The evolution of the reading profile in children with developmental dyslexia in a regular ortographies

Several researchers have demonstrated that dyslexia develops differently in shallow orthographies in terms of accuracy and speed. In fact, slow reading speed persists and accuracy improves. The aim of this study is to investigate the evolution of the specific reading disorder over the years of compulsory education, from primary to upper secondary school. Furthermore, it has the aim to verify if there are different evolutionary trajectories of reading skills in relation to the severity of the disorder. The study was carried out on 71 Italian dyslexic children, according to the diagnostic criteria established by the diagnostic manual ICD – 10 and the Consensus Conference. Two groups were selected: children who met criteria for mild dyslexia (mild dyslexics, with n=36) and a comparison group of moderate-severe dyslexics (n=35). All participants were tested at least twice in two different school grades. Comparisons were made on the average performances in each school grade. The results reveal similar patterns of growth over time in reading ability, with the mild dyslexics group outperforming the moderate-severe dyslexics group. The performance trajectory for the moderate-severe dyslexics shows some plateaus and a decrease in performances in the last year analyzed (1st upper secondary school) while the trajectory for the mild dyslexics always show increases in performances. All subjects show a steady increase in word and text reading speed and a slower improvement in pseudo-word decoding.