Figure 3. Small involuntary movements do not explain preparatory activity patterns in M1 and S1 (A).

Mean finger force (± standard error of the mean [SEM]) plotted in 10 ms bins, time aligned to instruction onset (dotted vertical line) and end of the preparation phase (dashed vertical lines), separately for the three fingers and go (blue) and no-go (orange) trials. (B) Example of an individual trial with a 6-s preparation phase, followed six presses of the little finger (green). Horizontal solid line denotes press threshold (1 N). Dash-dotted lines denote the boundaries of the finger preactivation red area in Figure 1A (see Materials and methods). Reaction time (RT) was defined as the time from the go cue (dashed vertical line) to the onset of the first press (left solid vertical line). Movement time (MT) was defined as the time from the onset of the first press (left solid vertical line) until the release of the last press (right solid vertical line). (C) Pearson’s correlation (r) between behavioral and neural distances in M1 and S1 (see Materials and methods) during the preparation phase (planning, orange). Each dot represents an individual participant (N = 22). Solid line shows linear regression fit; p values pairs refers to the slope and the intercept of the fitted line. (D) Same as C, but during the movement phase (execution, blue).