par Sprenger-Charolles, Liliane;Lacert, Ph;Béchennec, Danielle;Colé, P.;Serniclaes, Willy
Référence ANAE. Approche neuropsychologique des apprentissages chez l'enfant, 62-63, page (115-128)
Publication Publié, 2001
Article révisé par les pairs
Résumé : Three goals were set for the present paper. First we reviewed different studies on dyslexia subtypes to determine the prevalence of each subtype across languages (English or French), measures (accuracy scores or time latencies), and methods (the classical method and the regression method). Next, we assessed the reliability across time of the subtypes. Last, we examined whether different subtypes could be induced by specific underlying deficits, for example, specific phonological deficits underlying phonological dyslexia, and specific visual deficits underlying surface dyslexia. This review lead to a striking result as it showed that the classification in surface versus phonological dyslexia subtypes is all but reliable. The proportion of these two subtypes, not only strongly differed according to the language, but also according to the method they were classified with, and even in a given language, according to the measure used. All the more, longitudinal data surprisingly showed that over time the relative proportion of each these two subtypes was totally inconsistent. Finally, no consistent data have been found to support the hypothesis that different profiles in developmental dyslexia were induced by different underlying deficits. Conversely, the data suggested that most of the dyslexies suffered from a double deficit in both the phonological and the orthographic reading routes, one of these reading routes just appearing less efficient than the other at a given point of the development and/or according to a given measure. Longitudinal data also showed that specific deficits in phonemic awareness and in phonological short-term memory were found in both phonological and surface subtypes. We tentatively suggest that differences in environmental factors could better explain the observed differences in dyslexic behavior than differences in cognitive profiles.