Orthographic and phonological processing in English word learning

This thesis investigates the process of orthographic and phonological word learning in adults. Speed of reading aloud is used as the main measure, specifically the reduction in naming reaction times (RTs) to short and long novel words through repetition and the convergence of RTs to short and long items. The first study (Chapter 2) fully described this fundamental learning paradigm and it is then used to compare various types of training in different groups of readers in the following chapters. Second, the role of phonology in visual word learning was investigated in Chapter 3. Novel words that received the training of both orthography and phonology (reading aloud condition) was found to be more efficient and effective compared to solely training the phonology of the novel words (hear-and-repeat with and without distractors). Yet, all three experiments in Chapter 3 also showed that the establishment of a phonological representation of a novel word can be sufficient of result in representations in the mental lexicon even without any encounter with the orthographic form of the novel word. Linear mixed effect modelling also found that literacy and phonological awareness made a significant contribution to nonwords naming speed when vocabulary and rapid digit naming were taken into account. Expressive vocabulary was found to be a significant predictor of the change in naming speed across the learning session when the effects of literacy, phonological awareness were controlled. Third, Chapter 4 then involved the repeated presentation of interleaved high-frequency words, low-frequency words and nonwords to native speakers of English in two testing sessions 28 days apart. Theoretical interest lies in the relative effects of length on naming latencies for high-frequency words, low-frequency words and nonwords, the extent to which those latencies (RTs) converge for shorter and longer words and nonwords, and the persistence of training/repetition effects over a 28-day retention interval. Finally, Chapters 5 and 6 try to bring these theories in a more applied context to understand orthographic word learning in adults with dyslexia and in bilingual speakers.