Reading and Non-word Repetition Skills in Bilingual Developmental Dyslexia: The Case of a Greek - Italian Bilingual Dyslexic Adult

Abstract

Studies of bilinguals with developmental dyslexia learning to read in two alphabetic orthographies have shown that they demonstrate similar reading and phonological short-term memory (STM) deficits in both their languages. The present study aimed at exploring whether dyslexia in adults affects similarly decoding skills in two transparent languages, Greek and Italian, whether there are similar deficits in phonological STM and whether the dominance of one of the two languages affects the manifestation of the deficits. We compared the performance of a young Greek-Italian bilingual dyslexic adult (exposed to Italian from birth, L1: Greek) to that of a young monolingual Greek dyslexic adult, a young Greek-Italian typically developing (TD) bilingual adult (exposed to Italian from birth, L1: Greek) and a young Greek monolingual TD adult. We assessed them in word and non-word reading and non-word repetition. Results showed that bilingual dyslexic adult performed significantly poorer than the bilingual TD adult on all tasks in both languages, suggesting that dyslexia affects similarly decoding and phonological STM across languages. On reading, bilingual outperformed monolingual dyslexic, while monolingual outperformed bilingual TD adult. On phonological STM, both bilinguals outperformed monolinguals. A positive effect of bilingualism was found for reading skills only for dyslexics, while it was found for phonological STM for both dyslexic and TD adults. Finally, the dominance of L1 affected bilinguals' performance in reading but not in non-word repetition, where they showed better performance in Italian, perhaps due to the phonotactic complexity of the Greek orthography compared to Italian.