Temporospatial identification of language‐related cortical function by a combination of transcranial magnetic stimulation and magnetoencephalography
Introduction Identification of language‐related cortical functions can be carried out noninvasively by transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG), which allow for lesion‐based interrogation and global temporospatial investigation of cortices, respectively. Combining the...
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Published in | Brain and behavior Vol. 5; no. 3; pp. e00317 - n/a |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
John Wiley & Sons, Inc
01.03.2015
Blackwell Publishing Ltd |
Subjects | |
Online Access | Get full text |
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Summary: | Introduction
Identification of language‐related cortical functions can be carried out noninvasively by transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG), which allow for lesion‐based interrogation and global temporospatial investigation of cortices, respectively. Combining these two modalities can improve the accuracy of the identification, but the relationships between them remain unclear. We compared TMS and MEG responses during the same language task to elucidate their temporospatial relationships and used the results to develop a novel method to identify language‐related cortical functions.
Methods
Twelve healthy right‐handed volunteers performed a picture‐naming task during TMS and MEG. TMS was applied on the right or left inferior frontal gyrus (IFG) at five time points, and the reaction times (RTs) for naming the pictures were measured. The temporospatial oscillatory changes measured by MEG during the same task were then compared with the TMS results.
Results
Transcranial magnetic stimulation of the left IFG significantly lengthened RTs at 300 and 375 msec after picture presentation, whereas TMS of the right IFG did not change RTs significantly. Interestingly, the stimulus time point at which RTs increased significantly for each individual was correlated with when the low gamma event‐related desynchronizations (ERDs) peaked in the left IFG. Moreover, combining the results of TMS and MEG improved the detection rate for identifying the laterality of language function.
Conclusions
These results suggest that the low gamma ERDs measured by MEG strongly relate to the language function of picture naming in the left IFG. Finally, we propose a novel method to identify language‐related cortical functions by combining TMS and MEG.
This study has shown that combining TMS and MEG improves the accuracy to identify the laterality of language function. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Funding Information This work was supported in part by KAKENHI (26560467, 26282165), “Development of BMI Technologies for Clinical Application” carried out under the Strategic Research Program for Brain Sciences of MEXT. |
ISSN: | 2162-3279 2162-3279 |
DOI: | 10.1002/brb3.317 |