title: Lexical and sublexical orthographic processing: an ERP study with skilled and dyslexic adult readers.
abstract: This ERP study investigated the cognitive nature of the P1-N1 components during orthographic processing. We used an implicit reading task with various types of stimuli involving different amounts of sublexical or lexical orthographic processing (words, pseudohomophones, pseudowords, nonwords, and symbols), and tested average and dyslexic readers. An orthographic regularity effect (pseudowords-nonwords contrast) was observed in the average but not in the dyslexic group. This suggests an early sensitivity to the dependencies among letters in word-forms that reflect orthographic structure, while the dyslexic brain apparently fails to be appropriately sensitive to these complex features. Moreover, in the adults the N1-response may already reflect lexical access: (i) the N1 was sensitive to the familiar vs. less familiar orthographic sequence contrast; (ii) and early effects of the phonological form (words-pseudohomophones contrast) were also found. Finally, the later N320 component was attenuated in the dyslexics, suggesting suboptimal processing in later stages of phonological analysis.
authors.affiliation: Cognitive Neuroscience Research Group, Department of Psychology, & Centre for Molecular and Structural Biomedicine, CBME/IBB, Portugal; Faculty of Psychology & Center for Psychological Research, University of Lisbon, Portugal. Electronic address: smaraujo@ualg.pt.
authors.forename: Susana
authors.initials: S
authors.lastname: Araújo
authors.affiliation: Cognitive Neuroscience Research Group, Department of Psychology, & Centre for Molecular and Structural Biomedicine, CBME/IBB, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Faísca
authors.affiliation: Department of Psychology, Lund University, Lund, Sweden.
authors.forename: Inês
authors.initials: I
authors.lastname: Bramão
authors.affiliation: Cognitive Neuroscience Research Group, Department of Psychology, & Centre for Molecular and Structural Biomedicine, CBME/IBB, Portugal.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Reis
authors.affiliation: Cognitive Neuroscience Research Group, Department of Psychology, & Centre for Molecular and Structural Biomedicine, CBME/IBB, Portugal; Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
authors.forename: Karl Magnus
authors.initials: KM
authors.lastname: Petersson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004410:Dyslexia / Q000503:physiopathology*; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D011932:Reading
keywords: Dyslexia; ERPs; Orthographic processing; Phonological processing