A comparative study of simulated electric fields of transcranial magnetic stimulation targeting different cortical motor regions

This computational simulation study investigates the strength of transcranial magnetic stimulation (TMS)-induced electric fields (EF) in primary motor cortex (M1) and secondary motor areas. Our results reveal high interindividual variability in the strength of TMS-induced EF responses in secondary motor areas, relative to the stimulation threshold in M1. Notably, the activation of the supplementary motor area requires high-intensity stimulation, which could be attributed to the greater scalp-to-cortex distance observed over this area. These findings emphasize the importance of individualized planning using computational simulation for optimizing neuromodulation strategies targeting the cortical motor system.