12 research outputs found
Effortful Cognitive Resource Allocation and Negative Symptom Severity in Chronic Schizophrenia
Background: The relationship between negative symptoms, early visual information–processing deficits, and effortful processing resource allocation was investigated. Methods: Older patients with chronic schizophrenia (n = 58) and healthy controls (n = 71) participated. Pupillary responses were recorded during performance of the span of apprehension task (blocks of 3- and 10-letter arrays) as an index of resource allocation or mental effort during the task. Results: Patients and controls showed larger pupillary responses in higher relative to lower processing loads both during array processing and just prior to array onset (preparation). Both groups, therefore, invested more cognitive effort preparing for and then processing larger arrays. A subgroup of patients with abnormally small pupillary responses and impaired performance showed greater negative symptom severity relative to a subgroup of patients with normal pupillary responses. Smaller pupillary responses in the patients were also significantly correlated with greater negative symptom severity, independent of positive symptom severity. Patients with reduced effortful resource allocation, therefore, exhibited greater negative symptomatology. A subgroup of patients with normal pupillary responses still showed impaired detection accuracy relative to controls, suggesting that reduced cognitive effort or resource allocation problems cannot account for impairments in early visual information processing in this subgroup. Conclusions: The study illustrates important relationships between cognitive effort and performance that can impact conclusions about the nature of cognitive impairments and associations between negative symptoms and neurocognition in schizophrenia
Control of rodent and human spatial navigation by room and apparatus cues
A growing body of literature indicates that rats prefer to navigate in the direction of a goal in the environment (directional responding) rather than to the precise location of the goal (place navigation). This paper provides a brief review of this literature with an emphasis on recent findings in the Morris water task. Four experiments designed to extend this work to humans in a computerized, virtual Morris water task are also described. Special emphasis is devoted to how directional responding and place navigation are influenced by room and apparatus cues, and how these cues control distinct components of navigation to a goal.Experiments 1 and 2 demonstrate that humans, like rats, perform directional responses when cues from the apparatus are present, while Experiment 3 demonstrates that place navigation predominates when apparatus cues are eliminated. In Experiment 4, an eyetracking system measured gaze location in the virtual environment dynamically as participants navigated from a start point to the goal.Participants primarily looked at room cues during the early segment of each trial, but primarily focused on the apparatus as the trial progressed, suggesting distinct, sequential stimulus functions. Implications for computational modeling of navigation in the Morris water task and related tasks are discussed
Lower body functioning and correlates among older American Indians: The Cerebrovascular Disease and Its Consequences in American Indians Study
Abstract Background More than six million American Indians live in the United States, and an estimated 1.6 million will be aged ≥65 years old by 2050 tripling in numbers since 2012. Physical functioning and related factors in this population are poorly understood. Our study aimed to assess lower body functioning and identify the prevalence and correlates of “good” functioning in a multi-tribe, community-based sample of older American Indians. Methods Assessments used the Short Physical Performance Battery (SPPB). “Good” lower body functioning was defined as a total SPPB score of ≥10. Potential correlates included demographic characteristics, study site, anthropometrics, cognitive functioning, depressive symptomatology, grip strength, hypertension, diabetes mellitus, heart disease, prior stroke, smoking, alcohol use, and over-the-counter medication use for arthritis or pain. Data were collected between 2010 and 2013 by the Cerebrovascular Disease and Its Consequences in American Indians Study from community-dwelling adults aged ≥60 years (n = 818). Results The sample’s mean age was 73 ± 5.9 years. After adjustment for age and study site, average SPPB scores were 7.0 (95% CI, 6.8, 7.3) in women and 7.8 (95% CI, 7.5, 8.2) in men. Only 25% of the sample were classified with “good” lower body functioning. When treating lower body functioning as a continuous measure and adjusting for age, gender, and study site, the correlates of better functioning that we identified were younger age, male gender, married status, higher levels of education, higher annual household income, Southern Plains study site, lower waist-hip ratio, better cognitive functioning, stronger grip strength, lower levels of depressive symptomatology, alcohol consumption, and the absence of hypertension, diabetes mellitus, and heart disease. In our fully adjusted models, correlates of “good” lower body functioning were younger age, higher annual household income, better cognitive functioning, stronger grip, and the absence of diabetes mellitus and heart disease. Conclusions These results suggest that “good” lower body functioning is uncommon in this population, whereas its correlates are similar to those found in studies of other older adult populations. Future efforts should include the development or cultural tailoring of interventions to improve lower body functioning in older American Indians
“Improving Native American elder access to and use of health care through effective health system navigation”
Abstract Background Public insurance reforms of the past two decades have failed to substantively address the healthcare needs of American Indians in general, let alone the particular needs of American Indian elders, ages 55 years and older. Historically, this population is more likely to be uninsured and to suffer from greater morbidities, poorer health outcomes and quality of life, and lower life expectancies compared to all other United States aging populations, representing a neglected group within the healthcare system. Despite the pervasive belief that the Indian Health Service will address all their health-related needs, American Indian elders are negatively affected by gaps in insurance and lack of access to health care. While the 2010 Patient Protection and Affordable Care Act included provisions to ameliorate disparities for American Indians, its future is uncertain. In this context, American Indian elders with variable health literacy must navigate a complex and unstable healthcare system, regardless of where they seek care. Methods This community-driven study features a mixed-method, participatory design to examine help-seeking behavior and healthcare experiences of American Indian elders in New Mexico, in order to develop and evaluate a tailored intervention to enhance knowledge of, access to, and use of insurance and available services to reduce healthcare disparities. This study includes qualitative and quantitative interviews combined with concept mapping and focus groups with American Indian elders and other key stakeholders. Discussion The information gathered will generate new practical knowledge, grounded in actual perspectives of American Indian elders and other relevant stakeholders, to improve healthcare practices and policies for a population that has been largely excluded from national and state discussions of healthcare reform. Study data will inform development and evaluation of culturally tailored programming to enhance understanding and facilitate negotiation of the changing landscape of health care by American Indian elders. This work will fill a gap in research on public insurance initiatives, which do not typically focus on this population, and will offer a replicable model for enhancing the effects of such initiatives on other underserved groups affected by healthcare inequities. Trial registration This protocol does not include the collection of health outcome data. Clinicaltrials.gov, NCT03550404. Registered June 6, 2018
Health literacy, sociodemographic factors, and cognitive training in the active study of older adults
OBJECTIVE:Health literacy is critical for understanding information from health-care providers and correct use of medications and includes the capacity to filter other information in navigating health care systems. Older adults with low health literacy exhibit more chronic health conditions, worse physical functioning, and poorer mental health. This study examined the relationship between sociodemographic variables and health literacy, and the impact of cognitive training on change in health literacy over 10 years in older adults. METHODS:Participants (N = 2,802) aged 65 years and older completed assessments, including reading and numeracy health literacy items, as part of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study. We evaluated baseline sociodemographic variables and change in health literacy over a 10-year period in individuals exposed to cognitive training in reasoning, processing speed, memory, or a no-contact control condition. RESULTS:Age, sex, race, education level, and general cognitive functioning at baseline were all associated with baseline health literacy in older adults. Predictors of change in health literacy over the 10-year follow-up were age, race, education level, general cognitive functioning, and neighborhood income; disparities in health literacy because of race attenuated over time, while the effect of age increased over time. Health literacy was generally stable across the ACTIVE intervention groups over 10 years. CONCLUSIONS:The present study showed important disparities in health literacy level and change over 10 years. Cognitive training did not significantly impact health literacy, suggesting that alternative approaches are needed to reduce the disparities