Cognitive and Neural Preservation in Older Language Learners: The CNPOLL Framework.

The plasticity of bilingual language systems across the lifespan remains a central issue in theories of language representation and control, yet late-life language learning is rarely integrated into these accounts. This review synthesizes behavioral and neurocognitive evidence on older adults acquiring an additional language, with the aim of clarifying how aging shapes bilingual language learning mechanisms. We first report a quantitative synthesis of behavioral studies examining the effects of late language learning on control-related domains implicated in bilingual language processing, including executive coordination, attentional regulation, and working memory. Results indicate a small but reliable effect, with modest improvements primarily observed in higher-order executive processes rather than broad enhancements in general cognitive function. We then review neuroimaging evidence showing that late language acquisition engages language, control, and memory systems, including frontal-parietal and memory-related networks, in patterns shaped by task demands, age-related constraints, and learning stage. Building on these findings, we propose the Cognitive and Neural Preservation in Older Language Learners (CNPOLL) framework as a lifespan account of bilingual language plasticity in older adulthood. By situating late-life language learning within contemporary models of bilingualism, this review highlights older learners as a theoretically informative population for understanding the adaptability and limits of bilingual language systems.