EXPRESS: How Orthographic Transparency Shapes Word Learning and Retention in Monolingual and Bilingual Adults

This study examined how orthographic characteristics relate to the learning and retention of novel written words in monolingual English and bilingual Welsh-English adults. Participants learned pseudowords designed to follow either English-like (opaque) or Welsh-like (transparent) orthotactic patterns using a paired-associate learning paradigm with repeated training cycles, followed one or two days later by a word recognition task. Monolingual and bilingual participants showed comparable learning trajectories for English-like words. Within bilinguals, learning trajectories differed across orthographic conditions, with accuracy increasing more steeply at later learning cycles for English-like than Welsh-like words. Word recognition accuracy and discrimination sensitivity (d') did not differ across orthographic conditions, although English-like items were recognised more quickly. Welsh vocabulary knowledge and language exposure did not predict learning accuracy or recognition sensitivity. Together, these findings indicate that orthographic characteristics and language experience influence the efficiency of learning and accessing novel written forms, while longer-term recognition accuracy converges across conditions following consolidation.