Unconstrained, phonemic and semantic verbal fluency: age and education effects, norms and discrepancies

OBJECTIVE: To present performance norms and discrepancy score of three one-minute verbal fluency tasks (VFTs); to investigate age and education effects; to analyze the differences between time intervals; and to investigate whether these differences varied according to age and education. METHOD: Three hundred adults divided into three age groups (19-39; 40-59; 60-75) and two groups of educational level (2 to 7 years; 8 years or more) performed unconstrained, semantic, and phonemic VFTs. We compared the performance of the groups using two-way ANOVA with post-hoc Bonferroni test. The depression scale score was covariate. The time interval of verbal fluency was the variable used for subjects' comparison (repeated measures ANOVA). RESULTS AND CONCLUSIONS: Our results suggest that there are age and education effects on phonemic and unconstrained VFTs. We also found an interaction between those variables in the semantic VFT (time intervals and total time) and in the differences between semantic and phonemic tasks. The repeated measures analysis revealed age effects on semantic VFTs and education effects on the phonemic and semantic VFTs. Such findings are relevant for clinical neuropsychology, contributing to avoid false-positive or false-negative interpretation.