Developmental dyslexia: The visual attention span deWcit hypothesis

The visual attention (VA) span is deWned as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deWcit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was assessed in two large samples of French and British dyslexic children whose performance was compared to that of chronological-age matched control children. Results of the French study show that the VA span capacities account for a substantial amount of unique variance in reading, as do phonological skills. The British study replicates this Wnding and further reveals that the contribution of the VA span to reading performance remains even after controlling IQ, verbal Xuency, vocabulary and single letter identiWcation skills, in addition to phoneme awareness. In both studies, most dyslexic children exhibit a selective phonological or VA span disorder. Overall, these Wndings support a multi-factorial view of developmental dyslexia. In many cases, developmental reading disorders do not seem to be due to phonological disorders. We propose that a VA span deWcit is a likely alternative underlying cognitive deWcit in dyslexia. © 2006 Elsevier B.V. All rights reserved. This manuscript was accepted under the editorship of Jacques Mehler. * Corresponding author. Tel.: +33 4 76 82 56 30; fax: +33 4 76 82 78 34. E-mail addresses: [email protected] (M.-L. Bosse), [email protected] (S. Valdois). 0010-0277/$ see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.cognition.2006.05.009 M.-L. Bosse et al. / Cognition 104 (2007) 198–230 199