With the field of late-life language learning (LLLL) expanding fast, ample attention has been paid to cognitive benefits ensuing from LLLL. However, these studies have yielded mixed results, which may be partly explained by seniors' language learning needs not being taken into account, and theoretical insights on effective language teaching have not included seniors. In order to link seniors' language learning needs to possible cognitive benefits, and to expand the second language acquisition literature, 16 Dutch seniors took part in a three-month English course, with or without explicit grammar instruction, to ascertain the effects of more implicit versus more explicit language teaching pedagogies on cognitive flexibility. More specifically, we used linear mixed effects models to determine these methods' differential effects on attention, working memory, processing and switching speed, inhibition, and shifting and switching abilities, as subdomains of cognitive flexibility, by using a pretest-post-test-retention test design. On the digit span tasks, the explicitly taught group showed significant improvements compared to the implicitly taught group. For Dutch verbal fluency, participants' performance significantly improved regardless of condition. On the other measures, no differences between the groups were found. Hence, if the goal is to improve seniors' working memory, then explicit language instruction appears more fruitful than implicit language instruction.
Keywords: cognitive flexibility; implicit/explicit grammar instruction; language learning pedagogies; late-life language learning; older adults.