Baseline cognitive status and adherence are associated with cognitive change following language learning in older adults: an exploratory study.

Introduction: Given cognitive benefits observed in lifelong bilinguals, a key question is whether L2 learning can boost cognition in later life. Methods: In a pre-post intervention study, we assessed cognitive effects of learning a new language in older adults as measured by global cognition and domain-specific cognitive tests. Results and Discussion: While the MMSE, MoCA, and domain-specific measures (Stroop, Simon, nonword repetition, phonemic fluency, and semantic fluency) did not show significant whole-group pre-post change, a number of individual participants improved on all or some of these measures. Further, both linear regression and machine learning models indicated that participants with lower baseline scores on the MMSE, MoCA, phonemic fluency, and semantic fluency showed greater improvement in post-intervention measurements, reflecting greater cognitive gains, with phonemic fluency emerging as the best predictor of intervention outcome. A Conclusion: These results provide preliminary evidence that engagement in a structured and sustained L2-learning program may be associated with measurable pre-post cognitive changes in some older adults, especially when baseline performance leaves room for improvement. Further, high intervention adherence and engagement are critical to the extent of cognitive benefits derived from L2 learning interventions. Clinically, structured language learning programs that emphasize adherence, dose, and fidelity appear promising for older adults, especially those with emerging decline. These results are noteworthy, given the scarcity of effective options to improve cognitive health in aging, and the fact that L2 learning is low-cost and broadly accessible.