[PS-2.11] Orthographic sensitivity and the integration of orthographic and phonological processing in adult dyslexia

Tóth, D. & Csépe, V.

Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences

Developmental dyslexia is characterized by reading and spelling deficits which might be attributable to the suboptimal integration of orthographic and phonological representations. Additionally, orthographic sensitivity might be attenuated per se, that is inefficient orthographic processing (if present) might do not relate to phonological deficits. In a large sample of adult readers (N>50) covering a broad range of reading skill (from dyslexic to skilled reading) we investigated the electrophysiological (EEG) correlates of automatic orthographic processing. After performing a behavioural screening procedure measuring word- and sentence-level reading, orthographic knowledge and other reading-related skills (phoneme awareness, RAN), participants were given an implicit reading task in uni- and multimodal (audiovisual) modalities while EEG was recorded. The implicit reading task required the processing of item pairs (words and pseudowords). Items could be same, one-letter different or transposed-letter pairs. The complex pattern of results suggested that poor readers showed more severe deficits if the task tapped on the integration of orthographic and phonological processing, but their brain responses (at least in some readers) also differed in the visual-only condition. However, our correlational analyses focusing on the relationship between behavioural and EEG-measures revealed that the commonly investigated event-related brain components (N170, N270-N300, etc.) should be treated more cautiously and group differences should not be over-interpreted.