Speech disfluencies in children with developmental dyslexia: how do they differ from typical development?

Résumé 0

Background. Disfluency is a multifactorial concept that can be linked to several of the language production levels, both in typical and atypical populations. In children, the language system is still developing and few studies have explored disfluency patterns. In Typical Development (TD) in particular, studies have shown discrepancies according to the language being considered. In neurodevelopmental disorders, such as Developmental Dyslexia, it is still unclear whether the pattern of disfluency is similar to TD children. Aims. Our study had two objectives. First, we analyzed the type of disfluencies and their evolution in French children aged 8 to 12 years old. Second, we compared the pattern of disfluency in DD and TD, and tested whether these difficulties were correlated with reading difficulties. Methods & Procedures. 25 children with DD and 21 children with TD aged from 8 to 12.6 years were compared based on an autobiographical oral narrative. Seven types of disfluencies were coded: part-word repetitions; repetitions of monosyllabic words; other types of repetitions (words and phrases); filled pauses; revisions-substitutions; revisions-additions; abandoned utterances. We compared the proportion of each disfluency in DD and TD. Spearman correlations were then performed between disfluencies, reading performances and age. Outcomes and Results. Our results showed that both DD and TD children mainly produced filled pauses, repetitions of monosyllabic words, and substitutions. In both groups, children had a high rate of disfluency (>10%). Correlations with reading performance were significant in the TD group only. Conclusions & Implications. Our study showed that DD in not characterized by a specific pattern of disfluency, and the type of disfluencies produced was stable in children aged from 8 to 12 years old. In contrast to other languages, our study suggest that French-speaking children have a high rate of disfluency. In other words, disfluency should be interpreted with caution in DD, given that TD children also have a high rate of disfluency. It seems important to adapt the pathological threshold of disfluency to the language being spoken, in order to avoid an overestimation of the prevalence of these deficits in French-speaking children.