Executive-linguistic coordination in aging: the impact of education on alternating and constrained verbal fluency

Verbal fluency tasks provide a sensitive measure of lexical retrieval and executive control. Beyond classical semantic and phonemic paradigms, complex variants such as the Alternating Fluency Task (EAF) and the Orthographic Constrained Semantic Fluency Task (EOCSF) impose higher demands on cognitive flexibility, inhibition, and strategic regulation. A total of 122 French-speaking adults were divided into two age groups (50-60 years, n = 61; 75+ years, n = 61). Participants completed both the EAF and EOCSF, each lasting 90 s. Linear regression and mixed-effects models with robust standard errors examined the effects of age, education, and time interval on productivity, clustering, switching, and error measures. Age-group differences were observed in overall performance, with older adults producing fewer correct words, particularly during early retrieval phases. This pattern supports a reduction in initiation speed and strategic control in older participants. Performance was lower in the EOCSF than in the EAF, reflecting higher inhibitory and monitoring demands. Education positively predicted total output and strategic efficiency - especially clustering - and attenuated age-group differences across both tasks. Age-group differences were most evident in initiation and flexibility, whereas education enhanced compensatory control and monitoring, consistent with a cognitive-reserve framework. The EAF and EOCSF thus offer complementary indices of executive - linguistic coordination and may increase the sensitivity of fluency assessment to early age-related changes.