Long-term effects of a psycholinguistic treatment for dyslexia

Short and long-term effects of a treatment for dyslexia are evaluated. The treatment is based on psycholinguistic theory and assumes that dyslexia is due to poor lexico-phonological processing of words. The treatment is computer-based and focuses on learning to recognise and to make use of the phonological and morphological structure of Dutch words. The results of the treatment were clear improvements in reading words, reading text and spelling. Effect sizes of standardised treatment gains were large (Cohenʹs d>0.80 for all variables). Following the treatment, participants attained an average level of text-reading and spelling. The attained level of reading words and reading text was found to be stable over a four-year follow-up period. Spelling showed a slight decline one year after the treatment, but remained stable thereafter.