Poster C72, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Language Improvement in Aphasia Therapy is Reflected by the Mismatch Negativity to Meaningful and Meaningless Constructions, but not by That to Ungrammatical Strings
Guglielmo Lucchese1, Friedemann Pulvermüller1,2, Benjamin Stahl1,3, Felix Dreyer1, Bettina Mohr4; 1Brain Language Laboratory, Freie Universtät Berlin, 14195, Berlin Germany, 2Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, 10099 Berlin, Germany., 3Charité Universitätsmedizin Berlin, Campus Mitte, 10117, Berlin Germany, 4Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203, Berlin Germany
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 hours per week), clinical language assessment with the Aachen Aphasia Test (AAT) 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.
Topic Area: LANGUAGE: Other