Abstract
Introduction: With increasing age, many adults experience reduced spatial navigation ability, with the most prominent reductions in tasks dependent on the hippocampus. Hippocampal dysfunction may be linked to age-related increases in sleep fragmentation, which results in reduced neurogenesis and long-term potentiation. This project aims to determine if age-related reductions in hippocampal-dependent navigation ability and strategy selection are mediated by impaired sleep. Further, we propose that the effects of sleep on navigation are moderated by psychological stress and physical activity. Methods: 36 older (m: 70, sd: 7) and 33 younger (m: 20, sd: 1.5) adults recorded one week of sleep via wrist actigraphy. Sleep parameters included sleep fragmentation and total sleep time. Subsequently, participants completed navigation tasks probing hippocampal-dependent navigation performance (i.e., cognitive mapping) and striatal dependent navigation performance (i.e., route learning), as well a measure of spontaneous hippocampal vs. striatal strategy selection. Self-reported stress and physical activity were also collected. Results: Age was significantly associated with reduced performance on the hippocampal-dependent and striatal-dependent navigation tasks as well as reduced use of a hippocampal-dependent strategy (psps>0.1) but was associated with reduced total sleep time (ps<0.05). Sleep fragmentation and total sleep time were associated with lower cognitive mapping performance across age groups (pppps>.05). Discussion: Fragmented sleep impairs hippocampal-dependent navigation performance and may be independent of age-related impairment. However, total sleep time may be one factor contributing to age-related reductions in hippocampally-based navigation performance.
Committee Chair
Denise Head
Committee Members
David Balota Jeffrey Zacks
Degree
Master of Arts (AM/MA)
Author's Department
Psychology
Document Type
Thesis
Date of Award
Spring 5-2020
Language
English (en)
DOI
https://doi.org/10.7936/0s36-f987
Author's ORCID
https://orcid.org/0000-0001-6905-5411
Recommended Citation
Maybrier, Hannah, "Quality of Sleep, Stress, and Exercise: Effects of Environmental and Lifestyle Factors on Spatial Navigation in Older Adults" (2020). Arts & Sciences Theses and Dissertations. 2040.
The definitive version is available at https://doi.org/10.7936/0s36-f987