Distinct neural processing underlying visual face and object perception in dyslexia

Abstract

Developmental dyslexia is a disorder marked by difficulties in reading, spelling, and connecting sounds to written language. The high-level visual dysfunction hypothesis suggests these difficulties may partially arise from abnormalities in high-level visual cognition such as the ability to integrate visual input for higher-order cognitive functions such as reading. Here we examined adult (mean age = 35) dyslexic readers’ neural functioning as they recognized identities of nonlinguistic visual objects, specifically houses and faces. We measured two event-related potential (ERP) components, the N170 and N250, which are linked to face and object processing – N170 with early structural encoding and N250 with familiarity and identification. In this study, dyslexic readers consistently showed reduced N250 amplitude, potentially suggesting abnormal neural processes relating to the individuation or subordinate-level representation of visual objects. This was despite similar behavioral performance for dyslexic readers. Early neural processes in dyslexic readers were largely intact as shown by their N170. These results highlight the distinct underlying neural processes that contribute to high-level visual cognition in dyslexia and help to further our understanding of how these neural processes might contribute to reading challenges that are characteristic of the disorder.