[Educational implications of the cognitive impairment in developmental dyslexia]

In this study we review the main theories put forward to account for developmental dyslexia, as well as the intervention procedures deriving from these theories that enjoy the most empirical support.

Developmental dyslexia is a complex disorder that reflects cognitive impairment related to neurobiological anomalies, although researchers still do not agree on fundamental aspects regarding its aetiology. There are at present a number of different theories that can be grouped in two antagonistic lines of work. On the one hand, one of them considers that the exclusive and direct cause of dyslexia is a specific cognitive disorder. On the other hand, however, there are several theories that consider the impairments experienced by dyslexic patients to be part of a wide range of tasks and processes that are secondary to an underlying primary deficit. As a consequence of the progress made in the characterisation of dyslexia, an unprecedented effort has been made in recent decades in the development of intervention programmes and in the analysis of their effectiveness.

Research into the explanation for dyslexia finds itself faced with the challenge of determining whether the different cognitive problems identified in dyslexic patients represent different cognitive routes towards the same dyslexic phenotype, whether they correspond to different types of dyslexia or whether they refer to the sum of the problems resulting from different comorbid conditions. Until this issue is resolved, as educators, we must carry out more comprehensive evaluations in order to determine the profile of the difficulties that are experienced in each particular case and to be able to tailor the interventions employed in this enigmatic problem.