کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
925374 921486 2013 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tracking the speech signal – Time-locked MEG signals during perception of ultra-fast and moderately fast speech in blind and in sighted listeners
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی روانپزشکی بیولوژیکی
پیش نمایش صفحه اول مقاله
Tracking the speech signal – Time-locked MEG signals during perception of ultra-fast and moderately fast speech in blind and in sighted listeners
چکیده انگلیسی

Blind people can learn to understand speech at ultra-high syllable rates (ca. 20 syllables/s), a capability associated with hemodynamic activation of the central-visual system. To further elucidate the neural mechanisms underlying this skill, magnetoencephalographic (MEG) measurements during listening to sentence utterances were cross-correlated with time courses derived from the speech signal (envelope, syllable onsets and pitch periodicity) to capture phase-locked MEG components (14 blind, 12 sighted subjects; speech rate = 8 or 16 syllables/s, pre-defined source regions: auditory and visual cortex, inferior frontal gyrus). Blind individuals showed stronger phase locking in auditory cortex than sighted controls, and right-hemisphere visual cortex activity correlated with syllable onsets in case of ultra-fast speech. Furthermore, inferior-frontal MEG components time-locked to pitch periodicity displayed opposite lateralization effects in sighted (towards right hemisphere) and blind subjects (left). Thus, ultra-fast speech comprehension in blind individuals appears associated with changes in early signal-related processing mechanisms both within and outside the central-auditory terrain.


► Cross-correlation shows time locking of MEG with features the speech signal.
► Speech-correlated MEG activity is not restricted to auditory cortex.
► Blind subjects show enhanced phase locking to continuous speech.
► Blind and sighted subjects show different hemisphere effects.
► Right visual system tracks syllable onsets during ultra-fast speech perception.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain and Language - Volume 124, Issue 1, January 2013, Pages 9–21
نویسندگان
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