Cognitive impairment no dementia (CIND) is conceptualized as a stage of cognitive decline between normal aging and onset of dementia. As persons with CIND are at high risk of developing dementia, efforts to determine early predictors of cognitive decline are warranted to advance both clinical knowledge and practice. Recent evidence suggests persons with CIND may have changes in vascular function compared to non-impaired peers, which may have clinical potential to differentiate those with and without CIND. The purpose of this study is to determine whether vascular functioning, examined both by individual indicators and as an aggregate vascular factor, will be associated with cognitive impairment. It is expected that the individual vascular indicators of hypertension, diabetes, stroke, and heart problems will be related to cognitive status classification, with poorer vascular function being more strongly associated with CIND as compared to the control group. Further, it is expected that examining the aggregate vascular factor in a multivariate approach will be more strongly associated with cognitive status than examining the vascular indicators individually. Data for this study were collected in the Victoria Longitudinal Study (VLS), a large-scale longitudinal, sequential study of community-dwelling older adults in Victoria, British Columbia. Cognitive group status was determined by a distributional approach based on scores on 5 cognitive reference measures. The associations between all vascular factors and cognitive status groups were assessed using chi-square analyses. Univariate analyses were then carried out using ordinal logistic analysis. A multivariate approach using discriminant analysis was then used to determine if cognitive status group membership was associated with vascular function based on linear combinations of vascular indicators. Contrary to expected results, we did not find a significant association between any of the vascular indicators (i.e., blood pressure classification, severity of stroke, severity of heart troubles, and severity of diabetes) and the cognitive status classifications. Further, group membership was not associated with any of the individual vascular markers, or by a multivariate combination of the indicators. Several reasons for this study’s findings include discrepant definitions of cognitive impairment in the literature, sample characteristics (i.e. high education, low base rate of vascular problems), and methodological considerations. Future research objectives should address the longitudinal association of vascular function and cognitive status. / Graduate

Objective: This dissertation was undertaken to explore the clinical utility of physiological and behavioural metrics of neurocognitive adaptability in the screening of older adults for possible early signs of pathological cognitive aging. Methods: This was an intensive, multi-method study of 44 healthy (non-demented) Victoria-area older adults (ages 65 to 80 years). Study 1 examined timescale-specific differences in resting electroencephalographic (EEG) adaptability as a function of subtle cognitive decline. Study 2 described differences in retest practice effect -- within and across a burst of 4 to 6 occasions of computerized cognitive testing -- with respect to individual variation in estimated premorbid function and self-reported conscientiousness. Study 3 considered whether practice effects from Study 2 were related to individual differences in the resting EEG marker derived in Study 1, above and beyond the differences due to premorbid function and conscientiousness. Results: Study 1 revealed that older adults with neuropsychological performance indicators of subtle cognitive decline also showed subtle, timescale-specific differences in resting EEG adaptability. Study 2 illustrated the differentiable effects of individual differences in estimated premorbid function and conscientiousness on within- and across-occasion improvement on a computerized attention-shifting (switch) task. Study 3 demonstrated the unique promotional effects exerted by conscientiousness and resting EEG adaptability on the rate of across-occasion improvement in cognitive performance. Conclusions: Useful yet under-used tools for detecting early signs of neurocognitive decline include rigorous, standardized neuropsychological diagnostic criteria, the magnitude of practice-related improvement in cognitive performance, and characteristics of the brain's resting electrical activity. Future multi-method, ecologically-situated studies are needed to establish standardized protocol that can be used to screen growing worldwide numbers of older adults for losses in neurocognitive adaptability that may herald the earliest stages of pathological neurocognitive aging. / Graduate

Purpose of review: This article critically reviews the utility of “phenotypes” as behavioral descriptors in aging/HIV research that inform biological underpinnings and treatment development. We adopt a phenotypic redefinition of aging conceptualized within a broader context of HIV infection and of aging. Phenotypes are defined as dimensions of behavior, closely related to fundamental mechanisms, and, thus, may be more informative than chronological age. Primary emphasis in this review is given to comorbid aging and cognitive aging, though other phenotypes (i.e., disability, frailty, accelerated aging, successful aging) are also discussed in relation to comorbid aging and cognitive aging. Recent findings: The main findings that emerged from this review are as follows: (1) the phenotypes, comorbid aging and cognitive aging, are distinct from each other, yet overlapping; (2) associative relationships are the rule in HIV for comorbid and cognitive aging phenotypes; and (3) HIV behavioral interventions for both comorbid aging and cognitive aging have been limited. Summary: Three paths for research progress are identified for phenotype-defined aging/HIV research (i.e., clinical and behavioral specification, biological mechanisms, intervention targets), and some important research questions are suggested within each of these research paths.

Studying older adults who are aging ‘successfully’ (i.e., avoiding disease/disability; maintaining high cognitive and physical functioning; engaging in meaningful interpersonal/social engagement) may offer insight into variables that contribute to cognitive change throughout the lifespan. Successful aging is related to levels of engagement, which may be promoted by the problem solving and reevaluation encouraged by the creative process (Fisher & Specht, 1999). Creative thinking requires the consideration of diverse concepts and strategies (e.g., generating many solutions), as well as the regulated filtering of these possibilities (e.g., neither too permissive nor too narrow when eliminating ideas; Baas, De Dreu, & Nijstad, 2011). Cognitive inhibition is necessary for goal-directed behavior, and may also promote creativity by influencing abilities such as plasticity and innovation. Performance on executive control tasks, especially those that draw on inhibition, are impacted by age. Performance on inhibitory (but not excitatory) tasks may be sensitive to arousal levels that fluctuate with circadian rhythm (synchrony effect). The current study examined performance on a variety of neuropsychological and creativity measures at two times of the day in a sample of successfully aging adults aged 70-79. Assessments of executive function, inhibition, and creativity (i.e., verbal and non-verbal divergent thinking) were administered to older adults twice, once at a time when inhibitory performance was expected to be ideal (synchronous) and another at a time when inhibitory performance was expected to be reduced (non-synchronous). We hypothesized that morning testing (synchronous) trials of inhibitory tasks would exhibit lower latency and error rates than evening testing (non-synchronous) trials; morning testing (synchronous) trials of creative potential tasks would exhibit lower fluency, flexibility, and originality scores than evening testing (non-synchronous) trials; and that Need For Cognition (NFC) scores and Information-Orientation ISI subscale scores would be positively correlated with overall (AM + PM) creativity scores (fluency, flexibility, originality). Participants were expected to demonstrate time of day effects on Stroop and TMT performance. Synchrony effects were not observed in this study. There was a significant relation between creative potential and Need for Cognition scores but not between creative potential and scores on the Information-Orientation subscale of the ISI. The current sample may have compensated with cognitive challenges such as those induced by testing time effects. These findings may suggest that a successfully-aging cohort is not impacted by synchrony effects. No previous research has used synchrony to compare aging trajectories (pathological, usual, successful) on cognitive performance. It is feasible that a successfully aging population would have significant cognitive reserve, brain reserve, or scaffolding strategies to compensate for the additional cognitive challenge of non-optimal testing time (Düzel, Schütze, Yonelinas, & Heinze, 2011; Reuter-Lorenz & Park, 2014). Indeed, a marker of successful aging is to compensate well with age-related changes and demonstrate minimal- to no- deficits in performance (Rowe & Kahn, 1997). Synchrony changes in cognitive performance may not be evident in a successfully aging population. The current study provides evidence that motivates intriguing questions about successful aging, inhibition, creativity, and time of day.

No description available.

If not designed in consideration to the workings of the human mind, multimedia learning environments can impose too high a demand on working memory. While such high cognitive load presents challenges for learners of all ages, older learners may be particularly affected as research on cognitive aging has shown the efficiency of working memory declines with age. Research has suggested that cognitive load theory (CLT) and the cognitive theory of multimedia learning (CTML) are likely to accommodate the cognitive needs of older learners; however, few of the principles emerging from these theories have been examined in the context of cognitive aging. The abundance of studies has focused on younger learners, prompting the need for further research of CLT and CTML principles with regard to age. This study contributes to the body of research on the cognitive aging principle by extending research on the modality effect with middle-aged learners. Ninety-two participants ranging in age from 30 to 59 were exposed to multimedia learning treatments presented as animation with concurrent narration and animation with concurrent text, followed by retention, concept, and transfer tests of multimedia learning. Demographic and descriptive statistics were performed along with a multivariate analysis of variance. The findings did not show a modality effect with middle-aged learners; however, results need to be interpreted with care as possible explanations may entail other causes for the lack of a modality effect other than age.

Yes / Objective: To test the efficacy of a tablet computer training intervention to improve cognitive abilities of older adults. Design: Prospective randomized controlled trial. Setting: Community-based aging intervention study, Edinburgh, UK. Participants: Forty-eight healthy older adults aged 65 to 76 years were recruited at baseline with no or minimal tablet experience;43 completed follow-up testing. Intervention: Twentytwo participants attended a weekly 2-hour class for 10 weeks during which they learned how to use a tablet and various applications on it. Measurements: A battery of cognitive tests from theWAIS-IV measuring the domains ofVerbal Comprehension, Perceptual Processing,Working Memory, and Processing Speed, as well as health, psychological, and well-being measures. Results: A 2× 2 mixed model ANOVA suggested that the tablet intervention group (N = 22) showed greater improvements in Processing Speed (η2 = 0.10) compared with controls (N = 21), but did not differ in Verbal Comprehension, Perceptual Processing, or Working Memory (η2 ranged from −0.03 to 0.04). Conclusions: Engagement in a new mentally challenging activity (tablet training) was associated with improved processing speed.Acquiring skills in later life, including those related to adopting new technologies, may therefore have the potential to reduce or delay cognitive changes associated with ageing.It is important to understand how the development of these skills might further facilitate everyday activities, and also improve older adults’ quality of life. / Supported by the Dunhill Medical Trust (R359/0514). Funding from the BBSRC and MRC

This thesis project had the overall aim of investigating older adults (OA) representation of real-world objects through different cognitive paradigms probing visual working memory (vWM) and attention. OAs are known to demonstrate difficulties in these two cognitive domains, however, an under-researched in the aging field is the possible influence of the quality of representations in conjunction with the amount of representations in determining OA’s performances. Moreover, a majority of research in the aging field has utilized geometrical shapes, therefore I was interested to investigate whether the previous findings extend when real-world objects are used. Accordingly, the main questions accordingly probed in this study were 1) whether the content of object representations influence OAs’ performances when vWM and attention are probed, or whether effects are solely due to the amount, and 2) whether age-effects found in previous vWM and attention studies in aging, extend when real-world objects are used. To this aim, Chapter 3 describes two experiments where I manipulated the perceptual and conceptual similarity amongst objects presented to OAs and young adults (YAs) when performing a change detection task taxing vWM. Results indicated both age groups had significantly lower performances when there 3 objects to retain and recall, but no age-related differences in the maintenance and recall of these types of objects. Chapter 4 and Chapter 5 report three experiments addressing the impact of object numerosity and/or nature in OAs’ attention deployment during a visual search task. Results of two experiments in Chapter 4 with manual responses found that OAs’ performance was detrimentally impacted by the amount of object representations, irrespective of the relation amongst the items. Chapter 5 illustrates an eye movement study, aimed at exploring more in detail the visual exploratory behavior of older and young individuals. Overall, OAs were slower and showed a larger tendency to get distracted than YAs, regardless of the perceptual or conceptual target-distractor similarity. Overall, the studies presented in this thesis indicated that aging negatively affects the ability to ignore distracting information. However, little evidence was provided as to whether aging negatively influences the content representation of an object. This result confirms previous research indicating that some, but not all aspects, decline in late adulthood.

Cognitive control allows us to function in a world filled with constant stimulation. For example, the act of reading a book requires the ability to inhibit irrelevant information while focusing attention towards the letters on the page. Our cognitive control system regulates what information receives attention and what is denied resources. The goal of the current paper is to investigate the mechanisms underlying the activation and maintenance of the control system and how this process changes in healthy aging. First, the ability of younger and older adults to activate and maintain control in response to trial type manipulations is investigated. Second, improvements are made to recent experimental evidence suggesting younger adults are able to modulate performance based on specific stimulus history. Third, this work is extended to an older population suggesting the ability to modulate performance based on specific stimulus history is maintained in healthy aging. Finally, it is demonstrated that current theories of control fail to account for age-related differences in performance based on the comparison of trial type and specific stimulus manipulations.

Nutrition can be viewed as a modifiable factor related to maintaining and preserving health in older adults. Previous studies have found that nutritional factors can influence cognitive abilities, however few studies have examined macronutrients and micronutrients as they relate to cognitive functioning. Research has yet to examine the mechanisms related to nutrition, cognition and aging in an older adult population from a holistic and interactive perspective. This dissertation examined three research questions to better understand the relationship between age, nutrition, cognition, and inflammatory biomarkers. First, is nutrition related to cognition beyond demographic factors? Do individual nutrients serve as mediators? Second, are inflammatory biomarkers significant mediators to cognitive performance? Third, do nutrients and inflammatory markers interact as moderators to cognitive performance? This study examined 1,317 adults 60 years and older from the National Health and Nutrition Examination Survey III (NHANES III). Macronutrients were collected from a retrospective 24-hour dietary recall, micronutrient values were obtained from blood serum/plasma for vitamin C, vitamin D, vitamin E, homocysteine, iron, folate, and inflammatory biomarkers values were obtained from blood serum/plasma for C-reactive protein, fibrinogen, and ferritin. Cognition was measured by 6 tasks: immediate and delayed word recall, immediate and delayed story recall, orientation, and digit subtraction. All tasks were then combined to form a global cognitive measure. Results for question one found that after controlling for age, sex, education, and total calorie intake, higher intake of polyunsaturated fat was related to better global cognition and delayed story recall score (std β= .08, p= .028, std β= .08, p=.04 respectively). Greater than 28% of calories from carbohydrate indicated worse global cognition and delayed story recall (std β= -.013, p= .028, and std β= -.158, p= .01). Higher intake of saturated fat and protein were related to worse digit subtraction scores (std β= -.160, p= .02, std β= -.064, p= .02). Higher serum vitamin C, D, and folate levels were related to better global cognition and digit subtraction. Additionally, higher serum vitamin C and D were associated with better orientation score, and folate was related to better immediate and delayed story recall. Building from these relationships, individual mediation models found that serum vitamin C, vitamin D, folate, and ferritin were significant mediators between age and the previously mentioned cognitive tasks. Results for question two examined mediation between inflammatory markers and cognition and found that higher fibrinogen was related to worse global cognition and digit subtraction. Higher ferritin was associated with better delayed word recall. Question three investigated the moderating relationship between age, nutrients, and biomarkers, and results found that folate and fibrinogen were significant moderators. Higher serum folate was related to better global cognition and immediate story recall. Ferritin values below 1.2 and above 3.2g/l indicated worse digit subtraction performance. Evidence for a dose-dependent relationship was confirmed. Results from this project demonstrated that select nutrients (polyunsaturated fat, vitamin C, D, and folate), and inflammatory markers (ferritin and fibrinogen) were associated with cognitive performance across various cognitive domains. Consuming a diet rich in healthy fatty acids, and antioxidants may be beneficial for cognitive health. Future studies should continue to examine the underlying mechanisms connected to maintaining, preserving, and protecting cognitive abilities in older adults.