Atypical perceptual processing of faces in developmental dyslexia

- Word, face and car processing were examined in dyslexic and typical readers.
- Typically, the processing of words and faces, but not cars, is well learned and lateralized.
- Only word and face processing were significantly impaired in the dyslexic readers.
- Atypical hemispheric lateralization was also observed in the dyslexic readers.
- Results are consistent with domain-general accounts of developmental dyslexia.

Developmental Dyslexia (DD) is often attributed to phonological processing deficits. Recent evidence, however, indicates the need for a more general explanatory framework to account for DD's range of deficits. The current study examined the specificity versus domain generality of DD by comparing the recognition and discrimination of three visual categories (faces and words with cars as control stimuli) in typical and dyslexic readers. Relative to controls, not only did dyslexic individuals perform more poorly on word recognition, but they also matched faces more slowly, especially when the faces differed in viewpoint, and discriminated between similar faces (but not cars) more poorly. Additionally, dyslexics showed reduced hemispheric lateralization for words and faces. These results reveal that DD affects both word and face, but not car, processing, implicating a partial domain general basis of DD. We offer a theoretical proposal to account for the multifaceted findings and suggestions for further, longitudinal studies.