Abstract
The study tested the cognitive reserve hypothesis by quantifying cognitive reserve (CR) and subsequently determining its role in executive function and verbal episodic memory performance. A neuropsychological battery was administered to 383 Greek-Cypriot older adults. A multiple indicators multiple causes (MIMIC) latent construct was utilized to define CR incorporating three indicators: years of education, vocabulary, and reading performance. Findings from two structural equation models supported the moderating role of CR in reducing the direct negative effect of age on verbal episodic memory and on executive function. The study illustrates a parsimonious way of defining CR and provides empirical support for the CR hypothesis.
The authors would like to thank the many volunteers and their families for participating in this project. We are indebted to the staff from the many adult community centers who assisted our research team in the recruitment of study participants and facilitated our extensive testing processes, especially Kallia Sophocleous and Anna Filippou from the Strovolos Municipality, Sophia Metti from the Lacadamia Municipality, Panagiotis and Christina Karamani from Nicosia Municipality, Elena Theodoulidou Polidorou from Ayios Dometios Municipality, and the staff from EOKA Veterans Association and the Cypriot Retiree Union (EKYSY). Additionally, we are very thankful to the many researchers in the Neurocognitive Research Laboratory at the University of Cyprus who participated in the data collection and data management, and especially Juliana Prokopiou who manages the Neurocognitive Study on Aging.
This work was funded by the Cyprus Research Promotion Foundation through grant awarded to Fofi Constantinidou ANΘPΩΠIΣTIKEΣ/KOINΩ/0308(BE)/07 and NEA YΠOΔOMH/ΣTPATH/0309/37.
Notes
3. 1Two error covariances were added in the verbal episodic memory indicators between (a) Logical Memory immediate and Logical Memory delayed, which can be explained by the fact that the two scores are based on the same test, and (b) HVLT1 and Logical Memory delayed possibly indicating a common underlying mechanism of encoding. Two error covariances were added in the executive function indicators between (a) the TimeA and TimeB observed measurements probably because both are forms of the same test and (b) fluency category and phonemic fluency, as they are both measures of verbal fluency ability.