Dissertations / Theses: 'Cognitive ageing'

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Schweitzer, Pierre. "Cognitive ageing in everyday life." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEP061/document.

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Les objectifs de cette thèse sont multiples: 1. concevoir un nouvel outil d'échantillonnage des expériences utilisant les technologies mobiles, qui soit durable et évolutif, et qui permette d'implémenter des tests cognitifs mobiles; 2. utiliser cet outil pour obtenir des informations écologiques sur les comportements et les performances cognitives; 3. valider la méthode; 4. analyser les interactions entre comportement et performance afin d'identifier les comportements sains ou à risque
This thesis has several objectives: 1. design a new experience sampling tool that is durable and evolutive, and allows to implement mobile cognitive tests; 2. use this tool to obtain ecological information on behaviors and cognitive performance; 3. validate the method; 4. analyze the relationships between behavior and performance to identify which behaviors are healthy or risky

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Majdi, Maryam. "Brain ageing : cognitive status and cortical synapses." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115704.

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This thesis focused on the spatiotemporal patterning of classical excitatory and inhibitory synaptic contacts accounting for the majority of cerebral cortical connections, in relation to ageing and cognitive status. These investigations tested the hypothesis that higher CNS functions depend on the balance between excitatory and inhibitory synaptic connections. Glutamatergic and GABAergic presynaptic bouton densities were determined in aged animals segregated according to their cognitive status into aged and cognitively unimpaired (AU) and aged and cognitively impaired (AI), using the Morris water maze. These two groups were compared in terms of behaviour and the pattern of excitatory and inhibitory synapses. It was evident that an excitatory and inhibitory presynaptic decline is associated with age-related cognitive impairments; whereby both glutamatergic and GABAergic boutons gradually diminish from young to AU to AI. Nevertheless, the balance between excitatory and inhibitory presynaptic inputs was maintained. To determine whether postsynaptic sites differed with respect to ageing and cognitive impairments, excitatory and inhibitory postsynaptic scaffold proteins were investigated in the same cohort of segregated aged animals. There was an imbalance in density ratio between immunoreactive sites of excitatory versus inhibitory postsynaptic scaffold proteins in AI animals. This resulted from a marked decrease in the density of excitatory postsynaptic sites. To further investigate ultrastructural aspects of excitatory synapses I carried out electron microscopical studies of cerebral cortex to measure the abundance of NR2 receptor subunits of the NMDA receptor- a receptor site directly associated with excitatory postsynaptic scaffold proteins. This study revealed that NR2 immunoreactive sites were largely preserved during age-related cognitive decline with an uneven profile distribution. Finally, protein expression of specific receptor subunits and key proteins representative of excitatory and inhibitory postsynaptic sites was investigated by semi-quantitative Western blot analyses in selected cortical areas. It was clear that many of these postsynaptic proteins are affected by age and cognitive status. The most striking change was a marked up-regulation in neuroligin-1 in AI animals, which may affect the delicate balance between excitatory versus inhibitory synaptic inputs. Another notable finding was the down-regulated expression of GluR2 receptor subunits in AI animals, which should have implications for neuronal Ca2+ regulation. In conclusion, we have demonstrated the greater vulnerability of excitatory postsynaptic sites in aged and cognitively impaired animals.

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Spokes, Tara. "Ageing and Cognitive Inhibition: An ERP analysis." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/365459.

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Impaired cognitive inhibition is one of a number of changes in cognitive functioning that are associated with healthy ageing. Cognitive inhibition is the ability to suppress or withhold some cognitive process and includes the ability to block out distracting information. Successful cognitive inhibition underlies improved performance on a range of executive functions including problem solving, long-term planning and goal-directed behaviour (Darowski, Helder, Zacks, Hasher, & Hambrick, 2008). One theory posits that age-related deficits in cognitive inhibition may underlie general cognitive decline associated with older adults (Hasher & Zacks, 1988; Hasher, Zacks, & Rahhal, 1999). Previous behavioural studies have found that automatic, or unintentional cognitive inhibition is preserved with age while controlled, intentional cognitive inhibition is impaired in older adults (Collette, Germain, Hogge, & Van der Linden, 2009). In contrast, a number of neuroimaging studies suggest that older adults show less differentiation than young adults in neural processing of automatic and controlled tasks. In particular, it has been suggested that automatic tasks are processed more like controlled tasks, suggesting increased cognitive effort required to complete them (Germain & Collette, 2008).
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Applied Psychology
Griffith Health
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Norris, Jade Eloise. "Numerical cognition in ageing : investigating the impact of cognitive ageing on foundational non-symbolic and symbolic numerical abilities." Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:13762.

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Healthy ageing is associated with a gradual decline in several cognitive functions, including processing speed, inhibitory control, memory, executive functions, and problem solving. However, the trajectory of ability in numerical cognition in older age remains unclear. Some research investigating exact skills such as arithmetical problem solving have found declined numerical abilities in older age due to reduced access to effective strategies. However, other research has indicated stable or even enhanced mathematical and arithmetical abilities in older age. Furthermore, limited research is available on the impact of ageing on foundational numerical abilities. The effect of cognitive ageing on such foundational abilities poses an interesting question due to the innate, evolutionary nature of foundational numerical skills. It is possible that such automatic, innate and primitive abilities may be spared in ageing, alongside emotional processing, autobiographical memory, and vocabulary and verbal skills. Available studies investigating basic numerical abilities in ageing present contradictory results and methodological variation. Furthermore, although a limited number of studies have investigated foundational non-symbolic abilities in ageing, the effect of older age on foundational symbolic abilities is yet to be directly tested. The thesis therefore explicitly investigated the impact of healthy ageing on foundational non-symbolic and symbolic numerical processing with a series of experiments. Chapter 2 presents the first study to use classic numerosity discrimination paradigms to compare the non-symbolic and symbolic foundational numerical skills of a group of younger and older adults. Chapter 3 served to further investigate enhanced symbolic numerical abilities in older age found in chapter 2 using a number priming paradigm. The impact of life experience using numbers on foundational numerical skills in older age was studied in chapter 4, whereby older adults with a degree in mathematics were compared with those without explicit further mathematical education. The final two experimental chapters of the thesis examine the reliable measurement of the Approximate Number System in ageing, considering the impact of inhibitory control and mathematical achievement on acuity. Chapter 5 compares non-symbolic acuity in younger and older adults when using either spatially separated or intermixed non-symbolic dot displays. Finally, chapter 6 directly studies the impact of perceptual variables on ANS acuity in ageing, specifically focusing on total cumulative area, dot size, and convex hull (perimeter) congruency. The series of experiments presented in the thesis indicate that foundational numerical abilities are preserved in healthy ageing. Specifically, non-symbolic numerical abilities remain stable in older age, whereas foundational symbolic abilities are enhanced, possibly due to lifetime exposure to and experience with symbolic numbers. Furthermore, the thesis demonstrates the importance of task design in measuring non-symbolic numerical abilities in ageing, identifying methodological aspects which may lead to poorer acuity in older adults as a result of decline in other cognitive functions (e.g. inhibitory control). The thesis therefore contributes to the literature regarding numerical cognition in ageing, with foundational numerical abilities found to be preserved in healthy ageing. Preservation of such abilities in healthy ageing poses implications for pathological ageing, in that declined foundational numerical skills may serve to indicate pathological processes.

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Cook, Joanna Clare. "Ageing and inhibition in memory." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288442.

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Dijkstra, Jeanette Bernadette. "An operation under general anaesthesia and cognitive ageing." Maastricht : Maastricht : Neuropsych Publishers ; University Library, Maastricht University [Host], 1997. http://arno.unimaas.nl/show.cgi?fid=5798.

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Brailean, Anamaria. "Cognitive ageing and late-life depression across cultures." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/cognitive-ageing-and-latelife-depression-across-cultures(7cdddef5-ebe0-42ce-a264-3eedff0354be).html.

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This thesis examined the role of education and depression symptoms to late-life cognitive inequalities. The inquiry was conducted in several stages. The first line of investigation examined whether a more highly educated recently born cohort had higher levels of cognitive performance and slower rates of cognitive decline in late life compared to a less highly educated earlier born cohort of the same age (65 to 75 years old at baseline). Data were used from the Longitudinal Ageing Study Amsterdam (LASA). Findings from Linear Mixed Models suggest that the later born cohort had higher baseline levels of processing speed, inductive reasoning and general cognitive performance, but showed similar or steeper rates of cognitive decline compared to the earlier born cohort. Education duration accounted for cohort differences in baseline levels of inductive reasoning and general cognitive performance, but it did not account for cohort differences in cognitive decline over 6 years of follow-up. The second line of research examined which symptom dimensions of depression may show stronger associations with cognitive dysfunctions in late life. This research question was addressed in two separate psychometric studies, one conducted among older adults in Latin American countries (10/66 study) and the other conducted among older adults in the Netherlands (LASA study). Multiple Indicators Multiple Causes Models were used to examine cross-sectional associations between cognitive abilities and latent depression dimensions in the context of adjustment for differences in item response behaviour due to country of residence, age, gender and cognitive function levels. Findings from the 10/66 study suggest that poorer delayed recall performance was related to higher affective suffering symptoms and higher motivational symptoms. Motivational symptoms had a stronger negative association with verbal fluency performance than affective suffering symptoms. In both studies item response biases were of small magnitude and did not affect substantive conclusions. The third line of investigation informs on the longitudinal direction of influence and timing of the association between cognitive abilities and depression symptoms (conceptualized as a unitary construct and as specific symptom dimensions). This inquiry was conducted in two separate studies: the 10/66 study with a follow-up duration of 3 years (using cross-lagged path analyses), and the LASA study with a follow-up duration of 13 years (using cross-domain latent growth curve models). Findings from the 10/66 study suggest that most prospective associations between cognitive abilities (i.e., verbal fluency, immediate recall and delayed recall) and overall depression symptoms/specific symptom-dimensions were bidirectional. Baseline motivational symptoms of depression were not related to follow-up verbal fluency performance, whereas baseline delayed recall performance was not related to follow-up affective suffering levels. Findings from the LASA study suggest that poor initial memory performance predicted an increase in overall depression symptoms and a specific increase in depressed affect over time, whereas processing speed decline was accompanied by an increase in overall depression symptoms and a specific increase in somatic symptoms. In conclusion, findings from this thesis suggest that education alone has a limited role in accounting for cohort differences in cognitive ageing. The interplay between depression and cognitive functioning is complex. Whether depression co-occurs, precedes, accompanies, or follows cognitive dysfunctions may depend on the depression symptom dimensions experienced and on the timing of the assessments.

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Penke, Lars. "Neuroscientific approaches to general intelligence and cognitive ageing." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/13979.

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Nach einem ausführlichem Überblick über den Kenntnisstand der Genetik und Neurowissenschaft von allgemeiner Intelligenz und einer methodischen Anmerkung zur Notwendigkeit der Berücksichtigung latenter Variablen in den kognitiven Neurowissenschaften am Beispiel einer Reanalyse publizierter Ergebnisse wir das am besten etablierte Gehirnkorrelat der Intelligenz, die Gehirngröße, aus evolutionsgenetischer Perspektive neu betrachtet. Schätzungen des Koeffizienten additiv-genetischer deuten an, dass es keine rezente direktionale Selektion auf Gehirngröße gegeben hat, was ihre Validität als Proxy für Intelligenz in evolutionären Studien in Frage stellt. Stattdessen deuten Korrelationen der Gesichtssymmetrie älterer Männer mit Intelligenz und Informationsverarbeitungsgeschwindigkeit an, dass organismusweite Entwicklungsstabilität eine wichtige Grundlage von unterschieden in kognitiven Fähigkeiten sein könnte. Im zweiten Teil dieser Arbeit geht es vornehmlich um die Alterung kognitiver Fähigkeiten, beginnend mit einem allgemeinen Überblick. Daten einer Stichprobe von über 130 Individuen zeigen dann, dass die Integrität verschiedener Nervenbahnen im Gehirn hoch korreliert, was die Extraktion eines Generalfaktors der Traktintegrität erlaubt, der mit Informationsverarbeitungsgeschwindigkeit korreliert. Der einzige Trakt mit schwacher Ladung auf diesem Generalfaktor ist das Splenium des Corpus Callosum, welches mit Veränderungen der Intelligenz über 6 Jahrzehnte korreliert und den Effekt des Bet2 adrenergischem Rezeptorgens (ADRB2) auf diese Veränderung mediiert, möglicherweise durch Effekte auf neuronale Komopensationsprozesse. Schließlich wird auf Basis neuer Analyseverfahren für Magnetresonanzdaten gezeigt, dass vermehrte Eiseneinlagerungen im Gehirn, vermutlich Marker für zerebrale Mikroblutungen, sowohl mit lebenslang stabilen Intelligenzunterschieden als auch mit der altersbedingten Veränderung kognitiver Fähigkeiten assoziiert sind.
After an extensive review of what is known about the genetics and neuroscience of general intelligence and a methodological note emphasising the necessity to consider latent variables in cognitive neuroscience studies, exemplified by a re-analysis of published results, the most well-established brain correlate of intelligence, brain size, is revisited from an evolutionary genetic perspective. Estimates of the coefficient of additive genetic variation in brain size suggest that there was no recent directional selection on brain size, questioning its validity as a proxy for intelligence in evolutionary analyses. Instead, correlations of facial fluctuating asymmetry with intelligence and information processing speed in old men suggest that organism-wide developmental stability might be an important cause of individual differences in cognitive ability. The second half of the thesis focuses on cognitive ageing, beginning with a general review. In a sample of over 130 subjects it has then been found that the integrity of different white matter tracts in the brain is highly correlated, allowing for the extraction of a general factor of white matter tract integrity, which is correlated with information processing speed. The only tract not loading highly on this general factor is the splenium of the corpus callosum, which is correlated with changes in intelligence over 6 decades and mediates the effect of the beta2 adrenergic receptor gene (ADRB2) on cognitive ageing, possibly due to its involvement in neuronal compensation processes. Finally, using a novel analytic method for magnetic resonance data, it is shown that more iron depositions in the brain, presumably markers of a history of cerebral microbleeds, are associated with both lifelong-stable intelligence differences and age-related decline in cognitive functioning.

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Marioni, Riccardo Emilio. "Inflammation and cognition : the association between biomarker levels, their genetic determinants, and age-related cognitive decline." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4436.

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Chronic in ammation and variations in blood flow have been implicated in the pathogenesis of cardiovascular disease. It is also possible that inflammatory and rheological processes are involved in the development of mild cognitive impairment and dementia, either through their association with vascular disease or via some other, more direct effect on the brain. Evidence is increasing for a causal relationship between Alzheimer's disease and inflammation, possibly related to inflammatory activation of microglia. Inflammatory processes may also be involved in the pathogenesis of cerebral small vessel disease, which in turn has been linked to cognitive impairment and dementia. There is also evidence showing that rheological factors affect cerebral blood flow. However, despite these findings, the associations between inflammatory and rheological markers and cognitive ability have not been extensively studied in large groups of ageing people. The primary aim of this thesis was to test for associations between late-life levels of inflammatory and rheological markers (C-reactive protein (CRP), fibrinogen, tumor necrosis factor (TNF)-α, interleukin (IL)-6, plasma viscosity, and haematocrit) and cognitive ability. A genetic analysis was then performed to model single nucleotide polymorphisms (SNPs) in the genes encoding the markers against cognition in an attempt to determine the weight of evidence for a causal inflammation-cognition association. Four studies were used to test these aims with the majority of the analysis being performed on the Aspirin for Asymptomatic Atherosclerosis (AAA) Trial (n = 3,350), and the Edinburgh Type 2 Diabetes Study (ET2DS) (n = 1,066). The Edinburgh Artery Study (n = 534), and the 1936 Lothian Birth Cohort (n = 1,091), were used as replication cohorts for the genetic analysis. All cohorts comprised community-dwelling, elderly citizens (aged around 70 years) living in central Scotland. With the exception of the ET2DS, all data used were for secondary analyses. Cognitive ability was assessed in all studies using comprehensive batteries of neuropsychological tests that included a measure of crystallised intelligence in the form of a vocabulary test. As performance on such tests varies little across a lifespan, adjusting for these scores in the late-life models enabled the determination of estimated lifetime cognitive change. In the case of the 1936 Lothian Birth Cohort an actual age-11 IQ measure was available in addition to the cognitive follow-up scores recorded at age-70. Linear regression showed small but significant associations between CRP, fibrinogen, and plasma viscosity, and cognition and estimated lifetime cognitive decline in the AAA Trial. Similar results were observed in the ET2DS for CRP, IL-6, and TNF-α. These associations tended to be of a magnitude whereby the markers explained 1% of the variance of the cognitive test scores. The cognitive domains most consistently associated with the markers were processing speed, and a data derived general intelligence factor. A novel genetic analysis was then undertaken to model SNPs against cognitive ability and decline. Most of the results generated were null findings. However, strongly significant associations were found between the rs2227412 fibrinogen beta gene SNP and the cognitive test scores in the ET2DS. Furthermore, the genotype associated with the lowest cognitive scores was also related to higher levels of plasma fibrinogen. Whilst replication of the association between the fibrinogen SNPs and cognition was not found across all cohorts, these results still indicate a potentially causal role for this haemostatic/inflammatory marker. To date, the majority of inflammation-cognition associations have focussed on the acute-phase protein CRP. The main outcomes from this thesis suggest that its close correlate, fibrinogen, is an equally, if not more important factor in the complex process of cognitive ageing.

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Rose, Rachel Anne. "The performance of older eyewitnesses on photographic identification lineups." Thesis, University of Portsmouth, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247494.

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Littlejohn, Jenna. "Central and peripheral auditory changes and cognitive decline in ageing." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/21719/.

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Hearing loss (HL) is a common disorder of the elderly, and is associated with communication difficulties and social isolation. Most recently, HL has been inconsistently linked to cognitive decline and it has been postulated that HL may be an independent risk factor for dementia. The aim of this thesis is to determine whether HL is associated with cognitive decline during normal and/or pathological ageing by specifically investigating contributions from peripheral HL, central auditory processing and the psychosocial pathway. Results show that central auditory processing was linked with cognition during normal and pathological ageing, but there was no independent association with peripheral hearing levels or psychosocial factors. The prevalence of HL was not significantly higher in the patient sample compared with matched controls, nor did HL influence the cognitive profiles in normal ageing or neurodegeneration. There was, however, a statistically significant interaction between HL and decline in executive function only in participants with HL who were high performers at baseline, thereby suggesting that peripheral HL is not an independent risk factor for cognitive decline. Higher scores on central auditory processing were associated with better performance on a test of visual long term memory, after controlling for the effects of peripheral HL, and could predict decline in cognitive performance over time on the Short Cognitive Evaluation battery. In keeping with this, the severity of pathological cognitive impairment was closely related to central auditory processing performance, and patients with mild cognitive impairment recruited the right hemisphere for linguistic processing, which was corroborated with findings of increased grey matter in the right auditory association areas. In summary, it was concluded that the inconsistent findings in the literature may be due to differing influence of HL on normal and pathological cognitive ageing. Peripheral and central hearing changes may be a marker of impending neuronal decline or vulnerability to dementia in people with pathological cognitive impairment, but during healthy ageing, HL does not influence cognitive performance or increase the risk of developing dementia.

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Strozyk, Jessica Vanessa. "The effects of conflict strength and ageing on cognitive control." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3549.

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In this thesis, I investigated effects of conflict strength and ageing on cognitive control. Conflict strength was manipulated in the Eriksen flanker task using two different approaches: 1. independent variation of flanker and target contrast; 2. manipulation of stimulus onset asynchrony (SOA). Reducing flanker contrast relative to target contrast decreased conflict strength, as shown by a reduction in compatibility effects, when contrast conditions were presented in a randomized fashion but not when they were presented block-wise. An SOA of 100 ms did lead to increased compatibility effects compared to SOAs of 0 ms and 200 ms. Effects of conflict appear to be reflected in the N2 component of the ERP. Although priming played a crucial role in the emergence of the sequential adjustment effect, conflict strength also influenced this effect to a certain degree, supporting the claim that sequential adjustments represent an adaptation of cognitive control. Post-error slowing and error-related ERP components, on the other hand, were not affected by the conflict manipulations, suggesting that errors cannot be explained in terms of conflict processing. Effects of ageing on cognitive control were investigated in a group of middle-aged participants. Although physiological indicators of conflict and error processing were compromised in this age group and overall response times were increased, compatibility, sequential adjustment, and post-error slowing effects were of comparable size as in young adults. These findings suggest that participants could successfully compensate for age-related physiological changes at this early stage of ageing. In conclusion, the research presented in this thesis provided important information to extend our knowledge of factors influencing cognitive control processes.

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Gale, Catherine Rose. "Antioxidant vitamins, cerebrovascular disease and cognitive function in elderly people." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264648.

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De, Keijzer Carmen 1992. "Long-term exposure to greenspace and healthy ageing." Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/667792.

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As the world population is rapidly ageing and experiencing an ongoing urbanization, there is an emerging need for environments that are supportive of healthy ageing. Greenspace exposure may foster healthy ageing by promoting physical activity, mental health, and social support, and reducing exposure to air pollution, heat, and noise. Therefore, the aim of this thesis was to investigate the longitudinal association of long-term exposure to greenspace with healthy ageing encompassing cognitive, physical, cardiovascular, and metabolic function. This thesis includes two systematic reviews and four prospective cohort studies. The cohort studies were based on repeated follow-ups of the Whitehall II cohort of middle-aged and older adults from the UK. Our findings suggested that participants who lived in areas with more greenspace had a slower decline in cognitive function and physical functioning, decreased progression of arterial stiffness, and lower risk of metabolic syndrome over the study period. Concluding, the findings of this thesis suggest that long-term exposure to greenspace could contribute to the promotion of healthy ageing.
La población mundial está envejeciendo rápidamente y hay un incremento de la población en áreas urbanas. Por este motivo, existe una necesidad emergente de entornos que beneficien un envejecimiento saludable. La exposición a espacios verdes puede fomentar un envejecimiento saludable, promoviendo la actividad física, la salud mental y el apoyo social y reduciendo la exposición a la contaminación del aire, el calor y el ruido. Por lo tanto, el objetivo de esta tesis fue investigar la asociación entre la exposición a espacios verdes a largo plazo y el envejecimiento saludable, considerando la función cognitiva, física, cardiovascular y metabólica. Esta tesis incluye dos revisiones sistemáticas y cuatro estudios longitudinales de cohorte. Los estudios longitudinales se basaron en seguimientos repetidos de la cohorte de Whitehall II de adultos de mediana edad y adultos mayores del Reino Unido. Nuestros resultados sugirieron que los participantes que vivían en áreas con más espacios verdes tenían un deterioro cognitivo más lento, una menor pérdida de la capacidad física, una progresión reducida de la rigidez arterial y un menor riesgo de síndrome metabólico durante el período de estudio. En conclusión, los resultados de esta tesis sugirieron que la exposición a espacios verdes a largo plazo podría contribuir a la promoción de un envejecimiento saludable.

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Moore, Adam William. "Facilitating healthy ageing : neuroprotective effects of mindfulness practice." Thesis, Liverpool John Moores University, 2013. http://researchonline.ljmu.ac.uk/4385/.

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Mindfulness-based meditation practices involve various attentional skills including the ability to sustain and focus ones attention. During a simple mindfulness based breath awareness meditation, sustained attention is required to maintain focus on the breath while meta-cognitive awareness and executive control are required to detect and correct mind wandering. The purpose of this thesis was to investigate whether a simple, mindfulness based breath awareness meditation, administered over a short period to meditation naïve individuals could modulate core attentional functions and associated task related neural activity. Two longitudinal randomised control studies were conducted. The aim of the first study was to establish if said modulations were possible in a sample of healthy adults, meeting a current research need for longitudinal evidence in this field and providing important information regarding a potential mechanism for the salutary effects widely observed from the use of mindfulness based interventions. It was found that short term engagement with a mindfulness based breath awareness meditation can modulate core attentional functions and task related neural activity, with specific modulations found in electrophysiological markers of sustained attention to the goal/task at hand and perceptual stimulus discrimination. In line with current theoretical models it is argued that modulations to such core attentional processes following short term training may provide a platform upon which mindfulness related salutary effects are built. The second study was designed to establish if such modulations were possible in older adults. It is argued that mindfulness training may have utility for increasing cognitive reserve, a potential mechanism by which age related declines in cognitive functions may be mitigated. It was found that both behavioural and electrophysiological markers of core attentional functions were modulated following 8 weeks mindfulness training but not following a matched active control group condition (simple brain training exercises). The reviewed extant evidence and findings of this study suggest that mindfulness meditation may enhance cognitive reserve through the repeated activation of attentional functions and associated neural activity during practice and are consistent with recent theoretical models of cognitive reserve. The potential for mindfulness training to positively modulate core attentional functions in older adults and to potentially impact cognitive ageing demands further investigation.

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Cross, Nathan. "Obstructive sleep apnoea in older adults: Predictors of cognitive decline and neurodegeneration." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17763.

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There is growing evidence that sleep disturbances share associations with neurodegeneration, and poor sleep is emerging as an independent risk factor for dementia. As a common sleep disorder, obstructive sleep apnea (OSA) has been connected to compromised cognition, brain integrity and an increased risk for dementia. However, there is a need to clarify these relationships in older adults and understand the mechanisms underpinning the link between OSA and cognitive decline. The aims of this thesis were: 1) to characterise and quantitatively analyse the relationship between OSA and cognitive function in older adults, 2) to determine whether any changes in neural oscillations during sleep or brain grey matter thickness and volume, might be associated with OSA and related to makers of cognitive decline (e.g. memory) in a sample of older adults at-risk for dementia. At-risk adults were diagnosed as health-seeking older adults (>50 years) with subjective or objective cognitive impairment. Neural oscillations were recorded using electroencephalography and brain grey matter thickness and volume were measured using magnetic resonance imaging. These findings showed that the presence of OSA in at-risk older adults is related to a marked reduction in specific neural oscillations (sleep spindles), key aspects of sleep microarchitecture that are integrally linked with memory consolidation. Furthermore, OSA-related oxygen desaturation was associated with decreased cortical thickness in both the left and right temporal lobes, while sleep disturbance was related to increased cortical thickness in in frontal, central and occipital regions of the right cortex. This work has provided evidence that OSA is related to features which may contribute to early-stage neurodegeneration and cognitive decline, which are important in identifying critical periods for intervention. Given that effective treatment exists for OSA, efforts to increase OSA screening in older adults are now warranted.

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Corley, Janie Elizabeth. "Lifestyle factors and cognitive ageing in the Lothian Birth Cohort 1936 : exploring the role of confounding by prior cognitive ability." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20984.

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With an increase in life expectancy, the number of older people affected by cognitive decline and dementia is rising, causing major, global public health concerns. However, there is substantial variation in the rate and magnitude of cognitive decline experienced among ageing individuals. Evidence suggests that many age-associated changes in cognitive functioning can be explained by modifiable lifestyle factors such as smoking, physical activity and diet choices. The weight of the evidence supports the promotion of a healthy lifestyle as an effective strategy for healthy cognitive ageing. Many epidemiological studies have drawn causal conclusions with regard to the positive and direct benefits of lifestyle, yet few have considered the possible confounding role of prior cognitive ability in explaining the lifestyle and cognition relationship in older age. Given the potential for reverse causation, whereby better prior cognitive functioning leads to a greater uptake of healthy behaviours rather than vice versa, it is a mechanism which should be studied, but rarely is. The present thesis focuses on the possible confounding effect of prior cognitive ability on the cross-sectional relationships between lifestyle factors and cognitive ability domains in later-life. The core of the thesis is a series of independent, peer-reviewed (six first-author and one co-author) journal articles in the public domain. Data were derived from the Lothian Birth Cohort 1936 study (n = 1091), a sample of relatively healthy, community-dwelling men and women aged 70 years from Edinburgh, Scotland, for whom childhood (age 11) mental test scores are available. The lifestyle factors investigated were caffeine consumption, alcohol consumption, dietary patterns, body mass index, smoking, serum cholesterol, and physical activity. Cognitive function was assessed across five major ageing-related domains: age 70 IQ (based on the same test that was taken in childhood), general cognitive ability (g), processing speed, memory, and verbal ability. General linear models (ANCOVA) were adjusted for the following covariates: age; sex; childhood cognitive ability; and socioeconomic status (SES). Other potential covariates were additionally adjusted for as necessary. Overall, the positive and significant associations observed between ‘healthy’ lifestyle factors and better cognitive functions at age 70 were consistent with previous research; their effect size was around 1% of the variance in cognitive tests scores. However, these relationships were markedly attenuated (by on average 80%) by a higher childhood cognitive ability and adult SES; for the most part, associations were reduced to non-significance. None of the lifestyle factors were consistent predictors of performance across cognitive domains, though smoking avoidance, a physically active lifestyle, and moderate intake of alcohol, appeared to have the most potential. The key novel finding of this thesis is that, in addition to having predictive value for lifestyle choices over 60 years later, cognitive ability at age 11 accounted for the majority of the cross-sectional associations between lifestyle factors and cognitive abilities in later-life. This finding is consistent with the theory of confounding or even reverse causation. That is, individuals with higher lifetime ‘trait’ cognitive ability may be more likely to adopt a lifestyle which protects against cognitive decline. Rather than a unidirectional or indirect effect of health behaviours on cognitive function, the present findings suggest there may be a dynamic cycle involving cognition, self-management of health and ultimate cognitive outcomes.

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Vines, John Charles. "Ageing futures : towards cognitively inclusive digital media products." Thesis, University of Plymouth, 2011. http://hdl.handle.net/10026.1/541.

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This thesis is situated in a moment when the theory and practice of inclusive design appears to be significantly implicated in the social and economic response to demographic changes in Western Europe by addressing the need to reconnect older people with technology. In light of claims that cognitive ageing results in an increasing disconnection from novel digital media in old age, inclusive design is apparently trapped in a discourse in which digital media products and interfaces are designed as a response to a deterministic decline in abilities. The thesis proceeds from this context to ask what intellectual moves are required within the discourses of inclusive design so that its community of theorists and practitioners can both comprehend and afford the enaction of cognitive experience in old age? Whilst influential design scholarship actively disregards reductionist cognitive explanations of human and technological relationships, it appears that inclusive design still requires an explanation of temporal changes to human cognition in later life. Whilst there is a burgeoning area of design related research dealing with this issue—an area this thesis defines as ‘cognitively inclusive design’—the underlying assumptions and claims supporting this body of research suggests its theorists and practitioners are struggling to move beyond conceptualising older people as passive consumers suffering a deterioration in key cognitive abilities. The thesis argues that, by revisiting the cognitive sciences for alternative explanations for the basis of human cognition, it is possible to relieve this problem by opening up new spaces for designers to critically reflect upon the manner in which older people interact with digital media. In taking a position that design is required to support human cognitive enactment, the thesis develops a new approach to conceptualising temporal changes in human cognition, defined as ‘senescent cognition’. From this new critical lens, the thesis provides an alternative ‘senescentechnic’ explanation of cognitive disconnections between older people and digital media that eschews reductionism and moves beyond a deterministic process of deterioration. In reassessing what ageing cognition means, new strategies for the future of inclusive design are proposed that emphasise the role of creating space for older people to actively explore, reflect upon and enact their own cognitive couplings with technology.

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Biundo, Roberta. "Lexical-semantic parameters as robust endophenotypes of abnormal cognitive decline in ageing." Thesis, University of Hull, 2010. http://hydra.hull.ac.uk/resources/hull:5713.

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The objective of this dissertation was to characterise the relative contribution of genetic influences to individual differences in cross sectional performance and decline of semantic-lexical abilities and to investigate whether these linguistic effects indicating semantic degradation are sensitive indicators of medial temporal atrophy in early Alzheimer's disease and in patients with mild cognitive impairment of amnestic type (aMCI). The effect of ApoE status in the genetic profile of these groups on deterioration of semantic abilities was studied to verify whether there was any relationship between variation in lexical factors and genetic variability. Oral generation of words belonging to two categories (animal and fruits) during a fluency tasks was required. In AD patients there was an effect of genotype but, although strong, this was diluted by the advanced cognitive deterioration and could only be seen as a tendency to be stronger in ε4 carriers. The words produced by the aMCI carriers were significantly earlier acquired than those of non-carriers and controls. These behavioural findings confirmed evidence from other recent studies and showed that a significant proportion of phenotype variability in performance on fluency tasks was influenced by genetic factors. Impairments in semantic tasks in the ε4 allele carrier population might indicate either that individuals who will develop AD never fully develop semantic skills, or that the neuroanatomical substrate of semantic abilities is selective sensitive to the earliest effects of the AD neuropathology. On the basis of this result it seemed reasonable to hypothesise that the presence of the “semantic endophenotype” in people carriyng the ApoE vulnerability mutation might be associated with atrophy in areas early affected by neuropathology due to AD and involved in semantic memory retrieval. Using lexical semantic competency in aMCI carriers as an endophenotype, grey matter volume loss in aMCI ε4 carriers/non-carriers and in controls was compared and the residual volume correlated with allele burden and with age of acquisition values for words produced in a category fluency task. Direct group comparisons showed that carriers had grey matter volume loss which was generally confined to limbic regions and medial temporal structures, and non-carriers had greater atrophy in temporal and parieto-occipital neocortex. aMCI subjects had significantly impoverished lexical semantic output compared to controls, more marked in aMCI carriers. A voxel based correlation analysis showed that greater volume loss in parahippocampal gyrus and thalamus was associated with a tendency to retrieve earlier acquired words in the category fluency task. The results suggest a relatively specific impact of ApoE 4 burden and underline the value of linguistic assessment in preclinical diagnosis. The detrimental role of this mutation found in aMCI individuals was also assessed at the larger stage in the disease process by direct comparisons in minimal to mild AD ε4 carriers/non-carrier patients. VBM comparison analysis confirmed the observation done in the genetically determined aMCI subgroups. AD ε4- carriers showed greater atrophy in mediotemporal structures compared to non-carriers whose grey matter volume loss was more widespread in more neocortical areas. Finally, an age, gender and education based norms for AoA, Typicality and Familiarity was built up in order to create a valid psychometric instrument able to detect and monitor subtle semantic deficits in ApoE ε4 carriers over time.

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Charlton, Rebecca Ann. "The ageing brain and cognitive decline : investigating the relationship with MRI techniques." Thesis, St George's, University of London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441948.

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Lyall, Donald. "Genetic contributions to cognitive ageing and structural brain magnetic resonance imaging phenotypes." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8834.

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As humans age, specific mental faculties deteriorate even in the absence of dementia. Age related cognitive decline affects quality of life, and has significant implications from a socio-economic perspective; however not everyone declines to equal degrees, at equal rates, or from the same baseline. This PhD examined a large sample of community-dwelling older adults called the Lothian Birth Cohort 1936, most of whom completed an intelligence test at age 11 years, and again around age 73 as part of a detailed assessment that also included detailed brain magnetic resonance imaging (N range = 700-866). I investigated the independent effects of two linked genetic loci which have been associated with greater risk of Alzheimer’s disease – the APOE ε haplotype (commonly ‘genotype’) and a poly-T repeat in the TOMM40 gene. Are 'risk' variants in these loci associated with specific measures of cognitive ageing and brain structure - specifically white matter microstructural integrity, hippocampal volumes, white matter lesions or cerebral microbleeds – in this sample? Firstly, a pilot study aimed to replicate significant associations between the ADRB2 gene and brain imaging/cognitive phenotypes, that had previously been reported in a smaller subsample of the cohort that had by that time undergone MRI (n = 132). Previously reported significant associations were not significant in the larger, full LBC1936 sample (n = 700-866), but novel significant associations were found (P < 0.05). Specifically, integrity of the left arcuate fasciculus white matter tract significantly mediated part of the association between specific genetic variations at ADRB2, and the Digit Symbol Coding task of information processing speed. These findings indicated that this approach – testing three-way genetic/brain imaging/cognitive associations for mediation - was viable for the main APOE/TOMM40 analyses. Results in the main APOE/TOMM40 analyses showed that specific variants in the APOE and TOMM40 gene loci were statistically significantly associated (at raw P value <0.05) with white matter tract microstructural integrity, but not white matter lesions, hippocampal volume or cerebral microbleeds. Inconsistencies with previous, positive reports showing significant associations between APOE ε and these latter phenotypes may reflect a degree of type 1 error or more study-specific discrepancies (which are detailed throughout). APOE ε was significantly associated with average scores on a large proportion of cognitive tests, independent of age 11 intelligence (i.e. ‘cognitive ageing’; Deary et al., 2004). These associations were partly – but not completely – mediated by white matter tract microstructural integrity. TOMM40 poly-T repeat genotype was associated with cognitive ageing to a much lesser extent. A range of brain phenotypes may form the anatomical basis for significant associations between APOE genotype and cognitive ageing, among which includes white matter tract microstructural integrity.

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Duncombe, Jessica. "Imaging cerebrovascular alterations in experimental models of ageing and vascular cognitive impairment." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28828.

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Vascular cognitive impairment describes a heterogeneous condition in which cognitive decline is precipitated by underlying cerebrovascular dysfunction. Ageing, as well as vascular diseases such as hypertension, stroke, cerebral small vessel disease and cerebral amyloid angiopathy, are risk factors for vascular cognitive impairment. The precise mechanisms by which these conditions impact the cerebral vasculature to drive cognitive decline, however, are unknown. Previous research has indicated that vascular risk factors can lead to microvascular oxidative stress, inflammation and endothelial dysfunction that can lead to tissue hypoperfusion, the development of white and grey matter vascular lesions (microinfarcts and microbleeds) and cognitive impairment. It was hypothesised that ageing, a prominent risk factor for cognitive decline, would induce impairments on neurovascular coupling resulting from neurovascular unit disruption. It was further hypothesised that induction of chronic cerebral hypoperfusion would mediate neurovascular dysfunction and vascular lesion development through increased oxidative stress, resulting in cognitive decline. Finally, it was also hypothesised that neurovascular impairments resulting from ageing and chronic cerebral hypoperfusion would be exacerbated in the presence of amyloid deposition. Four studies were performed in order to test these hypotheses. Vascular risk factors can be reproduced using experimental mouse models and provide a valuable basis in which to test hypotheses and therapeutic interventions. As such, a primary aim of this thesis was to develop and validate sensitive MRI approaches that would allow the detection of vascular alterations in vivo. In the first series of studies, MRI techniques to assess resting cerebral blood flow, vessel number, vascular lesions and inflammation in experimental mice were validated using established in vivo and ex vivo techniques, so that these techniques could be used in subsequent studies for vascular assessments in vivo. Arterial spin labelling was developed to assess resting cerebral blood flow, and was able to detect reductions in blood flow following cerebral hypoperfusion that correlated well with those obtained from laser speckle imaging. Q-map imaging was able to detect reductions in vessel number in acute lesions, and in non-lesioned mice measures of vessel number correlated well with histopathological measures. Structural T2 imaging was performed in order to detect ischaemic and haemorrhagic lesions in chronically hypoperfused mice, and was validated using H&E and Perls’ staining. Finally, contrast-enhanced T2* imaging was used to detect iron oxide uptake by macrophages in the brains of hypoperfused mice, which was further validated by the identification of iron-containing macrophages in immunostained brain sections. The second study was conducted to test the hypothesis that ageing would impair neurovascular unit function and structure, and that these impairments would be exacerbated in the presence of amyloid pathology. The aim of the study was to incorporate previously developed in vivo imaging approaches in the assessment of vascular function and alterations in neurovascular unit structure in both wild type and TgSwDI mice. As predicted, ageing caused a pronounced deficit on measures of neurovascular coupling, however this was not exacerbated by accumulation of amyloid in TgSwDI mice and was not associated with alterations in baseline blood flow measured by arterial spin labelling. Structural assessment of the neurovascular unit revealed a loss of contact between astrocytic endfeet and vasculature, which was significantly associated with the impairment on neurovascular coupling, in addition to other markers of breakdown of the neurovascular unit such as loss of pericyte coverage and microglial activation. Age and thalamic vascular amyloid accumulation were also associated with an increase in the NADPH oxidase (NOX) subunit p47, indicative of increased oxidative stress. Data from this experiment indicate that ageing can profoundly impair neurovascular coupling, mediated by gliosis and loss of astrocytic contacts with vasculature. The third study aimed to test the hypothesis that chronic cerebral hypoperfusion (a prominent early feature of vascular cognitive impairment) would impair vascular function and induce the development of vascular lesions and cognitive decline. The impact of hypoperfusion on neurovascular coupling, ischaemic and haemorrhagic lesion burden and cognition was investigated in wild type and TgSwDI mice. Hypoperfusion induced deficits on neurovascular coupling, increased lesion burden and inflammation assessed with T2 and contrast-enhanced T2* imaging, and caused impairment on measures of learning and memory. Hypoperfusion was also associated with an increase in the levels of NOX2, NOX4 and 3-NT at 3 months following surgery, indicating persistent reactive oxygen species production and oxidative damage in hypoperfused mice. The findings from this study indicate that vascular dysfunction and cognitive impairment following hypoperfusion may be mediated by increased NADPH oxidase activity and resulting oxidative stress. The previous studies indicated that markers of oxidative stress were induced in response to ageing, vascular amyloid accumulation and cerebral hypoperfusion. The final study sought to determine whether increased NOX activity mediates downstream pathological effects on vascular function, vascular lesion development and cognitive decline following hypoperfusion. NOX activity was inhibited pharmacologically by administration of apocynin to hypoperfused TgSwDI mice for 3 months following surgery. Treatment with apocynin significantly restored neurovascular coupling to a level similar to sham-operated mice, and there was a trend toward reduction of ischaemic vascular lesions. However, it was unable to rescue the prominent inflammatory response or decline in cognitive ability, as apocynin-treated mice were no different on these measures to non-treated hypoperfused mice. The data indicate that whilst inhibiting NOX may have potential therapeutic value in improving vascular function, additional interventions, for example to reduce inflammation, may also be required in order to prevent cognitive decline. Overall, the work outlined within the thesis indicate that vascular risk factors of ageing, cerebral amyloid angiopathy and cerebral hypoperfusion may converge on common pathways involving oxidative stress and increased inflammation in order to drive vascular dysfunction and lead to cognitive decline. Inhibition of NOX activity was able to rescue vascular function, however the results indicate that this was not sufficient to protect against cognitive impairment, suggesting additional therapeutic targets may need to be sought in order to fully preserve vascular health and prevent cognitive decline.

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Khan, Wasim Nawaz. "Neuroimaging markers of Alzheimer's disease, mild cognitive impairment and normal healthy ageing." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/neuroimaging-markers-of-alzheimers-disease-mild-cognitive-impairment-and-normal-healthy-ageing(c507bdb2-721c-4060-8a06-9f01b39d3de1).html.

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Alzheimer’s disease (AD) is a progressive neurodegenerative disorder clinically characterised by memory loss and cognitive decline that severely affect activities of daily living. Neuropathologically, the disease is characterised by two major proteinopathies, extracellular amyloid-beta (Aβ) plaques and intraneuronal neurofibrillary tangle pathology. The development of neuroimaging biomarkers for AD have transformed the assessment of brain changes associated with these pathological processes for the earlier detection of AD. However, additional work is needed to validate more robust neuroimaging techniques for early diagnosis in the predementia stages of AD pathophysiology. The aim of this PhD is to investigate the utility of advanced Magnetic Resonance Imaging (MRI) techniques for the earlier detection of AD across different biomarker endophenotypes of pathogenesis. These PhD investigations consist of: 1) A comparison of an automated hippocampal subfield technique over standard hippocampal volumetry for AD classification and Mild Cognitive Impairment (MCI) to AD conversion prediction, 2) A neuroimaging-proteomic study for testing the prognostic ability of novel cerebrospinal fluid (CSF) proteins in combination with structural MRI measurements for AD classification and MCI to AD conversion prediction, 3) An extensive multi-cohort study testing the neuroanatomic relationship between Apolipoprotein E (APOE), hippocampal volume, and Aβ deposition across the AD spectrum, 4) A study of the neurodevelopmental effect of APOE polymorphisms on brain structure in adolescence and 5) A neuroimaging study testing the utility of resting-state functional MRI (rsfMRI) for characterising the functional systems-level pathology of intrinsic networks anchored in the highly metabolically active posteromedial cortex. In conclusion, in this thesis I provide evidence to show the diagnostic efficacy of structural MRI techniques across different biomarker interactions for disease classification and prediction in AD, and explain the neuroanatomic role of APOE on the hippocampus across the AD spectrum, as well as demonstrating the utility of rsfMRI methods as an emerging biomarker of AD.

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Sjölinder, Marie. "Age-related cognitive decline and navigation in electronic environments." Doctoral thesis, Stockholm University, Department of Psychology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1038.

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The older population is increasing, as is life expectancy. Technical devices are becoming more widespread and used for many everyday tasks. Knowledge about new technology is important to remain as an active and independent part of the society. However, if an old user group should have equal access to this technology, new demands will be placed on the design of interfaces and devices. With respect to old users it is and will be important to develop technical devices and interfaces that take the age-related decline in physical and cognitive abilities into account. The aim of this work was to investigate to what extent the age-related cognitive decline affects performance on different computer-related tasks and the use of different interfaces. With respect to the use of computer interfaces, two studies were conducted. In the first study, the information was presented with a hierarchical structure. In the second study the information was presented as a 3D-environment, and it was also investigated how an overview map could support navigation. The third study examined the age-related cognitive decline in the use of a small mobile phone display with a hierarchical information structure. The results from the studies showed that the most pronounced age-related difference was found in the use of the 3D-environment. Within this environment, prior experience was found to have the largest impact on performance. Regarding the hierarchical information structures, prior experience seemed to have a larger impact on performance of easy tasks, while age and cognitive abilities had a larger impact on performance of more complex tasks. With respect to navigation aids, the overview map in the 3D-environment did not reduce the age-differences; however, it contributed to a better perceived orientation and reduced the feeling of being lost.

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Bailey, Phoebe Elizabeth Psychology Faculty of Science UNSW. "The social cognitive neuroscience of empathy in older adulthood." Awarded By:University of New South Wales. Psychology, 2009. http://handle.unsw.edu.au/1959.4/44506.

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Empathy is an essential prerequisite for the development and maintenance of close interpersonal relationships. Given that older adults are particularly vulnerable to the negative consequences of loneliness and social isolation, it is surprising that few studies have assessed empathy in this group. The current programme of research addressed this gap in the literature by testing competing predictions derived from Socioemotional Selectivity Theory and the Ageing-Brain Model for age-related sparing and impairment of empathy, respectively. Study 1 compared young (N = 80) and older (N = 49) adults?? self-reported levels of cognitive and affective empathy, and engagement in social activities. It was found that although affective empathy is spared, cognitive empathy is subject to age-related decline, and this decline mediates reductions in social participation. These data therefore affirmed the importance of further investigation into the nature, causes and potential consequences of age-related differences in empathy. Since disinhibition is one mechanism contributing to difficulty taking the perspective of another, and is known to increase with age, in Study 2, behavioural measures sensitive to inhibitory failure and to cognitive empathy were administered to young (N = 36) and older (N = 33) adults. One of the measures of cognitive empathy directly manipulated inhibitory demands, involving either high or low levels of self-perspective inhibition. The results indicated that older adults were selectively impaired on the high-inhibition condition, with cognitive disinhibition mediating this association. Study 2 therefore provided important evidence relating to one potential mechanism that contributes to age-related difficulties in perspective-taking. Studies 3 and 4 provided the first behavioural assessments of age-related differences in affective empathy by using electromyography to index facial expression mimicry. Study 3 found that young (N = 35) and older (N = 35) adults?? demonstrate comparable mimicry of anger, but older adults?? initial (i.e., implicit) reactions were associated with reduced anger recognition. Thus, to test the possibility that despite explicit recognition difficulties, implicit processing of facial expressions may be preserved in older adulthood, Study 4 compared young (N = 46) and older (N = 40) adults?? mimicry responses to subliminally presented angry and happy facial expressions. As predicted, the two groups demonstrated commensurate subconscious mimicry of these expressions. Taken together, these studies indicate that separate components of empathy are differentially affected by healthy adult ageing. Implications for competing perspectives of socioemotional functioning in older adulthood are discussed.

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Edwards, Carolyn Anne. "The role of the frontal cortex in normal age-related memory performance." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389161.

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Chapko, Dorota. "Life-course determinants of resilience to cognitive ageing : empirical evidence and policy implications." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=230978.

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Introduction: Understanding the life-course determinants of resilience to brain ageing could significantly reduce the burden of cognitive impairment and dementia on individuals, heath care providers, and societies. The focus of this work is the concept of cognitive reserve (CR), which implies that some individuals are able to remain cognitively healthy despite the accumulation of age-related neuropathology. Methods: The determinants of brain structure and function were statistically modelled using three ongoing ageing cohort studies [Aberdeen Birth Cohort of 1936 (ABC1936), Aberdeen Children of the 1950s (ACONF), The Three-City French Cohort (3C)]. First, I performed a systematic literature review to identify life-course determinants of CR. Then, I examined whether other potentially modifiable life-course factors such as birth weight, mid-life occupational profile, and late-life social relationships and technology use provided individuals with greater CR. I modelled data in STATA and SPSS/AMOS. Results: I found that the effects of low birth weight and pre-term delivery on cognitive functions persists into mid-life (ACONF). I showed that childhood intelligence at age 11 has almost twice the protective effect on cognitive ageing than mid-life occupation (ABC1936). The quantity and quality of social relationships (3C), and the aspects of technology use in latelife (ABC1936) did not provide greater CR. Conclusion: Early-life factors contribute to later-life brain health. A major implication of this work is that studies and/or programs should consider a life-course perspective (with a focus on early-life) to accurately assess and to improve the brain health of older adults.

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Webb, Shannon Lee. "Does mood matter? Investigation of its influence on Cognitive Training performance and engagement in older adults." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23008.

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With the ageing population, increasing rates of disorders of aging such as dementia are of global concern due to the lack of efficacious preventative or curative interventions. This thesis addresses two key issues contributing to the lack of consensus for the efficacy of Cognitive Training (CT) in the treatment of cognitive decline. First, it highlights the issue of methodological heterogeneity between studies and reviews in outcome task classification. The meta-analysis addressed this through the development and evaluation of a theoretically driven taxonomy—the CHC-M—for cognitive outcome classification. Application of the CHC-M to the Lampit et al. (2014) meta-analysis data uncovered a significant benefit of CT on EF outcomes that had previously been obscured. Second, it addressed the lack of consideration of clinical individual differences factors such as mood and motivation in CT research; a critical oversight due to major depressive disorder being a significant risk factor for dementia. The systematic review highlighted that direct causal evidence regarding the influence of depression on CT outcomes is scarce. Three experimental studies are thus presented to bridge this gap, investigating the influence of mood in a CT context through utilisation of a standardised Mood Induction Procedure (MIP). The three studies investigated the influence of the MIP on performance on EF tasks within online CT-type sessions (Study 1 and Study 2), and participant ratings of their level of expended effort, motivation, and engagement within these sessions (Study 3). Results were complex but trended towards support for a facilitative effect of negative mood on performance on the EF tasks; while positive mood was associated with higher ratings of expended effort, motivation, and engagement. Thus, while the relationship between mood and cognition is complex, better understanding is crucial to the development of tailored interventions for the populations most at risk of dementia.

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Lancaster, Claire. "Apolipoprotein ε4 and attentional control : understanding the trajectory of cognitive ageing from mid-life." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/73536/.

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The greatest genetic factor in how well we age cognitively is Apolipoprotein E (APOE), a single nucleotide polymorphism with three allelic variants: epsilon-2, epsilon-3 and epsilon-4 (hereafter ε2, ε3, ε4). The ε4 allele is associated with an increased risk of cognitive disadvantage in later life, however, the effects of this variant are not isolated to old-age, with some studies reporting cognitive advantages in youth. This thesis investigates the influence of APOE ε4 on cognition from mid-adulthood, a point in the lifespan when the detrimental effects of this allele may be emerging. This thesis begins with a systematic review and meta-analysis of the literature to-date, and suggests attention may be sensitive to ε4 differences in mid-adulthood, however, effects of the allele are not consistently shown, perhaps due to methodological limitations including the use of insensitive neuropsychological batteries (Chapter 1). Next, behavioural paradigms providing a sensitive index of both selective (Chapter 2) and executive attention (Chapter 3), suggest many attentional processes are intact in mid-age (45-55 years) ε4 carriers. Subtle deficits, however, are apparent on prospective memory (PM) and Stroop-switch paradigms, indicating a goal maintenance disadvantage. In addition, a proxy of cognitive reserve was found to moderate the effects of ε4 on executive attention in mid-adulthood (Chapter 4). Follow-up research used paradigms that target the distinct processes supporting focal and non-focal PM to interrogate the profile of change observed in mid-age ε4 carriers, identifying a profile of disadvantage consistent with that observed in pathological ageing (Chapter 5). PM, however, was not found to differentiate ε4 carriers in older individuals at heightened risk of converting to dementia (Chapter 6). Collectively, this research provides evidence for a profile of accelerated ageing in ε4 carriers, with subtle disadvantages apparent in executive attention by the end of the 5th decade.

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Macleod, Mairi S. "Cognitive ageing and the role of the frontal lobes in prospective memory and planning." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU137019.

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A recent theory postulates that the cognitive functions associated with the frontal lobes are likely to selectively deteriorate with age (West, 1996). In line with this theory, it was predicted that an age-related decline in measures of prospective memory and planning would be observed. In order to investigate this hypothesis, a series of five experiments were conducted using groups of young, middle aged and older normal participants. In Experiment 1, participants were asked to follow a recipe while remembering to do various prospective memory tasks at the same time. Older participants performed significantly worse on all measures of prospective memory. Significant age differences in measures of planning were observed in the computerised &'34;Tower of London&'34; planning task in Experiment 2. In Experiment 3, participants were given an open-ended planning task involving allocating a list of tasks to three friends. Older participants made significantly more overall planning errors. In Experiment 4, few age differences were observed in general executive function. In Experiment 5, the role of attention in prospective memory and planning was examined. Older participants performed significantly worse than the younger participants at the prospective memory and planning tasks. Speed of information processing was more highly associated with performance on the planning and prospective memory tasks than the attentional measures. There was not enough evidence available from the two patient studies to suggest that prospective memory was differentially impaired in patients with frontal lesions. The overall results confirmed the experimental hypothesis that there is an age-related decline in prospective memory and planning. However, the extent to which these age-related declines can be attributed to selective declines in the frontal lobes remains unclear.

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MacPherson, Sarah E. S. "Age, executive function and social decision-making : a dorsolateral prefrontal theory of cognitive ageing." Thesis, University of Aberdeen, 2001. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU144679.

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Current neuropsychological models propose that the cognitive changes associated with healthy adult ageing are due to deterioration of the frontal lobes of the brain. Despite evidence that the frontal lobes are involved in age-associated cognitive decline, the behavioural and cognitive deficits demonstrated by older adults differ from the typical clinical picture presented by patients with frontal lobe damage. Furthermore, there are frontal lobe tests reported in the literature that are insensitive to the effects of healthy adult ageing despite being sensitive to the effects of frontal lobe dysfunction. These arguments speak against the current "frontal lobe hypothesis of ageing". Studies have demonstrated that the frontal lobes can be subdivided into at least two distinct areas: the dorsolateral and ventromedial prefrontal regions. Current neuropsychological models of ageing have failed to consider that age may differentially affect these regions and assume that there is uniform frontal decline. Autopsy and neuroimaging studies, however, suggest that the dorsolateral region deteriorates earlier and more rapidly than the ventromedial region. Therefore, the aim of this thesis was to outline and test a "dorsolateral" prefrontal theory of cognitive ageing where the dorsolateral functions deteriorate with age earlier and more rapidly than the ventromedial functions. In a series of experiments, age-associated declines in performance were found on all tasks sensitive to dorsolateral prefrontal dysfunction, but not on the majority of tasks sensitive to ventromedial prefrontal dysfunction. An attempt was also made to provide evidence for the specific localisation of the "dorsolateral" and "ventromedial" measures by assessing groups of patients with lesions to different areas of the frontal lobes. Whilst most of the tasks were sensitive to frontal lobe dysfunction, only two of the "dorsolateral" measures were found to be selectively sensitive to the dorsolateral prefrontal region. In conclusion, the profile of spared and impaired abilities in the older groups speaks against the traditional "frontal lobe" interpretation of cognitive ageing and is more supportive of a specific dorsolateral prefrontal theory of cognitive changes with age.

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Kilgour, Alexandra Helen Middleton. "Sarcopenia and cognitive ageing : investigating their interrelationship, biological correlates and the role of glucocorticoids." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/14231.

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Background Sarcopenia and age-related cognitive decline (ARCD) are important age-related conditions which significantly impact upon the quality of life of older adults. ARCD is a well-established research area, whereas sarcopenia is a relatively new field. Research into the inter-relationships between them and possible common underlying mechanistic processes is lacking. Methods Several research techniques were used: a large systematic review; the development of an image analysis technique to measure neck muscle size on volumetric MR brain scans; the subsequent use of the technique in elderly cohort studies; statistical modelling to investigate the role of glucocorticoids in sarcopenia; and an invasive clinical study to develop a novel technique to measure the activity of 11beta-hydroxysteroid dehydrogenase (11βHSD1) in the human brain in vivo. Results I consistently found a relationship between: some measures of brain structure and muscle size; markers of brain structure and muscle function, mostly grip strength and gait speed; and cognition and muscle function. However, I found no relationship between current cognition and muscle size in any of the above studies. Cortisol was identified as a possible explanatory factor in the relationship between both cognition and brain volume with gait speed. I found an association between markers of immunosenescence and sarcopenia (neck muscle CSA and grip strength) and an association between expression of the cortisol amplifying enzyme 11βHSD1 and quadriceps strength. I developed a technique to measure 11βHSD1 activity across the human brain, which found that the amount of cortisol produced within the brain was not detectable and highlighted the asymmetries within the cerebrovascular venous system. Conclusions Further longitudinal studies looking at the association between sarcopenia and ARCD are now required to investigate these important relationships further and hopefully this will lead to improved therapeutic options.

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Islam, Shamsun Nehar. "An exploratory study into the cognitive profile of those ageing with autism spectrum disorder." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1575447/.

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The long-established view of Autism Spectrum Disorder being a childhood disorder has concentrated research on childhood and adolescence, while the study of adulthood Autism Spectrum Disorder has been neglected until recent years. Although research with young adults has been initiated, very little is known about the impact of ageing and the lifespan trajectory for those over the age of fifty and with high-functioning Autism Spectrum Disorder. Part one of this thesis presents a systematic literature review of the efficacy of psychological interventions for adults with high-functioning Autism Spectrum Disorder and co-morbid psychiatric disorders. The literature review includes twelve studies. The findings suggest that the usual treatment interventions for neuro-typicals can be used with some adaptations for adults with high-functioning autism, and there is a need for robust evaluations of psychological interventions for different psychiatric disorders. Part two presents an empirical paper that investigates the cognitive profile of adults over the age of fifty with high-functioning Autism Spectrum Disorder. A total of twenty-six adults participated in neuropsychological assessments of general abilities and memory. The results indicate that the cognitive profile may be uneven and that performance in some domains is weaker than others. The clinical implications are discussed with emphasis on the need for further research to improve the understanding of the ageing experience in those with Autism Spectrum Disorder. Part three is a critical appraisal highlighting reflections on the research process undertaken in this thesis. It details the challenges experienced and the obstacles encountered during the process.

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Craig, Michael. "The effect of cognitive state on the consolidation of basic and complex memories." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25970.

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Recent research demonstrates that new verbal memories are retained better if learning is followed by a brief period of wakeful rest. This effect is hypothesised to be the result of wakeful rest providing a state that is conducive for early-stage cellular consolidation (i.e. strengthening of specific memory traces) by protecting this process from interfering sensory input and associated encoding. The aims of this PhD project were to (i) examine whether the benefit of wakeful rest extends to the retention of complex spatial memories, and (ii) explore the effects of different cognitive states on memory consolidation. In order to address the first aim, three virtual reality spatial memory experiments were conducted. In young and older adults, wakeful rest not only enhanced the retention of complex spatial memories, but it also promoted the systems-level integration of spatial memories into accurate cognitive maps, a function, hitherto, assumed to be specific to sleep (Chapters 2-4). Pilot work also tentatively suggested that wakeful rest enhances the retention of complex spatial memories (i.e. a recently travelled route) in patients with amnestic Mild Cognitive Impairment (Chapter 4). In order to address the second aim, five experiments were run in young adults. The first experiment directly compared the effects of wakeful rest and sleep, two states that are positively associated with consolidation. Wakeful rest enhanced the retention of a list of known words, whereas a similar-length period of sleep enhanced the acquisition of novel linguistic constraints (Chapter 5). The final four experiments revealed that, similar to continuous external sensory input, internally generated autobiographical thinking activities (recalling the past and imagining the future) interfere with consolidation (Chapter 6). Together, the findings reported in this thesis reveal that wakeful rest promotes the strengthening (cellular consolidation) and wider integration (systems consolidation) of basic and complex declarative memories, and that this effect is contingent on a reduction in external sensory input as well as rich autobiographical thought.

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Feinkohl, Insa. "Risk factors for cognitive decline in older people with type 2 diabetes." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9612.

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People with type 2 diabetes are at increased risk of age-related cognitive impairment. Previous literature has focused on case-control studies comparing rates of cognitive impairment in patients with and without diabetes. Investigations of potential risk factors for cognitive impairment (including those with increased prevalence in diabetes, such as macrovascular disease, and diabetes-specific factors such as hypoglycaemia) in study populations consisting exclusively of patients with type 2 diabetes have been largely neglected. Moreover, previous studies have failed to take advantage of the extensive characterisation and prospective nature of longitudinal cohort studies to investigate the relative predictive ability of a wider range of potential risk factors for cognitive decline. Using data from the prospective Edinburgh Type 2 Diabetes Study (ET2DS) the present thesis aimed (i) to determine associations of cognitive decline with macrovascular disease and with severe hypoglycaemia, and (ii) to compare a wider range of potential risk factors in their ability to predict cognitive decline. In 2006/2007, 1066 patients with type 2 diabetes (aged 60 to 75 years) attended the baseline ET2DS clinic and 831 returned for the follow-up at year 4. Subjects were extensively characterised for risk factor profiles at baseline, and at year 4 for incidence of severe hypoglycaemia. Socioeconomic status was estimated using postcode data. Scores on seven tests of age-sensitive ‘fluid’ cognitive function, which were administered at baseline and at year 4, were used to derive a general cognitive component (‘g’). A vocabulary-based test, administered at baseline, estimated pre-morbid ability. Findings are reported in three parts. 1.) Macrovascular disease and cognition: Subjects with higher levels of biomarkers indicative of subclinical macrovascular disease, including plasma N-terminal pro-brain natriuretic peptide and carotid intima-media thickness, had significantly steeper four-year cognitive decline, independent of traditional cardiovascular risk factors, stroke, socioeconomic status and estimated pre-morbid cognitive ability. For ankle-brachial pressure index, the association fell just short of statistical significance. Effect sizes were overall modest, with fully adjusted standardised beta coefficients ranging from 0.06 to -0.12. Little evidence was found for associations of the symptomatic markers of macrovascular disease with four-year change in cognitive function that was independent of participants’ pre-morbid ability and socioeconomic status. 2.) Severe hypoglycaemia and cognition: Subjects with lower cognitive ability at baseline were at two-fold increased risk of experiencing their first-ever incident severe hypoglycaemia during follow-up. The rate of four-year cognitive decline was significantly steeper in those exposed to hypoglycaemia compared with hypoglycaemia-free participants, independently of cardiovascular risk factors, microand macrovascular disease and of estimated pre-morbid cognitive ability. Effect sizes again were overall modest (Cohen’s d = 0.2 to 0.3 for statistically significant differences in four-year cognitive decline between subjects with and those without hypoglycaemia, following multivariable adjustment) 3.) Consideration of a wider range of risk factors and cognition: A stepwise linear regression model including a total of 15 metabolic and vascular risk factors identified inflammation, smoking and poorer glycaemic control (in addition to some of the subclinical markers of macrovascular disease) as predictive of a steeper four-year cognitive decline. Other traditional cardiovascular risk factors, diabetic retinopathy, clinical macrovascular disease and a baseline history of severe hypoglycaemia were not included in this model. The interpretation of the latter finding is limited, however, by the fact that the stepwise regression procedure may exclude true predictors from a model when they correlate with already included risk factors. This thesis has demonstrated associations of later-life cognitive decline in people with type 2 diabetes with markers of subclinical macrovascular disease and poor glycaemic control (including hypoglycaemia) as well as other cardiometabolic risk factors (inflammation, smoking). Findings suggest that associations are relatively weak and complex due to inter-relationships amongst risk factors, and indicate a role of pre-morbid ability and socioeconomic status (which as risk factors are difficult to modify) in the relationships of risk factors with cognitive decline. Future research including case-control studies to compare risk factor associations between people with type 2 diabetes and non-diabetic older adults and randomised controlled trials to evaluate potential causal effects of individual modifiable risk factors on cognitive decline, will help to evaluate the mechanisms underlying the observation that people with type 2 diabetes are at risk of cognitive impairment in later life.

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Chauvin, Joshua. "Temporal expectations in healthy ageing & neurological disorders." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:79292953-64db-4b67-bc40-f7172b1994a2.

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Previous research has shown that orienting attention in time can help to improve behavioural outcomes. However, the extent to which temporal orienting can be preserved in ageing and in the context of neurological disorders remains unresolved. This thesis therefore explores temporal expectations in the healthy ageing and diseased brain by taking a neuropsychological approach. To begin, I provide an overview of the literature in Chapter 1 most relevant for the following investigation. Four chapters of experiments then follow. To examine the effects of ageing on temporal expectation, the performance of healthy young adults and healthy older adults is presented and the results are discussed in Chapter 2 and 3. Though it had been previously shown that older adults seem to experience an expectation deficit on temporal expectation tasks, these chapters demonstrate the preservation of temporal expectation in ageing. On their own, these findings represent an important and novel contribution to the literature; however, this research is incapable of establishing the causal mechanisms involved in temporal expectation. To explore the causal role of relevant brain regions in temporal expectation, Chapter 4 and 5 investigate the effects of temporal orienting in participants with damage to the basal ganglia - a brain region strongly implicated in temporal processing. In Chapter 4, the role of the basal ganglia in temporal expectations is examined using data collected from participants with Parkinson's disease and contrasts their performance with age-matched healthy controls. To complement this investigation, and to provide converging evidence for the basal ganglia's role in temporal expectations, Chapter 5 investigates the behavioural performance of individuals with focal lesions to the basal ganglia. The findings in this thesis are discussed in their wider context in Chapter 6, and directions for future research are proposed.

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Mcfarquhar, Martyn. "The influence of a history of major depression on affective cognitive changes in normal ageing." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/the-influence-of-a-history-of-major-depression-on-affective-cognitive-changes-in-normal-ageing(a7d7abd3-1242-491a-b1fe-fb5a85272fcb).html.

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Background: Deficits in the processing of emotional stimuli have long been associated with major depressive disorder (MDD). These emotional biases are believed central to the symptomatology of MDD, with evidence growing that such biases can also be seen during remission. Although such changes are typical of psychiatric morbidity evidence is growing for the impact of ageing on emotional processing as well. Evidence shows that relative to younger adults, older adults demonstrate biases that favour positive information over negative. There is therefore overlap between MDD and normal ageing that has yet to be explored in the literature. Because positive biases are implicated in successful ageing it is important to consider the impact of previous MDD as individuals age. It is this question that is explored in this thesis. Study 1: A behavioural neuropsychological investigation was undertaken comparing older and younger adults with and without a history of MDD on a battery of affective cognitive tasks. Results suggested that the difference between the older adults with and without a history of MDD lay in their ability to disengage from negative information. Study 2: An fMRI investigation was undertaken in a subset of the study 1 sample using neuroimaging paradigms assessing memory encoding and attention for emotional stimuli. Broadly results suggested no influence of previous MDD on the processing of emotional information in the studied domains, with evidence seen in both tasks for the neural basis of the positivity effect of ageing. Study 3: A resting-state fMRI investigation of brain connectivity was undertaken to assess the influence of previous MDD and normal ageing on the communication structure of the brain. Results were largely suggestive of the influence of normal healthy ageing, with limited evidence of the influence of previous MDD or its interaction with ageing. Conclusions: Results were mixed across the investigations. Generally speaking the initial behavioural study was best powered to investigation the questions of interest, suggesting the potential for differential affective processing strategies in later life dependent on previous MDD. The subsequent imaging studies were perhaps less well placed to draw conclusions given limitations in terms of the domains investigated and the sample size. Evidence for the postulate that previous MDD impacts the development of the positivity effect has therefore been demonstrated, but for now remains limited to the behavioural domain.

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Carvalho, Anna Paula de. "Prevalência de comprometimento cognitivo em adultos e idosos indígenas." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/7/7139/tde-17052017-112020/.

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Introdução: O envelhecimento populacional vem sendo acompanhado por um aumento mundial na prevalência de demência. Entretanto, uma revisão sistemática da literatura evidenciou que pouco se sabe sobre a prevalência de demência e comprometimento cognitivo em populações etnicamente diferentes, como a indígena. Isto é, particularmente, relevante dado o aumento da expectativa de vida dessa população e, consequentemente, do número de idosos e das modificações em seu perfil de morbidade e mortalidade. Objetivo: Identificar a prevalência de comprometimento cognitivo na população indígena brasileira, caracterizando o perfil de desempenho cognitivo, de declínio cognitivo subjetivo e de humor e associando com fatores sociodemográficos, hábitos, antecedentes de saúde e humor. Método: Foram incluídos 217 indivíduos com idade igual a ou maior que 50 anos, de ambos os sexos, da etnia Mura, moradores da aldeia de Pantaleão, no município de Autazes, em Manaus - Amazonas. Os participantes foram submetidos a testes de avaliação de atenção, memória operacional, memória declarativa de curto e longo prazos, fluência verbal, habilidade visuoconstrutiva, bem como avaliação de humor, sintomas depressivos, declínio cognitivo subjetivo e desempenho funcional. Resultados: A prevalência de comprometimento cognitivo variou em função da faixa etária. A amostra total incluiu indivíduos com 50 anos de idade ou mais, a prevalência de comprometimento cognitivo foi 43,3%, nos participantes com 60 anos ou mais, a prevalência aumentou para 43,7% e para 51,1% naqueles com 65 anos ou mais. Em relação aos fatores associados, a idade e a escolaridade influenciaram as chances de comprometimento cognitivo em todas as faixas etárias. Nos participantes com 50 anos ou mais, a cada um ano de idade, aumenta em 3% a chance de comprometimento cognitivo (OR = 1,03), e a cada um ano de escolaridade esta chance diminui em 26% (OR = 0,74). Já nos participantes com 60 anos ou mais e nos com 65 anos ou mais, a cada um ano de idade, aumenta em 9% a chance de comprometimento cognitivo (OR = 1,09) e a cada um ano de escolaridade esta chance diminui em 29% (OR = 0,71). Além da idade e escolaridade, o IMC e a renda influenciaram a chance de comprometimento cognitivo nos participantes com idade 50 anos e 60 anos. A cada ponto no IMC, diminui em, aproximadamente, 10% a chance de comprometimento cognitivo (OR = 0,90). Em relação à renda, a cada unidade da renda familiar diminui em 48% a chance de comprometimento cognitivo nos idosos com idade 60 anos. Comparando com os indígenas sem comprometimento cognitivo, aqueles com comprometimento cognitivo tiveram pior desempenho em todos os testes cognitivos, exceto nos de fluência verbal e habilidade visuoconstrutiva, além de maior intensidade no declínio cognitivo subjetivo e nos sintomas depressivos (p 0,05). Conclusão: A prevalência de comprometimento cognitivo em adultos e indígenas aumenta nas faixas etárias maiores, e a chance de desenvolver algum comprometimento aumenta nos participantes mais velhos, com menor escolaridade e renda familiar. Estes achados podem contribuir para implementação de políticas públicas relacionadas ao cuidado da saúde do índio e à capacitação dos profissionais da saúde, incluindo a equipe de enfermagem, para identificação precoce de indivíduos vulneráveis ao desenvolvimento de comprometimento cognitivo.
Introduction: Population ageing has been accompanied by a worldwide increase in the pervasiveness of dementia. However, a systematic review of the literature shows that little is known about the prevalence of dementia and cognitive impairment among ethnically different, such as indigenous, populations. This is particularly relevant given the increase in life expectancy of this population and, consequently the number of elderly individuals, as well as the modification in their morbimortality profile. Objective: To identify the prevalence of cognitive impairment in the indigenous Brazilian population through an assessment of its cognitive performance profile, subjective cognitive decline and mood and associating it with sociodemographic factors, habits, health history and mood. Method: 217 individuals were included of equal to or greater than 50 years of age, of both sexes, of the Mura ethnic group, and residents of the Pantaleão village, in the municipality of Autazes, Amazonas. The participants were submitted to evaluation testing of attentiveness, operating memory, short-term and long-term declarative memory, verbal fluency, visual-constructional ability, as well as evaluation of mood, symptoms of depression, subjective cognitive decline and functional performance. Results: The prevalence of cognitive impairment varied according to age group. While in the total population sample, which included individuals 50 years of age and older, the prevalence of cognitive impairment was 43.3%, among participants 60 years or older, this prevalence increased to 43.7% and to 51.1% for those 65 years or older. In relationship to associated factors, age and schooling influenced the chances of cognitive impairment among all of the age groups. In participants of 50 years or older, for each year of age, there is a 3% increase in the chance of cognitive impairment (OR = 1,03) and for each year of schooling this chance diminishes by 26% (OR = 0,74). On the other hand, in participants of 60 years of age or more, for each year of age, there is a 9% increase in the chance of cognitive impairment (OR = 1,09) and for each year of schooling, this chance diminishes by 29% (OR = 0,71). Beyond age and schooling, the body mass index negatively influenced the chance of cognitive impairment in participants aged 50 years and 60 years. Beyond this, for each household income unit, there is a 48% decrease in the chance of cognitive impairment in the elderly participants aged 60 years. Compared with indigenous individuals without cognitive impairment, those with cognitive impairment performed worse on all cognitive tests, except those of verbal fluency and visual-constructional ability, besides a greater intensity of subjective cognitive decline and symptoms of depression (p 0.05). Conclusion: The prevalence of cognitive impairment in adults and indigenous individuals increases among older age groups and the chance of acquiring some kind of impairment increases among older participants with less schooling and lower household incomes. These findings can contribute to the implementation of public policies related to indigenous health care and the training of health professionals, including nursing teams, for the early identification of individuals vulnerable to the development of cognitive impairment.

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De, Bruin Angela Maria Theresia. "Do bilinguals have a cognitive advantage? : examining effects of bilingualism and language use on executive control." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/25450.

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The daily practice of bilingual language control has been argued to affect both lexical processing and non-verbal executive control in bilingual speakers. On the one hand, bilingualism may slow down lexical processing in both languages. On the other hand, bilinguals have been said to show cognitive advantages compared to monolinguals, for example on inhibition and switching tasks. However, this ‘bilingual advantage’ is hotly debated, can often not be replicated, and language groups have been poorly matched on background variables in previous studies. Furthermore, I examined the reliability of the literature and found evidence for the existence of a publication bias (Chapter 3). This over-representation of positive studies compared to studies with null or negative findings hinders a reliable interpretation of the actual effects of bilingualism. The current thesis therefore aimed to examine possible effects of bilingualism on both lexical processing and executive control. Specifically, I investigated the effects of an understudied, but important feature of bilingualism: language use. Effects of bilingualism have been argued to be largest in older adults. Chapter 4 presents a study discussing inhibition and possible effects of age across various tasks. I show that inhibitory control and age effects depend on task-specific features, including the type of interference, type of stimuli, and processing speed. Next, I present a study (Chapter 5 and 6) examining the relation between bilingualism and both lexical processing and executive control in older adults. Importantly, bilingual and monolingual groups were matched on background variables including immigrant status. I furthermore compared a group of active to inactive bilinguals to assess effects of language use. On a lexical processing task, bilinguals had a disadvantage compared to monolinguals. This effect was modulated by language use, implying that not only language proficiency but also actual language use are needed to explain lexical effects of bilingualism. However, the non-verbal executive control tasks showed no consistent effects of bilingualism or language use on inhibition or task switching. Thus, this study did not replicate positive effects on executive control in older adults. Between-subject comparisons remain problematic as groups can never be matched perfectly. Furthermore, these designs cannot assess a causal effect of bilingualism. Therefore, I conducted another study using behavioural and EEG measurements to test for causal effects of language switching on task switching (Chapter 7). When young bilinguals completed a language-switching task prior to a verbal task-switching paradigm, they showed larger switching costs than after a monolingual naming task. However, this effect of language switching was not found for non-verbal task switching. Language switching may thus have a negative impact on verbal switching, but these effects did not extend to non-verbal executive control. Together, these studies suggest that bilingualism and language use affect lexical processing, but there was no evidence for effects of bilingualism and language use on non-verbal executive control in younger or older adults. In combination with other failed replications and the biased literature, this questions the reliability of cognitive benefits associated with bilingualism. However, executive control is not a unity and its manifestation depends on task-specific features. This task impurity, together with the degree to which participant groups are matched, may explain the inconsistency with which effects of bilingualism on executive control have been observed.

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Raeburn, Alison Somers. "Depression in older people : meeting the challenges of an ageing population." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10428.

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This thesis has been conducted in part fulfilment of the Doctorate in Clinical Psychology. It comprises two parts: a systematic review and an empirical research study. These are two distinct articles both aiming to provide insight into the challenges of late life depression. Firstly, the ageing population will mean that mental health services are likely to see an increase in older people with depression, many of whom will have neurological conditions common in late life, including dementia, stroke and Parkinson’s disease. These conditions have a high risk of depression associated with them. Addressing depression can have a significant effect on quality of life and at present there is limited evidence for effective treatments for depression in neurological conditions. Researchers and therapists have previously been reluctant to conduct psychological therapy with this population, however, there is preliminary evidence that psychological therapies can be efficacious for this population. CBT is structured, goal focused and orientated in the present therefore may be easily adapted for the needs of people with neurological conditions and associated cognitive impairment. Chapter one presents systematic review of this literature, titled ‘Cognitive and behavioural therapies for the treatment of depression in people with dementia, stroke and Parkinson’s disease’. Secondly, depression in the general older adult population will also present challenges for mental health services. Psychological therapies have been shown to be equally effective for older people as they are for younger adults. However, there are a range of gerontological issues that must be considered when working with older people. For example, cohort beliefs, interpersonal role changes and physical health changes may all impact on the way an older person conceptualises their difficulties. In particular, depression in older people has been associated with negative attitudes about ageing. Cognitive theory states that attitudes are mood-state dependent and if negative or dysfunctional attitudes are modified, this can result in improvement in mood. Exploring the attitudes of older people with depression will aid our understanding of late life depression and may provide useful information on whether attitudes to ageing should be specifically addressed during therapy for depression. The current research study explores attitudes to ageing with a clinical sample of depressed older adults and compares attitudes with non depressed control participants. Chapter two outlines the full methodology used in the research study and chapter three contains the research study, titled ‘Attitudes to ageing and clinical depression in older people’, presented within a journal article format.

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Bauermeister, Sarah. "Lifestyle activities, mental health and cognitive function in adults aged 50 to 90 years." Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/7069.

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In a series of studies, lifestyle activities, mental health and aerobic fitness were investigated in relation to mean RT and response time variability (trial-to-trial variability in RT performance) obtained from a battery of cognitive measures in 257 healthy adults aged 50 to 90 years (M = 63.60). Cognition was assessed across four domains; psychomotor performance, executive function, visual search and word recognition. Hierarchical multiple regression analyses and structural equation modelling (SEM) were used to explore associations between age and outcome measures in a mediated-moderator analysis. The dedifferentiation of cognition and the dissociation between the outcome measures of mean RT and response time variability was also explored. Additionally, the neural correlates of response time variability were investigated using functional magnetic resonance imaging (fMRI). The findings indicated that poor mental health was associated with greater within-person (WP) variability and slower mean RTs and that this effect was greater in older adults. Higher lifestyle activity scores and higher aerobic fitness (VO2max) attenuated negative age gradients in WP variability and mean RT. Analyses suggested that the above effects were mediated by executive function. There was no evidence of dedifferentiation across cognitive domains and there was selective dissociation between the measures of mean RT and WP variability. The fMRI results suggested that WP variability was associated with fluctuations in executive control and, relatedly, attentional lapses. Overall, the findings suggest that executive function mediates a substantial portion of age-related variance in cognition and that this association is influenced by moderators such as an active lifestyle, aerobic fitness and mental health. The findings underline the potential benefits and importance of interventions to help maintain and promote mental health, and active lifestyles, in old age.

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Yip, Agustin Go. "Epidemiology of dementia in England and Wales : the Medical Research Council Cognitive Function and Ageing Study." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620650.

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Rhodes, Stephen. "Healthy ageing and binding features in working memory : measurement issues and potential boundary conditions." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/23447.

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Accurate memory for an object or event requires that multiple diverse features are bound together and retained as an integrated representation. There is overwhelming evidence that healthy ageing is accompanied by an associative deficit in that older adults struggle to remember relations between items above any deficit exhibited in remembering the items themselves. However, the effect of age on the ability to bind features within novel objects (for example, their colour and shape) and retain correct conjunctions over brief intervals is less clear. The relatively small body of work that exists on this topic to-date has suggested no additional working memory impairment for conjunctions of features beyond a general age-related impairment in the ability to temporarily retain features. This is in stark contrast to the feature binding deficit observed in the early stages of Alzheimer’s disease. Nevertheless, there have been reports of age-related feature binding deficits in working memory under specific circumstances. Thus a major focus of the present work was to assess these potential boundary conditions. The change detection paradigm was used throughout this work to examine age-differences in visual working memory. Despite the popularity of this task important issues regarding the way in which working memory is probed have been left unaddressed. Chapter 2 reports three experiments with younger adults comparing two methods of testing recognition memory for features or conjunctions. Contrary to an influential study in the field, it appears that processing multiple items at test does not differentially impact on participants’ ability to detect binding changes. Chapters 3, 4, and 5 report a series of experiments motivated by previous findings of specific age-related feature binding deficits. These experiments, improving on previous methodology where possible, demonstrate that increasing the amount of time for which items can be studied (Chapter 3) or mixing feature-conjunction changes in trial-blocks with more salient changes to individual features (Chapters 4 and 5) does not differentially impact on healthy older adults’ ability to detect binding changes. Rather, the argument is made that specific procedural aspects of previous work led to the appearance of deficits that do not generalise. Chapter 5 also addresses the suggestion that healthy ageing specifically affects the retention of item-location conjunctions. The existing evidence for this claim is reviewed, and found wanting, and new data are presented providing evidence against it. To follow-up on the absence of a deficit for simple feature conjunctions, Chapter 6 contrasts two theoretically distinct binding mechanisms: one for features intrinsic to an object and another for extrinsic, contextual features. Preliminary evidence is reported that the cost associated with retaining pairings of features is specifically pronounced for older adults when the features are extrinsic to each other. In an attempt to separate out the contribution of working memory capacity and lapses of attention to age-differences in overall task performance, Chapter 7 reports the results of an exploratory analysis using processing models developed in Chapter 2. Analysis of two data sets from Chapters 4 and 5 demonstrates that lapses of attention make an important contribution to differences in change detection performance. Chapter 8 returns to the issue of measurement in assessing the evidence for specific age-related deficits. Simulations demonstrate that the choice of outcome measure can greatly affect conclusions regarding age-group by condition interactions, suggesting that some previous findings of such interactions in the literature may have been more apparent than real. In closing the General Discussion relates the present work to current theory regarding feature binding in visual working memory and to the wider literature on binding deficits in healthy and pathological ageing.

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Cahill, Allison Louise. "The effects of ageing, task interruption and planning on prospective memory." Thesis, Griffith University, 2006. http://hdl.handle.net/10072/365957.

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Prospective memory involves an individual remembering to perform an intended action at some designated point in the future such as taking medication at a certain time. This type of memory has been demonstrated to decline with advancing age in previous computer-based, laboratory studies. However it appears intact when investigated via naturalistic, community-based designs. Because few studies have investigated everyday prospective memory tasks in a reliable and experimentally rigorous fashion this dissertation will attempt to do so via two studies. The main aim of Study 1 was to develop and test a new naturalistic paradigm set in a ‘homelike’laboratory and to empirically investigate the effects of three variables of interest on prospective memory performance (viz., ageing, interruption and planning). The performance of 79 younger (age range = 18-33 years, M = 21.44 years, SD = 4.53 years) and 67 older adults (age range = 60-75 years, M = 68.23 years, SD = 4.13 years) was compared on three prospective memory tasks (e.g. event-, time- and activity-based tasks). Participants were engaged in planning a meal (ongoing task) by searching through cupboards for ingredients, looking in a recipe book and checking prices in a price catalogue. Simultaneously, participants were required to place a white sticker on recipes with a dairy product (event-based task), press pause on the VCR every 5 minutes (time-based task) and ask for their watch or mobile phone at the completion of the ongoing task (activity-based task). Results of separate ANOVA’s suggested that younger adults outperformed older adults on the event- and time-based tasks, whilst no age-related differences were apparent on the activity-based task. Findings support the notion that cognitively demanding tasks disadvantage older adults due to reduced cognitive resources. In addition, Study 1 attempted to investigate two relatively neglected variables within the prospective memory field, namely; interruption and planning. Considering that the performance of prospective memory tasks is imperative for independent living, variables that disrupt (e.g., interruption) and facilitate (e.g., planning) this process need to be understood. A group of participants (younger and older adults) were interrupted twice by the unexpected ringing of a mobile phone and the experimenter entering and searching the laboratory. The event- (dairy product) and time-based (VCR) tasks were disrupted significantly by the interruption. Performance on all three prospective memory tasks was improved when participants had the opportunity to spend 5 minutes taking notes and planning how they would perform the tasks. Planning was able to overcome the negative (albeit non significant) effects of an interruption on the activity-based (item) task and age-related differences on the time-based (VCR) task. These findings suggest that interruptions are complex in nature and may have a greater effect on tasks that have cues of low saliency (e.g., time on a clock) that require self-initiated retrieval processes. In addition, self-reports of how participants recalled the tasks and why they forgot them suggested that one strategy was not effective for all three prospective memory tasks. These findings may be used to inform educational and training programs. The main aim of study 2 was to determine whether 6 neuropsychological measures (viz., 4 disc Tower of London (TOL-4), the Stroop Color-Word Interference Test (Stroop), Controlled Oral Word Association Test (COWAT), Trail Making Test-Part B (TMT-B), Wisconsin Card Sorting Test (WCST) and Letter/Number Sequencing Test (LNST)) of prefrontal functioning (e.g., planning, inhibition, cognitive fluency and flexibility, set shifting and working memory respectively) could predict prospective memory performance. A logistic regression indicated that the prefrontal measures were able to predict performance on the event-based (dairy product) task for younger adults only. More specifically, scores on the TMT-B and LNS were significant predictors of event-based task performance for younger adults. Older adults’ performance on the time-based (VCR) task was predicted by scores on the TMT-B. In addition, the performance of younger adults on the activity-based (item) task was predicted by scores on the COWAT. It was concluded that prefrontal processes are involved in prospective memory performance and that the characteristics of the prospective memory tasks influence which processes are involved. Support for the frontal lobe hypothesis of ageing was provided as age-related differences were found on the prefrontal measures, with the exception of the COWAT. Future research is recommended to compare the performance of participants on the three everyday prospective memory tasks and computerised tasks to determine whether the two paradigms are measuring the same construct.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Psychology
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Jordan, Catherine. "Exploring a possible tonal loop in musicians and non-musicians and the relationship between musical expertise and cognitive ageing." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31077.

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This thesis explored two main research questions, firstly investigating whether musical expertise offers a performance advantage in working memory for sequences of tones that vary in pitch, and secondly whether any advantage of musical expertise may be present in older as well as younger individuals. Previous research on working memory for tone sequences has reported that articulatory suppression interferes with temporary storage of verbal but not with tone sequences (Koelsch et al, 2009), suggesting a “tonal loop” within a musician’s working memory (Schulze, Zysset, Mueller, Friederici, & Koelsch, 2011) that complements the phonological loop for verbal material in musicians and non-musicians alike (e.g., Baddeley, 1986; 1992). The five experiments reported here explored detection of a pitch change between pairs of tone sequences with or without concurrent articulatory suppression or singing suppression. In Experiment 1, with pairs of auditory tonal (in a musical key) sequences to be compared, singing suppression impaired non-musicians significantly more than musicians, although both groups showed an impairment, whereas only non-musicians were affected by verbal articulatory suppression. In Experiment 2, conducted only with musicians who could read music, the first sequence of each pair was presented visually and the second sequence for comparison was presented aurally. Musicians were again impaired by singing suppression but not by articulatory suppression. For Experiment 3, for auditory atonal (no musical key) pairs of sequences, non-musicians performed at floor, and musicians were again significantly more impaired by singing suppression than by articulatory suppression. In contrast, for Experiment 4, only with musicians who could read music, for visually presented atonal sequences each followed by an auditory atonal sequence for comparison, musicians were significantly more impaired by articulatory suppression than singing suppression. These results suggest that for tonal sequences, musicians use their musical training and experience, coupled with subvocalised singing, but for atonal sequences, additional strategies involving phonological rehearsal may be used. Non-musicians may also rely on musical experience and subvocal singing for tonal sequences but seem to be unable to do so for atonal sequences. Results are consistent with the use by both musicians and non-musicians of a tonal loop for the rehearsal of tone sequences, which develops with musical training and may be used in addition to subvocal rehearsal. Previous research has suggested musical expertise may offer some protection against cognitive ageing (Hanna-Pladdy & MacKay, 2011; Amer, Kalender, Hasher, Trehub, & Wong, 2013). Experiment 5 in this thesis explored whether a lifetime of musical training and experience may offer the same advantages in old age for retaining tone sequences that had been found in Experiments 1 and 3 for younger musicians. This experiment also considered whether any advantage for older musicians on this task could be explained by the proposed “bilingual advantage” (e.g., Bialystok, Craik, Klein & Viswanathan, 2004), and what other aspects of cognition might be associated with tone sequence memory performance. A test battery was utilised with 74 older adults (60-80 years of age) to assess the influence of musical and language expertise, and cognitive abilities (attention, working memory capacity, self-reported prospective and retrospective memory) on the music-related pitch sequence comparison task from Experiments 1 and 3. Working memory capacity was found to predict individual differences in the ability to detect pitch changes between pairs of tone sequences, regardless of musical experience. Older musicians performed more poorly on the pitch change detection task overall than the younger musicians in the earlier experiments, but their performance on the task was significantly better than for age-matched non-musically trained peers who were close to floor for both tonal and atonal sequences, suggesting some benefit from a lifetime of musical experience.

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Lye, Mei Xuan. "The role of 11β-HSD1 in reference and working memory in ageing : investigating underlying mechanisms and biomarkers of age-associated cognitive decline." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22057.

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Glucocorticoids (GC) have a negative effect on age-associated cognitive decline and the GC metabolising enzyme 11β-hydroxysteroid dehydrogenase Type 1 (11β- HSD1) plays a key role in these effects. Increased glucocorticoids exert detrimental effects on the volume and function of brain regions such as the prefrontal cortex (PFC) and hippocampus that are necessary for cognitive functions such as memory and working memory. Previous research has identified changes in cell populations, metabolite levels and structure within the brain as well as altered levels of inflammation with age, and studies have suggested these biomarkers to be associated with cognitive impairments. Aged mice with a deletion in 11ß-HSD1 (11β-HSD1-/- mice), resulting in lower levels of glucocorticoids within the brain, exhibit attenuated cognitive decline in hippocampal dependent spatial learning and memory with age. However, the mechanisms through which 11β-HSD1 contribute to age-associated cognitive decline remain unknown. However, previous genetic models of 11β-HSD1- /- mice have demonstrated residual 11β-HSD1 activity in the brain which may still exert some effects on cognitive processes. Furthermore, the effect of 11ß-HSD1 on working memory – a more cognitively demanding process essential for everyday decision making - has yet to be determined. This thesis tests the hypothesis that glucocorticoid action mediates age-associated cognitive impairment in spatial learning and memory and spatial working memory through alterations in cell activity, brain metabolite levels and neuroinflammatory processes. Therefore, we aimed to investigate if complete lifelong 11β-HSD1 deficiency would protect against age-associated working memory deficits as well as spatial learning and memory deficits, and its effect on associated neural markers. In particular, we determined changes in hippocampal metabolite levels, cell activity and inflammation as a function of ageing in a longitudinal manner. At 6, 12, 18 and 22 months, male 11β- HSD1-/- and C57BL/6J control mice were cognitively assessed in the Morris Water Maze (MWM) and Radial Arm Water Maze (RAWM) – tests for spatial reference memory and spatial working memory respectively. Magnetic resonance spectroscopy (1H-MRS) was performed to examine the hippocampal metabolite profile in the same mice at 6, 18 and 22 months. Following their final scan, mice were culled and brains dissected for analysis. Results revealed unaltered spatial learning with age in C57BL/6J and 11β-HSD1-/- mice and pointed to a development of alternative strategies for task completion as a result of repeated testing. Spatial memory was more susceptible to age-associated effects with impairments in wild-type mice but not 11β-HSD1-/- mice, though not completely immune from the effects of repeated testing. These impairments were correlated with glutamate/glutamine levels and glial fibrillary acidic protein (GFAP), whilst GFAP was further correlated with 11β-HSD1 protein expression. Working memory was impaired with age in both 11β-HSD1-/- and wild-type mice, suggesting 11β-HSD1 deletion may be detrimental to cognitive processes in the prefrontal cortex. In conclusion, impaired memory with age may be attributed to increased glial reactivity and altered glutamate/glutamine cycling in the hippocampus, and lifelong removal of 11β-HSD1 may alter these processes. However, lifelong removal of 11β-HSD1 may not be as beneficial to working memory processes suggesting that 11β-HSD1 and glucocorticoid action play a key role in working memory processes.

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Johnston, Harriet N. "Cognitive and brain function in adults with Type 1 diabetes mellitus : is there evidence of accelerated ageing?" Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3446.

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The physical complications of Type 1 diabetes mellitus (T1DM) have been understood as an accelerated ageing process (Morley, 2008). Do people with T1DM also experience accelerated cognitive and brain ageing? Using findings from research of the normal cognitive and brain ageing process and conceptualized in theories of the functional brain changes in cognitive ageing, a combination of cognitive testing and functional magnetic resonance imaging (fMRI) techniques were used to evaluate evidence of accelerated cognitive and brain ageing in middle-aged adults with T1DM. The first part of this thesis comprises a cognitive study of 94 adults (≥ 45 years of age) with long duration (≥ 10 years) of T1DM. Participants completed cognitive assessment and questionnaires on general mood and feelings about living with diabetes. Findings highlighted the importance of microvascular disease (specifically retinopathy) as an independent predictor of cognitive function. The incidence and predictors of mild cognitive impairment (MCI) were then explored. Results indicate a higher percentage of the group met criteria for MCI than expected based on incidence rates in the general population, providing initial evidence of accelerated cognitive ageing. Psychological factors were explored next. The relationship between the measures of well-being, diabetes health, and cognitive function highlighted the need for attention to patient's psychological well-being in diabetes care. Finally, a subgroup of 30 participants between the ages of 45 and 65 who differed on severity of retinopathy were selected to take part in an fMRI study. Blood oxygen level dependent (BOLD) activity was evaluated while participants were engaged in cognitive tasks and during rest. The findings provided evidence that the pattern of BOLD activation and functional connectivity for those with high severity of retinopathy are similar to patterns found in adults over the age of 65. In line with the theories of cognitive ageing, functional brain changes appear to maintain a level of cognitive function. Evidence of accelerated brain ageing in this primarily middle-aged group, emphasizes the importance of treatments and regimens to prevent or minimize microvascular complications.

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Royle, Natalie Anne. "Quantifying structural changes in the ageing brain from magnetic resonance imaging." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15835.

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Understanding the ageing process is of increasing importance to an ageing society and one aspect of this is investigating what role the brain has in this process. Cognitive ability declines as we age and it is one of the most distressing aspects of getting older. Brain tissue deterioration is a significant contributor to lower cognitive ability in late life but the underlying biological mechanisms in the brain are not yet fully understood. One reason for this is the difficulty in obtaining accurate measures of potential ageing-related brain biomarkers. The chapters in this thesis explore the difficulties of quantifying brain changes in the ageing brain from Magnetic Resonance Imaging (MRI), and how the changes identified are related to cognition in later life. The data was acquired as part of the second wave of the longitudinal Lothian Birth Cohort 1936 study in which 866 people aged 73 years, returned for cognitive and medical assessment. At this stage of the study 702 underwent MR imaging resulting in 627 complete datasets across all testing. The entire data, a randomly chosen subset of 150 and 416 freely available data were used to investigate global and regional measurement methods in older brains and how the resultant measurements related to cognitive performance. Furthermore the presence of early life cognitive data in the form of a general intelligence test sat at age 11, served as an indicator of cognitive ability prior to the potential influence of the ageing process. The chapters concerning global measures at first establish, that a measure of intracranial volume (ICV) serves as both a way of correcting for individual differences in brain size between participants and as a proxy premorbid measure of brain size. The analysis, utilising freely available cross-sectional MRI data (http://www.oasis-brains.org) revealed that ICV differed very little between 18-28 year olds and 84-96 year olds where as total brain tissue volume (TBV) differed by 14.1% between the two groups, which was more than twice the standard deviation across the entire age range (18-96 years). Second a validated, reliable method for measuring ICV was investigated using 150 people randomly chosen from the LBC1936 study. Automated and semi-automated methods were validated against reference measurements the results of which showed that common ageing features make automated and semi-automated methods that do not have an additional manual editing step, ineffective at producing accurate ICV measurements. This analysis also highlighted the need to employ additional spatial overlap assessment to volumetric comparison of measurement methods to reduce the effect of false-positives and false-negatives skewing apparent discrepancies between methods. Using the information gained here ICV and TBV from the entire LBC1936 cohort were analysed in a structural equation model, alongside cognitive ability measures at both age 11 and age 73. We found that TBV was a stronger predictor of later life cognitive ability, after accounting for early life ability, but that a modest association remained between ICV and late life cognition. This suggests that early life factors pay a role in how well we age, though the relationship is complex. The regional measures chapters look at two brain regions commonly associated with ageing, the hippocampus and the frontal lobes. Measuring either of these brain regions in large samples of healthy older adults is challenging for many reasons. The hippocampus is small and as with all brain regions shows greater variation in older age, this makes employing automated methods that have the advantage of being fast and reproducible difficult. Following the results of our systematic review of automated methods for measuring the hippocampus, the two most commonly used and available automated methods were validated against reference standard measurements. The results indicated that although automated methods present an attractive alternative to laborious manual measurements they still require manual editing to produce accurate measurements in older adults. The modified strategy employed across the LBC1936 was to use an automated method and then manually edit the output; these segmentations were used to investigate the potential of multimodal image analysis in clarifying associations between the hippocampus and cognitive ability in old age. The analysis focused on associations between longitudinal relaxation time (T1), magnetization transfer ratio (MTR), fractional anisotropy (FA) and mean diffusivity (MD) in the hippocampus and general factors of fluid intelligence, cognitive processing speed and memory. The findings show that multi-modal MRI assessments were more sensitive than volumetric measurements at detecting associations with cognitive measures. The difficulty with producing a relevant frontal lobe measure was made apparent when the result of a large systematic review looking at the manual protocols used revealed 19 methods and 15 different landmarks had been employed. This resulted in an analysis that took the 5 most common boundaries reported and applied them to 10 randomly selected participants from the LBC1936. The results showed significant differences between the resultant volumes, with the smallest measurement when using the genu as the posterior marker representing only 35% of the measurement acquired using the central sulcus. The results from the studies presented in this thesis strongly highlight the need to develop age specific methods when using brain MRI to study ageing. Furthermore the implications of using unstandardised protocols, making assumptions about a methods performance based on validation in younger samples and the need to account for early life factors in this area of research have been made clearer. Studies building on these findings will be beneficial in elucidating the role of the brain in ageing.

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Wagner, Gabriela Peretti. "Disfunções executivas no envelhecimento cognitivo : investigações com os instrumentos Tarefa do Jogo e Teste Wisconsin de Classificação de Cartas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/11247.

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Esta dissertação consiste em dois estudos que têm por objetivo investigar a existência de disfunções executivas no envelhecimento. Estudos recentes sugerem a existência de disfunções executivas no Declínio Cognitivo Leve (DCL). O objetivo do Estudo 1 foi verificar a presença de disfunções executivas em pacientes com DCL. Os instrumentos utilizados foram o Teste Wisconsin de Classificação de Cartas (WCST) e a Iowa Gambling Test (IGT). Foram estudados dez pacientes com e 27 sem DCL. Os dados foram analisados através do teste t de Student para amostras independentes e da análise de variância (ANOVA) para medidas repetidas. Os resultados não evidenciaram diferença significativa entre os grupos nos índices de resposta do WCST e no número de cartas retiradas de cada baralho no IGT. O estudo da evolução do desempenho no IGT revelou diferença qualitativa entre os grupos. Idosos sem DCL aprendem ao longo da tarefa, enquanto idosos com DCL não o fazem, sugerindo uma interferência dos sistemas de memória na tomada de decisão. O Iowa Gambling Test tem sido um instrumento utilizado na avaliação da tomada de decisão. O objetivo do Estudo 2 foi investigar se alterações nos procedimentos de aplicação do instrumento interferem no desempenho durante a execução do teste. Foi realizado um estudo transversal comparando dois grupos de idosos saudáveis em duas variações do instrumento. O grupo I contou com 27 participantes, que executaram a tarefa sem pista de reforço visual. O grupo II foi composto por 17 participantes, submetidos à tarefa com pista. Os dados foram analisados através dos testes t de Student para amostras independentes e ANOVA para medidas repetidas. Houve diferença estatisticamente significativa entre os dois grupos na execução do teste em relação à aversão ao risco (F=2,466; p=0,05; df=2). Os resultados indicam que uma pista de reforço visual possibilita maior alocação de recursos atencionais e de memória de trabalho, permitindo que os idosos tomem decisões menos arriscadas.
This dissertation is formed by two works that aim to investigate executive dysfunction on ageing. Recent studies suggest the existence of executive dysfunctions in Mild Cognitive Impairment (MCI). The aim of the first study was to verify the presence of executive dysfunctions in patients with MCI. The instruments used were the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Test (IGT). Ten patients with and 27 without MCI were assessed. The data were analyzed through Student t test for independent samples and analysis of variance (ANOVA) for repeated measures. The results did not show significant difference between groups in the answer rates of WCST and in the number of cards withdrawn from each pack of cards in the IGT. The study of the performance evolution in the IGT revealed a qualitative difference between the groups. Elderly without MCI learn along the task, while elderly with MCI did not, suggesting an interference of memory systems in decision making. The Iowa Gambling Test has been an instrument used in the assessment of decision making. The aim of the second study was to investigate if changes in the application procedures of the instrument interfere in the performance through the test execution. A cross sectional study was carried out comparing two groups of healthy elderly in two variations of the instrument. The group I included 27 participants, which executed the task without clue of visual reinforcement. The group II was composed by 17 participants, submitted to the task with clue. The data were analyzed through the Student t test for independent samples and ANOVA for repeated measures. It was found statistically significant difference between the two groups in the execution of the test in relation to risk aversion (F=2,466; p=0,05; df=2). The results indicate that a clue of visual reinforcement permits greater allocation of attention resources and of working memory, allowing elderly to make least risky decisions.

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Ross, Amy Psychiatry Faculty of Medicine UNSW. "Longitudinal study of cognitive and functional brain changes in ageing and cerebrovascular disease, using proton magnetic resonance spectroscopy." Awarded by:University of New South Wales. School of Psychiatry, 2005. http://handle.unsw.edu.au/1959.4/27329.

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The neurophysiological basis of cognition changes with age is relatively unexplained, with most studies reporting weak relationships between cognition and measures of brain function, such as event related potentials, brain size and cerebral blood flow. Proton magnetic resonance spectroscopy (1H-MRS) is an in vivo method used to detect metabolites within the brain that are relevant to certain brain processes. Recent studies have shown that these metabolites, in particular N-acetyl aspartate (NAA), which is associated with neuronal viability, correlate with performance on neuropsychological tests or other measures of cognitive function in patients with a variety of cognitive disorders associated with ageing and in normal ageing subjects. We have studied the relationship between metabolites and cognitive function in elderly patients 3 months and 3 years after a stroke or transient ischemic attack (TIA) and in an ageing comparison group. Metabolites were no different between stroke/TIA patients and elderly controls, however, there were significant metabolite differences between stroke/TIA patients with cognitive impairment (Vascular Cognitive Impairment and Vascular Dementia) and those without. Frontal measures of NAA and NAA/Cr predicted cognitive decline over 12 months and 3 years in stroke/TIA patients and elderly controls, and these measures were superior predictors than structural MRI measures. Longitudinal stability of metabolites in ageing over 3 years was associated with stability of cognitive function. The results indicate that 1H-MRS is a useful tool in differentiating stroke/TIA patients with and without cognitive impairment, with possibly superior predictive ability than structural MRI for assessing future cognitive decline. The changes in 1H-MRS that occur with ageing and cognitive decline have implications for the neurophysiological mechanisms and processes that are occurring in the brain, as well as application to clinical diagnosis, the early detection of pathology and the examination of longitudinal change.

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Dissertations / Theses on the topic 'Cognitive ageing'

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