Proceedings of the Annual Meeting of the Cognitive Science Society

How orthographic representations encode letter identity and letter position, and how these mechanisms develop with reading experience, remains a central issue for cognitive models of reading. The present study examines developmental changes in orthographic processing by assessing real-time lexical competition elicited by transposed-letter (TL) and substituted-letter (SL) competitors during visual spoken word recognition. Using the Visual World Paradigm, we tracked eye movements in third-grade children, fifth-grade children, and adult, all native speakers of Spanish. Orthographic processing was examined as a function of competitor type and word frequency. We adopted a confidence-interval estimation approach to characterize the magnitude and time course of competition effects, prioritizing effect estimation over null-hypothesis testing. Results showed increasing reading accuracy across development and a developmental increase in TL competition, while SL competition remained consistently weaker across groups. Word frequency modulated the magnitude and time course of competition effects, particularly in more skilled readers. This pattern supports predictions from the Multiple-Route Model, while frequency-sensitive effects are consistent with aspects of the Lexical Tuning Hypothesis. Together, these findings provide developmental constraints on cognitive theories of orthographic processing and highlight the value of eye-tracking methods for model evaluation.