title: Left dominance for language perception starts in the extrastriate cortex: An ERP and sLORETA study.
abstract: While it is well known that the left hemisphere is more efficient than the right in most tasks involving perception of speech stimuli, the neurophysiological pathways leading to these lateralised performance differences are as yet rather unclear. In particular, the question whether language lateralisation depends on semantic processing or is already evident in early perceptual stimulus processing has not been answered unequivocally. In the present study, we therefore recorded event-related potentials (ERPs) during tachistoscopic presentation of horizontally or vertically presented verbal stimuli in the left (LVF) and the right visual field (RVF). Participants were asked to indicate, whether the presented stimulus was a word or a non-word. On the behavioural level, participants showed stronger hemispheric asymmetries for horizontal, than for vertical stimulus presentation. In addition, ERP asymmetries were also modulated by stimulus presentation format, as the electrode by visual field interactions for P1 and N1 were stronger after vertical, than after horizontal stimulus presentation. Moreover, sLORETA revealed that ERP left-right asymmetries were mainly driven by the extrastriate cortex and reading-associated areas in the parietal cortex. Taken together, the present study shows electrophysiological support for the assumption that language lateralisation during speech perception arises from a left dominance for the processing of early perceptual stimulus aspects.
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Germany. Electronic address: helene.selpien@rub.de.
authors.forename: Helene
authors.initials: H
authors.lastname: Selpien
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Siebert
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Germany.
authors.forename: Erhan
authors.initials: E
authors.lastname: Genc
authors.affiliation: Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Beste
authors.affiliation: Department of Neuroanatomy and Molecular Brain Research, Faculty of Medicine, Ruhr University Bochum, Germany.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Faustmann
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Germany.
authors.forename: Onur
authors.initials: O
authors.lastname: Güntürkün
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ocklenburg
mesh_terms: D001931:Brain Mapping; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007807:Language Tests; D008297:Male; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011932:Reading; D013067:Speech Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields; D055815:Young Adult
keywords: EEG; ERP; Hemispheric asymmetries; N1; P1; Sloreta