Aging Reduces Attentional Modulation of Speech-Evoked Cortical Responses While Preserving Adaptation

Background: This study examined age-related differences in repetition-related adaptation and attentional modulation of cortical auditory evoked potentials elicited by meaningful speech stimuli. Methods: Younger (18–35 years) and older (50–70 years) adults with clinically normal hearing were tested under active and passive listening conditions. N1 peak amplitudes were analyzed across early (first 30) and late (last 30) stimulus trials. Results: Repetition-related reductions in N1 amplitude were observed in both groups, indicating preserved adaptation. However, younger adults showed significant attentional enhancement of N1 amplitude, whereas older adults did not. Conclusions: These findings suggest that aging selectively reduces top-down attentional modulation while preserving repetition-related sensory adaptation.