Hierarchical processing of temporal information during naturalistic music production and perception
Presenter Name:Riesa Cassano
School/Affiliation:University of Rochester
Co-Authors:Jamal Williams, Marius Cătălin Iordan, Uri Hasson, Elise Piazza
Recent work using naturalistic stimuli—such as movies, verbal narratives, and music—has used scrambled versions of these stimuli to reveal hierarchies of temporal processing in the brain. A new fMRI dataset of expert pianists sight-reading naturalistic music scrambled at different timescales offers the opportunity to investigate hierarchical processing during music production. Intersubject correlation is used to measure the reliability of responses in a region. We expected early auditory areas to have reliable responses across all scrambled conditions, whereas higher-order areas should have more reliable responses for relatively more intact conditions. Surprisingly, both early auditory cortex and motor cortex showed sensitivity to the effects of scrambling: intersubject temporal correlation increased systematically for more intact conditions. However, when comparing average intersubject pattern correlation across varying segment lengths within the context of the “intact” condition, we found a more expected hierarchical effect: early auditory and motor regions showed reliable response patterns over shorter timescales (phrases and half-phrases), whereas higher-order regions (posterior medial cortex) showed more reliable response patterns over longer timescales (half-sections). This analysis may be more sensitive to hierarchical effects due to asymmetries in attentional load across the scramble conditions. During listening, response patterns are more reliable over longer timescales (half-sections and sections) in both auditory areas and higher-order areas. This suggests that subjects may devote more attentional resources to longer-term prediction and chunking during listening compared to playing. These analyses are a first attempt to characterize the hierarchical processing of highly natural musical structure during live performance.