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A Method for Tracking the Time Evolution of Steady-State Evoked Potentials
Published on: May 25, 2019
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Age-related changes in envelope-following responses at equalized peripheral or central activation
Jesyin Lai1, Alexandra L Sommer1, Edward L Bartlett2
1Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
Neurobiology of Aging
|July 29, 2017
Summary
Aging hearing shows enhanced central gain, impacting auditory brainstem responses (ABRs) and envelope-following responses (EFRs). This suggests new ways to measure hearing beyond simple thresholds.
Area of Science:
- Auditory Neuroscience
- Gerontology
- Neuroscience
Background:
- Hearing abilities change with age and acoustic trauma.
- Auditory brainstem responses (ABRs) and envelope-following responses (EFRs) are key measures.
- Comparing young and aged auditory systems is crucial for understanding hearing decline.
Purpose of the Study:
- To compare EFRs in young and aged rats.
- To investigate age-related changes in auditory processing.
- To differentiate peripheral and central auditory system contributions.
Main Methods:
- Matched wave I amplitudes of ABRs to 8-kHz tones between young and aged rats.
- Matched EFR amplitudes to sinusoidally amplitude-modulated (SAM) tones (100% depth).
- Assessed EFRs in silence at 100% and 25% modulation depth.
Main Results:
- Wave I amplitude matching required ~20 dB level difference.
- No age-related differences in wave V amplitudes for matched wave I.
- Enhanced EFRs in silence at 100% depth in aged rats, suggesting increased central gain.
- No age-related differences in AM depth/frequency processing for matched EFRs.
Conclusions:
- Aging enhances central gain in the auditory system.
- EFRs offer objective measures beyond thresholds.
- Differentiating peripheral and central auditory contributions is possible with EFRs.
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