Reduced neural sensitivity to musical tempo despite enhanced neural tracking of musical features in older adults

A substantial body of prior research has focused on how older adults process and comprehend speech, whereas less attention has been devoted to how older adults encode and perceive naturalistic music. In the current study, we investigated whether the neural tracking of different musical features in naturalistic music differs between age groups. Younger and older adults (both sexes) listened to the excerpts of naturalistic music with different tempi (1-4 Hz) while electroencephalography (EEG) was recorded. The results show an age-related enhancement of neural responses to sound onsets, suggesting a loss of inhibition in the aged auditory cortex. Neural tracking of different musical features, including the amplitude envelope, amplitude onset, and spectral flux, were also enhanced in older adults, indicating that the hyperresponsiveness generalizes to features of naturalistic music. However, our results show that, despite enhanced neural responses, older adults exhibit reduced neural sensitivity of early sensory responses to music pieces with different tempi. Moreover, spectral flux mostly effectively predicted the changes in EEG activity due to differences in musical tempo, but this was reduced in older adults compared to younger adults. The current findings suggest that hyperresponsiveness in auditory cortex of older adults is accompanied by a lack of sensitivity to the tempo in music. The results highlight the complex changes in the aged auditory system that affect the processing of naturalistic sounds.