Neural entrainment predicts the anticipatory P300 component during musical meter perception: An EEG study using dual-meter sound stimuli

Meter, the organization of beats into regular groupings, is a core element of music perception. Switches in meters frequently occur in music, reflecting the interplay between top-down attentional processes and the bottom-up processing of acoustic features. To disentangle this interplay in meter perception, we had previously invented a sound stimulus that simultaneously contained two meters. This dual-meter stimulus consisted of band-limited noise bursts that varied in center frequency and duration, with one feature following a triple-meter pattern and the other following a quadruple-meter pattern. Thus, the perceived meter switches between the two by changing attention from one acoustic feature to another, even when listening to identical stimuli. Using these stimuli, we here demonstrated the neural processes involved in meter perception by recording electroencephalogram (EEG) signals, while dissociating the influence of acoustic differences. We first found that the perceived meter structure was reflected in the entrained neural oscillations by comparing the spectral profiles of EEG signals when the participants focused on triple-meter versus quadruple-meter features. Second, an event-related potential component for anticipation (P300) was observed when the expected meter structure was disrupted by altering the frequency or duration of one sound at the end of the stimulus. Finally, individuals with stronger neural entrainment exhibited larger P300 responses to these disruptions. Our findings suggest that top-down attention modulates anticipation of the meter structure, and this anticipation induces neural entrainment that is involved in meter perception. Significance StatementUnderstanding how neural entrainment and anticipation interact is central to uncovering how the brain predicts and interprets incoming information. Musical meter provides an ideal model for investigating this process, as it emerges from the integration of bottom-up acoustic processing with top-down attention. However, traditional approaches have struggled to disentangle attention-driven neural entrainment and anticipation from acoustic variability. To address this, we introduced novel "dual-meter" stimuli that can be perceived as different meters depending on whether listeners attend to frequency or duration. EEG recordings revealed that neural entrainment to the perceived meter predicts the brains anticipatory P300 response to metrical violations, suggesting that attention links neural entrainment and anticipatory processing.