Aging effects on neural entrainment to a musical beat

When listening to music, the brain entrains to the musical rhythm and produces neural activity at the beat frequency. Younger (<35) and older (>60) adults listened to slow (1.25 Hz) and fast (2.5 Hz) syncopated and non-syncopated rhythms while intermittently performing a tapping task. EEG was recorded and frequency tagging was employed to analyze meter-related and meter-unrelated frequencies elicited by the rhythms. The meter-related frequencies included the beat frequency (BF), its first three harmonics (H1-H3) and the frequency of the whole pattern, or cycle rate (CR) while the meter-unrelated frequencies included the remaining harmonics of the CR up to the eleventh harmonic. Age effects were observed at the BF, where younger adults had larger amplitudes than older adults and at the CR. At the fast tempo, older adults did not differentiate between the CR, the BF and H3. Together, these results suggest older adults experience a breakdown of selective encoding at the fast tempo and reliance on high-level information, exhibiting aspects of both the inhibition and compensation theories of aging.