Déficits cognitivos e estabilidade da dislexia do desenvolvimento em português brasileiro

Abstract

Developmental dyslexia (DD) is a neurobiological disorder characterized by a specific reading and writing difficulty (American Psychiatric Association [APA], 2014). There is ample evidence that this difficulty is associated with deficits in phonological processing. Recently, however, several authors have questioned the hypothesis that phonological deficits are necessary or sufficient for the development of DD. In fact, according to the Multiple Deficits Model (Pennington, 2006), no deficit, including phonological deficit, is necessary or sufficient to explain the onset of DD. According to this model, DD is more adequately explained in terms of a multiplicity of cognitive deficits that together characterize the cognitive profile of DD. The objective of the present study was to describe the cognitive profile and the stability of DD in Brazilian Portuguese. Two studies were performed. Study 1 evaluated the adequacy of the Multiple Deficits Model for DD in Portuguese. Three groups of children between 7 and 9 years old participated in the study: 21 children with difficulties in spelling and reading (RSD), 24 children with spelling difficulties (SD) and 45 children without learning difficulties. The children of the first two groups were individually matched to the children without learning difficulties according to age and the school year (2nd or 3rd grades of elementary school). In addition to reading and spelling tasks, children were submitted to tasks of vocabulary, visuospatial ability, phonemic awareness, rapid automatized naming, phonological memory, verbal working memory and processing speed. In line with the Multiple Deficits Model, 90.5% of children with RSD and 45.8% of children with SD had deficits in two or more abilities. In both groups, the most frequent cognitive deficit was the phonological processing deficit, present in 100% of children with RSD and 58.3% of children with SD. The results also showed that children with reading and spelling difficulties had greater cognitive impairments than children with spelling difficulties, which in turn had more cognitive impairments than typical children. Twenty-six children with RSD and SD who had participated in Study 1, as well as their respective peers, underwent tests of reading and spelling of words on two different occasions: at the end of the 2nd grade and at the end of the 3rd grade of elementary school. The results showed great stability of the DD in Brazilian Portuguese, with maintenance of the initial spelling difficulties for 81% of the children. The theoretical and practical implications of these results are discussed taking into account the Multiple Deficits hypothesis and the dimensional perspective of developmental dyslexia.