Experimental apparatus and conditions. (A) High-resolution EEG recorded from 58 scalp positions together with electrooculogram (EOG). (B) Home-made manipulandum and EMG recorded from FDI muscle during the experiment. (C) Visual feedback of the ring position displayed on a monitor in front of the subject. (D) Target force profiles in the three conditions W1 = 0.6 Hz, W2 = 1 Hz and W3 = 1.6 Hz. The force level was 8% MVC in all three conditions. (E) Grand average across subjects of finger position for the three conditions. Note the three time periods T0 (3 s static force period), T1 (3 s period of transient fluctuations), and period T2 (period with steady-state force compensation).