Aging alters across-hemisphere cortical dynamics during binaural temporal processing
Differences in the timing and intensity of sounds arriving at the two ears provide fundamental binaural cues that help us localize and segregate sounds in the environment. Neural encoding of these cues is commonly represented asymmetrically in the cortex with stronger activation in the hemisphere co...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-01-01
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| Series: | Frontiers in Neuroscience |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fnins.2022.1060172/full |
| _version_ | 1828067668724285440 |
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| author | Ann Clock Eddins Ann Clock Eddins Erol J. Ozmeral David A. Eddins |
| author_facet | Ann Clock Eddins Ann Clock Eddins Erol J. Ozmeral David A. Eddins |
| author_sort | Ann Clock Eddins |
| collection | DOAJ |
| description | Differences in the timing and intensity of sounds arriving at the two ears provide fundamental binaural cues that help us localize and segregate sounds in the environment. Neural encoding of these cues is commonly represented asymmetrically in the cortex with stronger activation in the hemisphere contralateral to the perceived spatial location. Although advancing age is known to degrade the perception of binaural cues, less is known about how the neural representation of such cues is impacted by age. Here, we use electroencephalography (EEG) to investigate age-related changes in the hemispheric distribution of interaural time difference (ITD) encoding based on cortical auditory evoked potentials (CAEPs) and derived binaural interaction component (BIC) measures in ten younger and ten older normal-hearing adults. Sensor-level analyses of the CAEP and BIC showed age-related differences in global field power, where older listeners had significantly larger responses than younger for both binaural metrics. Source-level analyses showed hemispheric differences in auditory cortex activity for left and right lateralized stimuli in younger adults, consistent with a contralateral activation model for processing ITDs. Older adults, however, showed reduced hemispheric asymmetry across ITDs, despite having overall larger responses than younger adults. Further, when averaged across ITD condition to evaluate changes in cortical asymmetry over time, there was a significant shift in laterality corresponding to the peak components (P1, N1, P2) in the source waveform that also was affected by age. These novel results demonstrate across-hemisphere cortical dynamics during binaural temporal processing that are altered with advancing age. |
| first_indexed | 2024-04-10T23:49:11Z |
| format | Article |
| id | doaj.art-72251e3e75514c51baaf16bb46b601b6 |
| institution | Directory Open Access Journal |
| issn | 1662-453X |
| language | English |
| last_indexed | 2024-04-10T23:49:11Z |
| publishDate | 2023-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neuroscience |
| spelling | doaj.art-72251e3e75514c51baaf16bb46b601b62023-01-10T21:25:35ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2023-01-011610.3389/fnins.2022.10601721060172Aging alters across-hemisphere cortical dynamics during binaural temporal processingAnn Clock Eddins0Ann Clock Eddins1Erol J. Ozmeral2David A. Eddins3Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United StatesSchool of Communication Sciences and Disorders, University of Central Florida, Orlando, FL, United StatesDepartment of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United StatesDepartment of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United StatesDifferences in the timing and intensity of sounds arriving at the two ears provide fundamental binaural cues that help us localize and segregate sounds in the environment. Neural encoding of these cues is commonly represented asymmetrically in the cortex with stronger activation in the hemisphere contralateral to the perceived spatial location. Although advancing age is known to degrade the perception of binaural cues, less is known about how the neural representation of such cues is impacted by age. Here, we use electroencephalography (EEG) to investigate age-related changes in the hemispheric distribution of interaural time difference (ITD) encoding based on cortical auditory evoked potentials (CAEPs) and derived binaural interaction component (BIC) measures in ten younger and ten older normal-hearing adults. Sensor-level analyses of the CAEP and BIC showed age-related differences in global field power, where older listeners had significantly larger responses than younger for both binaural metrics. Source-level analyses showed hemispheric differences in auditory cortex activity for left and right lateralized stimuli in younger adults, consistent with a contralateral activation model for processing ITDs. Older adults, however, showed reduced hemispheric asymmetry across ITDs, despite having overall larger responses than younger adults. Further, when averaged across ITD condition to evaluate changes in cortical asymmetry over time, there was a significant shift in laterality corresponding to the peak components (P1, N1, P2) in the source waveform that also was affected by age. These novel results demonstrate across-hemisphere cortical dynamics during binaural temporal processing that are altered with advancing age.https://www.frontiersin.org/articles/10.3389/fnins.2022.1060172/fullelectrophysiologycortical auditory evoked potentialshemispheric asymmetryinteraural time differencebinaural interaction component |
| spellingShingle | Ann Clock Eddins Ann Clock Eddins Erol J. Ozmeral David A. Eddins Aging alters across-hemisphere cortical dynamics during binaural temporal processing Frontiers in Neuroscience electrophysiology cortical auditory evoked potentials hemispheric asymmetry interaural time difference binaural interaction component |
| title | Aging alters across-hemisphere cortical dynamics during binaural temporal processing |
| title_full | Aging alters across-hemisphere cortical dynamics during binaural temporal processing |
| title_fullStr | Aging alters across-hemisphere cortical dynamics during binaural temporal processing |
| title_full_unstemmed | Aging alters across-hemisphere cortical dynamics during binaural temporal processing |
| title_short | Aging alters across-hemisphere cortical dynamics during binaural temporal processing |
| title_sort | aging alters across hemisphere cortical dynamics during binaural temporal processing |
| topic | electrophysiology cortical auditory evoked potentials hemispheric asymmetry interaural time difference binaural interaction component |
| url | https://www.frontiersin.org/articles/10.3389/fnins.2022.1060172/full |
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