Auditory short-term memory affects earlier but not later learning phases: An individual differences study on...

Adults acquire new words, including written and spoken forms, across the lifespan. Learning novel words is a dynamic process that progresses from initial familiarization through repeated exposure and offline processes toward lexicalization. These processes exhibit substantial interindividual variability. In this study, we leverage this variability to investigate how domain-specific linguistic and domain-general skills relate to performance across different phases of learning. Across three sessions, distributed over 3 weeks, 140 native German participants learned Mandarin Chinese spoken and written (Pinyin) word forms and were tested on the retention of the new knowledge. Additionally, participants completed nine tests assessing linguistic experience, processing speed, auditory and visual short-term memory, and nonverbal reasoning. Structural equation modeling, including latent growth curve analysis, revealed that the acquisition and linking of word forms was primarily shaped by domain-general skills. Critically, whereas processing speed predicted learning performance across all sessions, auditory short-term memory supported earlier but not later learning. An association between learning performance and linguistic experience was observed in exploratory network analyses with links to receptive vocabulary across all and spelling during earlier learning phases. These findings highlight that learning is conditioned by how fast and efficient incoming information is processed and that earlier learning is constrained by short-term memory capacity. More broadly, the engagement of cognitive resources changes over the course of learning, in step with a change from effortful and controlled processing at earlier to more efficient automatic processing at later phases. Learners may benefit from tailoring input to individual memory capacity. (PsycInfo Database Record (c) 2026 APA, all rights reserved).