The cognitive aging literature contains abundant evidence of the natural vulnerability of the frontal areas of the brain and the associated impact on higher-order cognition. Namely, Executive Functions (EFs) have been repeatedly shown to decline steadily after 60 (Schaie, 2013). These age-related changes are said to impact most aspects of everyday life including quality of life (QoL; Davis et al., 2010), a key variable with regards to health, social service interventions and evidence-based clinical practices. Deepening our understanding of potential moderators of cognitive aging such as QoL is crucial to promoting well-being in the growing older adult population.
The overarching aim of this study was to investigate the moderating role of QoL over age-related EFs differences. A seminal taxonomy of EFs (Miyake et. al, 2000, 2012) and the work of the World Health Organization (WHO) on QoL (Power et al., 2005) inspired this endeavor. Six tasks of EFs related to Shifting, Updating, and Inhibiting and self-reported QoL based on the WHOQOL-BREF and -OLD were utilized with 102 community-dwelling, healthy older adults (M = 73.11 years; age range: 60 - 94). A moderation analysis was used to assess if QoL (moderator) buffers the relationship between age (IV) and EFs indicators (DV). Regression and MANCOVA analyses were conducted to evaluate age-related differences in EFs and the following prominent theories: the processing speed theory (Salthouse, 1996), inhibition deficit theory of cognitive aging (Hasher & Zacks, 1988), and dedifferentiation hypothesis (Garrett, 1946).
As predicted, age significantly contributed to task performance for most EFs indicators, above and beyond processing speed. As expected, statistically significant moderation interactions were found for several executive indicators and QoL domains, illustrating the buffering role of QoL over age-related differences in EFs. Specifically, QoL items related to the environment, sensory abilities, and social engagement domains, and EFs indicators related to Inhibiting, showed the most notable moderating effects. Implications for these results and the role of covariates were discussed. An emphasis was placed throughout on the importance of investigating QoL variables and other moderating factors of cognitive aging, for the development of prevention and intervention endeavors with older adults. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/8103 |
| Date | 11 May 2017 |
| Creators | Crevier-Quintin, Emilie |
| Contributors | Garcia-Barrera, Mauricio Alejandro |
| Source Sets | University of Victoria |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Available to the World Wide Web |
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