Impact of an 18-month non-native language intervention on episodic memory and the underlying neural mechanisms in cognitively unimpaired older adults.

INTRODUCTION

Episodic memory decline impairs daily functioning in aging. This secondary analysis of data from the Age-Well randomized controlled trial (RCT), we examined whether non-native language training (NNLT) benefits memory and its neural correlates in older adults.

METHODS

Participants from the Age-Well RCT (aged ≥ 65) were assigned to an 18-month NNLT (N = 45), or no-intervention (N = 44) group. Episodic memory (California Verbal Learning Test Second Edition [CVLT-II] and Logical Memory), and hippocampal and medial prefrontal cortex volumes and perfusion were assessed pre- and post-intervention. Linear mixed models tested visit x group interactions. Regressions examined associations between memory and neuroimaging changes, adjusted for age, sex, education, and baseline memory performance.

RESULTS

A visit x group interaction was observed (F = 6.77, p = 0.01): the NNLT group maintained CVLT-II delayed free recall performance, while the no-intervention group declined. Within the NNLT group, changes in this score correlated positively with changes in hippocampal perfusion.

DISCUSSION: These findings suggest that NNLT may help preserve hippocampus-dependent long-term episodic memory in aging.