Metric expectations drive auditory-motor connectivity: a combined TMS-EEG study

Poster Session F - Tuesday, April 1, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Giorgio Lazzari¹ (giorgio.lazzari01@universitadipavia.it), Connor Spiech², Oscar Bedford^3,4,5, Marcel Farrés-Franch^3,4,5, Virginia Penhune^2,4,5, Carlotta Lega¹; ¹University of Pavia, Pavia, Italy, ²Concordia University, Montreal, Canada, ³Montreal Neurological Institute, McGill University, Montreal, Canada, ⁴Montreal Laboratory for Brain, Music and Sound (BRAMS), ⁵Centre for Research in Brain, Language and Music (CRBLM)

Motor and premotor regions are theorized to generate timing predictions which auditory regions use to effectively perceive or imagine a beat. This strong auditory-motor coupling is bidirectional and involves β-band oscillations, as shown in prior electroencephalography (EEG) studies. Previous transcranial magnetic stimulation (TMS) research by our lab found that the right dorsal premotor cortex (dPMC) is critically involved in this process. In this study, we combined TMS stimulation and EEG recording to investigate the cortical excitability under different states of beat-based timing perception and prediction. Participants listened to or imagined accents during the presentation of an auditory tone sequence that created a march (binary) or a waltz (ternary) metric structure. EEG was recorded throughout the experiment, as single TMS pulses were delivered 50ms before either accented or unaccented events on the right dPMC. We measured neural excitability changes via TMS-evoked potential (TEP) amplitudes, and we investigated directed functional connectivity between dPMC and auditory regions. Preliminary results found increased TEP amplitudes for accented compared to unaccented events, in both the physical and imagined conditions, indicating greater dPMC reactivity when metric expectations are stronger. Additionally, if dPMC encodes metrical expectations, dPMC-to-auditory connectivity should be stronger than auditory-to-dPMC connectivity. Specifically, we predict this effect to occur in delta and in beta frequency bands, given the importance of these frequencies in motor processes. Together these results would clarify the causal relationships between premotor and auditory regions, highlighting the predictive role of the premotor cortex in metric processing.

Topic Area: PERCEPTION & ACTION: Audition