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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Predictors of Cognitive Decline in a Multi-Ethnic Sample of Midlife Women: A Longitudinal Study

Dixon, Jasmine 01 February 2020 (has links)
Hypertension, diabetes, depressive symptoms, and smoking are predictors of cognitive decline in late life. However, it is not known if these risk factors are associated with cognition during midlife orif the associations between these risk factors and cognition vary by race. This longitudinal study hypothesized that (1) the risk factors would predict cognitive decline in midlife, (2)African Americans would have greater cognitive decline than European Americans and East Asians, and (3) there would be stronger associations between risk factors and cognition for African American women compared to European American and East Asian women. Participants (aged 42-52) were European American (n= 1,000), African American (n= 516), and East Asian (n= 437) women from the Study of Women’s Health Across the Nation who were studied for 8 years. Risk factors (i.e., diabetes, hypertension, smoking, and depressive symptoms) and cognitive outcomes (i.e., episodic memory, processing speed, and working memory) were measured at multiple timepoints. Two-level hierarchical linear models tested change in cognition over time controlling for income, education, and age. African Americans had lower scores than European Americans and East Asians on all cognitive outcomes. East Asian smokers had greater episodic memory decline compared to European American smokers. Depressive symptoms did not adversely impact processing speed for East Asian relative to European Americans. Contrary to our hypothesis, hypertension was associated with improved processing speed over time for African Americans compared to European Americans. Racial disparities in cognition were evident for African American women.
22

The effects of elevated hemoglobin A1C on cognitive function in elderly type II diabetics in the Look Ahead study

Goldring, Anne E. 22 January 2016 (has links)
OBJECTIVE: Prolonged elevation of blood glucose levels in Type 2 Diabetes is related to a host of medical complications, most of which are mediated by micro and macro vascular damage. Importantly, diabetes is associated with accelerated cognitive decline and compromised brain health as the cerebral vasculature undergoes negative changes stemming from hyperglycemia. It is hypothesized that participants in the Look Ahead Brain study with higher HbA1c levels will exhibit worse performance on the cognitive measures, specifically on tasks assessing executive function. METHODS: Data on participants from the Look Ahead study who also participated in the Look Ahead Brain ancillary study (n = 113) were analyzed. This included HbA1c levels at year 10 (the year that participants were administered the cognitive assessment), mean HbA1c, and change in HbA1c from baseline to year. In order to assess executive function the results on two cognitive tests, the Modified Stroop Color and Word Test and the Trail Making Test, were analyzed. Then, relationships between HbA1c and performance on each of these cognitive tasks were analyzed using two approaches. First, the cohort was split into two group based on HbA1c (HbA1c ≤ 7% vs HbA1c > 7%). The latter of the two groups represented participants will poorer glycemic control. Second, linear correlations were assessed using the full range of HbA1c values as a continuous variable. RESULTS: There were no significant differences between HbA1c groups and performance on either of the cognitive tests. Interestingly, although not statistically significant, those with higher HbA1c levels performed slightly better on cognitive tasks. Correlation analyses revealed further trends in the direction opposite than expected, such that higher HbA1c levels were associated with better scores on both tests. CONCLUSION: The surprising results of this study are evidence of the fact that a great deal has yet to be learned about the effects of T2DM and cognitive decline. There are many potential future directions for the Look Ahead Brain data, and further analyses might provide clarifications to the results of this study.
23

Blood pressure dysregulation as a possible mechanism for cognitive decline in older adults with spinal cord injury

Chen, Harriet 15 February 2024 (has links)
Spinal Cord Injury (SCI) is a physically debilitative impairment with a poor prognosis that disrupts the connection between the brain and body. Reduced somatic and autonomic nervous system control over motor and sensory function of muscles and organs causes paralysis and dysregulation of physiological systems. Complications, such as deep vein thromboses, urinary tract infections, and chronic pain, often cause high, life-long economic burdens. Seniors with SCI also have an increased risk of developing cognitive decline. Development of Major Neurocognitive Disorder (Dementia) is characterized by a reduced ability to perform daily activities. In addition to the physical impairments due to SCI, older adults would experience further decreased quality of life. There are various postulations about what contributes to an increased risk of cognitive decline in SCI patients, although the specific mechanism is uncertain. This research project is focused on examining whether blood pressure dysregulation may play a key role in inducing cognitive decline in older adults with SCI. To fulfill this goal, published reviews and clinical and laboratory data from 1997 to 2023 have been analytically reviewed following the presentation of background physiological and pathophysiological information. The outcomes demonstrated that SCI above T6 leads to an increased risk of blood pressure dysregulation and other conditions associated with an increased risk of cognitive decline, including orthostatic hypotension, vascular dementia, and deficient dynamic cerebral autoregulation. Overall, the findings suggest that blood pressure dysregulation that causes cerebral hypoperfusion may be a major contributor to cognitive decline in older adults with SCI.
24

Does Chronic Stress Accelerate Late-aging Cognitive Decline In Memory And Executive Functioning?

Robinson, Diane 01 January 2010 (has links)
Few studies exist examining the relationship between self-reported stress and cognitive function in healthy nonpsychiatric older adults, and even less studies have examined whether high levels of self-reported stress accelerate the cognitive decline found in normal late-aging populations. A group of older nonpsychiatric adults, ages 54 years and above, were asked to complete three measures assessing their self-perceived stress over the past month, past year, and their lifetime. Sixty-one adults between the ages of 54 and 88 (52% female) participated in a second phase in which neuropsychological tasks were administered to assess three cognitive domains; memory, learning, and executive functioning. A hierarchical regression examined each of the three domain scores to explore whether self-perceived acute and chronic stress, after covaring for state anxiety, was related to neuropsychological performance. No statistically significant regressions were found, which was predicted for the learning domain, but contrary to the hypotheses for the memory and executive functioning domain. The potential influence of age in this study was explored in a series of ANOVAs examining the interactions between the three stress measures with state anxiety and age on the three cognitive domains. A statistically significant interaction was found between age and perceived lifetime stress when examining the memory domain score. In the young-old participants an increase in stress showed a non-significant relationship with a decrease in memory performance, while in the older-old participants the opposite non-significant tendency was found. The current study also partially replicated an earlier report of a relationship between an increase in recent self-reported stress and a decrease in performance on a specific divided attention task, and extended this finding to include older adults. While the majority of the study's hypotheses were not supported, these preliminary findings provide the field with interesting areas to explore in future studies.
25

Older and Weaker or Older and Wiser: Exploring the Drivers of Performance Differences in Young and Old Adults on Experiential Learning Tasks in the Presence of Veridical Feedback

Masterson, Ashley January 2016 (has links)
This dissertation proposes that while traditional cognitive psychology literature suggests that cognitive function decreases with age, these decreases are dependent on the types of testing being performed. While traditional cognitive tests of memory and processing speed show declines associated with age, this research suggests these declines are not robust across all types of learning. The coming pages present four studies aimed at furthering our understanding of how different age cohorts of consumers learn about products in active and complex marketplaces. Study one reveals an age advantage associated with learning experientially; an interesting and somewhat surprising result that warrants further investigation given the rapid rate at which populations are aging. The additional studies presented here begin that investigation through the application of several psychological theories. This research explores increased vigilance associated with the security motivation system (based on the principles of evolutionary psychology), the possible impact of mortality salience through the application of Terror Management Theory and a positive correlation between age and cognitive control, as possible explanations. / Business Administration/Marketing
26

WEAVING IN WOOD : An architectural strategy in Umeå that strive to decrease loneliness and include elderly with physical and cognitive impairments

Littbrand, Rebecka January 2020 (has links)
WEAVING IN WOOD  An architectural strategy in Umeå that strive to decrease loneliness and include elderly with physical and cognitive impairments A Master Thesis by Rebecka Littbrand                                                                                                   Spring 2020   Background Feelings of loneliness is common in the whole western world, especially among older people. Loneliness is of public health concerns as being a risk factor for many severe diseases and premature mortality. Scientists argues that an increase of social embeddedness is essential for improvements in well-being and quality of life. The focus group for this master thesis is elderly that lives in ordinary housing in Umeå, Sweden. Among elderly physical and cognitive impairments such as dementia are common, as well as getting help from the Home care service. Methodology This master thesis investigates different factors linked to loneliness, the current situation in Umeå regarding meeting places for elderly and architectural features to include elderly with impairments. Study visits to existing meeting places, interviews with local actors and experts within the field as well as reading literature have driven the project forward.   Findings Most districts in Umeå have no meeting place where elderly with impairments easily can participate. To include elderly with physical and cognitive impairments there are important to counteract 5 barriers: Long distance, Hidden placement, Need to plan and sign up in advance to participate, Insecurity if there will be someone there who can support you and Cost for participating.        To ease for people with dementia and to create a meeting place that feels welcoming and secure there are several architectural features that should be taken into consideration, e.g. arrange the rooms around a central common space, highlight functions by using powerful colours, being on ground floor and visual connections between certain spaces, which the “Open meeting places” provided by the municipality in Umeå have problems in fulfilling.    Conclusion  An architectural strategy in Umeå to reduce loneliness among elderly living in ordinary housing and that counteracts the barriers to include elderly with physical and cognitive impairments is needed. By placing New open meeting places next to the local food stores in the different districts of Umeå the barriers Hidden placement and Long distance are counteracted, enabling the Home care service to guide elderly to the places. The meeting places will consider important architectural features to include people with dementia and create a place that feels welcoming and secure.      The New open meeting places will collaborate with local actors, strive to highlight the importance of social interaction, take away the stigma related to loneliness as well as give the elderly population more prominent and visible places in society.
27

Computer-Based Cognitive Training for Age-Related Cognitive Decline and Mild Cognitive Impairment

Fortman, James Alexander 27 November 2012 (has links)
No description available.
28

The impact of cochlear implantation on cognition in older adults: a systematic review of clinical evidence

Miller, Gina, Miller, Craig, Marrone, Nicole, Howe, Carol, Fain, Mindy, Jacob, Abraham January 2015 (has links)
BACKGROUND: Hearing loss is the third most prevalent chronic condition faced by older adults and has been linked to difficulties in speech perception, activities of daily living, and social interaction. Recent studies have suggested a correlation between severity of hearing loss and an individual's cognitive function; however, a causative link has yet to be established. One intervention option for management of the most severe to profound hearing loss in older adults is cochlear implantation. We performed a review to determine the status of the literature on the potential influence of cochlear implantation on cognition in the older adult population. METHODS: Over 3800 articles related to cochlear implants, cognition, and older adults were reviewed. Inclusion criteria were as follows: (1) study population including adults > 65 years, (2) intervention with cochlear implantation, and (3) cognition as the primary outcome measure of implantation. RESULTS: Out of 3,886 studies selected, 3 met inclusion criteria for the review. CONCLUSIONS: While many publications have shown that cochlear implants improve speech perception, social functioning, and overall quality of life, we found no studies in the English literature that have prospectively evaluated changes in cognitive function after implantation with modern cochlear implants in older adults. The state of the current literature reveals a need for further clinical research on the impact of cochlear implantation on cognition in older adults.
29

Prévention des démences : analyse du déclin cognitif à l’aide d’un modèle longitudinal non linéaire à variable latente. / Prevention of dementia : analysis of cognitive decline using a nonlinear model with latent process for longitudinal data.

Mura, Thibault 10 December 2012 (has links)
Ce travail doctoral a pour premier objectif de replacer les démences dans leur contexte de santé publique en estimant des projections de nombre de cas de démences en France et en Europe jusqu'en 2050. La sensibilité de ces projections aux changements d'hypothèses sur les valeurs d'incidence ou de mortalité des sujets déments, sur le scenario démographique utilisé, et sur la mise en place d'une intervention de prévention, a également été évaluée. Dans ce contexte de forte augmentation du nombre de cas à venir, la prévention des démences, qu'elle soit primaire ou secondaire, sera amenée à tenir une place primordiale dans la prise en charge sociétale de ce problème. Pour pouvoir aboutir à des résultats, les recherches en prévention primaire et secondaire ont besoin de s'appuyer sur une méthodologie adaptée et de sélectionner des critères de jugements pertinents. Le déclin cognitif semble être un critère de jugement de choix, mais son l'utilisation doit éviter un certain nombre d'écueils et de biais. Nous avons dans un premier temps illustré l'analyse de ce critère dans le cadre d'un questionnement de prévention primaire à l'aide d'un modèle non linéaire à variable latente pour données longitudinales. Nous avons pour cela étudié la relation entre consommation chronique de benzodiazépines et déclin cognitif, et montré l'absence d'association sur un large échantillon. Dans un second temps nous avons utilisé ce type de modèle pour décrire et comparer les propriétés métrologiques d'un large ensemble de tests neuropsychologiques dans une cohorte clinique de sujets atteints de déficit cognitif modéré (MCI), et pour étudier la sensibilité de ces tests aux changements cognitifs lié aux prodromes de la maladie d'Alzheimer. Nos travaux ont ainsi permis de fournir des arguments permettant de sélectionner des tests neuropsychologiques susceptibles d'être utilisés dans le cadre de recherches de prévention secondaire pour identifier et/ou suivre les patients présentant un déficit cognitif modéré (MCI) lié à une maladie d'Alzheimer. / The first aim of this doctoral work is to replace dementia in its public health context by estimating the number of dementia cases expected to occur in France and Europe over the next few decades until 2050. The sensitivity of these projections to hypotheses made on dementia incidence and mortality, demographic scenario used, and implementation of a prevention intervention, was also assessed. In this context of increasing number of future cases, the primary and secondary prevention of dementia will take a prominent place in the social management of this problem. Relevant research in the field of primary and secondary prevention requires an appropriate methodology and the use of relevant outcome. Cognitive decline seems to be an appropriate outcome, but a number of biases must be avoided. First, we illustrated the use of this criterion in the context of primary prevention using a nonlinear model with latent variable for longitudinal data to investigated the association between chronic use of benzodiazepines and cognitive decline. We showed the absence of association in a large population-based cohort. Secondly we used this model to describe and compare the metrological properties of a broad range of neuropsychological tests in a clinical cohort of patients with mild cognitive impairment (MCI). We also investigated the sensitivity of these tests to cognitive changes associated with prodromal Alzheimer's disease. Our work provides arguments for selecting neuropsychological tests which can be used in secondary prevention research, to identify and / or to follow patients with mild cognitive impairment (MCI) due to Alzheimer's disease.
30

Alterações cerebrais associadas à presença de déficits cognitivos em idosos: um estudo usando morfometria voxel-a-voxel por ressonância magnética / Brain abnormalities associated with the presence of cognitive impairment in elderly: an MRI study using voxel-based morphometry

Silveira, Paula Squarzoni da 30 November 2010 (has links)
Introdução: Em estudos de ressonância magnética (RM) estrutural e tomografia por emissão de pósitrons (positron emission tomography; PET), métodos de análise voxel-a-voxel permitem comparações entre grupos do volume de substância cinzenta ou do metabolismo de glicose de forma automatizada, em todo o cérebro. Em estudos com portadores de transtornos cognitivos como a Demência de Alzheimer (DA) comparados a controles saudáveis, tais métodos mostram alterações não só em regiões cerebrais classicamente envolvidas na DA (como hipocampo), mas também em áreas não investigadas anteriormente. Mesmo na ausência de demência, sujeitos idosos apresentam freqüentemente alterações cognitivas, sobretudo em associação com fatores de risco cardiovascular, tais como hipertensão arterial sistêmica. Metodologia: Foi realizado numa amostra de 265 idosos na faixa etária entre 66 e 75 anos exames de RM. A amostra foi dividida em dois grupos, o primeiro com perda cognitiva compatível com diagnóstico prejuízo cognitivo (caracterizado pelo desempenho de 1.5 desvio padrão abaixo da média do grupo) e o segundo grupo sem perda cognitiva. A presença de alterações cerebrais associadas à presença de déficit cognitivos entre os grupos foi investigada utilizando uma metodologia automatizada de avaliação voxel-a-voxel através do SPM. Resultados: Identificamos 5 sujeitos com prejuízo cognitivo numa amostra populacional de 244 indivíduos. A presença de prejuízo cognitivo foi associada à presença de lesão silenciosa (p=0,001), idade (p=0,002), e a presença de diabetes (p=0,026). Prejuízos no desempenho cognitivo total foram associados à redução de SC envolvendo o hipocampo e giro parahipocampal à direita (p=0,049 e p=0,036, respectivamente). Prejuízos no desempenho em tarefas de memória foram associados à redução de SC envolvendo regiões de hipocampo, giro parahipocampal e amídala à esquerda (p=0,026, p=0,031, e p=0,007, respectivamente). Prejuízos em tarefas de atenção foram associados à redução de SC envolvendo hipocampo e giro parahipocampal à esquerda (p=0,019 e p=0,013, respectivamente). Finalmente, prejuízos no desempenho cognitivo em tarefas fluência verbal foram associados à redução de SC envolvendo córtex temporal medial à direita (p=0,041). Conclusão: A presença de prejuízo cognitivo foi observada numa pequena porcentagem da população geral quando avaliada através da comparação com o desempenho no próprio grupo. Estudo de volumetria cerebral, após exclusão dos sujeitos com lesão silenciosa, observou que o desempenho cognitivo de idosos da comunidade apresentou relação direta com o volume cerebral de regiões límbicas, importantes para a cognição e memória. / Introduction: In studies with structural magnetic resonance imagery (MRI) and positron emission tomography (PET), methods of analysis voxel-by-voxel allow comparisons among groups of gray matter volume or glucose metabolisms in an automatized fashion all around the brain. In studies with cognitive disorder carriers, such as Alzheimer\'s Disease (AD) compared to healthy controls, such methods show alterations not only in the brain regions classically involved in AD (such as hippocampus), but also in areas not previously investigated. Even in the absence of dementia, elderly people often present cognitive changes, mainly in association with cardiovascular risk factors, such as systemic arterial hypertension. Methodology: We performed MRI in a sample of 265 elderly people in the age range between 66 to 75 years old. The sample was divided in two groups: the first one with cognitive loss compatible to cognitive impairment diagnosis (characterized by the performance of 1.5 standard deviation below the group average) and the second group without cognitive loss. The presence of brain alterations associated to the presence of cognitive deficits between the groups was investigated using an automatized methodology of voxel-to-voxel evaluation through statistical parametric mapping (SPM). Results: It was identified 5 subjects with cognitive impairment in a population sample of 244 individuals. The presence of cognitive impairment was associated to the presence of silent lesion (p=0.001), age (p=0.002), and the presence of diabetes (p=0.026). Impairments in the overall cognitive performance were associated to the reduction of the gray matter (GM) involving the hippocampus and parahippocampal gyrus to the right (p=0.049 and p=0.036, respectively). Impairments in the performance of memory tasks were associated to the reduction of GM involving the hippocampus, parahippocampal gyrus and amygdala regions to the left (p=0.026, p=0.031, and p=0.007, respectively). Impairments in attention tasks were associated to the reduction of GM involving the hippocampus and the parahippocampal gyrus to the left (p=0.019 and p=0.013, respectively). Finally, impairments in the cognitive performance of verbal fluency tasks were associated to the reduction of GM involving the medial temporal cortex to the right (p=0.041). Conclusion: The presence of cognitive impairment was observed in a small percentage of the general population when evaluated through the comparison of the performance in the group itself. The study of brain morphometry after the exclusion of subjects with silent lesion observed that the cognitive performance of the elderly people from the community presented direct relationship with the brain volume of the limbic regions, important for the cognition and memory.

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