title: Left inferior frontal gyrus mediates morphosyntax: ERP evidence from verb processing in left-hemisphere damaged patients.
abstract: Neurocognitive models of language comprehension have proposed different mechanisms with different neural substrates mediating human language processing. Whether the left inferior frontal gyrus (LIFG) is engaged in morpho-syntactic information processing is currently still controversially debated. The present study addresses this issue by examining the processing of irregular verb inflection in real words (e.g., swim > swum > swam) and pseudowords (e.g., frim > frum > fram) by using event-related brain potentials (ERPs) in neurological patients with lesions in the LIFG involving Broca's area as well as healthy controls. Different ERP patterns in response to the grammatical violations were observed in both groups. Controls showed a biphasic negativity-P600 pattern in response to incorrect verb inflections whereas patients with LIFG lesions displayed a N400. For incorrect pseudoword inflections, a late positivity was found in controls, while no ERP effects were obtained in patients. These findings of different ERP patterns in the two groups strongly indicate an involvement of LIFG in morphosyntactic processing, thereby suggesting brain regions' specialization for different language functions.
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, Germany. Electronic address: regel@cbs.mpg.de.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Regel
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, Germany; Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Sonja A
authors.initials: SA
authors.lastname: Kotz
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, Germany.
authors.forename: Ilona
authors.initials: I
authors.lastname: Henseler
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, Germany.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Friederici
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000503:physiopathology*; D001931:Brain Mapping; D065711:Broca Area / Q000503:physiopathology*; D032882:Comprehension / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D013067:Speech Perception / Q000502:physiology*
keywords: (Morpho-)syntax; Broca's area; Event-related potentials (ERPs); Language processing; Left inferior frontal gyrus (LIFG)