Static magnetic field stimulation of the supplementary motor area modulates resting-state activity and motor behavior.

Focal application of a strong static magnetic field over the human scalp induces measurable local changes in brain function. Whether it also induces distant effects across the brain and how these local and distant effects collectively affect motor behavior remains unclear. Here we applied transcranial static magnetic field stimulation (tSMS) over the supplementary motor area (SMA) in healthy subjects. At a behavioral level, tSMS increased the time to initiate movement while decreasing errors in choice reaction-time tasks. At a functional level, tSMS increased SMA resting-state fMRI activity and bilateral functional connectivity between the SMA and both the paracentral lobule and the lateral frontotemporal cortex, including the inferior frontal gyrus. These results suggest that tSMS over the SMA can induce behavioral aftereffects associated with modulation of both local and distant functionally-connected cortical circuits involved in the control of speed-accuracy tradeoffs, thus offering a promising protocol for cognitive and clinical research. Pineda-Pardo et al. show that focal application of a strong permanent magnet over the supplementary motor area shifts the speed-accuracy tradeoff towards accuracy by modulating both cortical circuits and distant cortical networks. This study suggests the utility of transcranial static magnetic field stimulation for cognitive research. [ABSTRACT FROM AUTHOR]