The interplay between cortical tracking and functional connectivity in musicians and non-musicians listening to speech and music

Musical expertise is associated with auditory processing advantages which can extend to the speech domain. However, the origins of such domain-general benefits remain unclear. Recent frameworks propose that better rhythm processing in musicians might be at the basis of the observed advantages in processing music and speech. Auditory cortical tracking and inter-regional interactions between auditory and motor areas have been proposed as key neural mechanisms. In this study, we asked whether expertise-related increase in cortical tracking would be elicited by naturalistic stimuli in clear listening conditions, and whether such effects would be related to audiomotor functional connectivity and individual rhythmic abilities. We compared MEG data from expert musicians and controls with no musical playing experience while they listened to two-minutes long stories and excerpts of piano music. We also collected behavioral data in a rhythmic task testing speech (syllable) production. We found that musicians showed enhanced tracking and enhanced functional connectivity in both speech and music conditions, as well as better rhythmic abilities relative to non-musicians. Alpha connectivity between the right auditory cortex and inferior frontal gyrus negatively predicted cortical tracking across all participants in the speech condition, while no relation was observed for music. We suggest that stronger cortical tracking in musicians is due to domain-general differences in auditory sensory processes and is not driven by motor influences in our experiment. Moreover, a trade-off between cortical tracking and inter-regional communication might be at the basis of optimal perception of speech in both musicians and non-musicians in clear listening conditions.