Abstract
Introduction. Auditory processing is guided by exogenous and endogenous processes: neural responses adapt to hierarchically organized structures and task-specific conditions across development. Here, we investigated the endogenous selective attention mechanisms influencing subjective metric tracking of an isochronous sequence of identical tones in children 6-10-years-old. Methods. We adapted an adult imagined meter paradigm to map the developmental neural trajectories of implicit metric coding. High-density electroencephalography data were recorded from 112 children listening to undifferentiated tones grouped subjectively into quaternary or ternary meters in fast (450ms SOA) and slow (625 SOA) tempi. We predicted that mature metric encoding would manifest as adult-like N1 and late metric negativity (LMN) amplitudes to metrically strong beats. Results. Across four age cohorts, we replicated established findings on cortical auditory evoked potential morphological development. Behavioral accuracy on the task reflected more mature neural responses to imagined strong beats. High-scorers reliably showed negative responses in the N1 and LMN time windows for strong beats across hierarchies. Low scorers showed positive responses in the N1 and LMN time windows for strong beats, similar to other selective attention paradigms in this age range. Discussion. Metric tracking was modulated by tempo and meter: we suggest that fast tempo facilitated tracking by aligning with children's faster endogenous temporal preferences, while slower tracking was more difficult; similarly, tracking ternary meter was more challenging than quaternary, likely due to familiarity.