Bridging Declarative and Procedural Learning: The Interplay of Retrieval Practice and Motor Enactment in Sign Language Acquisition

Retrieval practice reliably enhances long-term memory across many learning domains, yet little is known about how this effect generalizes to sign languages, which require complex visual–spatial processing and coordinated motor production. Across two experiments, we investigated the roles of retrieval practice, motor enactment, and iconicity in American Sign Language (ASL) vocabulary learning among hearing adults, using both holistic and fine-grained phonological scoring. Critically, we observe a selective interaction between retrieval practice and enactment in the handshape dimension: testing improved handshape accuracy only when learners physically enacted the signs, suggesting that motorically complex articulators require the combined support of retrieval-based reinforcement and procedural motor rehearsal. In contrast, dimensions with lower motoric complexity (e.g., location, movement, orientation) showed additive or independent contributions of retrieval and enactment. Together, these findings show that retrieval practice extends to visual–manual language learning, but its effectiveness varies by phonological complexity and motor demands. The results highlight the importance of considering embodied processes in theories of retrieval-based learning and offer practical implications for optimizing sign language pedagogy.