Journal article
Differential responses to spectrally degraded speech within human auditory cortex: An intracranial electrophysiology study
Hearing research, Vol.371, pp.53-65
01/2019
DOI: 10.1016/j.heares.2018.11.009
PMCID: PMC6309487
PMID: 30500619
Abstract
Understanding cortical processing of spectrally degraded speech in normal-hearing subjects may provide insights into how sound information is processed by cochlear implant (CI) users. This study investigated electrocorticographic (ECoG) responses to noise-vocoded speech and related these responses to behavioral performance in a phonemic identification task. Subjects were neurosurgical patients undergoing chronic invasive monitoring for medically refractory epilepsy. Stimuli were utterances /aba/ and /ada/, spectrally degraded using a noise vocoder (1–4 bands). ECoG responses were obtained from Heschl's gyrus (HG) and superior temporal gyrus (STG), and were examined within the high gamma frequency range (70–150 Hz). All subjects performed at chance accuracy with speech degraded to 1 and 2 spectral bands, and at or near ceiling for clear speech. Inter-subject variability was observed in the 3- and 4-band conditions. High gamma responses in posteromedial HG (auditory core cortex) were similar for all vocoded conditions and clear speech. A progressive preference for clear speech emerged in anterolateral segments of HG, regardless of behavioral performance. On the lateral STG, responses to all vocoded stimuli were larger in subjects with better task performance. In contrast, both behavioral and neural responses to clear speech were comparable across subjects regardless of their ability to identify degraded stimuli. Findings highlight differences in representation of spectrally degraded speech across cortical areas and their relationship to perception. The results are in agreement with prior non-invasive results. The data provide insight into the neural mechanisms associated with variability in perception of degraded speech and potentially into sources of such variability in CI users.
•High gamma responses in posteromedial HG are similar across stimulus conditions.•A progressive preference for clear speech in anterolateral HG.•Responses on STG to vocoded speech are larger in better-performing subjects.•Behavioral and neural responses to clear speech are comparable across all subjects.
Details
- Title: Subtitle
- Differential responses to spectrally degraded speech within human auditory cortex: An intracranial electrophysiology study
- Creators
- Kirill V Nourski - Department of Neurosurgery, The University of Iowa, Iowa City, IA, USAMitchell Steinschneider - Departments of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USAAriane E Rhone - Department of Neurosurgery, The University of Iowa, Iowa City, IA, USAChristopher K Kovach - Department of Neurosurgery, The University of Iowa, Iowa City, IA, USAHiroto Kawasaki - Department of Neurosurgery, The University of Iowa, Iowa City, IA, USAMatthew A Howard - Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
- Resource Type
- Journal article
- Publication Details
- Hearing research, Vol.371, pp.53-65
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.heares.2018.11.009
- PMID
- 30500619
- PMCID
- PMC6309487
- ISSN
- 0378-5955
- eISSN
- 1878-5891
- Grant note
- DOI: 10.13039/100000002, name: National Institutes of Health, award: UL1RR024979, R01-DC04290, CRCNS-1515678; DOI: 10.13039/100000001, name: National Science Foundation, award: UL1RR024979, R01-DC04290, CRCNS-1515678
- Language
- English
- Date published
- 01/2019
- Academic Unit
- Neurology; Iowa Neuroscience Institute; Neurosurgery; Otolaryngology
- Record Identifier
- 9984020620902771
Metrics
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