Onset-Rime Orthographic Representations in Early Literacy Development: A Neural Link Between Spelling and Reading

Visual orthographic knowledge plays a critical role in early literacy development and may provide a shared foundation for reading and spelling, yet the nature of its underlying representations remains debated. Behavioral measures offer indirect evidence and may be influenced by other metalinguistic processes. It remains unclear whether beginning readers encode larger orthographic structures, such as onset-rime units, beyond individual letters and smaller letter combinations but below the whole-word level. It is also unknown whether neural sensitivity to these structures helps explain the relationship between spelling and reading. To address these questions, we used a fast periodic visual stimulation (FPVS) paradigm in first- and second-grade children to contrast pseudowords constructed with the typical ordering of onset followed by rime elements (i.e., onset-rime) against matched strings in which the same elements appeared in the reverse order (i.e., rime-onset). Neural sensitivity to onset-rime orthographic structure was associated with both spelling ability and word-reading efficiency and, critically, statistically mediated the relationship between these two literacy skills. These relationships remained significant after controlling for age and removing influential observations, and sensitivity to onset-rime orthographic structure explained additional variance in word-reading efficiency beyond spelling ability and age. Together, these findings provide neurophysiological evidence for onset-rime structure as an important sublexical orthographic unit in beginning readers, highlighting its potential role in linking spelling with efficient word recognition during early reading development.