Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name



Cognitive Neuroscience


Elizabeth Chua

Subject Categories

Cognitive Science | Geropsychology | Medicine and Health Sciences


vascular cognitive impairment, neurocardiovascular instability, healthy cognitive aging, syncope, falls, reduced baroreflex function


In aging populations, the abnormal neural control of the cardiovascular system has been examined within the construct of neurocardiovascular instability (NCVI). The main research aim addressed whether baseline features of NCVI could predict cognitive function (i.e., decline) at follow-up within long-lived families. Across 941 subjects, baseline NCVI risk was indexed by two features: (1) self-reported syncopal or fall events and (2) average seated BP. The Low NCVI risk group included those who were normotensive (e.g., within normal BP range) and reported no NCVI features (n=379). The Moderate NCVI risk group included those who elicited pre-hypertensive (elevated BP) or hypertensive (high BP) readings, indicating secondary NCVI risk (n=354). The High NCVI risk group included those who presented NCVI features (n=208). Generalized Estimating Equation models were run to compare baseline and follow-up cognitive performance (using global and multi-domain tests) by NCVI risk group. While NCVI exists in prodromal stages (as elicited by Moderate and High NCVI risk groups), its impacts on cognition seem to vary based on model type (e.g., cross-sectional, longitudinal). Subjects within the High NCVI risk group were found to elicit poorer processing speed cross-sectionally whilst semantic fluency remained intact at the longitudinal timepoint. In order to better understand NCVI etiology and progression towards cognitive impairment, we encourage future research models to incorporate both individuals at prodromal (e.g., elicit occasional NCVI features) and advanced stages (e.g., elicit pre-existing, chronic autonomic and/or neurodegenerative conditions) concurrently.