Auditory prediction cues motor preparation in the absence of movements

There is increasing evidence for integrated representation of sensory and motor information in the brain, and that seeing or hearing action-related stimuli may automatically cue the movements required to respond to or produce them. In this study we tested whether anticipation of tones in a known melody automatically activates corresponding motor representations in a predictive way, in preparation for potential upcoming movements. Therefore, we trained 20 non-musicians (8 men, 12 women) to play a simple melody. Then, while they passively listened to the learned or unlearned melodies, we applied single pulse transcranial magnetic stimulation (TMS) over M1 to measure motor evoked potentials from the associated finger muscle either preceding or following the onset of individual tones. Our results show that listening to the learned melody increased corticospinal excitability for specific finger muscles before tone onset. This demonstrates that predictable auditory information can activate motor representations in an anticipatory muscle-specific manner, even in the absence of intention to move. This suggests that the motor system is involved in the prediction of sensory events, likely based on auditory-parietal-prefrontal feedforward/feedback loops that automatically prepare predictable sound-related actions independent of actual execution and the associated auditory feedback. Overall, we propose that multimodal forward models of upcoming sounds and actions support motor preparation, facilitate error detection and correction, and guide perception.