Mu suppression reveals auditory-motor predictions after short motor training in non-musicians

Auditory-motor coupling is a bidirectional neural mechanism that supports speech and music, as demonstrated by motor system activation during passive listening to learned melodies. Such activation is predictive, occurs in non-musicians after a single motor training session, and can be elicited at the single-note level of the practiced melody. These findings support the idea that motor activity guides auditory perception by relaying predictive timing information. However, the evidence remains incomplete, as the neural processes underlying this anticipatory motor activity are not fully understood. EEG studies in musicians have linked it to mu-band suppression, but the temporal scale at which suppression occurs has not been established, and its generalizability to the broader population remains unclear. To address these gaps, we recruited 25 non-musicians who learned to play a simple melody on a piano-like keyboard. Before and after training, participants passively listened to the trained melody and control melodies. Offline, EEG data from the motor training were used to create a time-frequency mask identifying channels, frequencies, and timepoints likely to display mu suppression during passive listening. Significant mu suppression emerged before each note onset only during post-training exposure to the practiced melody, with no effects in other frequency bands. Results prove that mu suppression occurs at the single-note level following short auditory-motor training and is not dependent on prior musical training. Thus, mu suppression appears tied to the anticipatory motor activity observed in prior studies, supporting the notion that motor activity aids perception by anticipating the unfolding of learned auditory-motor sequences.