Factor analyses across lifespan: based on composite scores derived from the Rey - Auditory Verbal Learning Test (AVLT).

Abstract

Objective: The goal of this study, by using factor analyses, was to reveal the structure of the interrelations between the various total and composite scores generated by the Rey AVLT. A second goal was to address the question: does this structure remain constant across the lifespan?

Method: This study consists of three phases: In Phase I, six total scores were submitted to Exploratory Factor Analysis (EFA) conducted on the entire sample (n = 1471) with an age range of 8-91. In Phase II, EFA was conducted on seven composite scores - five process scores and two total scores, applied to the entire sample. In Phase III, the same scores were then submitted to separate Confirmatory Factor Analysis for five age cohorts (8-12, 13-17, 20-29, 30-59, & 60-91).

Results: In Phase I, when total scores were used, unconstrained rotation yielded a single factor. Only under constraining to a three-factorial model did Learning, Storage, and Retrieval emerge. In Phase II, when process scores were used, under unconstrained rotation, a three-factorial model, Learning, Storage, and Retrieval, emerged. The results in Phase III confirmed that the three-factor model shows a developmental trajectory throughout the lifespan. Furthermore, the factors' loading parameters were found to be similar across all age groups.

Conclusions: This study has major theoretical and clinical/diagnostic implications. On the theoretical level, it confirmed that there are three distinct memory processes underlying the Rey AVLT: Learning, Storage, and Retrieval. Furthermore, these processes remain constant across the entire age range, 8-91 years old. On a clinical level, the current results could lead the diagnostician to a conceptually driven diagnosis by pinpointing the exact impaired or preserved memory process, based on the constellation of the various Rey AVLT scores, according to the factor on which they are loaded.