TY  - JOUR
A1  - Murakami, Takenobu
A1  - Kell, Christian Alexander
A1  - Restle, Julia
A1  - Ugawa, Yoshikazu
A1  - Ziemann, Ulf
T1  - Left dorsal speech stream components and their contribution to phonological processing
T2  - The journal of neuroscience
N2  - Models propose an auditory-motor mapping via a left-hemispheric dorsal speech-processing stream, yet its detailed contributions to speech perception and production are unclear. Using fMRI-navigated repetitive transcranial magnetic stimulation (rTMS), we virtually lesioned left dorsal stream components in healthy human subjects and probed the consequences on speech-related facilitation of articulatory motor cortex (M1) excitability, as indexed by increases in motor-evoked potential (MEP) amplitude of a lip muscle, and on speech processing performance in phonological tests. Speech-related MEP facilitation was disrupted by rTMS of the posterior superior temporal sulcus (pSTS), the sylvian parieto-temporal region (SPT), and by double-knock-out but not individual lesioning of pars opercularis of the inferior frontal gyrus (pIFG) and the dorsal premotor cortex (dPMC), and not by rTMS of the ventral speech-processing stream or an occipital control site. RTMS of the dorsal stream but not of the ventral stream or the occipital control site caused deficits specifically in the processing of fast transients of the acoustic speech signal. Performance of syllable and pseudoword repetition correlated with speech-related MEP facilitation, and this relation was abolished with rTMS of pSTS, SPT, and pIFG. Findings provide direct evidence that auditory-motor mapping in the left dorsal stream causes reliable and specific speech-related MEP facilitation in left articulatory M1. The left dorsal stream targets the articulatory M1 through pSTS and SPT constituting essential posterior input regions and parallel via frontal pathways through pIFG and dPMC. Finally, engagement of the left dorsal stream is necessary for processing of fast transients in the auditory signal.
KW  - articulatory motor cortex
KW  - dorsal auditory stream
KW  - motor-evoked potential
KW  - phonological processing
KW  - repetitive transcranial magnetic stimulation
KW  - transient virtual lesion
Y1  - 2017
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/45006
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-450069
SN  - 1529-2401
SN  - 0270-6474
N1  - Copyright © 2015 Murakami, Kell et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
VL  - 35
IS  - 4
SP  - 1411
EP  - 1422
PB  - Society for Neuroscience
CY  - Washington, DC
ER  -