M1 large-scale network dynamics support human motor resonance and its plastic reshaping

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• Motor resonance, a measure of corticospinal excitability during action observation, reflects Action Observation Network (AON) activity.
• The neural mechanisms governing the development and modification of motor resonance are not fully understood.
• Investigating sensorimotor associative learning offers a pathway to explore these underlying neural dynamics.

Purpose of the Study:

• To investigate the role of sensorimotor associative learning in the neural mechanisms of motor resonance.
• To explore how novel visuomotor associations, induced by paired associative stimulation (PAS), alter motor resonance.
• To map the inter-areal connectivity profiles associated with typical and PAS-induced motor resonance.

Main Methods:

• Utilized cross-systems paired associative stimulation (PAS) to create novel visuomotor associations.
• Employed transcranial magnetic stimulation (TMS) and electroencephalography (EEG) co-registration during action observation.
• Tracked M1 functional connectivity to analyze neural dynamics during typical and induced motor resonance.

Main Results:

• Confirmed the emergence of newly acquired, PAS-conditioned motor resonance responses, replacing typical ones.
• Revealed distinct M1 interregional communication patterns for typical versus PAS-induced motor resonance.
• Typical motor resonance correlated with M1 alpha-band and reduced beta-band connectivity; atypical resonance involved M1 beta-band modulations.

Conclusions:

• Sensorimotor associative learning, via PAS, can induce atypical motor resonance by modulating M1 connectivity.
• Beta-phase synchronization in M1 appears critical for forming motor resonance, potentially coordinated with alpha-band top-down control.
• Findings illuminate the neural dynamics of motor resonance and the role of large-scale interregional communication in the AON.