Lallier, M. 1 , Thierry, G. 2 , Carreiras, M. 1, 3 & Tainturier, M. 2
1 Basque Center on Cognition, Brain and Language (BCBL). Donostia. Spain.
2 School of Psychology, Bangor, UK
3 Ikerbasque. Basque Foundation for Science
The study aimed at determining whether learning to read simultaneously in English and in a transparent orthography (Welsh) modulates the manifestations of developmental dyslexia. Our hypothesis was that learning to read in transparent Welsh should encourage the analytic reading process and phonological skills which may then be less affected in dyslexia even when tested in English. Thirty-six students at Bangor University took part in the experiment, including nine Welsh-English bilingual dyslexic adults and nine English monolingual dyslexic adults matched one-by-one for gender, chronological age, non-verbal IQ, vocabulary skills and general English literacy level, as well as a control group of 9 participants Welsh-English bilingual matched to 9 English monolingual participants. Participants underwent a neuropsychological screening in English assessing their single item reading and spelling skills and their meta-phonological abilities. Consistent with our hypothesis, the phonological disorder was more pronounced in monolingual English speaking dyslexic participants than in Welsh-English bilingual dyslexic participants. While monolinguals were impaired in relation to controls on pseudo-word reading accuracy, the Welsh-English bilinguals were impaired on irregular words reading accuracy. In addition, monolinguals were less accurate and slower in the pseudo-word spelling task. Finally, only the monolingual group showed a significant deficit in phonological awareness. Overall, the present study suggests that learning to read in a transparent orthography in parallel to English may help compensating for the phonological and analytic reading/spelling procedures highlighted in English monolingual dyslexic individuals. In addition, it highlights the existence of cross-linguistic interactions in written languages processes, as monolingual and bilingual dyslexic participants showed a differential pattern of performance despite being both tested in English.