Subjective Metric Organization Directs the Allocation of Attention across Time

Metric structure cues important moments, which can guide attention across time. Supporting this, metric strength improves performance and modulates early auditory processing. It is unclear whether the early effects of metric strength rely on stimulus cues, or if they also occur during entirely subjective metric listening. Here, we assess ERP responses to physically identical tones at subjectively strong and weak moments in an imagined metric structure. Isochronous tone streams at two rates were perceived as repeating subjective groups of either three or four beats, with listening pattern indicated by a visual cue prior to trial start. ERP responses to tones were compared among subjective beat positions and rates separately by listening pattern. Subjectively strong group-initial tones elicited a more negative auditory N1 response and a late metric negativity (LMN; 250–450 ms) under all conditions. Comparisons among metrically weaker beats suggested hierarchical listening, a sustained negativity prior to group onset, and a posterior positivity to group-initial tones. These results demonstrate that metric attentional modulation of early auditory processing occurs when metric structure is entirely subjective, suggesting that temporal attention is integral to metric perception. Further, subjective metric processing draws on multiple additional neurocognitive mechanisms indexed by scalp ERP responses.