Reliability and prevalence of an atypical development 3 of phonological skills in French - speaking dyslexics

9 Abstract In the present study, conducted with French-speaking children, we 10 examined the reliability group study) and the prevalence (multiple-case study) of 11 dyslexics’ phonological deficits in reading and reading-related skills in comparison 12 with Reading Level (RL) controls. All dyslexics with no comorbidity problem 13 schooled in a special institution for children with severe reading deficits were 14 included in the study (N = 15; Chronological Age [CA]: 111 ± 8 months; RL: 15 80 ± 3 months). For the group study, the 15 dyslexics were matched pairwise on 16 reading level, non-verbal IQ, and gender to 15 younger RL controls (CA: 17 85 ± 4 months). For the multiple-case study, the RL control group included 86 18 average readers (CA: 83 ± 4 months; RL: 85 ± 5 months). To assess the relative 19 efficiency of the sublexical (or phonological) and lexical reading procedures, we 20 relied on two comparisons: pseudowords vs. high-frequency regular words (the 21 comparison mainly used in languages with a shallow orthography); and pseudo22 words vs. high-frequency irregular words (the comparison mainly used with 23 English-speaking dyslexics), pseudowords and irregular words being either short or 24 long. The dyslexics’ skills in the domains supposed to explain their reading deficit 25 were also examined: phonemic awareness, phonological short-term memory and 26 rapid naming. In the group study, the dyslexics lagged behind the RL controls only 27 when they were required to read long pseudowords. The results of the multiple-case 28 study indicated that the prevalence of this deficit was high (the accuracy scores of 29 all but two of the 15 dyslexics being more than 1 SD below the RL control mean), 30 and that deficits in phonemic awareness were more prevalent (seven cases) than 31 deficits in phonological memory (one case) and in rapid naming (two cases). Three 32 unexpected results were observed in the group study: the difference between regular