| Discrimination of speech stimuli based on neuronal response phase patterns depends on acoustics but not comprehension. | |
| | |
MedLine Citation:
|
PMID: 20484530 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Speech stimuli give rise to neural activity in the listener that can be observed as waveforms using magnetoencephalography. Although waveforms vary greatly from trial to trial due to activity unrelated to the stimulus, it has been demonstrated that spoken sentences can be discriminated based on theta-band (3-7 Hz) phase patterns in single-trial response waveforms. Furthermore, manipulations of the speech signal envelope and fine structure that reduced intelligibility were found to produce correlated reductions in discrimination performance, suggesting a relationship between theta-band phase patterns and speech comprehension. This study investigates the nature of this relationship, hypothesizing that theta-band phase patterns primarily reflect cortical processing of low-frequency (<40 Hz) modulations present in the acoustic signal and required for intelligibility, rather than processing exclusively related to comprehension (e.g., lexical, syntactic, semantic). Using stimuli that are quite similar to normal spoken sentences in terms of low-frequency modulation characteristics but are unintelligible (i.e., their time-inverted counterparts), we find that discrimination performance based on theta-band phase patterns is equal for both types of stimuli. Consistent with earlier findings, we also observe that whereas theta-band phase patterns differ across stimuli, power patterns do not. We use a simulation model of the single-trial response to spoken sentence stimuli to demonstrate that phase-locked responses to low-frequency modulations of the acoustic signal can account not only for the phase but also for the power results. The simulation offers insight into the interpretation of the empirical results with respect to phase-resetting and power-enhancement models of the evoked response. |
| | |
Authors:
|
Mary F Howard; David Poeppel |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2010-05-19 |
Journal Detail:
|
Title: Journal of neurophysiology Volume: 104 ISSN: 1522-1598 ISO Abbreviation: J. Neurophysiol. Publication Date: 2010 Nov |
Date Detail:
|
Created Date: 2010-11-03 Completed Date: 2011-02-11 Revised Date: 2011-11-01 |
Medline Journal Info:
|
Nlm Unique ID: 0375404 Medline TA: J Neurophysiol Country: United States |
Other Details:
|
Languages: eng Pagination: 2500-11 Citation Subset: IM |
Affiliation:
|
Department of Linguistics, University of Maryland, College Park, MD 20742, USA. mfhoward@umd.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acoustic Stimulation Acoustics* Adult Analysis of Variance Brain Mapping Cerebral Cortex / physiology* Comprehension / physiology* Discrimination (Psychology) / physiology* Evoked Potentials, Auditory / physiology Female Humans Male Neurons / physiology* Speech Perception / physiology* |
| Grant Support | |
ID/Acronym/Agency:
|
2R01-DC-05660/DC/NIDCD NIH HHS; R01 DC005660-08/DC/NIDCD NIH HHS; R01 DC005660-09/DC/NIDCD NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Correcting the bias of spike field coherence estimators due to a finite number of spikes.
Next Document: Gain of function in FHM-1 Ca(V)2.1 knock-in mice is related to the shape of the action potential.