Figure 4.
The effect of transcranial magnetic stimulation (TMS, monophasic) coil orientation on motor-evoked potential (MEP) amplitude is strongest during the active movement pegboard task (experiment 3). Data show mean and 95% confidence intervals (N = 12) of MEP amplitudes (normalized by the maximum MEP amplitude per participant and condition, ranging from 0 to 1, radial axis) for 3 conditions, Rest (A), Isotonic contraction (B), and Pegboard (C); 5 TMS coil positions [red (primary motor cortex, L-M1-FDIR) through to blue (left supramarginal gyrus, L-SMG)], and 8 TMS coil orientations (from East at 0°, through North-East at 45°, to South-East at 315°, on polar axes; 90° is toward the nasion). See Supplemental Results S2 and Supplemental Fig. S7 for alternative visualizations of these data along with estimated MEP latency. Data are presented in the same perspective as the participant and brain in Fig. 1.