Natural Music Evokes Correlated EEG Responses Reflecting Temporal Structure and Beat

Abstract

The brain activity of multiple subjects has been shown to synchronize during salient moments of natural stimuli, suggesting that correlation of neural responses indexes a brain state operationally termed engagement. While past electroencephalography (EEG) studies have considered both auditory and visual stimuli, the extent to which these results generalize to music--a temporally structured stimulus for which the brain has evolved specialized circuitry--is less understood. Here we investigated neural correlation during natural music listening by recording dense-array EEG responses from N = 48 adult listeners as they heard real-world musical works, some of which were temporally disrupted through shuffling of short-term segments (measures), reversal, or randomization of phase spectra. We measured neural correlation across responses (inter-subject correlation) and between responses and stimulus envelope fluctuations (stimulus-response correlation) in the time and frequency domains. Stimuli retaining basic musical features evoked significantly correlated neural responses in all analyses. However, while unedited songs were self-reported as most pleasant, time-domain correlations were highest during measure-shuffled versions. Frequency-domain measures of correlation (coherence) peaked at frequencies related to the musical beat, although the magnitudes of these spectral peaks did not explain the observed temporal correlations. Our findings show that natural music evokes significant inter-subject and stimulus-response correlations, and suggest that the neural correlates of musical engagement may be distinct from those of enjoyment.