Developmental Dyslexia and Remediation Methods

Overview

At least, three theoretical frameworks are currently involved in therapeutic research in developmental dyslexia. Each theoretical framework relies on the type of underlying cognitive processes that is viewed as impaired: 1°) phonological processing, 2°) cross modal integration, 3°) visual attention processing. In this controlled and randomized study, three types of computerized training are combined in a multi-factorial remedial approach in 8 to 12 year old children with dyslexia. The main objective is to compare the effectiveness of this remedial approach which combines phonological, visual-attentional and cross-modal training with conventional non-intensive and non-specific rehabilitation

Developmental dyslexia is defined as a specific and lasting reading learning disorder. This neurodevelopmental disorder has a severe impact on overall academic learning and behavior, compromises professional and social development and affects 10% of school-age children. As a public health problem, its diagnosis and management are still highly controversial, and the lack of scientific consensus leads to great heterogeneity in clinical practices and post-treatment outcomes. Three therapeutic axes guide research for developmental dyslexia. The first axis is based on phonological deficits. According to the phonological representation hypothesis, a specific deficit in the processing of phonological representations that support the identification of sounds is the cause of the reading disorder. The second axis focuses on attention-related cognitive deficits. According to the visuo-attention deficit hypothesis, a lack of the visuo-attention processing can be viewed as one of the explanatory causes of a dysfunction in letter identification and reading procedures. The third axis aims to achieve automatized processing for letter/sound association. According to the axis, a lack of cross-modal integration in word decoding is altered by a lack of simultaneous association between of a visual and an auditory stimulus. Many studies attempted to exclusively validate selective remediation according to causal hypotheses that are mainly cross-modal, phonological or visuo-attentional. However, the evaluation of these underlying processing in dyslexic children shows great clinical heterogeneity since most of children simultaneously have the three deficits. Furthermore, no study evaluates the benefits of combining these different trainings on reading skills. In this controlled and randomized study, three types of computerized training are combined in a multi-factorial remedial approach in 8 to 12 year old children with dyslexia. The main objective is to compare the effectiveness of this remedial approach which combines phonological, visual-attentional and cross-modal training with conventional non-intensive and non-specific rehabilitation. The secondary objectives will be 1°) to compare the effectiveness on reading skills of a phonological training, versus a visuo-attentional training, 2°) to compare the effectiveness on reading skills from in the order of phonological and visuo-attentional training, 3°) to compare the evolution of performance in comprehension and written production at the end of the three training sessions and 4°) to evaluate child and parents' perception for the outcome of the reading disorder at the end of the training sessions using Likert scales, by means of a questionnaire. The analysis of the results will make possible to evaluate a remedial approach to dyslexia in a clinical context and to better understanding and management of written language disorders.