Does a generalised binding deficit account for the visual-verbal association deficit seen in developmental dyslexia?

Abstract

Developmental dyslexia is defined as a problem with the decoding of the written word despite adequate intelligence, education, and socioeconomic status. It is characterised by a difficulty in making letter-sound (visual-verbal) associations, a process crucial when learning to read (e.g., Hulme, Goetz, Gooch, Adams, & Snowling, 2007). To further our understanding of this visual-verbal association deficit, we investigated the ability of dyslexic readers to bind information in the visual working memory to determine if a generalised binding deficit could account for the visual-verbal deficit. We carried out two experiments, a change-detection and a cue-recall task, on 16 high-functioning dyslexic participants and 16 age- and IQ-matched control participants to access their ability to bind features. We hypothesised that dyslexic participants would perform less well when binding features in their visual working memory, compared to controls. Results demonstrated that dyslexic readers had no difficulty in binding features in their visual working memory and were actually quite good at it. We concluded that a generalised binding deficit did not account for the visual-verbal association deficit seen in developmental dyslexia. We discussed these findings with reference to coping strategies and possible alternative explanations for the deficit.