Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Gerontology

Background:

• Speech perception declines with age, particularly in noise.
• Temporal processing, mediated by neural oscillations, is crucial for speech perception.
• Deviations in neural synchronization may underlie age-related speech perception deficits.

Purpose of the Study:

• To investigate age-related changes in neural synchronization within the auditory system.
• To examine the relationship between neural synchronization patterns and speech perception in aging.
• To identify specific oscillatory frequencies (theta, beta, gamma) affected by aging.

Main Methods:

• Recorded auditory steady-state responses (ASSRs) at 4, 20, 40, and 80 Hz in young, middle-aged, and older adults.
• Ensured participants had normal hearing and no cognitive impairment to isolate age effects.
• Analyzed synchronized neural activity across different frequency bands and hemispheric lateralization.

Main Results:

• Older adults exhibited increased theta oscillation synchronization.
• High gamma oscillation synchronization was decreased in older adults compared to younger individuals.
• Young adults showed right hemispheric dominance for high gamma processing, while older adults displayed symmetrical processing.

Conclusions:

• Age-related alterations in neural synchronization, specifically in theta and high gamma bands, are evident in the auditory system.
• These changes in neural synchronization patterns may contribute to the decline in speech perception observed in older adults.
• Altered hemispheric processing of high gamma modulations in aging warrants further investigation.