Disparities in Cognition Among U.S. and Foreign-Born Minority Populations With and Without Diabetes

Adults with cognitive limitations and diabetes may be less able to adhere to treatment recommendations. Our aims were to: 1) estimate and compare the prevalence of cognitive limitations and diabetes among foreign-born non-Hispanic whites, blacks, Hispanics, Asians, and Arab Americans to US-born non-Hispanic whites; and 2) examine associations after controlling for covariates. We linked 2002-2016 National Health Interview Survey and 2003-2017 Medical Expenditure Panel Survey data (ages >=45 years, n=122,898). The prevalence of cognitive limitations was highest among foreign-born non-Hispanic whites (9.71%) and Arab Americans (9.40%) and lowest among foreign-born blacks (5.19%). Foreign-born non-Hispanic whites had higher odds (OR=1.36; 95% CI=1.05-1.49) of cognitive limitations than their US-born counterparts. Foreign-born Hispanics with diabetes had greater odds of cognitive limitations (OR=1.91; 95% CI=1.63, 2.24) compared to US-born non-Hispanic whites. Additional findings will be discussed focused on stressors that may contribute to cognition disparities using the immigrant health paradox framework.

Comparing Cognitive and Physical Limitations as Predictors of Depression Among Older Adults

Depression in older adults is associated with loss of functioning and increased mortality. While many factors contribute to depression among this population, activities of daily living (ADL) limitations and cognitive impairment have been identified as key risk factors. However, no study, to our knowledge, has examined the extent to which physical and cognitive limitations independently and jointly contribute to the risk of depression. The current study describes the prevalence and compares the independent and joint associations of these limitations with depression in a nationally representative sample of adults aged 51 and older in the US. Analyses are based on a sample of 17,044 repeated observations on 6,636 unique primary respondents from three waves of pooled data from the Health and Retirement Study. We estimate linear and logistic multivariate regression models investigating the association between ADL limitations (any limitation on Katz ADL scale), cognitive impairment (<12 on the TICS-27 scale), and depressive symptoms (8-item CES-D), controlling for a standard set of socioeconomic and health factors. First, we find that 66% of respondents report no limitations, 16% report only cognitive impairment, 11% report only ADL limitations, and 7% report both types of limitations. Multivariate analyses suggest that ADL limitations have a much stronger association with depression compared to cognitive impairment, and this association is robust across alternative specifications. In next steps, we will take advantage of the longitudinal nature of these data to estimate changes in these characteristics over time and within individuals and explore heterogeneity in associations across relevant groups.

Physical and Cognitive Correlates of GPS-Derived Life-Space Characteristics in Older Adults

Life-space mobility, movement within one’s living environment, is important for functional independence in later life. It is unclear which life-space characteristics (i.e., space, duration, shape) are most affected by physical and cognitive limitations. GPS-derived measures mitigate recall bias and offer novel ways to characterize life-space. We examined associations between physical and cognitive performance and GPS-derived life-space characteristics. Participants were 164 community-dwelling adults (Age: M=77.3±6.5) from baseline data of a clinical trial to improve walking in older adults. Participants carried a portable GPS for 7 days, which passively collected real-time location. Standard deviational ellipses (SDEs) and minimum convex polygons (MCPs) were derived for each day. Area and compactness of these measures quantified activity space and shape, respectively. For each measure, 7-day medians and median absolute deviations (MAD) were computed to capture both central tendency and variability of weekly activity. Activity duration was quantified as percentage of time outside home. Adjusting for age and sex, percent time outside home was associated with lower mobility performance (i.e., 6-minute walk (6MWT), figure 8 walk, ρ’s=.17-.18, p’s<.05) and executive functioning (i.e., Trail Making Test, Part A: ρ=.16, p=.04, Part B: ρ=.19, p=.01). Median MCP and SDE areas, but not compactness, were associated with 6MWT performance (ρ’s=.18-.20, p’s<.05). MCP area MAD was associated with greater global cognition (3MSE, ρ=.15, p=.05). Life-space characteristics were differentially associated with performance measures, suggesting physical and cognitive limitations may constrain life-space mobility via different mechanisms. Variation in these associations by neighborhood walkability and active versus passive travel will also be examined.

Stress, Cognition, and Minority Health

This symposium examines the many factors influencing cognition and health among ethnically and racially diverse groups. Kindratt et al. use representative, national data to examine cognitive limitations and diabetes among foreign born Non-Hispanic Whites, Blacks, Hispanics, Asians and Arab Americans. Results indicate that prevalence of cognitive limitations was highest among non-Hispanic Whites and Arab-Americans, lowest among Blacks and Asians. Diminich et al. investigate the association of stressors and metabolic risk factors with cognitive/emotional functioning in a population of Hispanic/Latina(o) immigrants. They find a link between components of metabolic syndrome that are associated with domain specific deficits in cognition. These impairments are linked to posttraumatic stress, immigration related trauma and emotional health and wellbeing. Arevalo et al. examine cross-sectional and prospective associations of sleep duration and insomnia symptoms with measures of cognitive functioning among older Latinos from Puerto Rican ancestry with a longitudinal sample of older adults from the Boston Puerto Rican Health Study. Findings indicate that hours of sleep and insomnia symptoms are significantly associated with a number of global and specific cognitive factors. Finally, Munoz and colleagues, using a regional racially and ethnically diverse sample of people living in a large northeastern city, identified four stress profiles. These profiles (which focus on different types of stress) were differentially associated with working memory performance. In sum, these four papers document the experiences of stress and their association with cognitive functioning in diverse minority groups each of whom are disproportionately at risk for ADRD/RD. Gerald, from NIA, will serve as discussant.

Less is worse than none: ineffective adaptive foraging can destabilise food webs

Consumers can potentially adjust their diet in response to changing resource abundances, thereby achieving better foraging payoffs. Although previous work has explored how such adaptive foraging scales up to determine the structure and dynamics of food webs, consumers may not be able to perform perfect diet adjustment due to sensory or cognitive limitations. Whether the effectiveness of consumers' diet adjustment alters food-web consequences remains unclear. Here, we study how adaptive foraging, specifically the effectiveness (i.e. rate) with which consumers adjust their diet, influences the structure, dynamics, and overall species persistence in synthetic food webs. We model metabolically-constrained optimal foraging as the mechanistic basis of adaptive diet adjustment and ensuing population dynamics within food webs. We compare food-web dynamical outcomes among simulations sharing initial states but differing in the effectiveness of diet adjustment. We show that adaptive diet adjustment generally makes food-web structure resilient to species loss. Effective diet adjustment that maintains optimal foraging in the face of changing resource abundances facilitates species persistence in the community, particularly reducing the extinction of top consumers. However, a greater proportion of intermediate consumers goes extinct as optimal foraging becomes less-effective and, unexpectedly, slow diet adjustment leads to higher extinction rates than no diet adjustment at all. Therefore, food-web responses cannot be predicted from species' responses in isolation, as even less-effective adaptive foraging benefits individual species (better than non-adaptive) but can harm species' persistence in the food web as a whole (worse than non-adaptive). Whether adaptive foraging helps or harms species coexistence has been contradictory in literature. Our finding that it can stabilise or destabilise the food web depending on how effectively it is performed help reconcile this conflict. Inspired by our simulations, we deduce that there may exist a positive association between consumers' body size and adaptive-foraging effectiveness in the real world. We also infer that such effectiveness may be higher when consumers cognise complete information about their resources, or when trophic interactions are driven more by general traits than by specific trait-matching. We thereby suggest testable hypotheses on species persistence and food-web structure for future research, in both theoretical and empirical systems.

Identifying barriers and problems of physical environment in older adults’ homes: An ergonomic approach

BACKGROUND: The main purpose of ergonomics is environment adaptation to humans, and the root cause of the barriers and problems of the older adults is the mismatch between the home environment and their limitations. OBJECTIVE: The present study aimed to identify and explain physical environment barriers and problems among older adults’ homes in Yazd, Iran. METHODS: This qualitative study was conducted as conventional content analysis. In total, 53 participants including 36 older adults and 17 caregivers were enrolled in the study. The participants were selected using convenience and purposive sampling methods, while the data collection method was a semi-structured interview. The interviews were recorded and transcribed, and then analyzed using MAXQDA11 software. RESULTS: Following data analysis, 268 initial codes were extracted. They were classified into three major categories and 31 sub categories. The main categories are “barriers and problems associated with older adults’ sensory limitations,” “barriers and problems associated with older adults’ motor limitations,” and “barriers and problems associated with older adults’ cognitive limitations.” CONCLUSIONS: Although the data collected from the older adults and their caregivers are in many cases similar, caregivers can provide reasons for the barriers and problems as well as solutions better than the older adults. The data also indicate that most of the problems and barriers are related to motor limitations.

Dolls, Diagrams and Drawings: Interviewers’ Perspectives on Visual Aids in Child Witness Interviews

<p>In cases of child maltreatment child witnesses are often the sole sources of information about the suspected events, meaning their contribution to an investigation is critical. However, children may find recounting their experiences in sufficient detail challenging (Poole & Bruck, 2012). Visual aids are the tools (e.g. diagrams, drawings, and dolls) forensic interviewers often use in interviews to help children remember or describe their experiences and overcome children’s social and cognitive limitations. Research evaluating these aids indicates that any gains in information, reported by children, are typically accompanied by significant increases in false details, thus compromising the accuracy of accounts (Brown, 2011). The purpose of this study was to establish the extent to which interviewers in New Zealand use visual aids with children, and their knowledge of relevant research and the national interviewing protocol. Thirty-one New Zealand Specialist Child Witness Interviewers completed a questionnaire that assessed how and why they use aids, and their knowledge of, and adherence to, the literature and protocols guiding interviewer practice with visual aids. Interviewers’ responses indicated they used a range of aids, with both younger and older children, for a range of reasons, many of which have not been extensively researched. Generally, interviewers had poor knowledge of the existing research and protocol guidelines, and knowledge did not predict adherence to the recommendations. The findings identify the need to educate interviewers about the evidence-base surrounding various aids, as well as conducting research that more closely reflects how aids are used with children.</p>

Dolls, Diagrams and Drawings: Interviewers’ Perspectives on Visual Aids in Child Witness Interviews

<p>In cases of child maltreatment child witnesses are often the sole sources of information about the suspected events, meaning their contribution to an investigation is critical. However, children may find recounting their experiences in sufficient detail challenging (Poole & Bruck, 2012). Visual aids are the tools (e.g. diagrams, drawings, and dolls) forensic interviewers often use in interviews to help children remember or describe their experiences and overcome children’s social and cognitive limitations. Research evaluating these aids indicates that any gains in information, reported by children, are typically accompanied by significant increases in false details, thus compromising the accuracy of accounts (Brown, 2011). The purpose of this study was to establish the extent to which interviewers in New Zealand use visual aids with children, and their knowledge of relevant research and the national interviewing protocol. Thirty-one New Zealand Specialist Child Witness Interviewers completed a questionnaire that assessed how and why they use aids, and their knowledge of, and adherence to, the literature and protocols guiding interviewer practice with visual aids. Interviewers’ responses indicated they used a range of aids, with both younger and older children, for a range of reasons, many of which have not been extensively researched. Generally, interviewers had poor knowledge of the existing research and protocol guidelines, and knowledge did not predict adherence to the recommendations. The findings identify the need to educate interviewers about the evidence-base surrounding various aids, as well as conducting research that more closely reflects how aids are used with children.</p>

Fast but Not Furious. When Sped Up Bit Rate of Information Drives Rule Induction

The language abilities of young and adult learners range from memorizing specific items to finding statistical regularities between them (item-bound generalization) and generalizing rules to novel instances (category-based generalization). Both external factors, such as input variability, and internal factors, such as cognitive limitations, have been shown to drive these abilities. However, the exact dynamics between these factors and circumstances under which rule induction emerges remain largely underspecified. Here, we extend our information-theoretic model (Radulescu et al., 2019), based on Shannon’s noisy-channel coding theory, which adds into the “formula” for rule induction the crucial dimension of time: the rate of encoding information by a time-sensitive mechanism. The goal of this study is to test the channel capacity-based hypothesis of our model: if the input entropy per second is higher than the maximum rate of information transmission (bits/second), which is determined by the channel capacity, the encoding method moves gradually from item-bound generalization to a more efficient category-based generalization, so as to avoid exceeding the channel capacity. We ran two artificial grammar experiments with adults, in which we sped up the bit rate of information transmission, crucially not by an arbitrary amount but by a factor calculated using the channel capacity formula on previous data. We found that increased bit rate of information transmission in a repetition-based XXY grammar drove the tendency of learners toward category-based generalization, as predicted by our model. Conversely, we found that increased bit rate of information transmission in complex non-adjacent dependency aXb grammar impeded the item-bound generalization of the specific a_b frames, and led to poorer learning, at least judging by our accuracy assessment method. This finding could show that, since increasing the bit rate of information precipitates a change from item-bound to category-based generalization, it impedes the item-bound generalization of the specific a_b frames, and that it facilitates category-based generalization both for the intervening Xs and possibly for a/b categories. Thus, sped up bit rate does not mean that an unrestrainedly increasing bit rate drives rule induction in any context, or grammar. Rather, it is the specific dynamics between the input entropy and the maximum rate of information transmission.

The Effect of Physical Exercise on Cognitive Impairment in Neurodegenerative Disease: From Pathophysiology to Clinical and Rehabilitative Aspects

Neurodegenerative diseases are a group of pathologies that cause severe disability due to motor and cognitive limitations. In particular, cognitive impairment is a growing health and socioeconomic problem which is still difficult to deal with today. As there are no pharmacologically effective treatments for cognitive deficits, scientific interest is growing regarding the possible impacts of healthy lifestyles on them. In this context, physical activity is gaining more and more evidence as a primary prevention intervention, a nonpharmacological therapy and a rehabilitation tool for improving cognitive functions in neurodegenerative diseases. In this descriptive overview we highlight the neurobiological effects of physical exercise, which is able to promote neuroplasticity and neuroprotection by acting at the cytokine and hormonal level, and the consequent positive clinical effects on patients suffering from cognitive impairment.