Do children with dyslexia present a handwriting deficit? Impact of word orthographic and graphic complexity on handwriting and spelling performance.

Several studies have demonstrated that children with dyslexia frequently show poor and slow handwriting skills. It is not clear whether these difficulties are a consequence of their spelling deficit or if they arise from graphomotor difficulties. The present study aims to test the hypothesis of the presence of handwriting difficulties in dyslexia, through the investigation of the impact of graphic and orthographic complexity of words on writing. Participants were all monolingual French-speaking children. Twenty-three children with dyslexia (DYS) were compared to two groups of typically developing children: 23 chronological-age (CA) matched children and 23 spelling-age (SA) matched children. They were assessed on a single-word dictation task of 40 words on a digital tablet. The target words varied in orthographic complexity and in graphic complexity (simple vs. difficult). This task was scored on spelling accuracy, handwriting quality and handwriting speed. General Linear Mixed Model analyses revealed no global differences between the three groups for handwriting quality. However, the DYS children were more impacted by the graphic complexity of words than both the CA and SA children. These findings support the idea that children with dyslexia struggle with the graphomotor aspects of writing and have potential implications for educational and clinical supports.