Phase-locked responses to speech in human auditory cortex are enhanced during comprehension

A growing body of evidence shows that ongoing oscillations in auditory cortex modulate their phase to match the rhythm of temporally regular acoustic stimuli, increasing sensitivity to relevant environmental cues and improving detection accuracy. In the current study, we test the hypothesis that non...

Full description

Saved in:
Bibliographic Details
Published in:Cerebral cortex (New York, N.Y. 1991) N.Y. 1991), 2013-06, Vol.23 (6), p.1378-1387
Main Authors: Peelle, Jonathan E, Gross, Joachim, Davis, Matthew H
Format: Article
Language:English
Subjects:
Acoustic Stimulation
Adult
Analysis of Variance
Auditory Cortex - physiology
Brain Mapping
Comprehension - physiology
Contingent Negative Variation - physiology
Electroencephalography
Evoked Potentials, Auditory
Female
Fourier Analysis
Humans
Linguistics
Magnetic Resonance Imaging
Magnetoencephalography
Male
Sound Spectrography
Speech - physiology
Speech Perception
Time Factors
Vocabulary
Young Adult
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A growing body of evidence shows that ongoing oscillations in auditory cortex modulate their phase to match the rhythm of temporally regular acoustic stimuli, increasing sensitivity to relevant environmental cues and improving detection accuracy. In the current study, we test the hypothesis that nonsensory information provided by linguistic content enhances phase-locked responses to intelligible speech in the human brain. Sixteen adults listened to meaningful sentences while we recorded neural activity using magnetoencephalography. Stimuli were processed using a noise-vocoding technique to vary intelligibility while keeping the temporal acoustic envelope consistent. We show that the acoustic envelopes of sentences contain most power between 4 and 7 Hz and that it is in this frequency band that phase locking between neural activity and envelopes is strongest. Bilateral oscillatory neural activity phase-locked to unintelligible speech, but this cerebro-acoustic phase locking was enhanced when speech was intelligible. This enhanced phase locking was left lateralized and localized to left temporal cortex. Together, our results demonstrate that entrainment to connected speech does not only depend on acoustic characteristics, but is also affected by listeners' ability to extract linguistic information. This suggests a biological framework for speech comprehension in which acoustic and linguistic cues reciprocally aid in stimulus prediction.
ISSN:1047-3211
1460-2199
DOI:10.1093/cercor/bhs118