Figure 7.
Linear relationship between regional activation during motor preparation and the relative undershoot in maximal grip force in trails where an incorrect S1 pre-cue announced a light weight after sham cTBS30% (A) or real cTBS80% (B) of left PMd. A, In the control session without effective cTBS, preparatory activity during the S1–S2 period predicted the individual undershoot in maximal grip force. The higher the preparatory activity in the left PMd, the larger was the undershoot in trials with an incorrect S1 pre-cue indicating a light weight. B, This linear relationship was abolished after real cTBS80% of left PMd. The left panels show axial slices of the statistical parametric map for the linear relationship between preparatory activity and force undershoot. The corresponding scatter plots for the peak voxel in left PMd are presented on the right (x, y, z = −30, −3, 54). The parameter estimates of preparatory BOLD signal changes are plotted along the y-axis. The maximal grip force ratios (LH/LL trials) are displayed along the x-axis. The gray color marks the area with negative LH/HH force ratio (i.e., undershoot). The regression line gives the estimated linear relation.