Sluggish dorsally-driven inhibition of return during orthographic processing in adults with dyslexia

    loading  Checking for direct PDF access through Ovid


HighlightsDyslexia is characterized not only by phonological but also orthographic deficits.Orthographic processing assigns letter identities to different spatial locations.Spatial location encoding is driven by the “where” dorsal-attentional stream.Adults with dyslexia show impaired IOR during orthographic processing.Adults with dyslexia show a “where” dorsal-attentional dysfunction.Dyslexia (D) is a neurodevelopmental reading disorder characterized by phonological and orthographic deficits. Before phonological decoding, reading requires a specialized orthographic system for parallel letter processing that assigns letter identities to different spatial locations. The magnocellular-dorsal (MD) stream rapidly process the spatial location of visual stimuli controlling visuo-spatial attention. To investigate the visuo-spatial attention efficiency during orthographic processing, inhibition of return (IOR) was measured in adults with and without D in a lexical decision task. IOR is the delay in responding to stimuli displayed in a cued location after a long cue-target interval. Only adults with D did not showed IOR effect during letter-string recognition, despite the typical left-hemisphere specialization for word identification. A specific deficit in coherent-dot-motion perception confirmed an MD-stream disorder in adults with D. Our results suggest that adults with D might develop an efficient visual word form area, but a dorsal-attentional dysfunction impairs their reading fluency.

    loading  Loading Related Articles