independent effect of bilingualism on dementia conversion. Covariates included country of origin, gender, education, time spent in the United States, recruitment cohort, and age at enrollment. Results Independent of the covariates, bilingualism was associated with better memory and executive function at baseline. However bilingualism was not independently associated with rates of cognitive decline or dementia conversion. Results were similar whether bilingualism was measured via self-report or an objective test of reading level. Conclusions This study does not support a protective effect of bilingualism on age-related cognitive decline or the development of dementia. In this sample of Hispanic immigrants, bilingualism is related to higher initial scores on cognitive tests and higher educational attainment and may not represent a unique source of cognitive reserve.

Unawareness of memory loss is a challenging characteristic of Alzheimer’s disease (AD) and other age-related neurodegenerative conditions at their earliest stages, adversely affecting important outcomes such as patient decision making and safety. The basis of this metacognitive disturbance has been elusive; however it is almost certainly determined in part by compromise to brain regions critical for self-assessment. The subjectivity of traditional measurements of self-awareness in dementia has likely limited the rigor with which its neuroanatomic correlates can be established. Here we objectively measure memory awareness (metamemory) using a Feeling of Knowing (FOK) task in a group of cognitively diverse older adults, including 14 with mild AD and 20 cognitively healthy older adults. Performance on the metamemory task was examined in relation to the structural integrity of 14 bilateral neuroanatomic regions hypothesized to support self-awareness. Less accurate metamemory was associated only with reduced right insular volume (r = .41, p = .019). Implications of the current findings for models of metacognitive aging are discussed, with attention to the role of the insula in the conscious detection of errors.

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Background Subjective Cognitive Decline (SCD) is increasingly considered promising to detect preclinical Alzheimer’s disease. How SCD is ascertained is critical for determining its potential utility in identifying at-risk individuals, yet SCD measures differ along several dimensions. Objective We aimed to examine the extent to which reports of SCD in healthy elders (HE) may be influenced by the characteristics of the SCD measures. We investigated variations in rates of SCD endorsement across different measures, including an open-ended question. We also examined the association of responses across measures, and the degree to which specific SCD items were associated with objective memory performance. Methods 99 HE completed a series of questionnaires from which 10 items examining SCD for memory and other aspects of cognition were drawn. We applied Cochran’s Q tests to assess differences in rates of SCD, correlation analyses to examine association of SCD responses and regression models to determine the association between SCD items and delayed verbal memory. Results Rates of SCD varied as a function of the assessment format, ranging from 1 to 7 % for memory and 5 to 20% for concentration. SCD was lower for memory versus non-memory domains. SCD items were associated both within and across domains. The most accurate predictor of memory was memory-related SCD in comparison to others the same age. Conclusion Characteristics of SCD items influence rates of endorsement. Querying SCD using an “age-anchored” question may provide the most accurate reflection of actual cognitive performance.

Background Several theories seek to explain how social connections and cognitive function are interconnected in older age. These include that social interaction protects against cognitive decline, that cognitive decline leads to shedding of social connections and that cognitive decline leads to increased instrumental support. We investigated how patterns of social contact, social support and cognitive health in rural South Africa fit with these three theories. Method We used data from the baseline of “Health and Aging in Africa: a Longitudinal Study of an INDEPTH community in South Africa” (HAALSI), a population-based study of 5059 individuals aged ≥ 40 years. We evaluated how a range of egocentric social connectedness measures varied by respondents' cognitive function. Results We found that respondents with lower cognitive function had smaller, denser social networks that were more local and more kin-based than their peers. Lower cognitive function was associated with receipt of less social support generally, but this difference was stronger for emotional and informational support than for financial and physical support. Impairment was associated with greater differences among those aged 40–59 and those with any (versus no) educational attainment. Conclusions The patterns we found suggest that cognitively impaired older adults in this setting rely on their core social networks for support, and that theories relating to social connectedness and cognitive function developed in higher-income and higher-education settings may also apply in lower-resource settings elsewhere.