Figure 2.

A, Experiment 1: Mean MEP amplitudes (±SE) in the left FDI muscle were reduced relative to baseline in all delay conditions (left), as well as 150 ms after a choice imperative or a simple imperative cuing the right finger, in the absence of a preparatory delay (right). B, Experiment 2: Mean left FDI MEP amplitudes (±SE) were also reduced during the delay period whenever a simple response was prepared but remained at baseline whenever a response was not being prepared and 150 ms after the right pinky was cued to respond in the absence of a preparatory delay. C, Experiment 3: the likelihood of a catch trial and the type of catch trial did not impact the observed reduction in mean MEP amplitudes (±SE). *p < 0.05, **p < 0.01, ***p < 0.001.