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Process Dissociation Analyses Of Memory Changes In Healthy Aging, Preclinical, And Very Mild Alzheimer Disease: Evidence For Isolated Recollection Deficits, Peter R. Millar

Arts & Sciences Electronic Theses and Dissertations

Recollection and familiarity are independent processes that contribute to memory performance. Recollection is dependent on attentional control, which breaks down in early-stage Alzheimer disease (AD), whereas familiarity is independent of attention. The present study examines the sensitivity of recollection estimates based on Jacoby’s (1991) process dissociation procedure to AD-related biomarkers in a large sample of well-characterized cognitively normal older adults (N = 519) and the extent to which recollection discriminates these individuals from individuals with very mild symptomatic AD (N = 64). Participants studied word pairs, e.g., “knee bone,” then completed a primed, explicit, cued fragment-completion memory task, e.g., “knee …

Apoaequorin Differentially Modulates Fear Conditioning In Adult And Aged Rats, Vanessa Ehlers

Theses and Dissertations

Normal aging is associated with a number of changes in behavioral and cellular function, and is often linked to increased susceptibility to cognitive impairment. The hippocampus has been widely implicated in learning and memory, and many forms of learning that are hippocampus-dependent (e.g. trace fear conditioning) are impaired in aged animals. A proposed contributor to aging-related cognitive impairment is aging-related calcium (Ca2+) dysregulation. This dysregulation is thought to result from changes in specific Ca2+-regulatory mechanisms, including abnormal Ca2+ ion channel activity or expression, as well as reduced Ca2+-binding protein (CaBP) expression, which is associated with cognitive and synaptic impairment. Previous …

Intraindividual Variability As A Predictor Of Cognitive Decline In Elderly, Wendy S. Ramratan

Dissertations, Theses, and Capstone Projects

Mild cognitive impairment (MCI) is conceptualized as a transitional state between normal aging and fully developed clinical features of dementia. The literature on MCI is notable for varied measurement approaches and lack of stability in the diagnostic entity, with many individuals remaining stable or reverting to normal cognitive status. Researchers agree that multiple neuropsychological domains should be assessed to enhance the assessment and prediction of cognitive decline. In addition, within-person assessments capture trajectories of decline, which are better suited for understanding individual change than simple comparison to group norms. The current study investigated the ability of within-person change on novel …

Emotion Regulation In Relation To Cognitive Functioning In The Preclinical Stages Of Dementia, Erica P. Meltzer

Dissertations, Theses, and Capstone Projects

Emotion regulation (ER) is essential for effective functioning in daily life. Research suggests that ER improves in older adulthood despite concomitant declines in cognition and the presumed neural substrates of ER. The current understanding of ER in older adulthood, and particularly of the relationship between ER and cognition in older adulthood, is limited. This is likely because the construct of ER is challenging to operationalize and, therefore, difficult to study.

The current study investigates ER in relation to cognitive functioning, specifically executive functioning and memory, in individuals with varying degrees of cognitive difficulties (i.e., in the preclinical stages of dementia). …

Category Learning In Older Adulthood: Understanding And Reducing Age-Related Deficits, Rahel R. Rabi

Electronic Thesis and Dissertation Repository

Executive functions are important for learning rule-based (RB) categories, as well as non-rule-based (NRB) categories (e.g., categories learned implicitly, without a verbal rule). However, executive functioning is known to decline with age, leading to age-related deficits in category learning. The current thesis examines RB and NRB category learning in older adults using category sets that vary in difficulty (e.g., rule complexity, number of stimulus dimensions, salience of stimulus dimensions). In Chapter 2, older adults and younger adults completed three category sets (simple single-dimensional RB, disjunctive RB, and NRB). Older adults learned the simple, single-dimensional rules quite well. In contrast to …

Decision Making In Older Adults: A Comparison Of Delay And Probability Discounting Across, Ariana Vanderveldt

Arts & Sciences Electronic Theses and Dissertations

The value of an outcome is affected both by the delay until its receipt (delay discounting) and by the likelihood of its receipt (probability discounting). The discounting framework has greatly aided in modeling and understanding decision-making, particularly in the areas of impulsivity, but these findings have overwhelmingly been based on research with young adults. In three experiments, the current study extended the discounting framework by examining choice by older adults. Experiments 1 and 2 found that both young and older adults discounted delayed outcomes and probabilistic outcomes and that their choices were well-described by the same hyperboloid model. Both young …

The Interaction Of Crystallized And Fluid Abilities In Aging And Speech Perception, Avanti Dey

Arts & Sciences Electronic Theses and Dissertations

In a series of studies, I examined the degree to which fluid and crystallized abilities contribute to and interact during speech perception. During the aging process, crystallized abilities (e.g., linguistic and word knowledge) are largely preserved, while fluid abilities involved in the online manipulation of information (e.g., working memory and inhibitory control) decline with age. Importantly, these two components are critical for successful speech perception and comprehension. While prior research has proposed that older adults rely on crystallized knowledge to compensate for cognitive deficits in difficult listening conditions, this hypothesis has not been directly tested. Younger and older adults completed …

Dynamic Adjustments Of Cognitive Control In Healthy Aging: A Diffusion Model Analysis, Andrew Jacob Aschenbrenner

Arts & Sciences Electronic Theses and Dissertations

The control of attention over salient yet irrelevant information is a critical component of goal-directed behavior. Compared to younger adults, older adults often produce larger interference effects in tasks which tap selective attention, a deficit that has typically been viewed as reflecting an age-related decline in attentional control processes. Interference in distinct, attentionally demanding tasks has produced different influences on the characteristics of underlying response time distributions leading to the assumption of different control mechanisms operating across various paradigms. More recently, accumulating research has shown that the magnitude of observed interference can be critically modulated by the congruency of the …

Moderation Analysis Of Bowel Function Among Nutrients And Physical Function Or Depression, As Well As Whether Bowel Function Is Related To Cognition In Older Adults, Jessie Alwerdt

USF Tampa Graduate Theses and Dissertations

As we age, the risk for gut issues, such as smooth muscle tone, may be an underlying indirect or direct cause or risk factor for many age-related issues, such as frailty. Consequences of decreased motility and depleted epithelial barrier may result in nutrient deficiencies that may increase the risk for malnutrition (Brownie, 2006). Further, there is increasing evidence that there is a gut-brain-axis relationship that may influence cognition and mental health issues, such as depression and anxiety. While there are relationships established, the interconnections of these factors have yet to be fully understood.

This dissertation examined several relationships specific to …

Dance And Well-Being In Older Adult Communities: Exploring Efficacy As A Mediator, Beth M. Mcgowan

Honors Thesis

As the population of older adults expands, it becomes increasingly important to develop effective interventions to ensure high levels of well-being. Previous research in a variety of populations has shown that dance produces broad benefits including improving physical mobility, social relationships, autonomy, and self-image. Given this, the present study attempted to clarify the mechanisms through which dance might lead to these improvements. Specifically, this research examined the role of self-efficacy, or beliefs that one can accomplish certain tasks, have in explaining the psychological benefits of dance. I hypothesized that when dance is a social activity it instills a sense of …

Genetic Moderators Of Cognitive Decline In The Health And Retirement Study, Shannon K. Runge

USF Tampa Graduate Theses and Dissertations

The current dissertation used a gene x environment (G x E) approach to examine the independent and interactive effects of specific genetic variants and participation in physical and cognitive/social activities (PA and CSA) on cognitive performance in 4,764 participants of the Health and Retirement Study. Using three-wave data, three sets of multi-level growth models were conducted to examine baseline, longitudinal, and interactive effects of genotype (i.e., ApoE, COMT, and BDNF) and CSA/PA on performance across five cognitive measures: immediate, delayed and total word recall, and serial 7s and backwards counting.

At baseline, the ApoE ε4 allele predicted …

The Impact Of Age On Workplace Motivation: A Person-Centered Perspective, Keith Lynn Zabel

Wayne State University Dissertations

The present study used the person-centered approach to examine how profiles based upon six different age conceptualizations differentially impact workplace motivation. In the first known study to examine all conceptualizations of age simultaneously, results suggested the age conceptualizations of subjective age and health significantly impact growth motives for older workers, but not social or security motives. Results suggest social motives are influenced more by chronological age as opposed to other conceptualizations of age. Implications for practitioners in designing and implementing HR activities (e.g., succession planning) and researchers in utilizing all the conceptualizations of age and studying workplace interventions are discussed.

Aging And Emotion Recognition: An Examination Of Stimulus And Attentional Mechanisms, Stephanie Nicole Sedall

ETD Archive

Emotion recognition is essential for interpersonal communication. However, previous research has suggested that older adults are not as accurate as younger adults in recognizing certain emotions, particularly negative facial expressions of anger, fear, and sadness. Including additional contextual information (e.g., manipulation of certain facial features) might help us better understand these age differences. The present study investigated how potential age differences in emotion recognition are influenced by stimulus factors (target eye gaze direction) as well as facial viewing patterns, cognitive functioning, and physiological processes. A sample of younger and older adults viewed static facial expressions depicting anger, fear, sadness, happiness, …

Stereotype Threat And Work Attitudes Of Older Workers, Cheryl A. Countryman

Walden Dissertations and Doctoral Studies

Abstract

Despite an aging U. S. workforce, age discrimination at work remains an issue. Researchers have found that beliefs about the aging process affect workers' performance and attitudes. There is little research available examining this phenomenon from the perception of older workers. The purpose of this qualitative phenomenological study was to understand the lived experiences of 7 workers aged 55 and older regarding ageism through the theoretical framework of stereotype threat theory. Research questions focused on identifying age-related stereotypes held by the participants, the influence of those stereotypes on perceptions of aging, perception of the impact of aging on job …