Mahe, G. , Bonnefond, A. & Doignon-Camus, N.
CNRS, University of Strasbourg, Strasbourg, France
The efficiency of visual word recognition relies on fast and parallel processing of letters involving the ventral visual pathway. However, words displayed in unfamiliar visual format require to be read serially under supervision of the dorsal visual pathway. The present ERP study investigated the involvement and the interactions of the ventral and dorsal visual pathways in adults with developmental dyslexia. Developmental dyslexia is a specific learning disability affecting reading acquisition. The involvement of the ventral visual system was assessed in a lexical decision task with stimuli (i.e., high and low frequency words, pseudowords or consonant strings) presented in a familiar visual format (i.e., horizontal). Same stimuli presented in an unfamiliar visual format (i.e., vertical) were used to investigate the involvement of the dorsal visual pathway. According to a visuo-spatial attention deficit hypothesis in developmental dyslexia, we expected an alteration of the dorsal pathway contribution in terms of impairment and/or delay when letter strings are presented in an unfamiliar visual format. Analysis of potential differences between dyslexics and normal readers could help us to understand the nature of their core deficit.