Imagining the Beat: Causal Involvement of Motor Areas in Musical Rhythm Imagery

Music is a peculiar human activity that engages numerous cognitive, emotional, and social processes, rendering it an interesting object of study for psychology. In recent years, different studies have highlighted the importance of motor areas of the brain in the perception of music and rhythm, leading to the Action Simulation for Auditory Perception (ASAP) hypothesis. In line with ASAP, consistent evidence demonstrated the active involvement of motor areas also during the process of music perception and music imagery. Using a Transcranial Magnetic Stimulation (TMS) protocol, we proposed to assess the causal role of the right dorsal pre-motor cortex (dPMC) and of the right supplementary motor area (SMA) in the process of auditory imagery for rhythm. 42 participants took part in the experiment. They were asked to complete a rhythmic imagery-related task while undergoing TMS stimulation in three conditions (dPMC- SMA-Control). Results showed a significant effect on participants’ response of dPMC but not of SMA. Also, individual differences in the vividness and control of auditory imagery measured through the Bucknell Auditory Imagery Scale modulated the TMS effect. Specifically, the effect of TMS was particularly evident in individuals with lower auditory imagery scores, thus indicating that the neural response to TMS is shaped by individual functional states. These results are in line with recent literature and provide causal evidence of the involvement of motor areas in auditory imagery for music, offering useful insight on the neural organization of human rhythmic abilities. Keywords: Imagery | Rhythm | Music | Premotor cortex | Supplementary motor area | Transcranial magnetic stimulation