Neuro-oscillatory tracking of low- and high-level musico-acoustic features during naturalistic music listening: Insights from an intracranial electroencephalography study.

Studies investigating the neural processing of musico-acoustic features have tended to do so using highly controlled musical stimuli. However, it is increasingly argued that failing to use naturalistic stimuli limits the extent to which findings from lab studies can be extrapolated to rich and varied real-world experiences. Here, we recorded electrical brain activity from 8 epileptic patients, implanted for pre-surgical evaluation with Stereo-encephalography (SEEG), while they listened to pieces from the western tonal music repertoire. We estimated the sound intensity and key and pulse clarity of the stimuli using a toolbox for automatic extraction of musico-acoustic features. We then used partial-correlation analyses to examine the patterns of neuro-oscillatory activity associated with the processing of these features. Our results showed clear tracking of sound intensity in high-gamma and alpha frequency bands in posterior superior temporal gyrus, reflecting neural firing and the transfer of auditory information from the thalamus to auditory cortices, respectively. Patterns of partial correlations, in line with our hypotheses, also suggested limbic and inferior frontal cortical tracking of tonal and rhythmic uncertainty, albeit without the robustness shown for sound intensity tracking in auditory areas. The study provides an important contribution to the existing literature in its adherence to the call for a greater use of ecologically valid stimuli in neuroscientific investigations of music listening. Our results, specifically, have implications for research on the neural processing of musical uncertainty and for future studies seeking to use intracranial EEG to examine naturalistic music processing.