TMS uncovers details about sub-regional language-specific processing networks in early bilinguals

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Sini Hämäläinen, Niko Mäkelä, Viljami Sairanen, Minna Lehtonen, Teija Kujala, Alina Leminen
Publication year: 2018
Journal: NeuroImage
Journal acronym: Neuroimage
Volume number: 171
Start page: 209
End page: 221
ISSN: 1095-9572
eISSN: 1095-9572


Abstract

Despite numerous functional neuroimaging and intraoperative electrical cortical mapping studies aimed at investigating the cortical organisation of native (L1) and second (L2) language processing, the neural underpinnings of bilingualism remain elusive. We investigated whether the neural network engaged in speech production over the bilateral posterior inferior frontal gyrus (pIFG) is the same (i.e., shared) or different (i.e., language-specific) for the two languages of bilingual speakers. Navigated transcranial magnetic stimulation (TMS) was applied over the left and right posterior inferior gyrus (pIFG), while early simultaneous bilinguals performed a picture naming task with their native languages. An ex-Gaussian distribution was fitted to the naming latencies and the resulting parameters were compared between languages and across stimulation conditions. The results showed that although the naming performance in general was highly comparable between the languages, TMS produced a language-specific effect when the pulses were delivered to the left pIFG at 200 ms poststimulus. We argue that this result causally demonstrates, for the first time, that even within common language-processing areas, there are distinct language-specific neural populations for the different languages in early simultaneous bilinguals.

Last updated on 2020-17-01 at 04:25