Functional reorganization of language networks for semantics and syntax in chronic stroke: Evidence from MEG

Aneta Kielar, Tiffany Deschamps, Regina Jokel, Jed A. Meltzer

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Using magnetoencephalography, we investigated the potential of perilesional and contralesional activity to support language recovery in patients with poststroke aphasia. In healthy young controls, left-lateralized ventral frontotemporal regions responded to semantic anomalies during sentence comprehension and bilateral dorsal frontoparietal regions responded to syntactic anomalies. Older adults showed more extensive bilateral responses to the syntactic anomalies and less lateralized responses to the semantic anomalies, with decreased activation in the left occipital and parietal regions for both semantic and syntactic anomalies. In aphasic participants, we observed compensatory recruitment in the right hemisphere (RH), which varied depending on the type of linguistic information that was processed. For semantic anomalies, aphasic patients activated some preserved left hemisphere regions adjacent to the lesion, as well as homologous parietal and temporal RH areas. Patients also recruited right inferior and dorsolateral frontal cortex that was not activated in the healthy participants. Responses for syntactic anomalies did not reach significance in patients. Correlation analyses indicated that recruitment of homologous temporoparietal RH areas is associated with better semantic performance, whereas higher accuracy on the syntactic task was related to bilateral superior temporoparietal and right frontal activity. The results suggest that better recovery of semantic processing is associated with a shift to ventral brain regions in the RH. In contrast, preservation of syntactic processing is mediated by dorsal areas, bilaterally, although recovery of syntactic processing tends to be poorer than semantic. Hum Brain Mapp 37:2869–2893, 2016.

Original languageEnglish (US)
Pages (from-to)2869-2893
Number of pages25
JournalHuman Brain Mapping
Volume37
Issue number8
DOIs
StatePublished - Aug 1 2016
Externally publishedYes

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Keywords

  • 8–30 Hz ERD
  • : aphasia
  • beamforming
  • compensation
  • language recovery
  • MEG
  • oscillations
  • semantics
  • sentence comprehension
  • stroke
  • syntax

ASJC Scopus subject areas

  • Anatomy
  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Clinical Neurology

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