title: Slow event-related brain activity of aphasic patients and controls in word comprehension and rhyming tasks.
abstract: Slow event-related potentials (ERP) were examined in healthy and aphasic subjects in two-stimulus designs comprising a word comprehension and a rhyming task. Aphasics, though selected to perform above chance level, made significantly more errors and responded more slowly than controls, although canonical correlations did not indicate a statistical relationship between performance measures and ERP amplitudes. A discriminant analysis of ERP amplitudes distinguished the groups for the slow wave (SW; 0.5-1.0 s post-S1 onset) in the word comprehension, for the SW and the initial contingent negative variation (iCNV; 1.0-2.0 s post-S1 onset) in the rhyming task. Similarly for both tasks, ERP topography showed left-anterior predominance of the negative SW and iCNV in controls, whereas participants with aphasia showed smaller anterior and larger left-posterior amplitudes. The centroparietal terminal CNV (tCNV; 1 s pre-S2) was smaller in participants with aphasia than in controls, but similar in topography. Results suggest left-anterior activation for those language processes that were presumably provoked in the present tasks, like lexical access, or phonological encoding. The pattern of participants with aphasia may indicate effects of language impairment and recovery, but also consequences of the brain damage.
authors.affiliation: Max-Planck-Institute for Psycholinguistics, Nijmegen, The Netherlands. cdobel@psy.nni-muenster.de
authors.forename: Christian
authors.initials: C
authors.lastname: Dobel
authors.forename: Rudolf
authors.initials: R
authors.lastname: Cohen
authors.forename: Patrick
authors.initials: P
authors.lastname: Berg
authors.forename: Willi
authors.initials: W
authors.lastname: Nagl
authors.forename: Elvira
authors.initials: E
authors.lastname: Zobel
authors.forename: Peter
authors.initials: P
authors.lastname: Köbbel
authors.forename: Paul-Walter
authors.initials: PW
authors.lastname: Schönle
authors.forename: Brigitte
authors.initials: B
authors.lastname: Rockstroh
mesh_terms: D000328:Adult; D000368:Aged; D000849:Anomia / Q000503:physiopathology*; D001039:Aphasia, Broca / Q000503:physiopathology*; D001041:Aphasia, Wernicke / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology; D004410:Dyslexia / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual; D011597:Psychomotor Performance / Q000502:physiology