Executive working memory, phonological short-term memory, and vocabulary size as predictors of immediate and delayed recall of low-frequency words among EFL learners

Abstract

Despite extensive research on vocabulary acquisition and memory processes in foreign language learning, limited attention has been given to how cognitive factors differentially influence distinct stages of early lexical retention. The present study examined whether vocabulary size, phonological short-term memory, and executive working memory predict immediate and delayed recall of unfamiliar words among 57 undergraduate EFL learners. Participants completed a Vocabulary Size Test and digit span tasks (forward and backward), as well as immediate and 30-minute delayed recall tasks involving low-frequency adjectives. Multiple regression analyses revealed a clear stage-specific pattern: none of the cognitive variables significantly predicted immediate recall, suggesting that early accessibility may reflect, at least in part, transient activation. In contrast, delayed recall was significantly predicted by vocabulary size and executive working memory, as indexed by backward digit span, whereas phonological short-term memory did not account for unique variance. These findings indicate that early lexical stabilization is associated with both the structural richness of prior lexical knowledge and the capacity to regulate attention and manage interference. The results highlight the importance of distinguishing between short-term accessibility and early representational stabilization when examining individual variables in foreign vocabulary learning.