Dissertations, Theses, and Capstone Projects

Date of Degree

9-2025

Document Type

Doctoral Dissertation

Degree Name

Doctor of Philosophy

Program

Psychology

Advisor

Laura Rabin

Committee Members

Justin Storbeck

Anjali Krishnan

Yvette Caro

Kathleen Mangiapanello

Subject Categories

Clinical Psychology | Geropsychology

Keywords

dementia, performance-based assessments, functional ability

Abstract

Deficits in instrumental activities of daily living (IADL) are a hallmark of dementia, and the unprecedented aging of the population strongly motivates early identification of older adults at-risk for functional decline. In 2015, the White House Conference on Aging emphasized the need to improve detection of diminished capacity across important areas of functioning. To date, there is very limited research on early IADL changes in cognitively unimpaired (CU) individuals and those with subjective cognitive decline (SCD) and mild cognitive impairment (MCI), who may be in early preclinical dementia stages. Additionally, little is known about how changes in functional brain networks contribute to IADL deficits. To address these critical gaps, we utilized objective performance-based assessments, the Night Out Task (NOT) and the Financial Capacity Instrument – Short Form (FCI-SF) to 1.) investigate the utility of performance-based assessments to characterize subtle changes in IADL; and 2.) examine the association between changes in functional brain networks such as the Default Mode Network (DMN) and Executive Control Network (ECN) and IADL performance in preclinical dementia stages. For aim 1, our study sample comprised of 93 older adults classified as CU (N = 30), SCD (N = 34), and MCI (N=29) and for aim 2, our sample included 82 older adults classified as CU (N = 27), SCD (N = 31), and MCI (N=24) due to inability of some participants to tolerate the resting state functional magnetic resonance imaging scan (rs-fMRI). Overall, this study holistically addressed gaps in the assessment of subtle to more pronounced functional deficits among older adults with SCD and MCI. Our results demonstrated that performance-based assessments IADL may allow for earlier detection of subtle functional changes that might not be adequately captured by traditional measures and decline in IADLs is linked to decreased connectivity between neural networks implicated in AD dementia, such as the DMN and ECN, during preclinical disease stages. As a matter of public health, early identification of compromised functional ability, which increases social dependence and vulnerability, is crucial. Taken together, this dissertation addresses critical gaps in the assessment of IADL changes and provides support for utilizing performance-based assessments to detect subtle changes in functional ability among older adults.

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