The contribution of verbal delayed recall to phonemic but not semantic fluency in aging individuals.

OBJECTIVE: The cognitive abilities contributing to verbal fluency performance in aging individuals remain discussed. Besides executive functioning and processing speed, memory retrieval is necessary for successful verbal fluency performance. The latter has often been overlooked, although it may use similar retrieval mechanisms with verbal fluency performance. We aimed to investigate cognitive abilities contributing to phonemic and semantic fluency during the time course of the tasks. METHODS: One hundred and thirty-two healthy aging individuals were assessed with measures of verbal fluency, processing speed, executive functioning, word knowledge and delayed recall. Correlation analyses assessed pairwise associations between variables. Verbal fluency performance was modeled using Poisson regression, accounting for repeated measures. RESULTS: We observed significant correlations between verbal fluency and several cognitive measures and sex. Different cognitive predictors were found for phonemic and semantic fluency performance. Phonemic fluency was associated with word knowledge and inhibition while shifting ability was important for semantic fluency. Delayed recall was a significant predictor in the late interval during phonemic fluency. CONCLUSION: Our findings demonstrate that multiple cognitive abilities contribute to verbal fluency performance. More cognitive measures were associated with phonemic than semantic fluency, delayed recall being one of them. An increased understanding of contributing factors to fluency enables clinicians and researchers to meet individuals experiencing age-related changes in fluency performance.