Abstract

Developmental dyslexia is defined as a specific disorder of learning to read. Contrary to the view that it results exclusively from a specific deficit of phonological processing, recent studies have found an abnormal processing of visual information in dyslexia. The Magnocellular (M) theory of dyslexia suggests that the neural basis underlying such disorder is an impaired processing of fast temporal information. The present study investigated the spatial shifting of visual attention in 24 dyslexics and 13 normally reading children using a covert orienting paradigm. Results showed an asymmetrical orienting effect in dyslexics, whereas it was symmetrical in normal readers. These data might be interpreted in the framework of studies on M deficits in dyslexia, whereby the anomalous spatial distribution of visual attention might explain how the transient pathway functioning influences the reading process. Such visual field asymmetry suggests an impairment of the right parietal functions in dyslexic children.