Transcranial static magnetic field stimulation over human middle temporal complex reduces spatial accuracy of continuous visuomotor performance.

The continuous visuomotor (CVM) performance of ball-sport athletes like table tennis players relies heavily on visual motion discriminability in a visual field-dependent manner. This discriminability reflects the cortical excitability of the motion-sensitive human middle temporal complex (hMT +). Therefore, hMT + excitability may play a critical role in determining CVM performance, but direct evidence supporting this relationship remains limited. In this study, we examined whether applying transcranial static magnetic field stimulation (tSMS), which reduces cortical excitability, over hMT + impairs CVM performance in table tennis players. Twenty table tennis players performed a CVM task requiring them to modulate their prehensile force on a force sensor to control a cursor to hit balls moving continuously from right to left on a screen. The task was performed both before (Pre-test) and during (During-test) tSMS application over the left hMT + . Since participants captured the moving target information in the right visual hemifield and processed it in the left hMT + , we hypothesized that reducing hMT + excitability would impair performance. Results showed a significant deterioration in the spatial accuracy of the cursor movements during the During-test compared to the Pre-test. These findings suggest that hMT + excitability is crucial for maintaining the spatial accuracy of CVM performance.