Formulation of the age–education index: Measuring age and education effects in neuropsychological performance.

The complex interplay of education, age, and cognitive performance on various neuropsychological tests is examined in the current study. New education indices were formulated and further investigated to reveal how age and education variances work together to account for performance on neuropsychological tests. Participants were 830 English-speaking ethnic Chinese. Neuropsychological measures such as Verbal Memory, Digit Sequencing, Token Motor Task, Semantic Fluency, Symbol Coding, Tower of London, Judgment of Line Orientation, and Matrix Reasoning of the Wechsler Adult Intelligence Scale were administered. Education was measured by total years of education and adjusted years of education, as well as ratios of both measures with age. Age and education were associated with neuropsychological performance. Adjusted years of education was associated with fluency and higher cognitive processes, while the ratio between adjusted years of education and age was associated with tasks implicating working memory. Changes in education modalities implicated tasks requiring language abilities. Education and age represent key neurodevelopmental milestones. In light of our findings, special consideration should to be given when neuropsychological assessments are carried out in cross-cultural contexts and in societies where educational systems and pedagogy tend to be complex.