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Activities and Seminars

Sylviane Valdois, CNRS and Université Pierre-Mendès France
 
Date: Dec 01, 2011

What: The visual attention span deficit hypothesis in developmental dyslexia

Where: BCBL, Paseo Mikeletegi 69, Floor 2

Who: Dr. Sylviane Valdois, CNRS and Université Pierre-Mendès France, Grenoble, France

What: The visual attention span deficit hypothesis in developmental dyslexia


The role of phonology in reading acquisition is well documented and it is widely accepted that developmental dyslexia results from a phonological disorder. However, the phonological hypothesis cannot acount for all cases of developmental dyslexia and some dyslexic children are obviously not phonological. The MTM connectionist model of reading (Ans, Carbonnel & Valdois, 1998) postulates that a visual attention component — the visual attentional window — plays a key role in skilled reading and reading acquisition. Within this framework, developmental dyslexia can follow from either a phonological or a visual attention span disorder. We will first review behavioural evidence from case and group studies in support of a visual attention span disorder in developmental dyslexia. A non trivial number of dyslexic individuals exhibit a visual attention span disorder and this disorder typically dissociates from phonological problems. The importance of the VA span in reading acquisition is further supported by data from typically developing children. However, VA span skills are typically assessed using tasks of letter report so that problems in letter naming, verbal short term memory or visual-to-phonological code mapping have been proposed as a better account of poor performance on the verbal report tasks. I will provide evidence against such a “phonological” account in showing (1) that the VA span disorder extends to non verbal tasks and non verbal material and (2) that the brain regions housing VA span skills are known for their involvement in visual attention not in phonology.