Abstract
The auditory system is organized such that progressively more complex features are represented across successive cortical hierarchical stages. Just when and where the processing of phonemes, fundamental elements of the speech signal, is achieved in this hierarchy remains a matter of vigorous debate. Non-invasive measures of phonemic representation have been somewhat equivocal. While some studies point to a primary role for middle/anterior regions of the superior temporal gyrus (STG), others implicate the posterior STG. Differences in stimulation, task and inter-individual anatomical/functional variability may account for these discrepant findings. Here, we sought to clarify this issue by mapping phonemic representation across left perisylvian cortex, taking advantage of the excellent sampling density afforded by intracranial recordings in humans. We asked whether one or both major divisions of the STG were sensitive to phonemic transitions. The high signal-to-noise characteristics of direct intracranial recordings allowed for analysis at the individual participant level, circumventing issues of inter-individual anatomic and functional variability that may have obscured previous findings at the group level of analysis. The mismatch negativity (MMN), an electrophysiological response elicited by changes in repetitive streams of stimulation, served as our primary dependent measure. Oddball configurations of pairs of phonemes, spectro-temporally matched non-phonemes, and simple tones were presented. The loci of the MMN clearly differed as a function of stimulus type. Phoneme representation was most robust over middle/anterior STG/STS, but was also observed over posterior STG/SMG. These data point to multiple phonemic processing zones along perisylvian cortex, both anterior and posterior to primary auditory cortex. This finding is considered within the context of a dual stream model of auditory processing in which functionally distinct ventral and dorsal auditory processing pathways may be engaged by speech stimuli.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1369-1383 |
| Number of pages | 15 |
| Journal | Brain Structure and Function |
| Volume | 219 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2014 |
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Keywords
- Auditory
- ECog
- Intracranial
- Phoneme
- Speech processing
- Superior temporal gyrus
ASJC Scopus subject areas
- Anatomy
- Histology
- Neuroscience(all)
- Medicine(all)
Cite this
Mapping phonemic processing zones along human perisylvian cortex : An electro-corticographic investigation. / Molholm, Sophie; Mercier, Manuel R.; Liebenthal, Einat; Schwartz, Theodore H.; Ritter, Walter; Foxe, John J.; De Sanctis, Pierfilippo.
In: Brain Structure and Function, Vol. 219, No. 4, 2014, p. 1369-1383.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mapping phonemic processing zones along human perisylvian cortex
T2 - An electro-corticographic investigation
AU - Molholm, Sophie
AU - Mercier, Manuel R.
AU - Liebenthal, Einat
AU - Schwartz, Theodore H.
AU - Ritter, Walter
AU - Foxe, John J.
AU - De Sanctis, Pierfilippo
PY - 2014
Y1 - 2014
N2 - The auditory system is organized such that progressively more complex features are represented across successive cortical hierarchical stages. Just when and where the processing of phonemes, fundamental elements of the speech signal, is achieved in this hierarchy remains a matter of vigorous debate. Non-invasive measures of phonemic representation have been somewhat equivocal. While some studies point to a primary role for middle/anterior regions of the superior temporal gyrus (STG), others implicate the posterior STG. Differences in stimulation, task and inter-individual anatomical/functional variability may account for these discrepant findings. Here, we sought to clarify this issue by mapping phonemic representation across left perisylvian cortex, taking advantage of the excellent sampling density afforded by intracranial recordings in humans. We asked whether one or both major divisions of the STG were sensitive to phonemic transitions. The high signal-to-noise characteristics of direct intracranial recordings allowed for analysis at the individual participant level, circumventing issues of inter-individual anatomic and functional variability that may have obscured previous findings at the group level of analysis. The mismatch negativity (MMN), an electrophysiological response elicited by changes in repetitive streams of stimulation, served as our primary dependent measure. Oddball configurations of pairs of phonemes, spectro-temporally matched non-phonemes, and simple tones were presented. The loci of the MMN clearly differed as a function of stimulus type. Phoneme representation was most robust over middle/anterior STG/STS, but was also observed over posterior STG/SMG. These data point to multiple phonemic processing zones along perisylvian cortex, both anterior and posterior to primary auditory cortex. This finding is considered within the context of a dual stream model of auditory processing in which functionally distinct ventral and dorsal auditory processing pathways may be engaged by speech stimuli.
AB - The auditory system is organized such that progressively more complex features are represented across successive cortical hierarchical stages. Just when and where the processing of phonemes, fundamental elements of the speech signal, is achieved in this hierarchy remains a matter of vigorous debate. Non-invasive measures of phonemic representation have been somewhat equivocal. While some studies point to a primary role for middle/anterior regions of the superior temporal gyrus (STG), others implicate the posterior STG. Differences in stimulation, task and inter-individual anatomical/functional variability may account for these discrepant findings. Here, we sought to clarify this issue by mapping phonemic representation across left perisylvian cortex, taking advantage of the excellent sampling density afforded by intracranial recordings in humans. We asked whether one or both major divisions of the STG were sensitive to phonemic transitions. The high signal-to-noise characteristics of direct intracranial recordings allowed for analysis at the individual participant level, circumventing issues of inter-individual anatomic and functional variability that may have obscured previous findings at the group level of analysis. The mismatch negativity (MMN), an electrophysiological response elicited by changes in repetitive streams of stimulation, served as our primary dependent measure. Oddball configurations of pairs of phonemes, spectro-temporally matched non-phonemes, and simple tones were presented. The loci of the MMN clearly differed as a function of stimulus type. Phoneme representation was most robust over middle/anterior STG/STS, but was also observed over posterior STG/SMG. These data point to multiple phonemic processing zones along perisylvian cortex, both anterior and posterior to primary auditory cortex. This finding is considered within the context of a dual stream model of auditory processing in which functionally distinct ventral and dorsal auditory processing pathways may be engaged by speech stimuli.
KW - Auditory
KW - ECog
KW - Intracranial
KW - Phoneme
KW - Speech processing
KW - Superior temporal gyrus
UR - http://www.scopus.com/inward/record.url?scp=84904331544&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84904331544&partnerID=8YFLogxK
U2 - 10.1007/s00429-013-0574-y
DO - 10.1007/s00429-013-0574-y
M3 - Article
VL - 219
SP - 1369
EP - 1383
JO - Referate und Beiträge zur Anatomie und Entwickelungsgeschichte
JF - Referate und Beiträge zur Anatomie und Entwickelungsgeschichte
SN - 0177-5154
IS - 4
ER -