title: Therapy-Induced Neuroplasticity of Language in Chronic Post Stroke Aphasia: A Mismatch Negativity Study of (A)Grammatical and Meaningful/less Mini-Constructions.
abstract: Clinical language performance and neurophysiological correlates of language processing were measured before and after intensive language therapy in patients with chronic (time post stroke >1 year) post stroke aphasia (PSA). As event-related potential (ERP) measure, the mismatch negativity (MMN) was recorded in a distracted oddball paradigm to short spoken sentences. Critical 'deviant' sentence stimuli where either well-formed and meaningful, or syntactically, or lexico-semantically incorrect. After 4 weeks of speech-language therapy (SLT) delivered with high intensity (10.5 h per week), clinical language assessment with the Aachen Aphasia Test battery demonstrated significant linguistic improvements, which were accompanied by enhanced MMN responses. More specifically, MMN amplitudes to grammatically correct and meaningful mini-constructions and to 'jabberwocky' sentences containing a pseudoword significantly increased after therapy. However, no therapy-related changes in MMN responses to syntactically incorrect strings including agreement violations were observed. While MMN increases to well-formed meaningful strings can be explained both at the word and construction levels, the neuroplastic change seen for 'jabberwocky' sentences suggests an explanation in terms of constructions. The results confirm previous reports that intensive SLT leads to improvements of linguistic skills in chronic aphasia patients and now demonstrate that this clinical improvement is associated with enhanced automatic brain indexes of construction processing, although no comparable change is present for ungrammatical strings. Furthermore, the data confirm that the language-induced MMN is a useful tool to map functional language recovery in PSA.
authors.affiliation: Brain Language Laboratory, Department of Philosophy and Humanities Freie Universität Berlin, Berlin Germany.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Lucchese
authors.affiliation: Brain Language Laboratory, Department of Philosophy and HumanitiesFreie Universität Berlin, Berlin Germany; Berlin School of Mind and Brain, Humboldt-Universität zu BerlinBerlin, Germany.
authors.forename: Friedemann
authors.initials: F
authors.lastname: Pulvermüller
authors.affiliation: Brain Language Laboratory, Department of Philosophy and HumanitiesFreie Universität Berlin, Berlin Germany; Department of Neurology, Charité Universitätsmedizin Berlin, Campus MitteBerlin, Germany; Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Stahl
authors.affiliation: Brain Language Laboratory, Department of Philosophy and Humanities Freie Universität Berlin, Berlin Germany.
authors.forename: Felix R
authors.initials: FR
authors.lastname: Dreyer
authors.affiliation: Department of Psychiatry, Charité Universitätsmedizin Berlin Campus Benjamin Franklin, Berlin Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Mohr
keywords: EEG; aphasia; cortical reorganization; intensive language therapy; mismatch negativity; syntax