Do visuo-motoric aspects of orthographic characters’ influence writing fluency in children with dyslexia?

Purpose:
Children with dyslexia make longer intra-word pauses when writing than typical readers, perhaps reflecting greater hesitation in orthographic activation/selection during spelling. However, it has been assumed that visuo-motor letter formation processes required during writing are unaffected in dyslexia. We addressed the latter assumption by comparing online writing behaviour among children with dyslexia and typical controls in learning novel letter-like symbols relative to highly-practiced alphabet letters.

Method:
14 children with dyslexia (Mage = 10.8 years) and 13 age-matched controls (Mage = 10.9 years) in grades 5 and 6 copied 25 isolated novel symbols onto a digitising tablet. They also wrote alphabet letters, matched to novel symbols on visual orientation (b/d) and motoric complexity (number of strokes). Novel symbol copying measures were taken at baseline, before training with repeated copying of the symbols, and again several days later (post-training); in an analogue task, children also copied alphabet letters.

Results:
Analysis of pausing durations on 14 letters/symbols with clear b/d orientation composed of 2/3 strokes revealed dyslexic children paused significantly longer than controls when copying alphabet letters. With novel symbols, dyslexics paused for significantly longer than controls at post-training (but not at baseline) irrespective of visual-motoric features. Moreover, all children paused significantly longer for more complex (three-stroke symbols and left orientation) items.

Conclusion:
Children are sensitive to visual-motoric features when learning novel letter-like symbols. Dyslexics attain lesser fluency than controls in producing not only trained novel letters but also highly practiced alphabet letters, suggesting impairments in retaining or accessing the relevant motor programmes of orthographic characters.