Date of Award

10-14-2024

Author's School

Graduate School of Arts and Sciences

Author's Department

Psychology

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

ABSTRACT OF THE DISSERTATION Age, Slow Wave Sleep, and Hippocampal-Dependent Memory: Insights into Cognitive Mapping by Hannah Maybrier Doctor of Philosophy in Psychological and Brain Sciences Clinical Science Aging and Development Washington University in St. Louis, 2024 Denise Head, Chair Aging affects the ability to form cognitive maps—mental representations of spatial layouts—leading to reduced driving mobility and reluctance to visit unfamiliar places (Bryden et al., 2013; Burns, 1999). Since independence is crucial for successful aging, reduced mobility is linked to lower quality of life and well-being in older adults (Spinney et al., 2009). Identifying lifestyle factors that impair cognitive mapping could inform strategies to prevent age-related declines, with sleep being a key factor. Poor sleep quality has been associated with impairments in brain regions, including the hippocampus, and hippocampal-dependent memory processes essential for cognitive mapping (Guzman-Marin et al., 2007; Hagewoud et al., 2010; Tartar et al., 2006). Additionally, slow wave activity (SWA) during NREM sleep has been linked to age-related deficits in overnight changes in cognitive map use (Varga et al., 2016). This study expanded on these findings by measuring at-home electroencephalography in young, middle-aged, and older adults. The first aim examined associations between SWA and encoding and use of cognitive maps, as well as verbal and spatial associative memory. Higher SWA was linked to better verbal associative memory encoding (B=2.51 (1.13), p=0.027), partially mediating the relationship between older age and lower verbal associative memory encoding performance (indirect effect: -0.148, bootstrapped 95% CI: -0.414 – -0.004). The second aim investigated whether SWA the night after encoding was related to overnight changes in cognitive map accuracy and use and verbal and spatial associative memory; no significant associations were found (ps > 0.315). Overall, findings suggest that SWA is more robustly associated with encoding than overnight changes in hippocampal-dependent memory, specifically in verbal but not spatial domains. Furthermore, results suggest that SWA is a contributing factor in age-related verbal associative learning deficits.

Language

English (en)

Chair and Committee

Denise Head

Committee Members

Ben Palanca; David Balota; Ian Dobbins; Michael Scullin

Available for download on Thursday, April 10, 2025

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