[TS-1.2] Behavioural and electrophysiological changes after an intensive visual-orthographic and auditory-phonological remediation program in developmental dyslexia

Jucla, M. 1, 2 , Chaix, Y. 3, 4, 5 & Démonet, J. 6

1 Laboratoire Octogone-Lordat EA 4156, 5 allées Antonio Machado, 31058 Toulouse Cedex 09, France
2 Université de Toulouse, UTM, 5 allées Antonio Machado, 31058 Toulouse Cedex 09, France
3 Inserm, Imagerie cérébrale et handicaps neurologiques UMR 825, F-31059 Toulouse, France
4 Université de Toulouse, UPS, Imagerie Cérébrale et Handicaps Neurologiques UMR 825, CHU Purpan, Place du Dr Baylac, F-31059 Toulouse Cedex 9, France
5 Unité de Neurologie Pediatrique, Hôpital des Enfants, Toulouse, France
6 Centre Leenaards de la Mémoire, Département des Neurosciences Cliniques, CHUV & Université de 8 Lausanne, Rue du Bugnon 46, CH-1011, Lausanne, Switzerland

Evidence-based intervention studies in developmental dyslexia usually aim at evaluating the outcomes of one specific skill training (for instance phonemic-grapheme mapping or visual attention) compared to more general reading exercises. In this presentation, our objective is to give an overview of the main results of a longitudinal study we conducted in 30, 9 to 11 years old, children with dyslexia. In France, those children barely benefit from special education in schools but are instead treated by language therapists in a once or twice a week basis. It is well known that intensive training is one of the main keys to reading improvement. We have therefore evaluated the effects of a 4-months intensive daily programme based on i) phonemic awareness (PA) and ii) visual attention (VA) training. All children received both training modalities in a cross over design. We tested them on written and oral language, short-term memory, and visual attention span before, between and after the training phases. During the same sessions, we recorded electrophysiological changes using visual and auditory lexical decision tasks and a rhyming judgment task. We also measured the mismatch negativity during a passive syllable listening with changes occurring at the acoustic or phonological level. Three main points arose from the different results we obtained. 1) As expected, targeted skills (PA and VA) were specifically improved by specific training with an even greater benefit for children impaired in these domains. ERP correlates of these effects were found for the rhyming task. 2) Reading performance increased after the whole programme without interaction with training modality (long-lasting effects were shown 6 months after the intensive training). 3) According to ERP results in the lexical decision task, better word identification was associated with a P300 decrease suggesting reading improvement could be related to a diminution of the cognitive load.